untitled European Journal of Chemistry 2 (3) (2011) 359‐364 European Journal of Chemistry ISSN 2153‐2249 (Print) / ISSN 2153‐2257 (Online)  2011 EURJCHEM DOI:10.5155/eurjchem.2.3.359‐364.439 European Journal of Chemistry Journal homepage: www.eurjchem.com Facile synthesis of 3‐(1‐(4'‐(3‐chloro‐2‐(substituted phenyl)‐4‐oxoazetidin‐1‐ yl)biphenyl‐4‐yl)‐5‐oxo‐2‐phenyl‐1H‐imidazol‐4(5H)‐ylidene)indolin‐2‐ones and 3‐(1‐(3‐chloro‐2‐(substituted phenyl)‐4‐oxoazetidin‐1‐yl)‐5‐oxo‐2‐phenyl‐ 1H‐imidazol‐4(5H)‐ylidene)indolin‐2‐ones: β‐Lactam derivatives as antimicrobes Abha Bishnoia,*, Krishna Srivastavab, Suruchi Singha and Chandrakant Mani Tripathic a Department of Chemistry, Lucknow University, University Road, Lucknow‐226007, India b Department of Chemistry, Shri Ramswaroop Memorial College of Engineering and Management, Faizabad Road, Lucknow‐227105, India c Division of Fermentation Technology, Central Drug Research Institute, Chattar Manzil Palace, Lucknow‐226001, India *Corresponding author at: Department of Chemistry, Lucknow University, University Road, Lucknow‐226007, India. Tel.: +91.9415028822; fax: +91.9415028822. E‐mail address: dr.abhabishnoi@gmail.com (A. Bishnoi). ARTICLE INFORMATION ABSTRACT Received: 06 April 2011 Received in revised form: 05 May 2011 Accepted: 06 May 2011 Online: 30 September 2011 KEYWORDS A facile synthesis of b‐lactam derivatives; 3‐(1‐(4'‐(3‐chloro‐2‐(substituted phenyl)‐4‐ oxoazetidin‐1‐yl)biphenyl‐4‐yl)‐5‐oxo‐2‐phenyl‐1H‐imidazol‐4(5H)‐ylidene)indolin‐2‐ones (6a‐e) and 3‐(1‐(3‐chloro‐2‐(substituted phenyl)‐4‐oxoazetidin‐1‐yl)‐5‐oxo‐2‐phenyl‐1H‐ imidazol‐4(5H)‐ylidene)indolin‐2‐ones (7a‐e) is described herein. The title compounds 6a‐e and 7a‐e were evaluated for their in vitro antimicrobial activity against Candida albicans and Bacillus subtilis respectively using a two fold serial dilution technique. Investigation revealed that 2‐hydroxy phenyl function at ‐lactam ring in compounds 6d and 7d is a key factor for both antifungal and antibacterial activity, as newly designed compounds 6d and 7d exhibited good biological activity with minimum inhibitory concentration (MIC)12.5 g/mL against Candida albicans and Bacillus subtilis respectively. Imidazole Azetidinones β‐lactam ring Bacillus subtilis Candida albicans Antimicrobial activity 1. Introduction Antimicrobial drugs are effective in the treatment of infections because of their selective toxicity‐the ability to kill an invading microorganism without harming the cells of the host. In most instances, the selective toxicity is relative rather than absolute, requiring the concentration of the drug be carefully controlled to attack the microorganism while still being tolerated by the host [1]. Azoles are widely used and studied class of antimicrobials due to their safety profile and high therapeutic index. Among these, Conazolones are a major class of azole based drugs such as Itraconazole, Fluconazole, Voriconazole, Ravuconazole etc. [2‐5]. It is also known that members of azole class of antimycotic drugs possess antibacterial properties against some gram positive bacteria [6‐7]. Clotrimazole and Econazole have been shown to be effective against Mycobacterium smegmatis and Streptomyces strains in vitro [8]. During the past decade, imidazole derivatives have occupied a unique place in the field of medicinal chemistry. They have a wide range of biological activities. They are well known analgesics, anti‐inflammatory, antiparasitic, antihelmintic, platelet aggregation inhibitors and antiepileptic agents [9‐14]. With this view, the present study was designed to evaluate the antimicrobial activity of some new 2’‐phenyl‐4’‐[3”‐(2”‐oxo‐ 1”H‐indolidene)‐5’‐oxo‐imdazolyl]‐1’‐[{p‐1(4‐aryl‐1‐biphenyl}] / 4‐aryl‐3‐chloro azetidinones (6a‐e and 7a‐d) consisting of three well established pharmacologically active nuclei‐ imidazole, azole, and β‐lactam [15‐19] ring in one molecular union (Scheme 1). Compounds 6a‐e and 7a‐e were characterized by spectral data and were screened in vitro against clinically isolated strains of Candida albicans and Bacillus subtilis, following two fold serial dilution technique as recommended by the National Committee for Clinical Laboratory Standard (NCCLS) [20‐21]. 2. Experimental 2.1. Instrumentation All the melting points were determined in open capillary tube and are uncorrected. The nitrogen analysis was carried out on CARLO‐ERBA EA 1108 elemental analyzer. Homogeneity of the compounds was checked by thin layer chromatography (TLC) using TLC grade silica gel (G) and was developed in an atmosphere of iodine vapors. IR spectra were recorded on a Perkin‐Elmer 1430 spectrophotometer using KBr pellets. 1H and 13C spectra were recorded in CDCl3 using TMS as an internal standard on a Bruker 200 MHz NMR spectro‐ photometer respectively. The splitting pattern abbreviations in NMR are as follows: s, singlet; d, doublet; t, triplet; br, broad; m, unresolved multiplet due to the strength of the instrument. Mass spectra were recorded on a Agilent 6520 Mass Spectrometer. 360 Bishnoi et al. / European Journal of Chemistry 2 (3) (2011) 359‐364 2.2. Synthesis 2.2.1. 4‐((2‐Oxoindolin‐3‐ylidene)methyl)‐2‐phenyloxazol‐ 5(4H)‐one (1) A mixture of isatin (0.03 moles), hippuric acid (0.03 moles), acetic anhydride (20 mL) and anhydrous sodium acetate (0.03 moles) was stirred mechanically for one hour and then refluxed on a water bath for two hours. Subsequently, ethanol (100 mL) was added, and the reaction mixture allowed to stand overnight. A yellow solid which separated out, was filtered off and washed successively with cold water. It was recrystallized from benzene. Yield: 85%. M.p.: 281 C. 2.2.2. 3‐(1‐(4'‐Amino biphenyl‐4‐yl)‐5‐oxo‐2‐phenyl‐1H‐ imidazol‐4(5H)‐ylidene)indolin‐2‐one (2) A mixture of 1 (0.05 mole) and 1,1‐diphenyl‐4,4‐diamine (0.05 mole) in anhydrous pyridine (50 mL) was heated under reflux on a sand bath for 6 hours under anhydrous reaction condition. Subsequently, the reaction mixture was poured in an ice cold water hydrochloric acid solution (100 mL, 2 N). A solid precipitated. It was filtered off and washed with water. After drying in vacuum, it was recrystallized from ethanol (Scheme 1). Yield: 80%. M.p.: 186 C. FT‐IR (KBr, cm‐1): 3375‐3410 (‐ NH) (amino of benzidine), 3127 (N‐H) (sec. amide), 3028‐ 3007 (Ar‐H) (aromatic), 1756 (C=O) (sec. amide), 1654 (C=N) (imidazole), 1642 (C=O) (tertiary amide), 1410 (C‐N) (imidazole). 1H NMR (200 MHz, CDCl3): 5.3 (s, 2H, NH2), 7.14‐ 7.58 (m, 17H, Ar‐H), 7.64 (brs, 1H, CONH). 13CNMR (25 MHz, CDCl3): 175 (1C, carbonyl of indolidene), 169.8 (1C, C‐4 of imidazole), 165 (1C, C‐2 of imidazole), 142.3 (1C, C‐5 of imidazole), 140.8 (1C, C‐1 of indolidene), 110, 119.5, 119.7, 122.4, 123.6, 124.1, 128.3, 128.5, 128.6, 128.7, 128.9, 129.2, 129.3, 129.5, 129.6, 129.7, 130.1, 130.4, 133.7, 135.8, 136.5, 138.4, 138.9, 140.2 (24C, Ar‐C). ESI‐MS (M+1): 456. Anal. Calcd. for C29H20N4O2: C, 76.31; H, 4.39; N 12.28. Found: C, 75.69; H, 4.50; N, 12.25%. 2.2.3. 3‐((1‐Amino‐5‐oxo‐2‐phenyl‐4,5‐dihydro‐1H‐imidazol‐ 4‐yl)methylene)indolin‐2‐one (3) A mixture of 1 (0.02 mole) and hydrazine hydrate (0.025 mole) in ethanol (50 mL) was heated under reflux for 4 hours. Ethanol was distilled off and the residual solid thus obtained was washed with water. It was dried with the help of a dryer and recrystallized from dilute methanol as yellow crystals (Scheme 1). Yield: 85%. M.p.: 214 C. FT‐IR (KBr, cm‐1): 3400‐ 3485 (‐NH) (amino), 3130(NH) (sec. amide), 3019‐3012 (Ar‐H) (aromatic), 1777 (C=O) (sec.amide), 1651 (C=O) (tertiary amide), 1647 (C=N) (imidazole), 1421 (C‐N) (imidazole). 1H NMR (200 MHz, CDCl3): 4.96 (s, 2H, NH2), 7.39‐ 7.65 (m, 9H, Ar‐H), 7.47 (brs, 1H, CONH). 13C NMR (25 MHz, CDCl3): 170 (1C, C‐2 of indolidene), 167.5 (1C, C‐5 of imidazole), 144.3 (1C, C‐2 of imidazole), 140 (1C, C‐4 of imidazole), 135.9 (1C, C‐3 of indolidene), 110.2, 122.8, 123.9, 124.3, 128.3, 128.8, 128.9, 130.9, 131.6, 131.7, 133.0, 141.2 (12C, Ar‐C). ESI‐MS (M+1): 304. Anal. Calc. for C17H12N4O2: C, 67.10; H, 3.95; N, 18.42. Found: C, 66.94; H, 4.02; N, 18.38%. 2.2.4. 3‐(1‐(4'‐(Substituted benzylideneamino)biphenyl‐4‐ yl)‐5‐oxo‐2‐phenyl‐1H‐imidazol‐4(5H)‐ylidene)indolin‐2‐ ones (4a‐e) and 3‐(1‐(Substituted benzylideneamino)‐5‐oxo‐ 2‐phenyl‐1H‐imidazol‐4(5H)‐ylidene)indolin‐2‐ones (5a‐e). A mixture of imidazole 2/3 (0.02 mole); an appropriate aldehyde (0.02 mole) and acetic acid (1 mL) in absolute alchohol (30 mL), was refluxed for about 8‐10 hours. Excess of solvent was removed under pressure. The solid thus obtained, was washed with cold water and recrystallized from methanol (Scheme 1). 3‐(1‐(4'‐(4‐hydroxybenzylideneamino)biphenyl‐4‐yl)‐5‐oxo‐ 2‐phenyl‐1H‐imidazol‐4(5H)‐ylidene)indolin‐2‐one (4a): R2= p‐ Hydroxyphenyl: Yield: 70%. M.p.: 226 C. FT‐IR (KBr, cm‐1): 3607 (OH) (para hydroxyl phenyl), 1769 (C=O) (sec. amide), 1670 (C=O) (tert. amide ), 1635 (C=N) (imidazole), 1660 (C‐ N) (imidazole). 1H NMR (200 MHz, CDCl3): 4.93 (s, 1H, Ar‐OH), 7.18‐7.66 (m, 21H, Ar‐H), 7.97 (brs, 1H, CONH), 8.65 (s, 1H, N=CH‐R). 13C NMR (25 MHz, CDCl3): 168.8, 169.4 (2C, C‐5 of imidazole, C‐2 of indolidene), 163.7 (1C, C‐2 of imidazole), 160.1 (1C, N=CHR2), 139.9, 141.2 (2C, C‐4 of imidazole, C‐3 of indolidene), 116, 122.8, 123.7, 124.0, 126.7, 127.2, 128.1, 128.3, 128.4, 128.6, 128.7, 128.8, 128.9, 129.2, 129.4, 129.5, 129.7, 129.8, 129.9, 130.3, 130.5, 130.8, 131.1, 134.9, 135.3, 135.8, 138.6, 138.9, 142.5, 144.5 (30C, Ar‐C). ESI‐MS (M+1): 561. Anal. Calcd. for C36H24N4O3: C, 77.14; H, 4.28; N, 10.00. Found: C, 77.10; H, 4.18; N, 9.97%. 3‐(1‐(4'‐(4‐chlorobenzylideneamino)biphenyl‐4‐yl)‐5‐oxo‐2‐ phenyl‐1H‐imidazol‐4(5H)‐ylidene)indolin‐2‐one (4b): R2= p‐ Chlorophenyl: Yield: 75%. M.p.: 217 C. FT‐IR (KBr, cm‐1): 3365 (N‐H) (sec. amide), 3010 (Ar‐H) (aromatic), 1680 (C=O ) (sec. amide), 1658 (N=C) (imidazole), 1650 (C=O) (tertiary amide), 690 (Ar‐Cl) (para substitution). 1H NMR (200 MHz, CDCl3): 7.11‐7.82 (m, 21H, Ar‐H) , 7.63 (brs, 1H, CONH), 8.76 (s, 1H, N=CH‐R). 13C NMR (25 MHz, CDCl3): 169.6, 171 (2C, C‐5 of imidazole, C‐2 of indolidene), 164 (C‐2 of imidazole), 160.1 (N=CHR2), 137.8, 138.4 (2C, C‐4 of imidazole, C‐3 of indolidene), 113.8, 121.8, 122.2, 123.1, 127.3, 127.6, 127.8, 127.9, 128.2, 128.5, 128.7, 128.8, 129.0, 129.3, 129.4, 129.6, 129.7, 130.1, 130.4, 130.7, 131.4, 133.9, 134.5, 135.7, 136.2, 136.6, 138.8, 139.0, 139.3, 139.9(30C, Ar‐C). ESI‐MS (M+1): 580. Anal. Calcd. for C36H23N4O2Cl: C, 74.68; H, 3.98; N, 9.68. Found: C, 74.68; H, 3.90; N, 9.66%. 3‐(1‐(4'‐(3‐hydroxy‐4‐methoxybenzylideneamino)biphenyl‐4‐ yl)‐5‐oxo‐2‐phenyl‐1H‐imidazol‐4(5H)‐ylidene)indolin‐2‐one (4c): R2= 3‐OH, 4‐OCH3‐phenyl: Yield: 80%. M.p.: 142 C. FT‐IR (KBr, cm‐1): 3523 (OH) (3‐hydroxy phenyl), 3256 (N‐H) (sec. amide), 3070 (Ar‐H) (aromatic), 1672 (C=O) (sec. amide), 1649 (N=C) (imidazole), 1638 (C=O) (teriary amide). 1H NMR (200 MHz, CDCl3): 3.83(‐OCH3), 7.11‐7.82 (m, 20H, Ar‐H), 7.29 (brs, 1H, CONH), 8.51 (s, 1H, N=CH‐R). 13C NMR (25 MHz, CDCl3): 168.4, 168.9 (2C, C‐5 of imidazole, C‐2 of indolidene), 163.7 (1C, C‐2 of imidazole), 159.8 (1C, N=CHR2), 136.1, 137.5 (2C, C‐4 of imidazole, C‐3 of indolidene), 114.4, 115.9, 116.4, 121.9, 122.2, 123.0, 125.5, 126.9, 127.2, 128.0, 128.2, 128.4, 128.5, 128.6, 128.7, 128.8, 129.0, 129.3, 129.6, 130.0, 130.5, 131.7, 132.7, 132.9, 133.2, 133.5, 134.2, 135.6, 135.8, 135.9 (30C, Ar‐C), 55.8 (1C, ‐OCH3). ESI‐MS (M+1): 591. Anal. Calcd. for C37H26N4O4: C, 75.25; H, 4.41; N, 9.49. Found: C, 75.21; H, 4.39; N, 9.45%. 3‐(1‐(4'‐(2‐hydroxybenzylideneamino)biphenyl‐4‐yl)‐5‐oxo‐ 2‐phenyl‐1H‐imidazol‐4(5H)‐ylidene)indolin‐2‐one (4d): R2= o‐ Hydroxyphenyl: Yield: 70%. M.p.: 220 C. FT‐IR (KBr, cm‐1): 3373 (N‐H) (sec. amide), 3056 (Ar‐H) (aromatic), 3589 (Ar‐ OH), 1677 (C=O) (sec. amide), 1643 (N=C), 1632 (C=O) (tertiary amide). 1H NMR (200 MHz, CDCl3): 6.59 (brs, 1H, CONH), 7.06‐8.74 (m, 21H, Ar‐H), 8.39 (s, 1H, N=CH‐R), 10.26 (s, 1H, OH, exchangeable). 13C NMR (25 MHz, CDCl3): 168.9, 169.4 (2C, C‐5 of imidazole, C‐2 of indolidene), 162.4 (1C, C‐2 of imidazole), 160.3 (1C, N=CHR2), 134.9, 135.2 (2C, C‐4 of imidazole, C‐3 of indolidene), 110.2, 116.8, 120.5, 121.3, 122.4, 122.7, 123.9, 126.9, 127.5, 127.9, 128.1, 128.3, 128.5, 128.6, 128.8, 129.2, 129.4, 129.5, 129.6, 129.8, 130.4, 132.1, 132.5, 135.2, 136.7, 139.3, 139.7, 141.3, 151.0, 161.1 (30C, Ar‐C). ESI‐ MS (M+1): 561. Anal. Calcd. for C36H24N4O3: C, 77.14; H, 4.28; N, 10.00. Found: C, 77.00; H, 4.26; N, 9.97%. 3‐(1‐(4'‐(4‐hydroxy‐3‐methoxy‐benzylideneamino)biphenyl‐ 4‐yl)‐5‐oxo‐2‐phenyl‐1H‐imidazol‐4(5H)‐ylidene)indolin‐2‐one (4e): R2= 4‐OH, 3‐OCH3‐phenyl: Yield: 77%. M.p.: 214 C. FT‐IR Bishnoi et al. / European Journal of Chemistry 2 (3) (2011) 359‐364 361 N HOOC-CH2-NH-C-C6H5 O O N O N C O C Ph O a 1 N O N C N C Ph O NH2 3 2 N O N C N C Ph O N=CHR2 5a-e 4a-e N O N C N C Ph O N CH R2 Cl HO 7a-e N O N C N C Ph O N CH R2 Cl HO 6a-e b c d d e e O H H H H H H N O N C N C Ph O H NH2 N O N C N C Ph O H N CHR2 4a, 5a, 6a, 7a : p-OH phenyl 4b, 5b, 6b, 7b : p-Cl phenyl 4c, 5c, 6c, 7c : p-OCH3, m-OH phenyl 4d, 5d, 6d, 7d : o-OH phenyl 4e, 5e, 6e, 7e : p-OH, m-OCH3 phenyl R2 a: Acetic anhydride, Sod. acetate (Anhy.) b: Hydrazine Hydrate, EtOH c: Benzidine, Pyridine; d: R2CHO, EtOH e: Chloro acetyl chloride, Dioxane, Et3N Scheme 1 (KBr, cm‐1): 3610  (OH) (aromatic), 3369  (N‐H) (sec. amide), 3022  (C‐H) (aromatic), 1668  (C=O) (sec. amide), 1653  (N=C) (imidazole), 1645  (C=O) (tertiary amide). 1H NMR (200 MHz, CDCl3): 3.62 (‐OCH3), 6.96‐7.77 (m, 20H, Ar‐H), 7.89 (brs, 1H, CONH), 8.41 (s, 1H, N=CH‐R). 13C NMR (25 MHz, CDCl3): 168.2, 169 (2C, C‐5 of imidazole, C‐2 of indolidene), 163.6 (1C, C‐2 of imidazole), 159.9 (1C, N=CHR2), 115, 115.6, 115.9, 122.3, 122.5, 123.3, 125.4, 127.4, 127.7, 128.2, 128.3, 128.5, 128.6, 128.7, 128.9, 129.2, 129.5, 129.6, 130.0, 130.3, 130.8, 131.6, 133.6, 133.8, 136.3, 136.7, 138.5, 139.2, 140.9, 141.4 (30C, Ar‐ C), 134.9, 135.7 (2C, C‐4 of imidazole, C‐3 of indolidene), 55.6 (1C, ‐OCH3). ESI‐MS (M+1): 591. Anal. Calc. for C37H26N4O4: C, 75.25; H, 4.41; N, 9.49. Found: C, 75.23; H, 4.46; N, 9.47%. 3‐(1‐(4‐hydroxybenzylideneamino)‐5‐oxo‐2‐phenyl‐1H‐ imidazol‐4(5H)‐ylidene)indolin‐2‐one (5a): R2= p‐Hydroxy phenyl: Yield: 80%. M.p.: 251 C. FT‐IR (KBr, cm‐1): 3412 (N‐ H) (sec. amide), 3020 (Ar‐H) (aromatic), 1718 (C=O) (sec. amide), 1693 (C=O) (tertiary amide), 1635 (C=N) (imidazole), 1175 (C‐O stretch) (p‐hydroxy phenyl). 1H NMR (200 MHz, CDCl3): 4.73 (s, 1H, Ar‐OH), 7.12‐7.66 (m, 13H, Ar‐ H), 7.92 (brs, 1H, CONH), 8.79 (s, 1H, N=CH‐R). 13C NMR (25 MHz, CDCl3): 170.3, 171 (2C, C‐5 of imidazole, C‐2 of indolidene), 164 (1C, C‐2 of imidazole), 154.1 (1C, N=CHR2), 139.8, 140.1 (2C, C‐4 of imidazole, C‐3 of indolidene), 110.2, 122.5, 123.5, 124.7, 128.3, 128.4, 128.6, 128.7, 128.9, 129.1, 129.4, 129.6, 129.7, 129.9, 130.6, 131.4, 133.8, 141.4 (18C, Ar‐ C). ESI‐MS (M+1): 409. Anal. Calcd. for C24H16N4O3: C, 70.59; H, 3.92; N, 13.72. Found: C, 70.61; H, 3.40; N, 13.69%. 3‐(1‐(4‐chlorobenzylideneamino)‐5‐oxo‐2‐phenyl‐1H‐ imidazol‐4(5H)‐ylidene)indolin‐2‐one (5b): R2= p‐Chlorophenyl: Yield: 70%. M.p.: 220 C. FT‐IR (KBr, cm‐1) 3325 (N‐H) (sec. amide), 3090 (Ar‐H) (aromatic), 1670 (N=C) (imidazole), 1664 (C=O) (sec. amide), 1633 (C=O) (tertiary amide), 655 (Ar‐Cl) (p‐chlorophenyl). 1H NMR (200 MHz, CDCl3): 7.32‐7.55 (m, 13H, Ar‐H), 7.52 (brs, 1H, CONH), 8.33 (s, 1H, N=CH‐R). 13C NMR (25 MHz, CDCl3): 168.4, 169.1 (2C, C‐5 of imidazole, C‐2 of indolidene), 162.7 (1C, C‐2 of imidazole), 153 (1C, N=CHR2), 138.5, 138.9 (2C, C‐4 of imidazole, C‐3 of indolidene), 111, 122.4, 123.5, 124.2, 128.4, 128.6, 128.8, 128.9, 129.0, 129.3, 129.4, 129.5, 130.2, 130.5, 130.7, 131.4, 136.2, 139.8 (18C, Ar‐ C). ESI‐MS (M+1): 428. Anal. Calcd. for C24H15N4O2Cl: C, 67.53; H, 3.52; N, 13.14. Found: C, 67.51; H, 3.49; N, 13.12%. 3‐(1‐(3‐hydroxy‐4‐methoxybenzylideneamino)‐5‐oxo‐2‐ phenyl‐1H‐imidazol‐4(5H)‐ylidene)indolin‐2‐one (5c): R2= 3‐OH, 4‐OCH3‐phenyl: Yield: 80% M.p.: 283 C. FT‐IR (KBr, cm‐1): 3422 (N‐H) (sec. amide), 3085 (Ar‐H) (aromatic), 1676 362 Bishnoi et al. / European Journal of Chemistry 2 (3) (2011) 359‐364 (N=C) (imidazole), 1672 (C=O) (sec. amide), 1648 (C=O) (tertiary amide). 1H NMR (200 MHz, CDCl3): 7.40 (brs, 1 H, CONH), 7.43‐7.61 (m, 12H, Ar‐H), 8.26 (s, 1H, N=CHR). 13C NMR (25 MHz, CDCl3): 166.9, 168 (2C, C‐5 of imidazole, C‐2 of indolidene), 160.7 (1C, C‐2 of imidazole), 152.8 (1C, N=CHR2), 137.8, 138.2 (2C, C‐4 of imidazole, C‐3 of indolidene), 121.0, 121.1, 121.3, 122.7, 122.9, 123.3, 124.1, 128.0, 128.3, 128.4, 128.6, 128.7, 128.8, 129.1, 130.4, 133.7, 135.5, 139.5 (18C, Ar‐ C). ESI‐MS (M+1): 439. Anal. Calcd. for C25H18N4O4: C, 68.49; H, 4.11; N, 12.78. Found: C, 68.00; H, 4.00; N, 12.74%. 3‐(1‐(2‐hydroxybenzylideneamino)‐5‐oxo‐2‐phenyl‐1H‐ imidazol‐4(5H)‐ylidene)indolin‐2‐one (5d): R2= o‐Hydroxy phenyl: Yield: 68% M.p.: 218 C. FT‐IR (KBr, cm‐1): 3325 (N‐H) (sec. amide), 3090 (Ar‐H) (aromatic), 1670 (N=C) (imidazole), 1664 (C=O) (sec. amide), 1633 (C=O) (tertiary amide). 1H NMR (200 MHz, CDCl3): 7.38‐7.64 (m, 13H, Ar‐H), 7.53 (br s, 1 H, CONH), 8.32 (s, 1H, N=CHR). 13C NMR (25 MHz, CDCl3): 168.1, 168.5 (2C, C‐5 of imidazole, C‐2 of indolidene), 162.5 (1C, C‐2 of imidazole), 153.3 (1C, N=CHR2), 138.4, 139.4 (2C, C‐4 of imidazole, C‐3 of indolidene), 115.0, 117.5, 118.2, 121.5, 122.4, 123.3, 124.6, 127.6, 128.1, 128.3, 128.4, 128.6, 128.7, 128.8, 129.9, 132.2, 139.4, 140.0 (18C, Ar‐C). ESI‐MS (M+1): 409. Anal. Calcd. for C24H16N4O3: C, 70.59; H, 4.11; N, 13.72. Found: C, 70.60; H, 3.80; N, 13.68%. 3‐(1‐(4‐hydroxy‐3‐methoxybenzylideneamino)‐5‐oxo‐2‐ phenyl‐1H‐imidazol‐4(5H)‐ylidene)indolin‐2‐one (5e): R2= 4‐OH, 3‐OCH3‐phenyl: Yield: 72%. M.p.: 200 C. FT‐IR (KBr, cm‐1): 3437 (N‐H) (sec. amide), 3079 (Ar‐H) (aromatic), 1682 (N=C) (imidazole), 1675 (C=O) (sec. amide), 1668 (C=O) (tertiary amide). 1H NMR (200 MHz, CDCl3): 7.41 (br s, 1 H, CONH), 7.49‐7.73 (m, 12H, Ar‐H), 8.22 (s, 1H, N=CHR). 13C NMR (25 MHz, CDCl3): 167.4, 168 (2C, C‐5 of imidazole, C‐2 of indolidene), 161 (1C, C‐2 of imidazole), 152.6 (1C, N=CHR2), 137.7, 138.1 (2C, C‐4 of imidazole, C‐3 of indolidene), 120.8, 120.9, 121.0, 122.4, 122.7, 123.6, 124.1, 127.9, 128.2, 128.4, 128.5, 128.7, 128.8, 129.8, 130.2, 136.3, 136.5, 138.9 (18C, Ar‐ C). ESI‐MS (M+1): 439. Anal. Calcd. for C25H18N4O4: C, 68.49; H, 4.02; N, 12.78. Found: C, 68.10; H, 4.05; N, 12.71%. 2.2.5. 3‐(1‐(4'‐(3‐Chloro‐2‐(substituted phenyl)‐4‐ oxoazetidin‐1‐yl)biphenyl‐4‐yl)‐5‐oxo‐2‐phenyl‐1H‐imidazol‐ 4(5H)‐ylidene)indolin‐2‐ones (6a‐e) and 3‐(1‐(3‐Chloro‐2‐ (substituted phenyl)‐4‐oxoazetidin‐1‐yl)‐5‐oxo‐2‐phenyl‐1H‐ imidazol‐4(5H)‐ylidene)indolin‐2‐ones (7a‐e). In a solution of compound 4, or 5, (0.01 mole) in dioxan (50 mL) was added chloroacetyl chloride (0.01 mol) and triethylamine (0.01 mol) at 0 oC with stirring. The reaction mixture was left at room temperature for 3 hours, and then refluxed for 10 hours. Excess of solvent was distilled off and the residue was poured onto crushed ice. The solid that separated was collected by filtration and recrystallized from diluted ethanol (Scheme 1). 3‐(1‐(4'‐(3‐chloro‐2‐(4‐hydroxyphenyl)‐4‐oxoazetidin‐1‐yl) biphenyl‐4‐yl)‐5‐oxo‐2‐phenyl‐1H‐imidazol‐4(5H)‐ylidene) indolin‐2‐one (6a): R2= p‐Hydroxyphenyl: Yield: 85%. M.p.: 202 C. FT‐IR (KBr, cm‐1): 3422 (N‐H) (indole), 3030 (Ar‐H) (aromatic), 1730 (C=O) (monocyclic β‐lactam), 1715 (>C=O) (sec. amide), 1695 (>C=O) (tertiary amide), 1645 (C=N) (imidazole), 1180 (C‐O str) (p‐hydroxyphenyl), 761 (C‐Cl) (β‐ lactam). 1H NMR (200 MHz, CDCl3): 4.96 (d, 1H, N‐CH‐R of β‐ lactam, J=8.2 Hz), 5.19 (s, 1H, Ar‐OH), 5.45 (d, 1H, ‐CHCl, J=7.1 Hz), 7.15‐7.76 (m, 21H, Ar‐H), 8.32 (brs, 1H, CONH). 13C NMR (25 MHz, CDCl3): 62.5 (1C, CH of β‐lactam), 64.4 (1C, CHCl of β‐ lactam), 110.2, 120.0, 121.5, 121.7, 122.6, 123.2, 125.8, 126.4, 126.9, 128.2, 128.7, 128.9, 129.3, 129.8, 129.9, 130.4, 130.7, 131.5, 131.9, 132.1, 132.3, 132.6, 133.8, 135.7, 136.6, 140.6, 141.8, 142.6, 154.2, 156.5 (30C, Ar‐C), 138.6, 139.5 (2C, C‐4 of imidazole, C‐3 of indolidene), 163.5 (1C, C=O of beta‐lactam), 164.7 (1C, C‐2 of imidazole), 169.3, 170 (2C, C‐5 of imidazole, C‐ 2 of indolidene). ESI‐MS (M+1): 637. Anal. Calcd. for C38H25N4O4Cl: C, 71.64; H, 3.93; N, 8.80. Found: C, 68.10; H, 4.03; N, 8.77%. 3‐(1‐(4'‐(3‐chloro‐2‐(4‐chlorophenyl)‐4‐oxoazetidin‐1‐yl) biphenyl‐4‐yl)‐5‐oxo‐2‐phenyl‐1H‐imidazol‐4(5H)‐ylidene) indolin‐2‐one (6b): R2= p‐Chlorophenyl: Yield: 74%. M.p.: 185 C. FT‐IR (KBr, cm‐1): 3395 (N‐H) (indole), 3010‐3025 (Ar‐H) (aromatic), 1790 (C=O) (sec. amide), 1729 (>C=O) (monocyclic β‐lactam), 1673 (C=O) (tertiary amide), 1615 (C=N) (imidazole), 1235 (C‐N) (β‐lactam), 760 (‐C‐Cl) (β‐ lactam). 1H NMR (200 MHz, CDCl3): 5.02 (d, 1H, N‐CH‐R of β‐ lactam, J=8.6 Hz), 7.11‐5.40 (d, 1H, ‐CHCl, J=7.5 Hz), 7.98‐7.72 (m, 21H, Ar‐H), 8.25 (brs, 1H, CONH). 13C NMR (25 MHz, CDCl3): 62.3 (1C, CH of beta‐lactam), 64.7 (1C, CHCl of β‐lactam), 121, 122.8, 123.8, 124.2, 124.8, 125.0, 127.3, 127.6, 127.8, 128.6, 128.7, 128.9, 129.0, 129.1, 129.6, 129.7, 130.3, 130.6, 130.9, 131.3, 131.4, 131.7, 132.6, 135.7, 137.5, 142.4, 143.4, 144.2, 147.0, 149.3 (30C, Ar‐C), 138.9, 139.5 (2C, C‐4 of imidazole, C‐3 of indolidene), 164.9 (1C, C‐2 of imidazole), 165.3 (1C, C=O of beta‐lactam), 170.11, 171.5 (2C, C‐5 of imidazole, C‐2 of indolidene). ESI‐MS (M+1): 655. Anal. Calcd. for C38H24N4O3Cl2: C, 69.62; H, 3.66; N, 8.84. Found: C, 69.67; H, 3.49; N, 8.81%. 3‐(1‐(4'‐(3‐chloro‐2‐(3‐hydroxy‐4‐methoxyphenyl)‐4‐ oxoazetidin‐1‐yl)biphenyl‐4‐yl)‐5‐oxo‐2‐phenyl‐1H‐imidazol‐ 4(5H)‐ylidene)indolin‐2‐one (6c): R2= 3‐OH, 4‐OCH3‐phenyl: Yield: 72%. M.p.: 127 C. FT‐IR (KBr, cm‐1): 3445 (N‐H) (indole), 3415 (OH) (3‐hydroxyphenyl), 3019 (Ar‐H) (aromatic), 1734 (>C=O) (monocyclic β‐lactam), 1690 (OCH3) (p‐methoxyphenyl), 1681 (C=O) (sec. amide), 1665 (C=O) (tertiary amide), 759 (C‐Cl) (β‐lactam). 1H NMR (200 MHz, CDCl3): 3.39 (s, 3H, Ar‐OCH3), 4.91 (s, 1H, Ar‐OH), 4.96 (d, 1H, N‐CH‐R of β‐lactam, J=8.2 Hz), 5.42 (d, 1H, ‐CHCl, J=6.95 Hz), 7.09‐7.69 (m, 20H, Ar‐H), 8.19 (brs, 1H, CONH). 13C NMR (25 MHz, CDCl3): 60.9 (1C, CH of beta‐lactam), 63.7 (1C, CHCl of beta‐lactam), 119.6, 119.8, 119.9, 120.0, 121.4, 122.8, 123.6, 124.1, 124.8, 127.9, 128.2, 128.6, 128.8, 129.2, 129.3, 129.7, 130.0, 130.5, 131.5, 131.8, 132.3, 132.7, 133.6, 135.6, 136.8, 139.2, 139.7, 140.2, 140.9, 141.2 (30C, Ar‐C), 137.2, 138.6 (2C, C‐4 of imidazole, C‐3 of indolidene), 164.5 (1C, C=O of beta‐ lactam), 168.3 (2C, C‐5 of imidazole, C‐2 of indolidene). ESI‐MS (M+1): 668. Anal. Calcd. for C39H27N4O5Cl: C, 70.22; H, 4.05; N, 8.40. Found: C, 70.09; H, 4.15; N, 8.29%. 3‐(1‐(4'‐(3‐chloro‐2‐(2‐hydroxyphenyl)‐4‐oxoazetidin‐1‐yl) biphenyl‐4‐yl)‐5‐oxo‐2‐phenyl‐1H‐imidazol‐4(5H)‐ylidene) indolin‐2‐one (6d): R2= o‐Hydroxyphenyl: Yield: 68%. M.p.: 195 C. FT‐IR (KBr, cm‐1): 3583 (OH) (o‐hydroxyphenyl), 3389 (N‐H) (indole), 3000 (Ar‐H) (aromatic), 1728 (>C=O) (monocyclic β‐lactam), 1669 (C=O) (sec. amide), 1656 (C=O) (tertiary amide), 770 (C‐Cl) (β‐lactam). 1H NMR (200 MHz, CDCl3): 4.97 (d, 1H, N‐CH‐R of β‐lactam, J=8.0 Hz), 5.40 (d, 1H, ‐ CHCl, J=7.1 Hz), 7.49‐7.63 (m, 21H, Ar‐H), 8.29 (brs, 1H, CONH). 13C NMR (25 MHz, CDCl3): 62.1 (1C, CH of beta‐lactam), 64.3 (1C, CHCl of beta‐lactam), 126.4, 126.5, 126.6, 126.7, 126.8, 127.2, 127.5, 127.6, 128.2, 128.6, 128.8, 129.0, 129.3, 130.1, 130.4, 130.9, 131.4, 132.2, 132.4, 132.6, 132.9, 134.5, 136.9, 137.5, 140.1, 142.2, 142.7, 144.8, 149.6, 150.8 (30C, Ar‐C), 138.3, 138.9 (2C, C‐4 of imidazole, C‐3 of indolidene), 165.6 (1C, C=O of beta‐lactam), 169.9, 171.2 (2C, C‐5 of imidazole, C‐2 of indolidene). ESI‐MS (M+1): 637. Anal. Calcd. for C38H25N4O4Cl: C, 71.64; H, 3.51; N, 8.80. Found: C, 71.71; H, 3.45; N, 8.78%. 3‐(1‐(4'‐(3‐chloro‐2‐(4‐hydroxy‐3‐methoxyphenyl)‐4‐ oxoazetidin‐1‐yl)biphenyl‐4‐yl)‐5‐oxo‐2‐phenyl‐1H‐imidazol‐ 4(5H)‐ylidene)indolin‐2‐one (6e): R2= 4‐OH, 3‐OCH3‐phenyl: Yield: 68%. M.p.: 154 C. FT‐IR (KBr, cm‐1): 3514 (OH) (p‐ hydroxyphenyl), 3438 (N‐H) (indole), 3011 (Ar‐H) (aromatic), 1676 (C=O) (sec. amide), 1661 (C=O) (tertiary amide), 1731 (>C=O) (monocyclic β‐lactam), 1686 (OCH3) (p‐ methoxyphenyl), 763 (C‐Cl) (β‐lactam). 1H NMR (200 MHz, CDCl3): 4.92 (d, 1H, N‐CH‐R of β‐lactam, J=8.0 Hz), 5.46 (d, 1H, ‐ Bishnoi et al. / European Journal of Chemistry 2 (3) (2011) 359‐364 363 CHCl, J=6.8 Hz), 7.16‐7.83 (m, 20H, Ar‐H), 8.13 (brs, 1H, CONH). 13C NMR (25 MHz, CDCl3): 61.2 (1C, CH of beta‐lactam), 63.6 (1C, CHCl of beta‐lactam), 120.3, 120.5, 120.6, 120.8, 122.1, 122.3, 123.2, 123.9, 124.3, 127.9 128.5, 128.6, 128.7, 128.8, 129.0, 129.6, 130.0, 130.3, 131.1, 131.5, 132.1, 136.1, 136.4, 136.8, 137.2, 139.3, 140.4, 140.6, 141.8, 144.7 (30C, Ar‐C), 137.6, 138.1 (2C, C‐4 of imidazole, C‐3 of indolidene), 164.2 (1C, C=O of beta‐lactam), 168.4, 169.3 (2C, C‐5 of imidazole, C‐2 of indolidene). ESI‐MS (M+1): 667. Anal. Calcd. for C39H27N4O5Cl: C, 70.22; H, 4.05; N, 8.40. Found: C, 70.30; H, 4.10; N, 8.37%. 3‐(1‐(3‐chloro‐2‐(4‐hydroxyphenyl)‐4‐oxoazetidin‐1‐yl)‐5‐ oxo‐2‐phenyl‐1H‐imidazol‐4(5H)‐ylidene)indolin‐2‐one (7a): R2= p‐Hydroxyphenyl: Yield: 60%. M.p.: 229 C. FT‐IR (KBr, cm‐1): 3345 (N‐H) (indole), 3360 (OH) (p‐hydroxyphenyl), 3015 (Ar‐H) (aromatic), 1729 (>C=O) (monocyclic β‐lactam), 1684 (C=O) (sec. amide), 1655 (C=O) (tertiary amide), 1649 (C=N) (imidazole), 768 (C‐Cl) (β‐lactam). 1H NMR (200 MHz, CDCl3): 4.78 (s, 1H, Ar‐OH), 4.88 (d, 1H, N‐CH‐R of β‐lactam, J=7.9 Hz), 5.39 (d, 1H, ‐CHCl, J=7.1 Hz), 7.71‐7.89 (m, 13H, Ar‐ H). 13C NMR (25 MHz, CDCl3): 60.3 (1C, CH of beta‐lactam), 64.1 (1C, CHCl of beta‐lactam), 110, 114.5, 119.6, 122.3, 124.9, 125.9, 127.9, 128.4, 128.5, 129.6, 130.3, 130.5, 131.1, 131.4, 132.1, 133.9, 154.4, 155.0 (18C, Ar‐C), 139.6, 140.6 (2C, C‐4 of imidazole, C‐3 of indolidene), 144.9 (1C, C‐2 of imidazole), 163.8 (1C, C=O of beta‐lactam), 168, 168.9 (2C, C‐5 of imidazole, C‐2 of indolidene). ESI‐MS (M+1): 485. Anal. Calcd. for C26H17N4O4Cl: C, 64.39; H, 3.69; N, 11.57. Found: C, 64.45; H, 3.51; N, 11.55%. 3‐(1‐(3‐chloro‐2‐(4‐chlorophenyl)‐4‐oxoazetidin‐1‐yl)‐5‐oxo‐ 2‐phenyl‐1H‐imidazol‐4(5H)‐ylidene)indolin‐2‐one (7b): R2= p‐ Chlorophenyl: Yield: 60%. M.p.: 218 C. FT‐IR (KBr, cm‐1): 3385 (N‐H) (indole), 2985 (Ar‐H) (aromatic), 1733 (>C=O) (monocyclic β‐lactam), 1689 (C=O) (sec. amide), 1675 (C=O) (tertiary amide), 1632 (C=N) (imidazole), 765 (C‐Cl) (β‐ lactam). 1H NMR (200 MHz, CDCl3): 5.02 (d, 1H, N‐CH‐R of β‐ lactam, J=8.7 Hz), 5.44 (d, 1H, ‐CHCl, J=7.1 Hz), 7.19‐7.69 (m, 13H, Ar‐H), 8.49 (brs, 1H, CONH). 13C NMR (25 MHz, CDCl3): 60.9 (1C, CH of beta‐lactam), 64.5 (1C, CHCl of beta‐lactam), 121, 122.3, 122.6, 123.0, 125.2, 126.6, 126.8, 128.3, 128.8, 129.4, 129.7, 129.9, 130.2, 130.4, 130.5, 134.2, 157.6, 158.1 (18C, Ar‐C), 140.6, 141.1 (2C, C‐4 of imidazole, C‐3 of indolidene), 145.3 (1C, C‐2 of imidazole), 164.1 (1C, C=O of beta‐lactam), 169.9, 171.3 (2C, C‐5 of imidazole, C‐2 of indolidene). ESI‐MS (M+1): 503.. Anal. Calcd. for C26H16N4O3Cl2: C, 62.03; H, 3.51; N, 11.15. Found: C, 61.98; H, 3.45; N, 11.11%. 3‐(1‐(3‐chloro‐2‐(3‐hydroxy‐4‐methoxyphenyl)‐4‐oxoazeti‐ din‐1‐yl)‐5‐oxo‐2‐phenyl‐1H‐imidazol‐4(5H)‐ylidene)indolin‐2‐ one (7c): R2= 3‐OH, 4‐OCH3‐phenyl: Yield: 55%. M.p.: 252 C. FT‐IR (KBr, cm‐1): 3352 (N‐H) (indole), 3022 (Ar‐H) (aromatic), 1716 (>C=O) (monocyclic β‐lactam), 1670 (C=O) (sec. amide), 1658 (C=O) (tertiary amide), 1640 (C=N) (imidazole), 760 (C‐Cl) (β‐lactam). 1H NMR (200 MHz, CDCl3): 3.25 (s, 3H, Ar‐OCH3), 4.95 (s, 1H‐Ar‐OH), 5.05 (d, 1H, N‐CH‐R of β‐lactam, J=8.7 Hz), 7.25‐5.45 (d, 1H, ‐CHCl, J=7.9 Hz), 7.85 (m, 12H, Ar‐H), 7.88 (brs, 1H, CONH). 13C NMR (25 MHz, CDCl3): 60.1 (1C, CH of beta‐lactam), 63.8 (1C, CHCl of beta‐lactam), 119, 119.6, 120.4, 122.1, 125.8, 126.3, 126.9, 128.0, 128.6, 128.9, 129.0, 129.3, 130.3, 130.8, 130.9, 133.7, 146.9, 149.8 (18C, Ar‐C), 139.6, 141.2 (2C, C‐4 of imidazole, C‐3 of indolidene), 144.5 (1C, C‐2 of imidazole), 163.6 (1C, C=O of beta‐lactam), 169.4, 170.6 (2C, C‐5 of imidazole, C‐2 of indolidene). ESI‐MS (M+1): 516. Anal. Calcd. for C27H19N4O5Cl: C, 62.97; H, 3.69; N, 10.89. Found: C, 62.85; H, 3.72; N, 10.86%. 3‐(1‐(3‐chloro‐2‐(2‐hydroxyphenyl)‐4‐oxoazetidin‐1‐yl)‐5‐ oxo‐2‐phenyl‐1H‐imidazol‐4(5H)‐ylidene)indolin‐2‐one (7d): R2= o‐Hydroxyphenyl: Yield: 68%. M.p.: 249 C. FT‐IR (KBr, cm‐1): 3290 (N‐H) (indole), 3007 (Ar‐H) (aromatic), 1727 (>C=O) (monocyclic β‐lactam), 1663 (C=O) (sec. amide), 1649 (C=O) (tertiary amide), 1632 (C=N) (imidazole), 758 (C‐Cl) (β‐ lactam). 1H NMR (200 MHz, CDCl3): 4.81 (s, 1H‐Ar‐OH), 5.42 (d, 1H, ‐CHCl, J=7.1 Hz), 4.99 (d, 1H, N‐CH‐R of β‐lactam, J=8.4 Hz), 7.23‐7.95 (m, 13H, Ar‐H), 8.02 (brs, 1H, CONH). 13C NMR (25 MHz, CDCl3): 60.3 (1C, CH of beta‐lactam), 63.6 (1C, CHCl of beta‐lactam), 120.6, 123.5, 123.7, 124.2, 125.6, 125.8, 125.9, 128.2, 129.2, 129.8, 130.1, 130.7, 131.5, 131.7, 132.2, 133.4, 151.6, 152.6 (18C, Ar‐C), 139.4, 140.3 (2C, C‐4 of imidazole, C‐3 of indolidene), 144.2 (1C, C‐2 of imidazole), 163.2 (1C, C=O of beta‐lactam), 169.1, 170.4 (2C, C‐5 of imidazole, C‐2 of indolidene). ESI‐MS (M+1): 486. Anal. Calcd. for C26H17N4O4Cl: C, 64.39; H, 3.51; N, 11.57. Found: C, 64.29; H, 3.48; N, 11.53%. 3‐(1‐(3‐chloro‐2‐(4‐hydroxy‐3‐methoxyphenyl)‐4‐ oxoazetidin‐1‐yl)‐5‐oxo‐2‐phenyl‐1H‐imidazol‐4(5H)‐ylidene) indolin‐2‐one (7e): R2= 4‐OH, 3‐OCH3‐phenyl: Yield: 71%. M.p.: 191 C. FT‐IR (KBr, cm‐1): 3333 (N‐H) (indole), 3100 (Ar‐H) (aromatic), 1717 (>C=O) (monocyclic β‐lactam), 1666 (C=O) (sec. amide), 1660 (C=O) (tertiary amide), 1646 (C=N) (imidazole), 767 (C‐Cl) (β‐lactam). 1H NMR (200 MHz, CDCl3): 3.16 (s, 3H, Ar‐OCH3), 4.43 (s, 1H‐Ar‐OH), 4.64 (d, 1H, N‐CH‐R of β‐lactam, J=8.9 Hz), 7.08‐4.99 (d, 1H, ‐CHCl, J=8.5 Hz), 7.60 (m, 12H, Ar‐H), 7.71 (brs, 1H, CONH). 13C NMR (25 MHz, CDCl3): 61.4 (1C, CH of beta‐lactam), 64.1 (1C, CHCl of beta‐lactam), 119, 122.7, 123.1, 124.2, 126.3, 126.7, 126.8, 128.4, 128.7, 129.1, 129.2, 129.4, 129.5, 129.6, 131, 133.5, 149, 153.5 (18C, Ar‐C), 140.7, 141.5 (2C, C‐4 of imidazole, C‐3 of indolidene), 145 (1C, C‐2 of imidazole), 165.7 (1C, C=O of beta‐lactam), 170.2, 171.8 (2C, C‐5 of imidazole, C‐2 of indolidene). ESI‐MS (M+1): 515. Anal. Calcd. for C27H19N4O5Cl: C, 62.97; H, 3.69; N, 10.89. Found: C, 62.78; H, 3.65; N, 10.80%. 3. Results and discussion The starting material 2‐phenyl‐4‐(2’‐oxo‐1’H‐3’‐ indolidene)‐1,3‐oxazol‐5‐one (1) was prepared by the reaction between isatin, hippuric acid and acetic acid in presence of sodium acetate. The oxazolone 1 on reaction with 1,1‐diphenyl‐ 4,4‐diamine or hydrazine hydrate in pyridine produced 2 and 3 in moderate yields, respectively. The structure of 2 and 3 has been confirmed by their spectral data. The 1H NMR spectrum of 2 and 3 showed a broad singlet integrating for two protons at  5.30 and  4.96 due to ‐NH2 group. The IR spectrum of these compounds exhibited two absorption bands due to symmetric and asymmetric stretching frequencies of primary amine between 3375‐3425 cm‐1 and another band at 3127 and 3130 cm‐1 due to >NH absorptions, respectively. The two other bands at 1410 and 1421 cm‐1 due to ‐C‐N< were also observed. Compounds 2 and 3 were then subjected to condensation with appropriate aromatic aldehydes in alcohol to give 4a‐e and 5a‐ e. These compounds were purified with column chromatography and the yields mentioned are of the major isolable fractions which were characterized by different spectroscopic techniques. The title compounds, 3‐(1‐(4'‐(3‐ chloro‐2‐(substituted phenyl)‐4‐oxoazetidin‐1‐yl)biphenyl‐4‐ yl)‐5‐oxo‐2‐phenyl‐1H‐imidazol‐4(5H)‐ylidene)indolin‐2‐ones (6a‐e) and 3‐(1‐(3‐chloro‐2‐(substituted phenyl)‐4‐ oxoazetidin‐1‐yl)‐5‐oxo‐2‐phenyl‐1H‐imidazol‐4(5H)‐ylidene) indolin‐2‐ones (7a‐e), were obtained by the treatment of 4a‐e and 5a‐e with chloroacetyl chloride in dioxane in presence of triethylamine and were found to have cis geometry [22‐23]. IR and 1H NMR spectra of these compounds were well in agreement with the structures assigned. Out of all tested compounds 6a‐e and 7a‐e, which were screened against Candida albicans and B. subtilis, as summarized in Table 1, compound 6d was found to possess interesting antifungal activity (MIC 12.5 g/mL). The compound contains an ortho hydroxy phenyl function at ‐ 364 Bishnoi et al. / European Journal of Chemistry 2 (3) (2011) 359‐364 lactam ring. Similarly, compound 7d was found to show reasonable degree of antibacterial activity against Bacillus subtilis with an MIC value of 12.5 g/mL, also bears an ortho hydroxyl phenyl function at ‐lactam ring. Table 1. Antimicrobial activities (MIC μg/mL) of compounds 6a‐e and 7a‐e. Compound C. albicans B. subtilis 6a >100 50 6b 25 50 6c 25 >100 6d 12.5 25 6e >100 25 7a 50 >100 7b 25 25 7c >100 50 7d 25 12.5 7e >100 >100 Based on current findings, it may be suggested that 2‐ hydroxy phenyl function at ‐lactam ring is a key factor for both antifungal and antibacterial activity. Interestingly, when hydroxyl group was substituted at para position the antimicrobial activity was lost. This clearly suggests that the position of the substituent has a greater role than the nature of the substituent or alternatively it seems that an ortho‐hydroxyl substituent finds comparatively a better fit at the receptor site than a para‐hydroxyl substituent. The loss of activity in other compounds could be explained by the contention that the change in the position of the substituent in the molecules has rendered them inactive. 4. Conclusion This report comprises a simple synthesis of ‐lactam derivatives without protection of other functional group in good yields. In the course of our study for seeking ‐lactam derivatives as antimicrobial agents, we found compounds that possessed well in vitro activities against Bacillus subtilis and Candida albicans. Biological screening data provide a new lead for further structure function studies of compounds. We are currently exploring modifications at this key position to obtain ‐lactam with promising antimicrobial activity. Acknowledgement The authors are greatly thankful to to the Head, Department of Chemistry, Lucknow University, Lucknow, for providing laboratory facilities. They are also thankful to the Director, Central Drug Research Institute, Lucknow for elemental analysis and spectral data. References [1]. Rang, H. P.; Dale, M. M.; Ritter, J. M.; Flower, R. J. Rang and Dale’s Pharmacology, Churchill Livingstone, International Edition, USA, 2003. [2]. Yu, L. T.; Ho, M. T.; Chang, C. Y.; Yang, T. K. Tetrahedron: Asym. 2007, 18(8), 949‐962. [3]. Gupta, A.; Unadkat, J. D.; Mao, Q. J. Pharma. Sci. 2007, 96(12), 3226‐ 3235. [4]. Schiller, S. D.; Fung, H. B. Clin. Ther. 2007, 29(9), 1862‐1886. [5]. Ashok, M.; Holla, B. S.; Poojary, B. Eur. J. Med. Chem. 2007, 42(8), 1095‐ 1101. [6]. Van Cutsem, J. M.; Thienpont, D. Chemotherapy 1972, 17(6), 392‐404. [7]. Kokjohn, K.; Bradly, M.; Griffiiths, B.; Ghannoum, M. Int. J. Dermatol. 2003, 42(S1), 11‐17. [8]. McLean, K. J.; Marshall, K. R.; Richmond, A.; Hunter, I. S.; Fowler, K.; Kieser, T. Microbiology 2002, 148, 2937‐2949. [9]. Ucucu, U.; Karaburun, N. G.; Isikdag, I. Farmaco. 2001, 56(4), 285‐290. [10]. Yesilada, A.; Koyunoglu, S.; Saygilia, N.; Kupeli, E.; Yesilada, E.; Bedir, E. Khanc, I. Arch. Pharm. Pharm. Med. Chem. 2004, 337, 96‐104. [11]. Quattara, L.; Debaert, M.; Cavier, R. Farmaco. (Sci) 1987, 42(6), 449‐ 456. [12]. Dutta, S.; Mariappan, G.; Roy, S.; Verma, M. Indian Drugs 2009, 46(7), 50‐53. [13]. Sengupta, A. K.; Bhattacharya, T. J. Indian Chem. Soc. 1983, 60, 373‐ 376. [14]. Navidpour, L.; Shadnia, H.; Shafaroodi, H.; Amini, M.; Dehpour, A. R.; Shafiee, A. Bioorg. Med. Chem. 2007, 15(5), 1976‐1982. [15]. Driscoll, M. O.; Greenhalgh, K.; Young, A.; Turos, E.; Dickey, S.; Lim, D. V. Bioorg. Med Chem. 2008, 16(16), 7832‐7837. [16]. Banik, B. K.; Becker, F. F.; Banik, I. Bioorg. Med Chem. 2004, 12(10), 2523‐2528. [17]. Banik, B. K.; Banik, I.; Becker, F. F. Bioorg. Med Chem. 2005, 13(11), 3611‐3622. [18]. Banik, B. K.; Banik, I.; Becker, F. F. Eur. J. Med Chem. 2010, 45(2), 846‐ 848. [19]. Zhang, W.; Richardson, R. D.; Chamni, S.; Smith, J. W.; Romo, D. Bioorg. Med Chem. Lett. 2008, 18(7), 2491‐2494. [20]. National Committee for Clinical Laboratory Standards. Performance standards for antimicrobial disk susceptibility tests. Approved standard. NCCLS document M2‐A5. Wayne, Pa: National Committee for Clinical Laboratory Standards; 1997. [21]. Sahm, D. F.; Washington, J. A. Manual of Clinical Microbiology, 5th Ed., ASM, Washington DC, 1991. [22]. Lopez, R.; Sordo, T. L.; Sordo, J. A.; Gonzalez, J. J. Org. Chem. 1993, 58, 7036‐7037. [23]. VanBrabandt, W.; Vanwalleghem, M.; D’hooghe, M.; De Kimpe, N. J. Org. Chem. 2006, 71, 7083‐7086.