الفهرس 
Electrophilic attack at nitrogenOnly 14 pages are availabe for public view
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Abstract
Arylidineethylcyanoacetate reagent 1 was synthesized by a base-catalyzed
Knoevenagel Condinsation reaction between para methoxy benzaldehyde and
ethylcyanoacetate in 90% yield. Equimolar amounts of 1, cyclohexanone in ethanol
and in the presence of ammonium acetate was heated under reflux to afford 2 in
85% yield (Scheme 1).
Scheme 1
The pyrazole derivative 3 was obtained by treatment of 2 with hydrazine
hydrate in ethanol in 70% yield (Scheme 2).
Scheme 2
The phenyl pyrazole derivative 4 was obtained by treatment of 3 with
malononitrile in ethanol in 77% yield (Scheme 3).
Scheme 3
Treatment of 3 with ethylcyanoacetate afforded derivative 5 in 70% yield
(Scheme 4).
Scheme 4
Formation of tetrazole derivative 6 was carried out by refluxing of 3 withethyl
acetoacetate in ethanol in 72% yield (Scheme 5).
Scheme 5
Treatment of 3 with carbon disulphide under basic condition afforded
derivative 7 in 70% yield (Scheme 6).
Scheme 6
Formation of tetrazole derivative 8 was carried out by refluxing of 4
withformic acid in ethanol in 72% yield (Scheme 7).
Scheme 7
Derivative 9 was obtained by refluxing of 4 with triethylorthoformate
in 60% yield. Treatment of 9 with hydrazine hydrate afforded 10 in 66% yield
(Scheme 8).
Scheme 8
Formation of tetrazole derivative 11 was carried out by refluxing of 5
with formic acid in ethanol in 72% yield (Scheme 9).
Scheme 9
Treatment of 5 with triethlorthoformat afforded derivative 12 in70% yield
(Scheme 10).
Scheme 10
Hydrazinolysis of 6 was carried out by refluxing in hydrazine hydrate in
ethanol which gave derivatie 13 in 66% yield (Scheme 11).
Scheme 11
Arylidinemalononitrile reagent 14 was synthesized by a base-catalyzed
Knoevenagel Condinsation reaction between para methoxy benzaldehyde and
malononitrile in 90% yield. Equimolar amounts of 14, cyclohexanone in ethanol and
in the presence of ammonium acetate was heated under reflux to afford 15 in 71%
(Scheme 12).
Scheme 12
Refluxing of 15 with formic acid in ethanol afforded 16 in 55% yield (Scheme
13).
Scheme 13
Refluxing of 15 in formamide afforded 17 in 64% yield (Scheme 14).
Scheme 14
Treatment of 15 with acetic anhydride in glacial acetic acid afford 18 in 71%
(Scheme 15).
Scheme 15
Sugar hydrazone 19 was obtained in 65% yield after refluxing of 17 with D-
(+)- Xylose in ethanol and in the presence of a catalytic amount of acetic acid.
Acetylation of 17 by refluxing in acetic anhydride afforded derivative 20 in 87%
yield (Scheme 16).
Scheme 16
Sugar hydrazone 21 was obtained in 65% yield after refluxing of 17 with D-
(+)-mannose in ethanol and in the presence of a catalytic amount of acetic acid.
Acetylation of 21 by refluxing in acetic anhydride afforded isoxazole derivative 22
in 87% yield (Scheme 17).
Scheme 17
Treatment of 18 with ethylchloroacetate under basic condition in DMF
afforded 23 in 63% yield (Scheme 18).