Synthesis of carbamate and sulfonamide derivatives of amlodipine and their antimicrobial activity

An efficient synthesis of two series of novel carbamate and sulfonamide derivatives of amlodipine, 3-ethyl 5-methyl 2-(2-aminoethoxy)-4-(2-chlorophenyl)-1,4-dihydropyridine-3,5-dicarboxylate (Amlodipine) 1 was accomplished. Various chloroformates 2(a-e) and sulfonyl chlorides 4(a-e) on reaction with 1 in the presence of N,N– dimethylpiperazine as a base in THF at 50-55 C yielded the corresponding title compounds 3(a-e) and 5(a-e) in high yields. The structures of the title compounds 3(a-e) and 5(a-e) were established by spectral (H, C NMR, mass) and elemental analysis. The title compounds were screened for their antimicrobial activity against bacterial and fungal strains and compared their activities with standards like ciprofloxacin and clotrimazole. The title compounds exhibited moderate to high antimicrobial activity due to the presence of different substituted functional groups at carbamate and sulfonamide moieties of amlodipine.