Synthesis and Biological Activities of Schiff Bases of 5,6,7,8-Tetrahydro[1]Benzothieno[2,3-D] Pyrimidin-4-Yl-Hydrazones

V. H. Bhaskar* and P. D. Gokulan

Sri RNS Institute of Pharmaceutical Sciences and Technology, Jhansi Road, Sitouli, Gwalior - 454 001( India)

Ethyl 2-amino-4,5,6,7-tetrahydro-1-benzothiophene-3-carboxylate (I) was treated with formamide to get 5,6,7,8-tetrahydro[1]benzothieno[2,3-d]pyrimidin-4(3H)-one (II). This was treated with phosphorus oxychloride to get 4-chloro-5,6,7,8-tetrahydro[1]benzothieno[2,3-d]pyrimidine (III). This was refluxed with 80% hydrazine hydrate in butanol yielded 4-hydrazino-5,6,7,8-tetrahydro[1]benzothieno[2,3-d]pyrimidine (IV). This was treated with different aromatic aldehydes in ethanol to yield the corresponding Schiff bases (Va-e). The structures of compounds have been established based on their analytical and spectral data. All the compounds have been screened for analgesic, anti bacterial and anti fungal activity. Compound Vb and Ve were found to show good analgesic activity. Compound Ve was found to be most active against bacterial strains Staphyloccocus aureus and Pseudomonas aeruginosa. Compound Vb was found to be most active against both the fungal strains Candida albicans and Rhizopus stolonifer.

Thienopyrimidine; Analgesic activity; Antimicrobial activity