Synthesis of some novel pyrimidine, thiophene, coumarin, pyridine and pyrrole derivatives and their biological evaluation as analgesic, antipyretic and anti-inflammatory agents

Abstract

Pyrimidine derivative 3 was afforded through the reaction of compound (1) with 5-ureidohydantion (2). Product 3 underwent a cyclization to produce fused pyrimidine derivative 7, although the latter product 7 was synthesized through one step via the reaction of compound (1) with 5-ureidohydantion (2) using another catalyst. Compound 3 was oriented to react with cyclic ketones 8a,b in the presence of elemental sulfur, salicylaldehyde (10), aryldiazonium chlorides 12a,b and ω-bromo-4-methoxy- acetophenone (14), which afforded, fused thiophene derivatives 9a,b, coumarin derivative 11, arylhdrazono derivatives 13a,b and 4-methoxyphenyl butenyl derivative 15, respectively. The latter product 15 was reacted with either potassium cyanide (16a) or potassium thiocyanide (16b) to form cyano and thiocyano derivatives 17a,b, respectively. Compound 17a underwent further cyclization to afford pyridopyrimidine derivative 19. Compound 15 was reacted with either hydrazine (20a) or phenylhydrazine (20b) to produce hydrazo derivatives 21a,b and these products were cyclize to produce pyrrole derivatives 23a,b. Finally, 5-ureidohydantion (2) was reacted with compounds 24a,b,c to afford pyrimidine derivatives 25a,b,c. The structures of the synthesized compounds were confirmed using IR, 1 H NMR, 13C NMR and mass spectrometry techniques. Compounds 11 and 19 have promising as analgesic and antipyretic activities.