10.22376/ijpbs.2019.10.1.p1-12 Volume 3 Issue 1 2012 (January - March) Chalcones (6a-f) have been prepared by the condensation of ketone (5) and different aromatic aldehydes. These chalcones (6a-f) on treatment with guanidine hydrochloride and phenyl hydrazine hydrochloride in presence of alkali give aminopyrimidines (7a-f) and phenylpyrazolines (8a-f) respectively. All the newly synthesised compounds have been characterised on the basis of IR, lessThan sup greaterThan 1 lessThan /sup greaterThan H NMR spectral data as well as physical data. Antibacterial activity(minimum inhibitory concentration MIC) against Gram-positive lessThan i greaterThan (S. aureus lessThan /i greaterThan MTCC 96 and lessThan i greaterThan S. pyogeneus lessThan /i greaterThan MTCC 442 ) and Gram-negative ( lessThan i greaterThan P. aeruginosa lessThan /i greaterThan MTCC 1688 and lessThan i greaterThan E. coli lessThan /i greaterThan MTCC 443) bacteria, as well as antifungal activities (MIC) against lessThan i greaterThan C. albicans lessThan /i greaterThan MTCC 227 lessThan i greaterThan , A. niger lessThan /i greaterThan MTCC 282 and lessThan i greaterThan A. clavatus lessThan /i greaterThan MTCC 1323 were determined by broth dilution method. Some of the compounds were endowed with a remarkable antibacterial as well as antifungal activities. Anjani N. Solankee And Kirti P. Patel Chalcones, aminopyrimidines, phenyl pyrazolines, spectral data, microbial studies. 338-344