Synthesis and Biological Activity of Some Mannich and Schiff Bases

Abstract

Fifteen Mannich bases and sixteen Schiff bases were synthesized . A general synthesis protocol was adopted . The following bases were synthesized : 2-dimethylaminomethyl-5,5-dimethylcyclohexane-1,3-dione (1) , 2-diethylaminomethyl-5,5-dimethylcyclohexane-1,3-dione (2), 2-pyrrolidinomethyl-5,5-dimethylcyclohexane-1,3-dione (3), 2-morpholinomethyl-5,5-dimethyl-cyclohexane-1,3-dione (4), 2-piperidinomethyl-5,5-dimethylcyclohexane-1,3-dione (5) , 2-diphenylaminomethyl-5,5-dimethylcyclohexane-1,3-dione (6) , 2-piperidinomethyl-5-nitrophenol (7) , 2-diphenylaminomethyl-3-nitrophenol (8) , 2-piperidinomethyl-4-chloro-5-methylphenol (9) , 2-diphenylaminomethyl-4-chloro-5-methylphenol (10) , 2-N-methylpiperazinomethyl-5,5-dimethylcyclohexan-1,3-dione (11) , 3-piperidinomethylpentane-2,4-dione (12) , 2-diphenylaminomethyl-4-aminophenol (13) , 2-N-methylpiperzinomethyl-5-nitrophenol (14) , 2-morpholinomethyl-5-nitrophenol (15) , (E)-2[(dimethylaminomethyl)-5,5-dimethyl-3-(phenylimino)]cyclohexanone (16) , (E)-2-[(diethylaminomethyl)-5,5-dimethyl-3-(phenylimino)]cyclohexanone (17) , (E)-5,5-dimethyl-3-(phenylimino)-2-(pyrrolidin-1-yl)cyclohexanone (18) , (E)-N-[2-(dimethylaminomethyl)-5,5-dimethyl-3-oxocyclohexylidene]benzamide (19) , (E)-N-[2-(diethylaminomethyl)-5,5-dimethyl-3-oxocyclohexylidene]benzamide (20) , (E)-N-[5-dimethyl-3-oxo(pyrrolidin-1-methyl)cyclohexylidene]benzamide (21), (E)-4-[2-(dimethylaminomethyl)- 5,5-dimethyl-3-oxocyclohexylideneamino]benzoicacid (22) , (E)-4-[2-(diethylaminomethyl)- 5,5-dimethyl-3-oxocyclohexylideneamino]benzoicacid (23) , (E)-4-[5,5-dimethyl-3-oxo-2-(pyrrolidin-1-ylmethyl)cyclohexylideneamino]benzoicacid ( 24) , (Z)-5,5-dimethyl-2-(morpholinomethyl)-3-(phenylimino)cyclohexanone ( 25) , (E)-4-[5,5-dimethyl-2-(morpholinomethyl)]-3-(oxocyclohexylideneamino)benzene sulfonic acid (26) , (E)-5,5-dimethyl-3-(phenylimino)-2-(piperidin-1-ylmethyl)cyclohexanone (27) , (E)-2-(diphenylaminomethyl)-5,5-dimethyl-3-(phenylimino)cyclohexanone(28) , (Z)-3-[(2-aminomethylimino)-2-(diphenylaminomethyl)]cyclohexanone(29) , (Z)-5,5-dimethyl-2-(morpholinomethyl)-3-(3-nitrophenylimino)cyclohexanone (30) , (Z)-2-(diphenylaminomethyl)-5,5-dimethyl-3-(3-nitrophenylimino)cyclohexanone (31) . The structure of the intermediates and targeted molecules was elucidated by a combination of spectral techniques (IR, 1HNMR, Ms). The targeted molecules were evaluated for antibacterial and antifungal activity. Compounds 9,10,13,14,15,25,29 and 31 showed significant antimicrobial activity. However, compounds 11 and 30 showed significant antifungal activity . Compounds 12 and 22 showed moderate antimicrobial activity, but compounds 3,7 and 16 exhibited only antibacterial activity . However, compound 5 exhibited only antifungal activity .Compounds 1,2,4,6,8,17,18,19,20,21,23,24,26,27 and 28 did not show any antimicrobial activity.