- Synthesis and antimicrobial activities of novel formazans incorporating pyrimidine ring
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Reaction of 5-substituted-4(3H)-one-2-mercaptopyrimidines 1a and 1b with hydrazine hydrate furnishes 5-substituted-4(3H)-one-2-hydrazinopyrimidines 2a and 2b. Condensation of compounds 2a and 2b with salicylaldehyde and anisaldehyde yields 2-hydroxybenzaldehyde-(5′-substituted- 4′(3′H)-one)-2′-pyrimidazolylhydrazones) 3a and 3b and 4-methoxybenzaldehyde-(5′-substituted-4′(3′H)-one) -2′-pyrimidazorylhydrazones) 3c and 3d respectively. Compounds 3a-d were reacted with diazonium salts of an appropriate primary amine in presence of base furnished the target formazans 4a-1. All the synthesized compounds were evaluated for antimicrobial activities.
- Goudgaon,Upendar Reddy
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experimental part
p. 617 - 623
(2010/07/03)
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- Reactions with 2-thiothymine; selective cyclization of S-substituted 2-thiothymine
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2-Thiothymine (I) undergoes S-alkylation when treated with some halo compounds such as methyl and ethyl iodides. The S-alkyl derivatives II are treated with hydrazine hydrate to produce the hydrazine derivative III, which condensed with p-chlorobenzaldehyde to give p-chlorobenzaldehydepyrimidinehydrazone derivative IV. Compound IIa reacts with phosphorus oxychloride to give 4-chloro derivative V. The chlorine atom in V undergoes nucleophilic substitution with p-chloroaniline and anthranilic acid to produce drivatives VIa,b. Dehydrative cyclization of VIb yields the pyrimido[6,1-b]quinazolin-10-one derivative VII. Treatment of V with ammonia solution gives the diamino derivative VId. Reaction of V with sodium azide produces the tetrazolo[1,5-c]pyrimidine derivative VIII. Compound I undergoes S-alkylation with α-haloketones followed by cyclization to produce the thiazolo[3,2-a]pyrimidine derivatives Xa-c. Reaction of I with bromomalononitrile produces thiazolo[3,2-a]pyrimidine-2-carbonitrile derivative XII. Treatment of XII with formic acid, formamide and ammonium thiocyanate produces thiazolo[3,2-a:4,5-d]dipyrimidine derivatives XIIIa-c. Finally, reacting XII with malononitrile yields ppyrido[2′,3′:4,5]thiazolo[3,2-a]pyrimidine-3-carbonitrile derivative XIV.
- Youssef, Mohamed M.,Youssef, Ayman M. S.
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