Use of 2-{[5-(2-Amino-4-oxoquinazolin-3(4H)-yl)-1,3,4-thiadiazol-2-yl]methyl}-1H-isoindole-1,3(2H)-dione in the Synthesis of Novel Quinazolinone Derivatives

Abstract

The 2-{[5-(2-Amino-4-oxoquinazolin-3(4H)-yl)-1,3,4-thiadiazol-2-yl]methyl}-1H-isoindole-1,3(2H)-dione 1 was synthesized and allowed to react with each of  p-methoxybenzaldehyde,  p-methoxyacetophenone and chloroacetyl chloride to produce the Schiff bases 2 and 3 and 2-chloro-N-(3-{5-[(1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)methyl]-1,3,4-thiadiazol-2-yl}-4-oxo-3,4-dihydroquinazolin-2-yl)acetamide 6, respectively. The products 2 and 3 were reacted with phenyl isothiocyanate to afford 4 and 5. Derivative 6 was reacted with various nucleophiles, namely: thioglycolic acid, ethyl glycinate and 2-aminoethanol giving 7-9 respectively. In turn, the derivative 8 was reacted with α-bromoglucose tetraacetate affording product 8a whereas 9 was reacted with p-acetylaminobenzenesulfonyl chloride affording derivative 9a. Moreover, the reactions of the derivative 6 with potassium thiocyanate, potassium cyanate, malonitrile, ethyl cyanoacetate and ammonium acetate gave derivatives 10-15, respectively. All the synthesized derivatives were confirmed by the IR, mass, ¹H-NMR and elemental analysis.

Key words: Quinazolinyl thiazolidine, thioxodiazetidinyl quinazoline, piperazinyl quinazolinone, thiomorpholine and  triazinoquinazoline.