Arch. Pharm. Chem. Life Sci. 2008, 341, 696–700
7-(Benzylideneamino)-4-methyl-2H-chromen-2-one
699
NMR (400 MHz, CDCl3, d ppm): 160.5 (2C, C2 of a-pyrone and -
CH=N-), 153.5–115.1 (13C, Ar-C), 112.5 (1C, C3 of a-pyrone), 19.0
(1C, 4-CH3).
4-Methyl-7-(4-methylbenzylideneamino)-2H-chromen-2-
one III i
IR (KBr) cm– 1: 1727.8 (AC=O, a-pyrone), 1597.1 (-CH=N-). 1H-NMR
(400 MHz, DMSO, d ppm): 8.7 (s, 1H of -C=N), 7.9–7.2 (m, 7H, Ar-
H), 6.3 (s, 1H, C3-H of a-pyrone), 2.5 (s, 3H, 4-CH3 of a-pyrone), 2.4
(s, 3H, 39-Ar-CH3).
7-(2-Hydroxybenzylideneamino)-4-methyl-2H-chromen-
2-one III b
IR (KBr, cm– 1): 1719.9 (AC=O, a-pyrone), 1597.2 (-CH=N-). 1H-NMR
(400 MHz, DMSO, d ppm): 11.3 (s, 1H, -OH), 8.7 (s, 1H of -CH=N-),
7.7–7.0 (m, 7H, Ar-H), 6.3 (s, 1H, C3-H of a-pyrone), 2.5 (s, 3H, 4-
CH3 of a-pyrone). 13C-NMR (400 MHz, CDCl3, d ppm): 162.3 (1C, 29-
Ar-OH), 160.5 (2C, C2 of a-pyrone and -CH=N-), 153.5–115.5 (12C,
Ar-C), 112.5 (1C, C3 of a-pyrone), 19.0 (1C, 4-CH3).
7-(3-Methoxybenzylideneamino)-4-methyl-2H-chromen-
2-one III j
IR (KBr) cm– 1: 1735.4 (AC=O, a-pyrone), 1596.7 (-CH=N-). 13C-NMR
(400 MHz, CDCl3, d ppm): 160.4 (3C, C2 of a-pyrone, 39-Ar-OCH3
and -CH=N-), 153.5–115.1 (12C, Ar-C), 112.5 (1C, C3 of a-pyrone),
55.9 (1C, 39-Ar-OCH3), 19.3 (1C, 4-CH3).
4-Methyl-7-(2-nitrobenzylideneamino)-2H-chromen-2-
one III c
7-(4-Methoxybenzylideneamino)-4-methyl-2H-chromen-
IR (KBr) cm– 1: 1727.8 (AC=O, a-pyrone), 1597.1 (-CH=N-). 13C-NMR
(400 MHz, CDCl3, d ppm): 160.5 (2C, C2 of a-pyrone and -CH=N-),
153.5–115.4 (12C, Ar-C), 148.0 (1C, 2'-Ar-NO2), 112.5 (1C, C3 of a-
pyrone), 19.3 (1C, 4-CH3).
2-one III k
IR (KBr) cm– 1: 1723.3 (AC=O, a-pyrone), 1600.1 (-CH=N-). 1H-NMR
(400 MHz, DMSO, d ppm): 8.4 (s, 1H of -C=N), 7.9–7.0 (m, 7H, Ar-
H), 6.2 (s, 1H, C3-H of a-pyrone), 3.9 (s, 3H, 39-Ar-OCH3), 2.4 (s, 3H,
4-CH3 of a-pyrone).
4-Methyl-7-(3-nitrobenzylideneamino)-2H-chromen-2-
one III d
IR (KBr) cm– 1: 1728.7 (AC=O, a-pyrone), 1603.5 (-CH=N-). 13C-NMR
(400 MHz, CDCl3, d ppm): 160.6 (2C, C2 of a-pyrone and -CH=N-),
153.5–115.4 (12C, Ar-C), 148.8 (1C, 2'-Ar-NO2), 112.5 (1C, C3 of a-
pyrone), 19.3 (1C, 4-CH3).
4-Methyl-7-(3-phenylallylideneamino)-2H-chromen-2-one
III l
IR (KBr) cm– 1: 1727.8 (AC=O, a-pyrone), 1602.6 (-CH=N-). 1H-NMR
(400 MHz, DMSO, d ppm): 7.8–7.2 (m, 8H, Ar-H), 7.5 (s, 1H of -
C=N), 7.2, 6.8 (s, 2H, -CH=CH-), 6.3 (s, 1H, C3-H of a-pyrone), 2.3 (s,
3H, 4-CH3 of a-pyrone).
4-Methyl-7-(4-nitrobenzylideneamino)-2H-chromen-2-
one III e
Biological assays
1
IR (KBr) cm– 1: 1730.8 (AC=O a-pyrone), 1602.6 (-CH=N-). H NMR
Albino mice of either sex weighing 20–25 g were used for acute
toxicity studies and analgesic activity. Healthy male albino adult
rats weighing 150–230 g were used for various pharmacological
screenings. Animal ethical clearance was obtained from Ethics
Committee of K. S. Hegde Medical Academy, Deralkatte, Manga-
lore, India (115/1999/CPCSEA). Animals were procured from
K. S. Hegde Medical Academy, Deralkatte, Mangalore, India, and
housed individually in polypropylene cages, maintained under
standard conditions of alternating 12-h light-and-dark cycles at
a constant temperature (25 l 28C and 35–60% relative humid-
ity). Animals were fed with standard rat pellet diet, (Hindustan
Lever Ltd., Mumbai, India) and water ad libitum.
(400 MHz, DMSO, d ppm): 8.6 (s, 1H of -C=N-), 8.4–7.2 (m, 7H, Ar-
H), 6.3 (s, 1H, C3-H of a-pyrone), 2.4 (s, 3H, 4-CH3 of a-pyrone).
7-(4-Chlorobenzylideneamino)-4-methyl-2H-chromen-2-
one III f
IR (KBr) cm– 1
:
1735.4 (AC=O, a-pyrone), 1596.7 13C-NMR
(400 MHz, CDCl3, d ppm): 160.6 (2C, C2 of a-pyrone and -CH=N-),
153.7–115.4 (12C, Ar-C), 136.8 (1C, 49-Ar-Cl), 112.5 (1C, C3 of a-
pyrone), 19.3 (1C, 4-CH3).
7-(2,4-Dichlorobenzylideneamino)-4-methyl-2H-
Acute toxicity
chromen-2-one III g
The acute toxicity test [13] was carried out according to the
Organization for Economic Co-operation and Development
(OECD)-guidelines to establish the effective dose of the test com-
pounds after obtaining ethical clearance from Ethics Committee
of K. S. Hegde Medical Academy, Deralkatte, Mangalore, India.
Albino mice of either sex weighing between 20–25 g were
grouped into six groups of six animals each, starved for 24 h
with water ad libitum prior to the test. On the day of the experi-
ment, animals were orally administered different compounds to
different groups with an increasing dose of 10, 20, 100, 200,
1000, and 2000 mg/kg body weight. Then, the animals were
observed continuously for 3 h concerning general behavioral,
neurological and autonomic profiles, then, every 30 min for the
next 3 h, and finally for the next 24 h or until death.
IR (KBr) cm– 1: 1723.8 (AC=O, a-pyrone), 1580.4 (-CH=N-). 1H-NMR
(400 MHz, DMSO, d ppm): 8.9 (s, 1H of -C=N-), 7.9–7.2 (m, 6H, Ar-
H), 6.3 (s, 1H, C3-H of a-pyrone), 2.4 (s, 3H, 4-CH3 of a-pyrone).
GCMS; m/z (M+): 331 (100%); 296 (60%); 268 (43%); 240 (20%); 131
(45%); 103 (55%); 77 (55%).
7-(4-Bromobenzylideneamino)-4-methyl-2H-chromen-2-
one III h
IR (KBr) cm– 1: 1723.3 (AC=O, a-pyrone), 1600.1 (-CH=N-). 13C-NMR
(400 MHz, CDCl3, d ppm): 160.6 (2C, C2 of a-pyrone and -CH=N-),
153.6–115.4 (12C, Ar-C), 126.4 (1C, 29-Ar-NO2), 112.5 (1C, C3 of a-
pyrone), 19.3 (1C, 4-CH3).
i 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim