60
AL-AWADI ET AL.
EXPERIMENTAL
Synthesis
yield 0.14 g (55%). IR: 3062, 3024, 2920, 2851, 1643,
1599, 1466, 1407, 1343, 1183, 949, 823, 746, 692. 1H
NMR (CDCl3): δ 7.78 (s, 1H, CH), 7.69 (d, 2H, J 8.4),
7.55 (m, 2H), 7.37 (m, 3H), 7.25 (d, 2H, J 8.0), 3.59
(s, 3H, N-CH3), 2.45 (s, 3H, CH3). LC–MS (m/z):
253 (M + 1). Anal. calcd for C16H16N2O (252.3): C
76.16; H 6.39; N 11.10. Found: C 75.97; H 6.64; N
10.32.
All melting points are uncorrected. IR spectra were
recorded in KBr disks using Perkin Elmer system
2000 FT-IR spectrophotometer. 1H NMR spectra were
recorded on a Bruker DPX 400 MHz Superconducting
NMR spectrometer. Mass spectra were measured on
Vg Auto-spes-q (high resolution, high performance,
tri-sector GC–MS–MS) and with LC–MS using Ag-
ilent 1100 series LC/MSD with an API-ES/APCI
ionization mode. Microanalyses were performed on
LECO CHNS-932 elemental analyzer.
Nꢁ-Benzylidene-N-methyl-N-p-methoxybenzoylhydra-
zine 2c. Colorless crystals from pet. ether mp 102◦C,
yield 0.137 g (51%). IR: 3068, 3000, 2923, 2838,
1640, 1602, 1467, 1404, 1345, 1253, 1173, 1052,
1027, 835, 756, 695.1H NMR (CDCl3): δ 7.81 (m,
2H), 7.77 (s, 1H, CH), 7.57 (m, 2H), 7.37 (m, 3H),
6.97 (m, 2H), 3.91 (s, 3H, OCH3), 3.58 (s, 3H,
N-CH3). LC–MS (m/z): 269 (M + 1). Anal. calcd
for C16H16N2O2 (268.3): C 71.62; H 6.01; N 10.44.
Found: C 71.47; H 5.98; N 10.52.
General Procedure for the Preparation of
Benzhydrazides. Benzhydrazide
benzhydrazide [3], 4-chlorobenzhydrazide [4], 4-
methoxybenzhydrazide [5], and 4-nitrobenzhydrazide
[6] were prepared as reported in the literature.
[2],
4-methyl-
Nꢁ-Benzylidene-N-methyl-N-p-chlorobenzoylhydra-
zine 2d. Colorless crystals from pet. ether mp 156◦C,
yield 0.147 g (54%). IR: 3194, 3027, 2956, 2835,
1631, 1609, 1547, 1507, 1364, 1313, 1259, 1173,
1035, 843, 765. 1H NMR (CDCl3): δ 7.79 (s, 1H, CH),
7.71 (d, 2H, J 8.4), 7.52 (m, 2H), 7.43 (d, 2H, J 8.4),
7.38 (m, 3H), 3.59 (s, 3H, N-CH3). LC–MS (m/z):
273 (M + 1). Anal. calcd for C15H13ClN2O (272.7):
C 66.06; H 4.80; N 10.27. Found: C 65.99; H 4.96; N
10.46.
General Procedure for the Preparation of Nꢁ-
Benzylidenebenzhydrazide (1a–e). Nꢁ-Benzylidene-
benzhydrazide 1a [7], Nꢁ-benzylidene-p-methyl-
benzhydrazide 1b [8], Nꢁ-benzylidene-p-methoxy-
benzhydrazide 1c [9], Nꢁ-benzylidene-p-chloro-
benzhydrazide 1d [10], Nꢁ-benzylidene-p-nitroben-
zhydrazide 1e [11], Nꢁ-benzylidene-N-phenylbenzhy-
drazide 4 [12], and N-benzyl-Nꢁ-benzylidenebenzhy-
drazide 5 [13] were prepared as reported in the
literature.
Nꢁ-Benzylidene-N-methyl-N-p-nitrobenzoylhydra-
zine 2e. Pale yellow crystals from pet. ether (40–60%)
mp 178˚C, yield 0.142 g (50%). IR: 3110, 3023, 2963,
2918, 2851, 1648, 1599, 1516, 1469, 1415, 1347,
Nꢁ-Benzylidene-N-methyl-N-aroylhydrazine (2a–e)
and N-Allyl-N-benzoyl-Nꢁ-benzylidenehydrazine (6).
1
1312, 1052, 854, 751, 721, 692. H NMR (CDCl3):
δ 8.32 (d, 2H, J 8.4), 7.85 (d, 2H, J 8.8), 7.82 (s,
1H, CH) 7.45 (m, 2H), 7.38 (m, 3H), 3.62 (s, 3H,
N-CH3). LC–MS (m/z): 285 (M + 1). Anal. calcd
for C15H13N3O3 (283.3): C 63.60; H 4.63; N 14.83.
Found: C 63.98; H 4.91; N 14.93.
General Procedure. To a suspension of NaH (0.4 g,
10 mmol) in dry THF (20 mL), the appropriate hy-
drazide 1a–e (10 mmol) was added, the mixture was
heated under reflux for 1 h, and then CH3I or allyl
bromide (10 mmol) was added. The mixture was then
further heated under reflux for 6 h. The remaining pre-
cipitate after removing the solvent in vacuo was crys-
tallized from pet. ether of boiling range 40–60◦.
Nꢁ-Benzylidene-N-methylthiobenzhydrazide 3. A
mixture of Nꢁ-benzylidene-N-methyl-N-benzoyl-
hydrazine 2a (0.224 g, 1 mmol) and phosphorus
pentasulfide (0.33 g, 1.5 mmol) in pyridine (7 mL) was
heated under reflux for 3 h. Aftercooling, the mixture
was poured over crushed ice and the precipitate was
collected and crystallized from EtOH to get 0.22 g
(90%) of yellow crystals, mp 112◦C. IR: 3062, 3021,
1465, 1419, 1395, 1336, 1274, 1101, 1069, 752,
Nꢁ-Benzylidene-N-methyl-N-benzoylhydrazine 2a.
Colorless crystals from pet. ether mp 84◦C (lit. [14]
85◦C), yield 0.12 g (52%). IR: 3055, 3027, 2960, 1650,
1
1604, 1463, 1408, 1346, 1180, 1051, 712, 687. H
1
690. H NMR (DMSO-d6): δ 7.91 (s, 1H), 7.49 (m,
NMR (CDCl3): δ 7.79 (s, 1H), 7.75 (d, 2H, J 8.0),
7.49 (m, 5H), 7.35 (m, 3H), 3.60 (s, 3H, NCH3). LC–
MS (m/z): 239 (M + 1). Anal. calcd for C15H14N2O
(238.2): C 75.61; H 5.92; N 11.76. Found: C 75.35; H
5.96; N 11.87.
2H), 7.44 (d, 2H, J 7.2), 7.40–7.32 (m, 6H), 4.13
(s, 3H). LC–MS (m/z): 255 (M + 1). Anal. calcd
for C15H14N2S (254.4): C 70.83; H 5.55; N 11.01; S
12.61. Found: C 70.75; H 5.63; N 11.09; S 12.61.
N-Allyl-Nꢁ-benzylidenebenzhydrazine 6. Colorless
liquid, yield 0.132 g (50%). IR: 3583, 3060, 3030,
Nꢁ-Benzylidene-N-methyl-N-p-methylbenzoylhydra-
zine 2b. Colorless crystals from pet. ether mp 124◦C,
International Journal of Chemical Kinetics DOI 10.1002/kin