Acta Pharm. 63 (2013) 19-30
Original research paper
Synthesis and biological evaluation of some
novel pyrazolopyrimidines incorporating a benzothiazole ring system
MOHAMMED
AFZAL AZAM, LOGANATHAN DHARANYA, CHARU CHANDRAKANT MEHTA and SUMIT SACHDEVA
Department
of Pharmaceutical Chemistry, J. S. S. College of Pharmacy, Ootacamund, India
Accepted September 28, 2012
In the present study, a series of benzothiazol derivatives 3a-l containing pyrazolo[3,4-d]pyrimidine moiety at the second position were synthesized and characterized by analytical and spectral data. The compounds were tested for their in vitro antimicrobial activity. Compounds 1-(1,3-benzothiazol-2-yl)-3-methyl-4-phenyl-1H-pyrazolo[3,4-d]pyrimidine (3a), 1-(1,3-benzothiazol-2-yl)-4-(4-chlorophenyl)-3-methyl-1H-pyrazolo[3,4-d]pyrimidine (3d) and 1-(1,3-benzothiazol-2-yl)-3-methyl-4-substituted phenyl-1H-pyrazolo[3,4-d]pyrimidines (3h-j) showed significant inhibitory activity against P. aeruginosa whereas compounds 1-(1,3-benzothiazol-2-yl)-4-(2-chlorophenyl)-3-methyl-1H-pyrazolo[3,4-d]pyrimidine (3b), 2-[1-(1,3-benzothiazol-2-yl)-3-methyl-1H-pyrazolo[3,4-d]pyrimidin-4-yl]phenol (3e), 1-(1,3-benzothiazol-2-yl)-4-(3,4-dimethoxyphenyl)-3-methyl-1H-pyrazolo[3,4-d]pyrimidine (3h), 4-[1-(1,3-benzothiazol-2-yl)-3-methyl-1H-pyrazolo[3,4-d]pyrimidin-4-yl]-N,N-dimethylaniline (3j) and 1-(1,3-benzothiazol-2-yl)-3-methyl-4-[2-phenylvinyl]-1H-pyrazolo[3,4-d]pyrimidine (3k) were found to be active against C. albicans. Some of these synthesized compounds were evaluated for their in vivo acute toxicity, analgesic, anti-inflammatory, and ulcerogenic actions. The tested compound 4-[1-(1,3-benzothiazol-2-yl)-3-methyl-1H-pyrazolo[3,4-d]pyrimidin-4-yl]-N,N-dimethylaniline (3j) exhibited maximum analgesic and anti-inflammatory activities. Compounds 1-(1,3-benzothiazol-2-yl)-3-methyl-4-(3-nitrophenyl)-1H-pyrazolo[3,4-d]pyrimidine (3i) and 3j showed a significant gastrointestinal protection compared to the standard drug diclofenac sodium.
Keywords: benzothiazoles, pyrazolo[3,4-d]pyrimidine,
antimicrobial activity, anti-inflammatory
activity