Reactivity of 2-ethoxyquinazolin- 4-yl hydrazine and its use in synthesis of novel quinazoline derivatives of antimicrobial activity.

The reactions of 2-ethoxy-4-hydrazinoquinazoline 2 with diethyl oxalate and ethyl chloroacetate gave 6-ethoxy-2H-[1,2,4]triazino[4,3-c]quinazoline-3,4-dione 3 and 6-ethoxy-2,3-dihydro-4H-[1,2,4]triazino[4,3-c]quinazolin-4-one 4 respectively. A series of 5-ethoxy-2-X-[1,2,4]triazolo[1, 5-c]quinazolines 5a-d was also produced by reacting 2 with the acid chlorides namely: benzoyl, crotonyl, cinnamyl and 2-furoyl chlorides via Dimroth rearrangement. Also, 2 reacted with ethyl chloroformate giving 6.

Uses of 2-ethoxy-4(3H) quinazolinone in synthesis of quinazoline and quinazolinone derivatives of antimicrobial activity: the solvent effect.

2- Ethoxy-4(3H) quinazolinone 1 was synthesized and allowed to react with various halides, namely: alkyl, benzyl, allyl, acyl, haloacetyl, crotonyl, benzoyl, 2-furoyl and 1-naphthalenesulphonyl halides affording quinazoline and quinazolinone derivatives. The reactions of compound 1 with phosphorus oxychloride, phosphorus pentasulfide, ethyl chloroformate, ethyl chloroacetate, ?-bromoglucose tetraacetate, p-acylaminobenzenesulfonyl chloride, acrylonitrile, chalcone and chalcone oxide were also investigated. Depending on the reaction condition and reactant halide, the type of substituent (alkyl, acyl, aroyl, etc.