Synthesis, Antimicrobial and Antioxidant Activities of Mannich Bases Derived from 1h-Indole-2,3-Dione and 3-Amino-2-Phenylquinazol-4-One.

The present studies is consist of the following sections. Taking into consideration the above findings it was considered worthwhile to synthesize some new isatin based mannich bases of quinazolin-4-one. General structure of mannich base undertaken in present study 1- substituted methyl-3-(2-phenyl-4-oxo-3-quinazolinylimino)-1, 3- dihydro-indol-2-one. Spectral studies: Structure of newly synthesized compounds were to be confirmed from UV, IR, PMR and mass datas. Antimicrobial studies : The compounds synthesized were to be screened against selected gram (+)ve and gram (-)ve micro organisms and activities to be compared against a standard antibiotic. The prepared compounds were also planned to be subjected to antifungal screening and the activities compared with a standard antifungal agent. Synthesis of 1-substituted-methyl-3-(2-phenyl-4-oxo-3- quinazolinylimino)-1, 3-dihydro-indole-2-one 4(a-k) In this scheme eleven different isatin based mannich bases of quinazolin- 4-one were synthesized by four step process. First step was the synthesis of 2- phenyl benzoxazin-4-one. In the second step the benzoxazin-4-one was converted to 3-amino-2-phenylquinazol-4-one by treating with hydrazine hydrate using ethanol as the solvent. In the third step, Schiff’s base was synthesized by the condensation of the keto group of isatin with 3-amino-2-phenylquinazol-4-one. In the fourth step, N- Mannich bases of the above Sciff’s base were synthesized by the reaction of amino group of isatin with formaldehyde and various primary and secondary amines