untitled European Journal of Chemistry 4 (4) (2013) 336‐342 European Journal of Chemistry ISSN 2153‐2249 (Print) / ISSN 2153‐2257 (Online)  2013 EURJCHEM DOI:10.5155/eurjchem.4.4.336‐342.828 European Journal of Chemistry Journal homepage: www.eurjchem.com Synthesis of intermediate compounds with P‐N bond from (thio)carbamates and chlorodioxaphospholanes and ‐phosphorinanes and their reactivity Dmitry Murzin a,b,* and Vera Kolesova b a Department of Chemical Engineering, Åbo Akademi University, Turku, 20500, Finland b Department of Chemistry and Technology of Organic Synthesis, Faculty of Technology of Organic Substances and Pharmaceutical Chemistry, Mendeleev University of Chemical Technology, Moscow, 125047, Russia *Corresponding author at: Department of Chemical Engineering, Åbo Akademi University, Turku, 20500, Finland. Tel.: +358.2.2154985; fax: +358.2.2154479. E‐mail address: dmurzin@abo.fi (D. Murzin). ARTICLE INFORMATION ABSTRACT Received: 13 May 2013 Received in revised form: 11 June 2013 Accepted: 14 June 2013 Online: 31 December 2013 KEYWORDS A variety of 2‐(N‐alkoxy(thio)carbonyl alkyl(aryl)amino)‐1,3,2‐dioxaphospholanes and phosphorinanes were prepared from chlorodioxaphospholanes and phosphorinanes. Their structures were determined by IR, Mass and NMR spectroscopy. These compounds were employed in direct reactions with elemental sulphur and methylester of chloroacetic acid giving potentially physiologically active N‐phosphorylated carbamates with P(O)‐N and P(S)N bonds. Mass‐spectra Sulfur addition Phosphorinanes Arbuzov rearrangement Chlorodioxaphospholanes N‐Phosphorylated carbamates 1. Introduction Synthesis of compounds with P‐N bonds has been extensively discussed in the literature due to their physiological and catalytic properties. For example, synthesis of N‐phosphorylated carbamates (Figure 1) is mainly driven by physiological properties of these compounds; those could be used as, for example, pesticides [1]. Figure 1. N‐phosporylated carbamates, X stands for oxygen or sulphur. An important property of such compounds is their selective toxicity. Carbamates with P‐N bonds, derivatives of P(III), can have high reactivity, which gives an opportunity to synthesize corresponding derivatives of P(V) containing also sulphur. Synthesis of compounds 1 and 2 when R2 is H, can be carried out through the route displayed in Scheme 1 [2]. Another synthetic option is the reaction of PCl3 with N‐chloroamides of carbonic acid ROC(O)NHCl or N‐chloroaminoethers (RO)2C=NCl leading to ROCON=PCl3 which can undergo hydrolysis to yield N‐dichlorophosphoryl carbamates [3]. The range of synthetic methods was enlarged when it turned out that unsubstituted phosphorylated carbamates can be formed when phosphory‐ lated isocyanates react with alcohols or mercaptanes [4]. This method can be applied for the synthesis of various types of phosphorylated carbamates. For example, bis(chlromethyl) phosphinoylisocyanate reacts easily with alcohols to give the corresponding phosphorylated carbamates (ClCH2)2P(O) NHC(O)OR [5]. The methods discussed above allow, however, only the synthesis of unsubstituted phosphorylated carbamates. Substituted carbamates, in turn, can be obtained by several methods, including for example Arbuzov rearrange‐ ment (Scheme 2) [6]. Another method involves the reaction of chloroanhydrides of various phosphor containing acids with sodium carbamates [7]. Utilization of such preparative methods in industrial scale is challenging due to the need of using metallic sodium for synthesis of sodium carbamates, making the process unnecessarily complicated. An alternative way is to form P‐N bonds directly from a nitrogen compound containing an N‐H bond. It is possible, for example, to react halogen containing compounds, such as chloroanhydrides of varios P(III) acids with amines giving a P(III)‐N bond. In the work of Dutton and coworkers [8], chloro‐ 2‐dimethyl‐5,5‐dioxaphosporinane‐1,3,2 was reacted with various amines, such as tert‐butylamine resulting in the formation of several 1,3,2 dioxaphosporinanes. A similar approach was adopted by Browne et al. [9] where phosporochloridite was reacted with amines followed by reaction with elemental sulfur to obtain potential insecticides. Another example has been reported by de Vries [10], where ethylene chlorophosphite was allowed to react with diisopropylamine in dichloromethane giving the cyclic ethylene phosphite ester. This synthetic methodology became popular recently in connection with the synthesis of a library of chiral ligands based on monodentate phosphoramidites [11,12] when stoichiometric amounts of reagents such as chlorodioxa phospholane (4) and diacetylamines are put in contact in the presence of a HCl acceptor (triethylamine) giving finally phosphoramidites (5) (Scheme 3). Murzin and Kolesova / European Journal of Chemistry 4 (4) (2013) 336‐342 337 Scheme 1 Scheme 2 Scheme 3 The protocol was even automated by using a 96 well filter plate, as simple filtration of the precipitated HCl salt can be performed without further ligand purification. In fact, triethylamine started to be used rather long time ago as a HCl acceptor not only for reaction of phosphorochloridite with amines per se, but also for reactants with the ‐NH‐C(O)‐ group, such as N‐methylacetamide [13,14]. Alternatively ‐caprolactam can be used [15]. In the latter case [15] it is supposed that the reaction proceeds via intermediate formation of a five membered complex. Interestingly, in earlier work [13], also phosphorylated carbamates with P‐N(R)‐C(O)OR motifs were synthesized, including 2‐(N‐ethoxycarbonyl methylamino)‐l,3,2‐dioxa‐ phospholane (6), diethyl N‐ethoxycarbonyl‐N‐methylphosphor‐ amidite (7) and 4,5‐benzo‐2‐(N‐ethoxycarbonymethylamino)‐ 1,3,2‐dioxaphospholane (8) (Figure 2). N‐phosphorylated methylcarbamates, in turn, were shown to react with elemental sulfur [9,15]. The products possess insecticidal activity resulting, however, in burns of the leaves. Chloroanhydrides can also react with compound 7 [15]. The aim of the present work was to synthesize components with P‐N bonds from (thio)carbamates and chlorodioxa‐ phospholanes and ‐phosphorinanes and to study their reactivity in reactions with elemental sulphur and chloro anhydrides. The compounds obtained from these reactions could be potential insecticides and regulators of plant growth. 2. Experimental 2.1. Synthesis In the current work, all synthesized phosphorylated carbamates were obtained by reactions of 2‐chloro‐1,3,2‐ dioxaphospholane/phosphorinane (9) with carbamates and thiocarbamates in the presence of HCl acceptor‐triethylamine (Scheme 4). The synthesized compounds are presented in Table 1. It should be noted that among these compounds only compound 10b was synthesized previously [13]. Synthesis of compounds 10a‐10m was performed under nitrogen atmosphere. To a solution of (thio)carbamate and triethylamine (1.5 fold mole excess) in 25 or 50 mL of dried dioxane an equimolar amount 2‐chloro‐1,3,2‐dioxaphospho‐ lane or chloro‐1,3,2‐dioxaphosphorinane was added drop‐wise. The quantities are given in Table 2. The mixture was stirred for 2 h at 55‐60 oC. After filtering triethylamine salt and evaporating the solvent in vacuum (1‐12 mm Hg) the residual was distilled at 0.1‐0.2 mm Hg. The yields reported below are isolated yields. Ethyl 1,3,2‐dioxaphospholan‐2‐ylcarbamate (10a): IR (KBr, , cm‐1): 2990 (C‐H), 1710 (C=O), 1230 (C‐O‐C), 1010 (P‐O‐C). 31P NMR (36.43 MHz, 85%H3PO4, δ, ppm): 133. nD20 = 1.4220 (Identical to the substrate). 338 Murzin and Kolesova / European Journal of Chemistry 4 (4) (2013) 336‐342 Figure 2. Phosphorylated carbamates with P‐N(R)‐C(O)OR motif. Scheme 4 Table 1. Structure of synthesized compound 10. Compound n X R R1 10a 2 O H C2H5 10b CH3 C2H5 10c C6H5 CH3 10d C6H5 i‐C3H7 10e C6H4Cl i‐C3H7 10f 2 S CH2‐CH=CH2 C2H5 10g C6H5 CH3 10h C6H5 i‐C3H7 10i C6H5 C4H9 10j 3 O H C2H5 10k C6H5 CH3 10l C6H5 i‐C3H7 10m S H CH3 Table 2. Ratio of reactants. Product/ Reactants , mole Carbamate, mole Et3N, mole Volume of solvent, mL 10a 0.10 0.150 0.150 50 10b 0.10 0.150 0.150 50 10c 0.03 0.030 0.045 50 10d 0.03 0.030 0.045 50 10e 0.04 0.040 0.060 50 10f 0.03 0.030 0.045 25 10g 0.09 0.090 0.140 50 10h 0.03 0.030 0.045 50 10i 0.01 0.010 0.015 25 10j 0.05 0.075 0.050 50 10k 0.10 0.100 0.150 70 10l 0.05 0.050 0.075 50 10m 0.05 0.050 0.100 50 Ethyl 1,3,2‐dioxaphospholan‐2‐yl(methyl)carbamate (10b): Yield: 32%. B.p.: 50 oC/0.1 mm Hg. IR (KBr, , cm‐1): 2990 (C‐H), 1710 (C=O), 1220 (C‐O‐C), 1010 (P‐O‐C). 31P NMR (36.43 MHz, 85%H3PO4, δ, ppm):128.5 (128.8 in [12]). nD20 = 1.4540. Methyl 1,3,2‐dioxaphospholan‐2‐yl(phenyl)carbamate (10c): Yield: 58%. B.p.: 85 oC/0.2 mm Hg. IR (KBr, , cm‐1): 2990 (C‐H), 1700 (C=O), 1600, 1500, 1450 (C6H5), 1000 (P‐O‐C). 31P NMR (36.43 MHz, 85%H3PO4, δ, ppm): 130. MS (EI, m/z (%)): 241 (M+, 0.55) M+. nD20 = 1.5268. Isopropyl 1,3,2‐dioxaphospholan‐2‐yl(phenyl)carbamate (10d): Color: White. Yield: 82%. M.p.: 80‐81 oC. IR (KBr, , cm‐1): 1700 (C=O), 1600, 1530, 1440 (C6H5), 1220 (C‐O‐C), 995 (P‐O‐C). Isopropyl (2‐chlorophenyl)(1,3,2‐dioxaphospholan‐2‐yl) carbamate (10e): Yield: 50%. B.p.: 95 oC/0.2 mm Hg. IR (KBr, , cm‐1): 2990 (C‐H), 1700 (C=O), 1600, 1530, 1440 (C6H5), 1220 (C‐O‐C), 990 (P‐O‐C). nD20 = 1.5415. O‐ethyl allyl(1,3,2‐dioxaphospholan‐2‐yl)carbamothioate (10f): B.p.: 65‐68 oC/0.1 mm Hg. IR (KBr, , cm‐1): 2990 (C‐H), 1390 (C=S), 1620 (C=C), 1010 (P‐O‐C). MS (EI, m/z (%)): 235 (M+, 190 [(CH2O)2PN(CS)CH2CH=CH2]+, 149 [(CH2O)2PN(CS)]+, 105 [(CH2O)2PN]+. nD20 = 1.5191. O‐methyl 1,3,2‐dioxaphospholan‐2‐yl(phenyl)carbamo thioate (10g): Yield: 63%. B.p.: 85 oC/0.2 mm Hg. IR (KBr, , cm‐ 1): 2990 (C‐H), 1590, 1520, 1490 (C6H5), 1360 (C=S), 1010 (P‐ O‐C). MS (EI, m/z (%)): 257(M+, 1.1), 243 [(CH2O)2PN(C6H5)CSOH]+, 4.19). nD20 = 1.6150. O‐isopropyl 1,3,2‐dioxaphospholan‐2‐yl(phenyl)carbamo thioate (10h): Color: White. Yield: 67%. M.p.: 84‐85 oC. IR (KBr, , cm‐1): 2990 (C‐H), 1600, 1510, 1440 (C6H5), 1375 (C=S), 1250 (C‐O‐C), 990 (P‐O‐C). O‐butyl 1,3,2‐dioxaphospholan‐2‐yl(phenyl)carbamothioate (10i): Color: White. Yield: 70%. M.p.: 68‐70 oC. IR (KBr, , cm‐1): 2990 (C‐H), 1600, 1520, 1450 (C6H5), 1360 (C=S). 31P NMR (36.43 MHz, 85%H3PO4, δ, ppm): 112. MS (EI, m/z (%)): 299 (M+, 0.11). Ethyl 1,3,2‐dioxaphosphinan‐2‐ylcarbamate (10j): IR (KBr, , cm‐1): 1790 (C=O), 1010 (P‐O‐C). Methyl 1,3,2‐dioxaphosphinan‐2‐yl(phenyl)carbamate (10k): Yield: 57%. B.p.: 115‐120 oC/0.2 mmHg. IR (KBr, , cm‐1): 3000 (C‐H), 1600, 1540, 1460 (C6H5), 1770 (C=O), 1020 (P‐O‐C), 1210 (C‐O‐C). MS (EI, m/z (%)): 255 (M+). Isopropyl 1,3,2‐dioxaphosphinan‐2‐yl(phenyl)carbamate (10l): Color: White. Yield: 64%. M.p.: 73‐75 oC (crystallized in petroleum ether). IR (KBr, , cm‐1): 3000 (C‐H), 1600, 1540, 1450 (C6H5), 1750 (C=O), 1040 (P‐O‐C). MS (EI, m/z (%)): 299 ((M+O)+). O‐methyl 1,3,2‐dioxaphosphinan‐2‐ylcarbamothioate (10m): Color: White. Yield: 52%. M.p.:90‐91 oC. IR (KBr, , cm‐1): 3000 (C‐H), 1600, 1500, 1450 (C6H5), 1370 (C=S), 1020 (P‐O‐C). 2.2. Reactions with elemental sulphur For synthesis of phosphorylated carbamates with P=S bond corresponding reactants were put in contact with elemental sulphur in dioxane (Scheme 5). The list of synthesized compounds in displayed in Table 3. Few drops of the catalyst ‐triethylamine were added. The mixture was kept boiling for ca. 6 h. After evaporating the solvent, the products underwent crystallization by adding first toluene and then petroleum ether (11a) or hexane (11c, 11d). Alternatively after solvent evaporation further distillation/treatment under vacuum (1 mm Hg) was performed (11e, 11f) leading to viscosous oil. Compound 11b was purified using TLC with eluent CHCl3. Conditions of experiments are summarized in Table 4. O‐Isopropyl phenyl(2‐sulfido‐1,3,2‐dioxaphospholan‐2‐yl) carbamate (11a): Color: White. Yield: 39%. M.p.: 96‐98 oC. IR (KBr, , cm‐1): 1600, 1500, 1470 (C6H5), 1740 (C=O), 840 (P=S). Murzin and Kolesova / European Journal of Chemistry 4 (4) (2013) 336‐342 339 10 + S 11 P O O n(H2C) N R X O R1 P O O n(H2C) N R X O R1 S Scheme 5 Scheme 6 31P NMR (36.43 MHz, 85%H3PO4, δ, ppm): 82.3. MS (EI, m/z (%)): 301 (15.47%) M+. Anal. calcd. for C5H10NO3PS: C, 47.77; H, 5.42; N, 4.70. Found: C, 47.80; H, 5.31; N, 5.22%. O‐Isopropyl 2‐chlorophenyl(2‐sulfido‐1,3,2‐dioxaphospholan‐ 2‐yl)carbamate (11b): Color: White. Yield: 20%. M.p.: 101‐103 oC. IR (KBr, , cm‐1): 2990 (CH), 1595, 1530, 1440 (C6H5), 1730 (C=O), 1230 (C‐O‐C), 995 (P‐O‐C), 770, 690 (P=S). O‐methyl phenyl 2‐sulfido‐ 1,3,2‐dioxaphospholan‐2‐yl‐ carbamothioate (11c): Color: White. Yield: 27%. M.p.: 110‐112 oC. IR (KBr, , cm‐1): 1590, 1530 (C6H5), 1730 (C=O), 1390 (C=S), 780 (P=S). O‐isopropyl phenyl 2‐sulfido‐ 1,3,2‐dioxaphospholan‐2‐yl carbamothioate (11d): Color: White. Yield: 34%. M.p.: 150‐151 oC. IR (KBr, , cm‐1): 2980 (CH), 1595, 1530, 1440 (C6H5), 1380 (C=S), 990 (P‐O‐C), 690, 770, (P=S). MS (EI, m/z (%)): 139 (CH2O)2PSNH2+, 8.65), 123 (CH2O)2PS+, (11.52)). O‐methyl phenyl(2‐sulfido‐1,3,2‐dioxaphosphinan‐2‐yl) carbamate (11e): Yield: 59%. IR (KBr, , cm‐1): 1600, 1530, 1450 (C6H5), 1720 (C=O), 1220 cm‐1(C‐O‐C), 1020 (P‐O‐C), 690, 760, (P=S). O‐methyl phenyl 2‐sulfido‐1,3,2‐dioxaphosphinan‐2‐yl carbamothioate (11f): Yield: 64%. IR (KBr, , cm‐1): 1590, 1490 (C6H5), 1380 (C=S), 1220 (C‐O‐C), 1030 (P‐O‐C), 680, 750, (P=S). Table 3. Structure of synthesized compound 11. Compound n X R R1 11a 2 O C6H5 i‐C3H7 11b C6H4Cl i‐C3H7 11c 2 S C6H5 CH3 11d C6H5 i‐C3H7 11e 3 O C6H5 CH3 11f S C6H5 CH3 Table 4. Ratio of reactants in reactions of carbamates with sulphur. Product/ Reactants Carbamate type Carbamate amount, mole S, mole Volume of solvent 11a 10d 0.025 0.025 30 11b 10e 0.010 0.010 50 11c 10g 0.030 0.030 25 11d 10h 0.020 0.020 15 11e 10k 0.025 0.025 20 11f 10m 0.025 0.025 20 2.3. Reaction with methylchlorformate Corresponding phosphorylated carbamates were put in contact with methyl chlorformate in dioxane (Scheme 6) and the synthesized compounds are presented in Table 5. Few drops of the catalyst ‐ triethylamine were added. The mixture was kept boiling. After evaporating the solvent the products 12a, 12b slowly crystallized. Compound 12a was purified using TLC with eluent CHCl3. Compound 12c is an oily compound which underwent vacuum treatment at 1 mm Hg. Alternatively after solvent evaporation subsequent distillation under vacuum (0.2 mm Hg) was performed (12d, 12e, 12f) leading to viscosous oils. Conditions of experiments are summarized in Table 6. Table 5. Structure of synthesized compound 12. Compound n X R R1 12a 2 O H C2H5 12b C6H5 i‐C3H7 12c C6H4Cl i‐C3H7 12d 2 S C6H5 CH3 12e C6H5 i‐C3H7 12f 3 O C6H5 CH3 Table 6. Conditions in reactions of carbamates with methylchlorformiate. Product/ Reactants Carbamate type Carbamate amount, mole MCF, mL Reaction time, h Yield, % 12a 10a 0.05 40 6 79 12b 10d 0.04 30 4 83 12c 10e 0.04 30 4 79 12d 10g 0.01 30 11 80 12e 10h 0.01 30 11 74 12f 10k 0.03 25 8 67 Ethyl (2‐chloroethoxy)(methoxy)phosphorylcarbamate (12a): Color: White. M.p.: 155‐156 oC. IR (KBr, , cm‐1): 1730, 1780 (C=O), 1010 (P‐O‐C), 1270 (P=O). Isopropyl (2‐chloroethoxy)(methoxy)phosphoryl(phenyl) carbamate (12b): Color: White. M.p.: 109 oC. IR (KBr, , cm‐1): 1600, 1520, 1440 (C6H5), 1720, 1732 (C=O), 1210 (C‐O‐C), 1025, 1170 (P‐O‐C), 1275 (P=O). MS (EI, m/z (%)): 363 (M+, 5.72), 328 ((M‐Cl)+, 1.34). Isopropyl (2‐chloroethoxy)(methoxy)phosphoryl(2‐chloro phenyl)carbamate (12c): Color: Viscosous oil. IR (KBr, , cm‐1): 1600, 1510, 1440 (C6H5), 1717, 1740 (C=O), 1035 (P‐O‐C), 1270 (P=O). MS (EI, m/z (%)):397 (M+, 1.24%). O‐methyl (2‐chloroethoxy)(methoxy)phosphoryl(phenyl) carbamothioate (12d): B.p: 125 oC/0.2 mm Hg. nD20 = 1.5510. IR (KBr, , cm‐1): 1590, 1530, 1440 (C6H5), 1750 (C=O), 1350 (C=S), 1210 (C‐O‐C), 1000 (P‐O‐C), 1300 (P=O). O‐isopropyl (2‐chloroethoxy)(methoxy)phosphoryl(phenyl) carbamothioate (12e): B.p.: 120‐122 oC/0.2 mm Hg, after that 340 Murzin and Kolesova / European Journal of Chemistry 4 (4) (2013) 336‐342 the product crystallized. Color: White. M.p.: 125 oC. IR (KBr, , cm‐1): 1590, 1530, 1440 (C6H5), 1730 (C=O), 1390 (C=S), 1230 (C‐O‐C), 1000 (P‐O‐C), 1300 (P=O). Ethyl (3‐chloropropoxy)(methoxy)phosphoryl(phenyl) carbamate (12f): B.p: 96 oC/0.2 mm Hg. IR (KBr, , cm‐1): 1600, 1520, 1450 (C6H5), 1750, 1705 (C=O), 1200 (C‐O‐C), 1000 (P‐O‐ C), 1300 (P=O). 31P NMR (36.43 MHz, 85%H3PO4, δ, ppm): ‐13.9. MS (EI, m/z (%)): 290 (M‐COOCH3)+, 5.72). nD20 = 1.5510. 2.4. Instrumentation Mass spectra were measured with Varian MAT CH‐7A instrument, while Bruker HX‐90E NMR spectrometer (36.43 MHz) with 85%H3PO4 as an external standard was used for 31P NMR measurements. IR spectra were measured with IR spectrophotometer UR‐20 either in CCl4 or using KBr. The 'hot‐ stage' apparatus was used to measure the melting point with a possibility to look at the sample through a microscope while its temperature is increased. 3. Results and discussion 3.1. Synthesis and characterization of phosphorylated carbamates In IR spectra of components 10a‐10e and 10j‐10l there were characteristic peaks of carbonyl group in the range 1700‐ 1720 cm‐1 for 10a‐10e (1715 cm‐1 as mentioned in [13]) and 1750‐1790 for 10j‐10l. Presence of the C=S group resulted in peaks at 1360‐1390 cm‐1. For the phospholane ring the characteristic peaks are in the region of 990‐1100 cm‐1. The spectra also contain peaks of the phenyl ring (1450‐1600 cm‐1), while components 10a and 10j have peaks corresponding to NH vibrations. 31P NMP confirms formation of trivalent phosphor carbamates derivatives with signals at 122 ppm. Mass spectra of some substances of type 10 contain molecular ions, such as for example component 10c, where the amount of molecular ion is 0.55%, which is high for phosphor containing compounds at rather severe conditions (70 eV), being a sign of a strong P‐N bond in phosphorylated carbamates. Calculations of the partial charge of P and N using extended Huckel method after structure optimization with MM2 (Chem 3D Pro) gave respectively the values 0.905374 and 0.164095, while P‐N bond length is 1.773 Å. The values of ion fragments in the mass spectra of compound 10c are given in Table 7. Table 7. Mass spectra fragments for 10c. m/e I/Imax Ions 241 0.55 M+ 151 100% [C6H5NCOOCH3]+ 119 37.17 [C6H5NCO]+ 93 7.15 [C6H5NH2]+ 92 28.37 [C6H5NH]+ 91 24.57 [C6H5N]+ 59 17.85 [COOCH3]+ The stability of the molecular ion depends on the number of carbon atoms in the chain, since for component 10k with three carbon atoms in the cycle the relative amount of an ion with m/e 255 is 11.71%. The main fragmentation for compound 10k path is [M+] ‐>[(CH2)3OOP]+ (m/e 105; 88.77%) + [NH(C6H5) COOCH3]+ (m/e 151; 48.08%) although in the spectra also ions with the P‐N bond are present. The main ions in the spectra of compound 10k are given in Table 8. In case of compound 10l it could be expected that the molecular ion is not present, since the isopropyl group could be easily cleaved. On the other hand there is an ion with m/e 299, corresponding to compound 10l with P=O. Moreover in mass spectra ions with m/e 105 (see Table 8) are absent, while there is an ion with m/e 121 (CH2(CH2O)2PO) albeit with low intensity (5.64%). Oxidation of P(III) to P(V) during synthesis and work up also follows from NMR spectra. Table 8. Mass spectra fragments for 10k. m/e I/Imax Ions 271 2.62 MO+ 255 11.71 M+ 196 1.53 [M‐ CO‐ CH3]+ 185 30.55 [HOPOHNC6H5COH]+ 151 48.08 [C6H5NCOOCH3]+ 139 22.12 [POHNC6H5]+ 120 11.52 [C6H5NCOH]+ 119 37.17 [C6H5NCO]+ 105 88.17 93 7.15 [C6H5NH2]+ 92 28.37 [C6H5NH]+ 91 24.57 [C6H5N]+ 77 25.3 [C6H5]+ 59 17.85 [COOCH3]+ 41 100% [CH2CH2CH]+ Introduction of sulphur typically diminishes the stability of thiocarbamates under conditions of mass spectra measure‐ ments compared to carbamates. Thus the intensity of the molecular ion (m/e 257) in phosphorylated thiocarbamate 10g is just 1.1%, while for compound 10i it is even lower ‐0.11%. The P‐N bond length calculated by extended Huckel method (Chem 3D Pro) after structure optimization for compound 10g is marginally larger (1.775 Å) than for compound 10c, while the partial charges for P and N get the values 1.06544 and 0.222732. In the case of compound 10c the ion with m/e 120 [C6H5NHCO]+ is the main one, while intensity of ion with m/e 136 [C6H5NHCS] + is 14.06% which is typical for thiocarbamates with a long chain substituent in the ester part of the molecule. Mass spectrum of the same compound 10c contains also ions with m/e 154 (16.04%) and 155 (5.5%) corresponding respectively to [OPONC6H5]+ and [OPONHC6H5]+. If a substituent at N is not phenyl, but for example allyl radical mass spectra are different, since then N‐C bond is much less stable (N‐C bond distances are respectively 1.316 and 1.470 Å for compound 10g and 10f). Thus mass spectrum of compound 10f (Table 9) demonstrates presence of an ion of m/e 206 with intensity 1.37% as well the ion with m/e 149 (1.85%). The rupture of the dioxaphospholane cycle is hindered, which is confirmed by the presence of such ions as m/e 105 (2.01%) and m/e 91 (26.69%). Table 9. Mass spectra fragments for 10f. m/e I/Imax Ions 255 1.05 M+ 206 1.3 [(CH2O)2PN(CSO)CH2CH=CH2]+ 190 3.28 [(CH2O)2PN(CS)CH2CH=CH2]+ 149 1.85 [(CH2O)2PN(CS)]+ 105 2.09 [(CH2O)2PN]+ 91 26.69 [(CH2O)2P]+ 58 19.38 [NCS]+ 45 30.29 [OC2H5]+ 41 36.65 [CH2CH=CH2]+ 28 100% ‐ 3.2. Reactivity Reactions of phosphorylated carbamates with an effective electrophile, elemental sulphur (S8) were conducted according to Scheme 5. Thin layer chromatography, IR, Mass and NMR spectra were used to identify the purity and structure of these not previously reported compounds. In the IR spectra there are vibrations corresponding to the carbonyl group at 1720‐1740 cm‐1 (11a, 11b, and 11e) and C=S group at 1380‐1390 cm‐1 (11c, 11d, and 11f). In the region 1600‐1470 cm‐1 there are peaks corresponding to the phenyl ring and dioxaphospholane cycle. For P=S bonds typically there are two peaks in a rather range of 770‐840 cm‐1 and 600‐700 Murzin and Kolesova / European Journal of Chemistry 4 (4) (2013) 336‐342 341 cm‐1 also seen for the compounds synthesized in the present work, where the peaks of P=S for compound 11d were noticeable at 660 and 770 cm‐1. In the mass spectrum of compound 11a (Table 10) the intensity of the molecular ion is rather high (15.47%) confirming the strength of P‐N bonds in the synthesized phosphorylated carbamates. Presence of [M+2]+ also confirms the structure of compound 11a since the signal is due to isotope S34. In the mass spectrum of compound 11d it could be expected that the intensity of molecular ion is low compared to compound 11a, since thiocarbamates are not stable at the conditions of electron beam. Indeed the molecular ion is absent, while an ion [(CH2O)2PS]+ with m/e 123 (11.53%) confirms addition of sulphur to the substrate 10h. In the case of compound 11d intensity of [C6H5NCS]+ ion (m/e 135) is rather low (2.37%) in comparison with [C6H5NCO]+, which is the main ion. The partial charges of P and N for compound 11a (1.9673 and ‐0.0143) as well as the bond length (1.773 Å) differ from the corresponding thiocarbamate 11d (Charges of P and N being 2.00269 and 0.17678, respectively, bond length 1.778 Å) in line with mass spectra. Table 10. Mass spectra fragments for 11a. m/e I/Imax Ions 303 0.55 [M+2]+ 302 1.90 [M+1]+ 301 15.47 M+ 242 2.55 [(CH2O)2PSNC6H5CO]+ 215 19.25 [(CH2O)2PSNHC6H5]+ 214 1.82 [(CH2O)2PSNC6H5]+ 199 6.58 [HOPSNC6H5CO]+ 183 2.38 [HPSNC6H5CO]+ 182 5.25 [PSNC6H5CO]+ 172 6.39 [HOPSNHC6H5]+ 171 8.02 [HOPSNC6H5]+ 170 3.54 [OPSNC6H5]+ 155 8.0 [PSNHC6H5]+ 154 2.59 [PSNC6H5]+ 141 12.43 [(CH2O)2PSHNH]+ 140 16.1 [(CH2O)2PSOH]+ 138 2.59 [(CH2O)2PSNH]+ 124 1.88 [(CH2O)2PSH]+ 123 15.24 [(CH2O)2PS]+ 119 100 [C6H5NCO]+ 91 19.43 [C6H5N]+ 77 3.1 [C6H5]+ 43 49.11 [C3H7]+ Reactivity of carbamates was also tested in the reaction with acetylchloride, which was taken in access (Scheme 6). Thin layer chromatography, IR, mass and NMR spectra were used to identify the purity and structure of these not previously reported compounds. In the IR spectra there are peaks corresponding to C=O group for compound 12a and 12c (1700‐1760 cm‐1), 12d and 12e (1730‐1760 cm‐1) as well as P=O group (1210‐1300 cm‐1) and the phenyl ring (1490‐1600 cm‐1) for compounds 12b‐12f. Intensity of molecular ions M+ and [M+2]+ was as high as 61.88% for compound 12f, while it was only 5.72% for compound 12b and 4.24 % for compound 12c. Among other ions in the mass spectrum of compound 12f the following ones should be mentioned corresponding to the removal of Cl [M‐ Cl]+, (m/e 314, 1.38%), methoxycarbonyl group [M‐CH3OC(O)]+ (m/e 290, 5.32%), as well as both of them [M‐Cl‐CH3OC(O)]+ (m/e 255, 4.21%). 4. Conclusions Several intermediates, derivatives of carbamates and cyclophosphoric acids with P‐N bond and the following structure (Scheme 7) were synthesized from (thio)carbamates and chlorodioxa‐phospholanes and ‐phosphorinanes using triethylamine as HCl acceptor. These compounds were identified using IR, mass spectroscopy and 31P NMR. n = 2, 3 R = H, ‐CH3, ‐CH2‐CH=CH2, C6H5, C6H4Cl R1 = CH3, C2H5, i‐C3H7, C4H9 Scheme 7 The reactivity of phosphorylated carbamates was investigated in the sulphur addition reaction giving the following previously not reported O‐alkyl phenyl‐2‐sulfido‐ 1,3,2‐dioxaphospholan (or dioxaphospinan)‐2‐yl)‐carbamates and ‐carbamothioates (Scheme 8). The structure was determined by IR, mass spectroscopy and 31P NMR. n = 2, 3 X = O, S R = C6H5, C6H4Cl, R1 = CH3, i‐C3H7 Scheme 8 A possibility to synthesize for the first time alkyl (2‐ chloroethoxy or propoxy)(methoxy)phosphoryl(2‐aryl) carba‐ mates (or carbamothioates) (Scheme 9) through an Arbuzov type rearrangement was demonstrated by reacting corresponding intermediates containing P‐N bonds and methyl formate. n = 2, 3 X = O, S R = H, C6H5, C6H4Cl R1 = CH3, i‐C3H7 Scheme 9 Detailed analysis of mass spectra of the intermediates and the products was performed and the main fragmentations pathways in mass spectra were discussed. Acknowledgement Technical help and assistance of Prof. Reko Leino during preparation of the manuscript are highly appreciated. References [1]. Fahmy, M. A.; Fukuto, T. R.; Myers, R. O.; March, R. B. J. Agr. Food Chem. 1970, 18, 793‐796. [2]. Derkach, G. I.; Samarai, L. I.; Kirsanov, A. V. Russ. J. Gen. Chem. 1962, 32, 3761‐3764. [3]. Ivanova, Z. 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