الفهرس 
Methods employing hydrazine derivativesOnly 14 pages are availabe for public view
 |  | from | 167 |  |  |
| | | from | 167 | | |
Abstract
2-benzylidenemalononitrile 1a and 2-(4-chlorobenzylidene) malononitrile
1b were prepared by treatment of malononitrile with aromatic aldehydes by reflux
to give white solid 1a, b in 90% and 92% yields, respectively
Ethyl (Z)-2-cyano-3-phenylacrylate 2a and ethyl (Z)-3-(4-chlorophenyl)-
2-cyanoacrylate 2b were prepared by treatment of ethylcyanoacetate with
aromatic aldehydes by reflux to give white solids 2a, b in 88% and 85% yields,
respectively
2-cyanoacetohydrazide 3 was synthesized by treating of ethylcyanoacetate
with hydrazine hydrate to afford white powder in 77% yield
The respective cyanoacetic acid hydrazide 3 in absolute ethanol and Dhexoses was refluxed to afford 2-cyano-N’-[(2S,3R,4R,5R,Z)-2,3,4,5,6-
pentahydroxyhexylidene]acetohydrazide 4a and 2-cyano-N’-[(2S,3R,4S,5R,Z)-
2,3,4,5,6-pentahydroxyhexylidene]acetohydrazide 4b respectively in different
yields
A solution of the respective product 4a with 2-benzylidenemalononitrile
1a and 2-(4-chlorobenzylidene) malononitrile 1b in ethanol was refluxed to
afford 5-oxo-2-[(1S,2R,3R,4R)-1,2,3,4,5-pentahydroxypentyl]-7-phenyl-1,5-
dihydro-[1,2,4]triazolo[1,5-a]pyridine-6,8-dicarbonitrile 5a and 7-(4-
chlorophenyl)-5-oxo-2-[(1S,2R,3R,4R)-1,2,3,4,5-pentahydroxypentyl]-1,5-
dihydro-[1,2,4]triazolo[1,5-a]pyridine-6,8-dicarbonitrile 5b as colourless
powder in 80% and 85% yields respectively
Ethyl-6-cyano-5-oxo-2-[(1S,2R,3R,4R)-1,2,3,4,5-penta hydroxypentyl]-7-
phenyl-1,5-dihydro-[1,2,4]triazolo[1,5-a]pyridine-8-carboxylate 6a and Ethyl-7-
(4-chlorophenyl)-6-cyano-5-oxo-2-[(1S,2R,3R,4R)-1,2,3,4,5-pentahydroxy
pentyl]-1,5-dihydro-[1,2,4]triazolo[1,5-a]pyridine-8-carboxylate 6b were
prepared in 87% and 83% yields, respectively by treating of 4a with ethyl (Z)-2-
cyano-3-phenylacrylate 2a and ethyl (Z)-3-(4-chlorophenyl)-2-cyanoacrylate 2b
in ethanol under reflux
A solution of the respective product 4b with 2-benzylidenemalononitrile
(1a) and 2-(4-chlorobenzylidene) malononitrile 1b in ethanol was refluxed to
afford 5-oxo-2-[(1S,2R,3S,4R)-1,2,3,4,5-pentahydroxy pentyl]-7-phenyl-1,5-
dihydro-[1,2,4]triazolo[1,5-a]pyridine-6,8-dicarbonitrile 7a 7-(4-chlorophenyl)-
5-oxo-2-[(1S,2R,3S,4R)-1,2,3,4,5-pentahydroxypentyl]-1,5-dihydro-[1,2,4]
triazolo[1,5-a]pyridine-6,8-dicarbonitrile 7b as colourless powder in 80% and
82% yields respectively
Ethyl-6-cyano-5-oxo-2-[(1S,2R,3S,4R)-1,2,3,4,5-pentahydroxypentyl]-7-
phenyl-1,5-dihydro-[1,2,4]triazolo[1,5-a]pyridine-8-carboxylate 8 was prepared
in 85% yield by treating of 4b with ethyl (Z)-2-cyano-3-phenylacrylate 2a in
ethanol under reflux
Ethyl-2-(6,8-dicyano-5-oxo-2-[(1S,2R,3R,4R)-1,2,3,4,5-pentahydroxy
pentyl]-7-phenyl-[1,2,4]triazolo[1,5-a]pyridin-1(5H)-yl)acetate 9a and ethyl-2-
(7-(4-chlorophenyl)-6,8-dicyano-5-oxo-2-[(1S,2R,3R,4R)-1,2,3,4,5-penta
hydroxypentyl]-[1,2,4]triazolo[1,5-a]pyridin-1(5H)-yl)acetate 9b were
synthesized by treating of 5a and/ or 5b with ethylcholoroacetate in dry DMF and
anhydrous K2CO3 by reflux to afford colourless powder 9a and 9b in 85% and
90% yields, respectively