الفهرس 
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Abstract
A new series of 3-hydrazone-quinoxaline-2-one derivatives were synthesized by both conventional and microwave conditions. 3-hydrazinoquinoxaline-2(1H)-one 4 was condensed with different carbonyl compounds namely, 2-acetylthiophene, 2- Acetylfuran, 4-acetylbiphenyl, 4-methylacetophenone, 6-chloro-4- oxo-4H- chromene-3-carbaldehyde, 1,3-diphenyl-1H-pyrazole-4-carbaldehyde, 1-indanone, and cyclohexanone to give hydrazone derivatives 5-12 (Scheme 1).
(Scheme 1)
Cyclocondensation of the 3-hydrazinoquinoxaline-2(1H)-one 4 with different aliphatic acids such as formic acid and acetic acid was carried out under conventional, microwave and ultrasonic conditions to afford the corresponding triazole derivatives 13, 14. On the other hand, reaction of 3-hydrazinoquinoxaline-
a
2(1H)-one 4 with carbon disulphide in pyridine occurred in both conventional and green conditions to afford the triazoloquinoxaline derivative 15 (Scheme 2).
(Scheme 2)
The nucleophilicity of SH group in the precursor 15 was investigated by its reactions with different halide derivatives namely, ethyl chloroacetate, chloroacetic acid, chloroacetone, chloroacetyl chloride, 3-chloro-acetylacetone, 2-chloro-N-(p- tolyl) acetamide, and furoyl chloride in DMF under basic condition using few drops of triethyl amine in both conventional and green conditions to afford the compounds 16-22 (Scheme 3).
b
(Scheme 3)
c
2,3-dichloroquinoxaline 23 was synthesized and used as key starting material for synthesis of different series of quinoxaline derivatives. Reaction of 2,3-dichloro quinoxaline 23 with different aromatic amines namely, 4-amino acetophenone, 4- amino ethylbenzoate led substitution reaction and formation of compounds 24, 25 respectively. On the other hand, cyclocondensation reaction of compound 23 with sodium azide and potassium 2,2-dicyanoethene-1,1-bis(thiolate) afforded compound 26, 27. 2,3-dichloroquinoxaline 23 react with hydrazine derivatives like hydrazine hydrate and benzoyl hydrazide led to formation of hydrazine moiety 28, 29. All of the previous reactions takes place on both reflux and US (Scheme 4).
(Scheme 4)
d
Cyclocondensation of hydrazinoquinoxaline 29 with formic acid led to formation of triazoloquinoxaline derivative 30. Reaction of compound 29 with N- (4-acetylphenyl)-2-chloroacetamide lead to condensation reaction and formation of compound 31, also hydrazinoquinoxaline 29 react with arylidene malononitrile to afford compound 32. Finally, reaction of compound 29 with thioglycolic acid afforded quinoxalinethioglycolic acid derivative 33 (Scheme 5).
(Scheme 5)
e