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European	Journal	of	Chemistry	5	(2)	(2014)	233‐236	

	

European	Journal	of	Chemistry	
ISSN	2153‐2249	(Print)	/	ISSN	2153‐2257	(Online)		2014	Eurjchem	Publishing	‐	Printed	in	the	USA	

http://dx.doi.org/10.5155/eurjchem.5.2.233‐236.979	

	
	

	

	

European	Journal	of	Chemistry	
Journal	homepage:	www.eurjchem.com	

	 	 	

One‐pot	three‐component	synthesis	of	some	new	azo‐pyrazoline	derivatives	

Farouq	Emam	Hawaiz	*,	Awaz	Jamil	Hussein	and	Mohammed	Kareem	Samad	

Department	of	Chemistry,	College	of	Education,	University	of	Salahaddin‐Hawler,	Erbil	44001,	Kurdistan	Region,	Iraq	

*Corresponding	author	at:	Department	of	Chemistry,	College	of	Education,	University	of	Salahaddin‐Hawler,	Erbil	44001,	Kurdistan	Region,	Iraq.		
Tel.:	+964.750.4605629.	Fax:	+964.750.4605629.	E‐mail	address:	farouqemam@yahoo.com	(F.E.	Hawaiz).	

	
	

	 	

	 	 	
ARTICLE	INFORMATION	 	 ABSTRACT	

	
DOI:	10.5155/eurjchem.5.2.233‐236.979	

Received:	30	November	2013	
Received	in	revised	form:	05	January	2014	
Accepted:	06	January	2014	
Online:	30	June	2014	

KEYWORDS	

	 The	 starting	material	 azo‐benzyloxy	 acetophenone	 (2)	 has	 been	 synthesized	 in	 three	 steps;
the	direct	diazotization	of	p‐aminoacetophenone	and	its	coupling	reaction	with	m‐cresol	gave
azo‐acetophenone	(1),	which	was	benzylated	with	p‐chlorobenzylchloride	to	give	the	starting
material	 (2).	 The	 later	 compound	 was	 subjected	 to	 the	 one‐pot	 three‐component
condensation	reaction	with	substituted	benzaldehydes	and	phenylhydrazine	 in	 the	presence
of	 sodium	hydroxide	 to	 afford	 the	 target	molecule	 azo‐pyrazoline	 derivatives	 (3a‐e)	 in	 high
yields	and	short	reaction	times.	The	structures	of	the	synthesized	compounds	were	elucidated
by	using	FT‐IR,	1H	NMR,	13C	NMR	and	13C	DEPT	135	spectra.		

Cyclization	
Benzylation	
Diazotization	
Azo‐pyrazoline	
One‐pot	synthesis		
Azo‐acetophenone	

	
1.	Introduction	
	

A	one‐pot	synthesis,	in	which	three	[1‐3],	four	[4]	or	more	
[5]	components	react	in	just	one	reactor	to	a	final	product	is	a	
synthetically	 useful	 method	 for	 improving	 the	 efficiency	 of	
chemical	 reaction,	 where	 interacting	 molecules	 subject	 to	
successive	chemical	reactions	in	just	a	single	vessel.	This	is	very	
useful	 for	 organic	 chemists,	 because	 of	 significantly	 shortens	
the	 reaction	 process	 by	 reducing	 the	 number	 of	 steps	 and	
avoiding	 a	 long	 separation	 processes	 and	 purification	 of	
chemical	 intermediates,	 would	 pay	 a	 way	 to	 green	 chemistry	
approach	 by	 save	 time	 and	 solvents	 for	 the	 purification	
processes,	 and	 increasing	 the	 proportion	 of	 output	 products	
[6].		

A	 traditional	 synthesis	 of	 pyrazoline	 derivatives	 involve	 a	
two‐step	process,	the	Claisen‐Schmidt	condensation	reaction	of	
substituted	 acetophenones	 and	 substituted	 benzaldehydes	 to	
give	 chalcones	 [7],	 which	 undergo	 a	 subsequent	 cyclization	
reaction	 with	 hydrazines	 producing	 2‐pyrazolines	 [8].	
Afterwards	 a	 number	 of	 synthetic	 approaches	 to	 synthesis	 of	
pyrazolines	 were	 reported,	 which	 include	 one‐pot	 three‐
component	 condensation	 reaction	 [9,10].	 Considerable	
attention	 has	 been	 focused	 on	 the	 synthesis	 of	 pyrazoline	
derivatives	 due	 to	 their	 wide	 spectrum	 of	 biological	 activity	
which	 include:	 anti‐malarial	 [11],	 anti‐fungal	 [12],	 anti‐
inflammatory	 [13],	 analgesic	 [14],	 antileishmanial	 [15],	
antioxidant	 [16]	 and	 other	 antimicrobial	 activities	 [17,18].	
Herein	we	have	described	the	synthesis	and	characterization	of	

some	 new	 azo‐pyrazoline	 derivatives	 containing	 benzyloxy	
moiety	 through	 a	 one‐pot	 three‐component	 condensation	
reaction	 of	 azo‐acetophenone,	 substituted	 benzaldehydes	 and	
phenylhydrazine.		
	
2.	Experimental		
	
2.1.	Instrumentation	
	

Melting	 points	were	 determined	 using	 an	 Electro	 thermal	
melting	 point	 apparatus,	 IR	 spectra	 were	 recorded	 on	
Shimadzu	 ‐FTIR	 Affinity‐1,	 using	 KBr	 disc.	 1H	 NMR,	 13C	 NMR	
and	 13C	 DEPT	 135	 spectra	 were	 recorded	 on	 a	 Bruker	 Ultra	
Shield	(300	MHz)	with	TMS	and	CDCl3	as	an	internal	reference	
and	solvent,	respectively.	
	
2.2.	Synthesis	of	1‐[4‐{(4‐(4‐chlorobenzyloxy)‐2‐methyl	
phenyl)diazenyl}	phenyl]	ethanone	(2)		
	

According	 to	 the	modified	 procedure	 [19]	 a	mixture	 of	 in	
situ	 prepared	 compound	1	 [20]	 (9.14	 g,	 0.036	mol),	 4‐chloro	
benzyl	chloride	(6.44	g,	0.04	mol)	and	anhydrous	K2CO3	(7.45	g,	
0.054	mol),	in	(30	mL)	ethanol	96%	was	refluxed	with	stirring	
for	 6hrs.	 The	 cooled	 solution	 poured	 into	 water,	 the	 solid	
material	 immediately	 was	 obtained,	 then	 filtered	 off,	 washed	
several	 times	with	 cold	water	dried	 and	 recrystallized	 from	a	
mixture	of	xylene:	ethanol	(1:10,	v:v)	to	give	orange	crystals	of	
compound	2	(Scheme	1).	



234	 Hawaiz	et	al.	/	European	Journal	of	Chemistry	5	(2)	(2014)	233‐236	
	

	

N

NHO O

N

NO O

CH3

Cl

CH3

H2N

OH

CH3

O

NHNH2

X
H

O

NaOH , ethanol
reflux 3-6h

Cl

CH2Cl

N

NO

Cl

CH3

NN

X

NaNO2

HCl (0-5 oC)

K2CO3
Ethanol
reflux 6h.

(2)

1

2
3

45

6

7 89

1011

12

13 141617

1819

20

21 22

1
2

4

3

5
6

7
8

910

15

1112

13

14 15

16

17
18

19

20 21

22

2324

2526

27

28 29
30

31

32
33

34

35

(3a-e)

(1)

X: H, 2-Cl, 4-F, 4-Me, 3(p-Cl-Benzyloxy)

+N2

O

NaOH

 
	

Scheme	1
	
	

Yield:	 13.20	 g,	 97%.	M.p.:	 139‐141	 oC.	 IR	 (KBr,	,	 cm‐1):	 1683	
(C=O),	1597	(C=C).	 1H	NMR	(300	MHz,	CDCl3	δ,	ppm):	2.30	(s,	
3H,	Ar‐CH3),	2.65	(s,	3H,	COCH3),	5.14	(s,	2H,	OCH2),	6.85‐8.10	
(m,	11H,	Ar‐Hˊ).	 13C	NMR	(75	MHz,	CDCl3	δ,	ppm):	17.88	(C15),	
26.55	(C1),	69.36	(C16),	113.28	(C13),	116.41	(C11),	117.21	(C5,7),	
122.72	 (C14),	 128.79	 (C18,22),	 128.87	 (C19,21),	 129.36	 (C4,8),	
134.01	 (C10),	 134.94	 (C20),	 137.75	 (C3),	 141.88	 (C17),	 145.39	
(C9),	155.59	(C2).	13C	DEPT	135	(75	MHz,	CDCl3	δ,	ppm):	17.88	
(C15),	26.55	(C1),	69.36	(C16),	113.28	(C13),	116.41	(C11),	117.21	
(C5,	7),	122.72	(C14),	128.79	(C18,	22),	128.87	(C19,	21),	129.36	(C4,	
8).	
	
2.3.	One	pot	synthesis	of	pyrazolines,	3‐{4‐[4‐(4‐chloro‐
benzyloxy)‐2‐methyl‐phenylazo]‐phenyl}‐5‐(substituted	
phenyl)‐1‐phenyl‐2‐pyrazolines	(3a‐e)	
	

A	 mixture	 of	 compound	 2	 (1	 mmol),	 substituted	
benzaldehyde	 (1	 mmol),	 NaOH	 (4%,	 3	 mmol)	 and	 phenyl	
hydrazine	 (1.5	 mmol)	 was	 mixed	 together	 in	 20	 mL	 ethanol	
96%	 and	 refluxed	 with	 stirring	 for	 appropriate	 time	 until	
completion	 the	 reaction	 which	 was	 monitored	 by	 TLC	 and	
colour	 change.	The	 solution	was	 cooled	 and	 the	 solid	product	
was	separated	by	suction	filtration,	washed	several	times	with	

cold	 water	 dried	 and	 recrystallized	 from	 acetone	 to	 give	
pyrazolines	(3a‐e)	(Scheme	1).		

3‐{4‐[4‐(4‐Chloro‐benzyloxy)‐2‐methyl‐phenylazo]‐phenyl}‐
5‐phenyl‐1‐phenyl‐2‐pyrazoline	(3a):	Yield:	78%.	M.p.:	181‐183	
°C.	Time:	4	h.	 IR	(KBr,	,	 cm‐1):	1595(C=N),	1573,	1554	(C=C).	
1H	 NMR	 (300	 MHz,	 CDCl3	 δ,	 ppm):	 2.73	 (s,	 3H,	 ‐Ar‐CH3‐C22),	
3.22	(dd,	1H,	CH2‐Ha‐C8),	3.88	(dd,	1H,	CH2‐Hb‐C8),	5.08	(s,	2H	‐
O‐CH2‐C23),	 5.33	 (dd,	 1H,	 CH‐Hx‐C7),	 6.78‐7.85	 (m,	 21H,	 Ar‐H).	
13C	 NMR	 (75	 MHz,	 CDCl3	 δ,	 ppm):	 17.87	 (Ar‐CH3‐C22),	 43.36	
(CH2‐C8),	64.59	(CH‐C7),	69.28	(O‐CH2C23),	113.12	(C20),	113.50	
(C18),	116.36	(C31,35),	117.04	(C33),	119.42	(C12,14),	123.05	(C21),	
125.51	(C4),	125.83	(C2,6),	127.66	(C3,5),	128.33	(C25,29),	128.78	
(C26,28),	 128.81	 (C11,15),	 128.94	 (C32,34),	 129.19	 (C17),	 133.91	
(C10),	 134.44	 (C27),	 135.07	 (C24),	 141.03	 (C1),	 142.35	 (C30),	
144.39	(C16),	145.88	 (C9),	152.74	(C13),	160.87	(C19).	 13C	DEPT	
135	 (75	MHz,	CDCl3	δ,	 ppm):	17.87	 (Ar‐CH3‐C22),	 ‐43.36	 (CH2‐
C8),	 64.59	 (CH‐C7),	 ‐69.28	 (O‐CH2C23),	 113.12	 (C20),	 113.50	
(C18),	116.36	(C31,35),	117.04	(C33),	119.42	(C12,14),	123.05	(C21),	
125.51	(C4),	125.83	(C2,6),	127.66	(C3,5),	128.33	(C25,29),	128.78	
(C26,28),	128.81	(C11,15),	128.94	(C32,34).	

3‐{4‐[4‐(4‐Chloro‐benzyloxy)‐2‐methyl‐phenylazo]‐phenyl}‐
5‐(o‐chlorophenyl)‐1‐phenyl‐2‐pyrazoline	(3b):	Yield:	95%.	M.p.:	
169‐170	 °C.	 Time:	 5	 h.	 IR	 (KBr,	 ,	 cm‐1):	 1597	 (C=N),	 1575,	



Hawaiz	et	al.	/	European	Journal	of	Chemistry	5	(2)	(2014)	233‐236	 235	
 

1546	(C=C).	1H	NMR	(300	MHz,	CDCl3	δ,	ppm):	2.96	(s,	3H,	Ar‐
CH3‐C22),	 3.20	 (dd,	 1H,	 CH2‐Ha‐C8),	 4.04	 (dd,	 1H,	 CH2‐Hb‐C8),	
5.11	 (s,	 2H	 ‐O‐CH2‐C23),	 5.72	 (dd,	 1H	 CH‐Hx‐C7),	 6.67‐7.80	 (m,	
20H,	 Ar‐H).	 13C	NMR	 (75	MHz,	 CDCl3	 δ,	 ppm):	 17.86	 (Ar‐CH3‐
C22),	 41.78	 (CH2‐C8),	 61.40	 (CH‐C7),	 69.33	 (O‐CH2C23),	 113.15	
(C20),	113.29	(C18),	116.40	(C31,35),	117.08	(C33),	119.57	(C12,14),	
123.06	 (C21),	 126.35	 (C5),	 127.30	 (C4),	 127.67	 (C6),	 128.21	
(C25,29),	 128.79	 (C3),	 128.83	 (	 C26,28),	 129.08	 (C11,15),	 129.55	
(C32,34),	 129.95	 (C17),	 132.88	 (C2),	 133.02	 (C27),	 134.30	 (C10),	
136.82	 (C24),	 139.01	 (C1),	 144.21	 (C30),	 145.92	 (C16),	 146.85	
(C9),	152.60	(C13),	159.45	(C19).	13C	DEPT	135	(75	MHz,	CDCl3	δ,	
ppm):	 17.86	 (Ar‐CH3‐C22),	 ‐41.78	 (CH2‐C8),	 61.40	 (CH‐C7),	 ‐
69.33	 (O‐CH2C23),	 113.15	 (C20),	 113.29	 (C18),	 116.40	 (C31,35),	
117.08	 (C33),119.57	 (C12,14),	 123.06	 (C21),	 126.35	 (C5),	 127.30	
(C4),	 127.67	 (C6),	 128.21	 (C25,29),	 128.79	 (C3),	 128.83	 (	 C26,28),	
129.08	(C11,15),	129.55	(C32,34).		

3‐{4‐[4‐(4‐Chloro‐benzyloxy)‐2‐methyl‐phenylazo]‐phenyl}‐
5‐(p‐fluorophenyl)‐1‐phenyl‐2‐pyrazoline	(3c):	Yield:	77%.	M.p.:	
181‐183	 °C.	 Time:	 5	 h.	 IR	 (KBr,	 ,	 cm‐1):	 1598	 (C=N),	 1576,	
1546	(C=C).	1H	NMR	(300	MHz,	CDCl3	δ,	ppm):	2.71	(s,	3H,	Ar‐
CH3‐C22),	 3.12	 (dd,	 1H,	 CH2‐Ha‐C8),	 3.83	 (dd,	 1H,	 CH2‐Hb‐C8),	
5.28	 (s,	 2H,	O‐CH2‐C23),	 5.28	 (dd,	 1H,	 CH‐Hx‐C7),	 6.81‐7.89	 (m,	
20H,	 Ar‐H).	 13C	NMR	 (75	MHz,	 CDCl3	 δ,	 ppm):	 17.90	 (Ar‐CH3‐
C22),	 43.37	 (CH2‐C8),	 64.10	 (CH‐C7),	 69.6	 (O‐CH2‐C23),	 113.16	
(C20),	 115.99	 (C18),	 116.40	 (C31,35),	 117.09	 (C3,5),	 119.63	 (C33),	
123.28	 (C12,14),	 126.32	 (C21),	 127.60	 (C25,29),	 128.38	 (C2,6),	
128.84	 (C26,28),	 128.93	 (C11,15),	 129.02	 (C32,34),	 129.49	 (C17),	
134.30	 (C27),	 135.10	 (C10),	 138.11(C1),	 141.10	 (C24),	 144.26	
(C30),	 145.47	 (C16),	 145.92	 (C9),	 152.84	 (C13),	 160.14	 (C4),	
160.82	(C19).	13C	DEPT	135	(75	MHz,	CDCl3	δ,	ppm):	17.90	(Ar‐
CH3‐C22),	 ‐43.37	 (CH2‐C8),	 64.10	 (CH‐C7),	 ‐69.6	 (O‐CH2‐C23),	
113.16	(C20),	115.99	(C18),	116.40	 (C31,35),	117.09(C3,5),	119.63	
(C33),	123.28	(C12,14),	126.32(C21),	127.60	(C25,29),	128.38	(C2,6),	
128.84	(C26,28),	128.93	(C11,15),	129.02	(C32,34).	

3‐{4‐[4‐(4‐Chloro‐benzyloxy)‐2‐methyl‐phenylazo]‐phenyl}‐
5‐(p‐methylphenyl)‐1‐phenyl‐2‐pyrazoline	 (3d):	 Yield:	 83%.	
M.p.:	119‐121	°C.	Time:	5	h.	IR	(KBr,	,	cm‐1):	1596	(C=N),	1572,	
1543	(C=C).	1H	NMR	(300	MHz,	CDCl3	δ,	ppm):	2.65	(s,	3H,	Ar‐
CH3‐C22),	2.95	(s,	3H,	Ar‐CH3‐C30),	3.17	(dd,	1H,	CH2‐Ha‐C8),	3.85	
(dd,	1H,	 CH2‐Hb‐C8),	 5.08	 (s,	 2H,	O‐CH2‐C23),	 5.30	 (dd,	 1H,	 CH‐
Hx‐C7),	 6.77‐8.10	 (m,	 20H,	 Ar‐H).	 13C	 NMR	 (75	 MHz,	 CDCl3	 δ,	
ppm):	 17.88	 (Ar‐CH3‐C22),	 21.11	 (Ar‐CH3‐C36),	 43.43	 (CH2‐C8),	
64.42	 (CH‐C7),	 69.36	 (O‐CH2C23),	 113.14	 (C20),	 113.28	 (C18),	
116.41	 (C31,35),	 117.21	 (C33),	 122.72	 (C12,14),	 123.06	 (C21),	
125.78	 (C2,6),	 126.26	 (C25,29),	 128.79	 (C3,5),	 128.79	 (C26,28),	
128.86	(C11,15),	129.36	(C32,34),	129.86	(C17),	134.01	(C27),	135.11	
(C10),	 137.75	 (C4),	 139.42	 (C24),	 141.88	 (C1),	 144.46	 (C30),	
145.40	(C16),	145.89	(C9),	152.74	(C13),	161.53	 (C19).	 13C	DEPT	
135	(75	MHz,	CDCl3	δ,	ppm):	17.88	(Ar‐CH3‐C22),	21.11	(Ar‐CH3‐
C36),	 ‐43.43	(CH2‐C8),	64.42	(CH‐C7),	 ‐69.36	(O‐CH2C23),	113.14	
(C20),	113.28	(C18),	116.41	(C31,35),	117.21	(C33),	122.72	(C12,14),	
123.06	(C21),	125.78	(C2,6),	126.26	(C25,29),	128.79	(C3,5),	128.79	
(C26,28),	128.86	(C11,15),	129.36	(C32,34).	

3‐{4‐[4‐(4‐Chloro‐benzyloxy)‐2‐methyl‐phenylazo]‐phenyl}‐
5‐(m‐(4‐chlorobenzyloxy)	 phenyl)‐1‐phenyl‐2‐pyrazoline	 (3e):	
Yield:	86%.	M.p.:	164‐166	°C.	Time:	3	h.	IR	(KBr,	,	cm‐1):	1596	
(C=N),	 1575,	 1542	 (C=C).	 1H	 NMR	 (300	MHz,	 CDCl3	 δ,	 ppm):	
2.73	(s,	3H,	Ar‐CH3‐C22),	3.19	(dd,	1H,	CH2‐Ha‐C8),	3.85	(dd,	1H,	
CH2‐Hb‐C8),	4.96	(s,	2H,	O‐CH2‐C36),	5.08	(s,	2H,	O‐CH2‐C23),	5.51	
(dd,	1H,	CH‐Hx‐C7),	6.80‐7.87	(m,	24H,	Ar‐H).	13C	NMR	(75	MHz,	
CDCl3	 δ,	 ppm):	17.88	 (Ar‐CH3‐C22),	 43.40	 (CH2‐C8),	 64.08	 (CH‐
C7),	 69.28	 (O‐CH2‐C36),	 69.32	 (O‐CH2‐C23),	 113.14	 (C20),	113.55	
(C18),	115.45	(C31,35),	116.39	(C3,5),	117.06	(C33),	119.42	(C12,14),	
123.07	 (C21),	 126.27	 (C2,6),	127.13	 (C25,29,38,42),	128.74	 (C26,28,39,	
41),	128.84	(C11,15),	128.94	(C32,34),	133.81	(C17),	134.51	(C27,40),	
134.95	 (C10),	 135.39	 (C1),	 141.04	 (C24,37),	 144.41	 (C30),	 145.49	
(C16),	 145.90	 (C9),	 152.76	 (C13),	 158.03	 (C4),	 160.90	 (C19).	 13C	
DEPT	135	(75	MHz,	CDCl3	δ,	ppm):	17.88	 (Ar‐CH3‐C22),	 ‐43.40	
(CH2‐C8),	64.08	(CH‐C7),	‐69.28	(O‐CH2‐C36),	‐69.32	(O‐CH2‐C23),	
113.14	(C20),	113.55	(C18),	115.45(C31,35),	116.39	(C3,5),	117.06	

(C33),	 119.42	 (C12,14),	 123.07	 (C21),	 126.27	 (C2,6),	 127.13	
(C25,29,38,42),	128.74	(C26,28,39,41),	128.84	(C11,15),	128.94	(C32,34).		
		
3.	Results	and	discussion		
	

In	the	last	century,	a	huge	number	of	pyrazoline	and	a	little	
bit	 of	 azo‐pyrazoline	 derivatives	 have	 been	 reported	 [21].	
While	there	is	no	research	in	the	literature	for	the	synthesis	of	
azo‐pyrazoline	derivatives	through	a	one‐pot	three‐	component	
reaction	process.	Therefore,	 the	aim	of	 the	work	 is	 to	prepare	
some	new	azo‐pyrazoline	compounds	 in	high	yields	and	short	
reaction	 times	 avoiding	 separation	 and	purification	 processes	
of	intermediate	chalcones	by	using	a	one‐pot	synthesis.	In	this	
study,	 firstly	 we	 have	 prepared	 the	 starting	 material	 azo‐
benzyloxy‐acetophenone	(2),	then	used	it	as	a	main	component	
with	both	phenylhydarzine	and	substituted	benzaldehyde	 in	a	
single	vessel	for	one‐pot	synthesis	approach	of	azo‐pyrazolines	
(3a‐e)	 as	 shown	 in	 Scheme	 1.	 The	 newly	 synthesized	
compounds	 were	 characterized	 spectrally	 by	 using	 FT‐IR,	 1H	
NMR,	13C	NMR	and	13C	DEPT	135	spectra.	In	the	IR	spectrum	of	
the	 starting	material	 azo‐benzyloxy	 (2),	 the	 disappearance	 of	
the	hydroxyl	group	of	compound	1,	and	shifting	an	absorption	
band	 of	 carbonyl	 group	 to	 1683	 cm‐1,	 a	 strong	 band	 at	 1597			
cm‐1	for	C=C	of	aromatic	rings	beside	a	two	weak	bands	at	2924	
and	 2880	 cm‐1	 attributed	 to	 the	 (‐CH2‐)	 group	 of	 4‐benzyloxy	
moiety	 are	 confirmed	 the	benzylation	of	hydroxyl	 group	 [22].	
The	 1H	 NMR	 spectrum	 of	 compound	 (2)	 shows	 three	 singlet	
signals	 at	 2.34,	 2.60	 and	 5.20	 ppm	belongs	 to	 the	 two	 (‐CH3)	
groups	 attached	 to	 the	 carbonyl	 and	 phenyl	 groups	 and	 two	
protons	 of	 ‐O‐CH2‐,	 respectively,	 a	 multiple	 signals	 at	 6.8‐8.2	
ppm	 for	 11	 protons	 of	 three	 aromatic	 rings.	 The	 13C	 NMR	
spectrum	 showed	 eighteen	 singlets	 for	 eighteen	 types	 of	
carbons	 in	 different	 environments	 in	 the	 molecule.	 The	 13C	
DEPT	135	of	azo‐benzyloxy	(2)	showed	nine	upward	signals	for	
two	 (CH3)	 groups	 and	 seven	 mono	 protonated	 carbons	 of	
aromatic	rings	and	one	downward	signal	corresponding	to	a	di‐
protonated	 carbon	atom	of	 ‐O‐CH2‐	 group	with	disappearance	
of	eight	singlets	for	non‐protonated	carbon	atoms	[23].		

In	the	IR	spectra	of	the	target	molecule	azo‐pyrazoline	the	
disappearance	 of	 carbonyl	 group	 band	 for	 both	 azo‐
acetophenone	and	substituted	benzaldehyde	and	appearance	of	
two	new	bands	around	1570	and	1550	 cm‐1	 for	 imine	system	
are	 good	 evidences	 for	 the	 formation	 of	 imine	 and	 the	
occurrence	of	cyclization	reaction	to	give	2‐pyrazoline.	The	1H	
NMR	spectra	of	pyrazoline	ring	shows	a	very	distinct	signals	for	
the	 protons	 attached	 to	 the	 C7	 and	 C8	 carbon	 atoms	 in	 the	 2‐
pyrazoline	as	an	(ABX)	spin	system	[24]	which	appeared	three	
doublet	to	doublet	(dd)	signals	around	δ	3.2	,	3.8,	and	5.4	ppm	
for	 two	geminal	 and	one	vicinal	protons	prove	a	2‐pyrazoline	
structure.	While	 the	 13C	 NMR	 spectrum	 shows	 two	 additional	
picks	for	 two	carbons	(C7	and	C8)	approximately	at	45	and	65	
ppm	of	 the	pyrazoline	ring	confirm	the	2‐pyrazoline	structure	
[25].	 Further	 support	 for	 the	 formation	 of	 the	 five	 member	
pyrazoline	ring,	is	a	downward	signal	of	13C	DEPT	spectrum	at	
(‐43	 ppm)	 for	 the	 CH2	 group	 of	 the	 ring	 in	 addition	 to	 the	
downward	signal	for	OCH2	group	at	(‐69	ppm).	
	
4.	Conclusion		
	

The	 introduction	 of	 the	 azo‐linkage,	 ortho	 to	 the	 acetyl	
group	 in	 acetophenone,	 will	 increases	 the	 conjugation	 and	
produce	 colored	 compounds	 that	 can	be	used	 as	new	starting	
materials	 for	 the	preparation	of	 different	 organic	 compounds.		
The	 preparation	 of	 azo‐pyrazoline	 compounds	 from	 azo‐
acetophenone,	substituted	benzaldehydes	and	phenylhydrazine	
can	be	achieved	in	high	yields	and	short	reaction	times	by	using	
a	one‐pot	synthesis	method,	via	reducing	the	number	of	steps	
and	 avoiding	 a	 long	 separation	 processes	 and	 purification	 of	
chemical	intermediates.				
	
	



236	 Hawaiz	et	al.	/	European	Journal	of	Chemistry	5	(2)	(2014)	233‐236	
	
Acknowledgements	
	

This	 study	 was	 supported	 by	 Chemistry	 Department,	
College	 of	 Education,	 Salahaddin	 University‐Hawler,	 Erbil,	
Kurdistan	region,	Iraq.	
	
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