A. A. Aly, A. B. Brown, and A. M. Shawky
Vol 000
one equivalent of 2 gave the same mono triazole with the
same yield percentages of the products 4a–e.
δH = 13.30 (bs, 1H, COOH), 7.80–7.76 (dd, 2H, Ar―H),
7.60–7.56 (dd, 2H, Ar―H), 7.40–7.30 (m, 5H, Ar―H),
7.20–7.16 (dd, 2H, Ar―H), 6.80–6.74 (m, 3H, Ar―H);
13C NMR (100 MHz, DMSO-d6):δC = 167.00 (CO-acid),
154.25 (C-3), 153.90 (C-5), 152.90 (C-20), 131.90 (C-10),
131.60, 130.50 (Ar―C), 130.11 (Ar―2C―CH-30/40),
129.82, 128.93 (Ar―CH), 128.58, 128.02 (Ph―2CH-o),
127.75, 127.14 (Ph―2CH-m), 126.91 (Ph0―CH-p),
124.45 (Ph―CH-p). MS (70 eV, EI, %), m/z = 341
(M+, 22), 313 (100), 296 (28), 220 (18), 144 (32).
Calcd for C21H15N3O2 (341.12): C, 73.89; H, 4.43; N,
CONCLUSION
Our results deal with the second reported reaction of
amidrazones with phthaloyl chloride to produce the
2-(10,20,40-triazolo)benzoic acids in good yields.
Interestingly, addition of two equivalents of triethyl
amine as we can see affects on the bi-acid chloride
functions and therefore causes facile elimination of
corresponding two equivalents triethyl amine·HCl. Free
bases of triazole·2HCl might be obtained via
neutralization with NaOH followed by hydrolysis of the
ester group, which of course would give low yields
compared with the established method. The short time
taken and the simplicity to obtain the free triazole moiety
give advantage on the previous one. Most indicative is
that our previous method gave the ester of benzoic acid,
whereas the new one produces directly the triazole
derivatives of benzoic group.
12.31. Found: C, 73.70: H, 4.60: N, 12.40.
2–40-(4″-Methylphenyl)-5-phenyl-4H-10,20,40-triazol-30-yl)benzoic
acid (4b). Yellow crystals (methanol), yield 0.29 g (82%),
mp 170–172°C. IR (KBr) (νmax, cmꢀ1): 3100–3030 (w,
Ar―CH), 2980–2890 (m, Aliph-CH), 2560 (s, CO-acid),
1708 (s, CO-acid), 1620 (s, C═N), 1560 (s, C═C). 1H
NMR (400 MHz, DMSO-d6): δH = 13.10 (bs, 1H, COOH),
7.60–7.56 (dd, 2H, Ar―H, J = 8.0, 1.0 Hz)), 7.50–7.40 (m,
4H, Ar―H), 7.10–6.90 (m, 3H, Ar―H), 6.80–6.60 (m, 4H,
Ar―H), 2.30 (s, 3H, CH3); 13C NMR (100 MHz,
DMSO-d6): δC = 167.10 (CO-acid), 154.15 (C-3), 153.90
(C-5), 152.65 (C-20), 132.00 (p-tolyl-C), 131.60 (C-10),
130.70, 130.50 (Ar―C), 130.10 (Ar―CH-30/40), 129.60,
128.60 (Ar―CH), 128.20, 127.90 (Ph―2CH-o), 127.10
(Ph―2CH-m), 126.60 (Ph0―CH-p), 122.60 (Ph―2CH-m),
22.40 (CH3―Ar). MS (70 eV, EI, %), m/z = 335 (M+,
20), 320 (18), 292 (100), 216 (14), 140 (24), 76 (40).
Calcd for C22H17N3O2 (355.13): C, 74.35; H, 4.82; N,
EXPERIMENTAL
NMR spectra were measured on a Bruker AV-400
spectrometer (Bruker BioSpin Corp., Billerica, MA)
1
(400 MHz for H, 100 MHz for 13C, and 40.55 MHz for
11.82. Found: C, 74.20; H, 4.85; N, 11.75.
1
15N) at Florida Institute of Technology, USA. The H and
2–40-(4″-Methoxyphenyl)-5-phenyl-4H-10,20,40-triazol-30-yl)
benzoic acid (4c). Yellow crystals (CHCl3/Cyclohexane),
13C chemical shifts are given relative to internal standard
TMS=0. Zones were detected by quenching of indicator
fluorescence upon exposure to 254 nm UV light. Elemental
analyses were carried in the National Research center,
Dokki, Cairo, Egypt. Mass spectrometry was performed by
electron impact at 70eV, with a Finnigan Mat 8430
spectrometer in the National Research center, Dokki, Cairo,
Egypt. IR spectra using KBr pellets, were run on a FT-IR
(Bruker), Minia University, El-Minia, Egypt. Amidrazones
1a-g were prepared according to reference [30,31].
yield: 0.32 g (85%), mp 196–8°C. IR (KBr) (νmax, cmꢀ1):
3080 (w, Ar―CH), 2950–2830 (w, Aliph-CH), 2510 (m,
CO-OH, st), 1708 (s, CO-acid), 1620 (s, C═N), 1560 (s,
C═C). NMR (DMSO-d6): Table 1. MS (70 eV, EI, %),
m/z = 371 (M+, 22), 356 (18), 341 (42), 267 (100), 191
(22), 77 (32). Calcd for C22H17N3O3 (371.13): C, 71.15;
H, 4.61; N, 11.31. Found: C, 71.00; H, 4.51; N, 11.20.
2–40-(4″-Chlorophenyl)-5-phenyl-4H-10,20,40-triazol-30-yl)benzoic
acid (4d).
Pale yellow crystals (methanol), yield: 0.28 g
(75%), mp 110–2°C. IR (KBr) (νmax, cmꢀ1): 3110–3020 (w,
Ar―CH), 2500 (m, CO―OH, st), 1710 (s, CO-acid), 1615
(s, C═N), 1560 (s, C═C). 1H NMR (400 MHz, DMSO-d6):
δH = 13.40 (bs, 1H, COOH), 7.60–7.40 (m, 5H, Ar―H),
7.30–7.20 (m, 4H, Ar―H), 6.82–6.66 (m, 4H, Ar―H). 13C
NMR (100 MHz, DMSO-d6): δC = 168.20 (CO-acid),
154.20 (C-3), 153.60 (C-5), 152.80 (C-20), 131.40 (C-10),
130.60, 130.10 (Ar―C), 130.30 (Ar―CH-30/40), 128.70
(Ar―C―Cl), 128.40, 128.00 (Ar―CH), 127.60, 127.20
(Ph―2CH-o), 126.80, 126.60 (Ph―2CH-m), 124.20
(Ar―CH-p). MS (70 eV, EI, %), m/z = 376 (M + 1, 20),
375 (32), 342 (18), 341 (24), 310 (100), 238 (16), 237 (24),
162 (18), 160 (32), 112 (18), 110 (14), 78 (26). Calcd for
Reaction of amidrazones 1a–e with phthaloyl chloride
(2).
A mixture of compounds 1a–e (1 mmol) with 2
(0.202 g, 1 mmol) in absolute 1,4-dioxane (30 mL)
containing 2 mmol of Et3N, was stirred at r.t. for 2–6 h.
The products formed were filtered off, and the
precipitates were washed with water (200 mL) and then
with 10 mL of ethanol. The products 4a–e were then
dried and recrystallized from the stated solvents.
2-(4″,5″-Diphenyl-4H-10,20,40-triazol-3-yl)benzoic
acid
(4a). Yellow crystals (ethanol), yield 0.27 g (80%), mp
180–2°C. IR (KBr) (νmax, cmꢀ1): 3060 (w, Ar―CH),
2508 (m, CO-acid), 1710 (s, CO-acid), 1618 (s, C═N),
1550 (s, C═C). 1H NMR (400 MHz, DMSO-d6):
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet