Synthesis and characterisation of new chromano pyrimidines and study of antimicrobial activity

Article abstract of DOI:10.1515/HC.2005.11.2.189

The title compounds, (five new chromano pyrimidines) were synthesized by condensation of chalcones with guanidine hydrochloride in the presence of potassium t- butoxide and t-butanol. The synthesis involves following steps- Starting with the acylation of Resorcinol using anhydrous ZnCl₂ and glacial acetic acid, which afforded Resacetophenone 1. Resacetophenone was then subjected to nuclear prenylation using isoprene in the presence of polyphosphoric acid and xylene, to form 7-hydroxy-6-acetyl 2,2′-dimethyl Chroman 2. Condensation of Chroman with various substituted benzaldehydes in the presence of alcoholic KOH furnished different chalcones 3-7. Finally, Chalcones were condensed with guanidine hydrochloride in the presence of potassium t- butoxide and t-butanol and the title compounds 8-12 were obtained. Compounds thus obtained were characterized by various spectroscopic techniques to confirm their structures. The title compounds were tested at different concentrations for their antibacterial activity against Gram-positive bacteria Bacillus subtillis and Bacillus pumilus and Gram-negative bacteria Escherichia coli and Proteus vulgaris. Antifungal activity of the title compounds was tested against Rhizopus oryzae and Aspergillus niger at different concentrations. Minimum inhibitory concentration was also determined.