Synthesis and antimicrobial evaluation of amide derivatives of benzodifuran-2-carboxylic acid

We have synthesized various amide derivatives of benzodifuran-2-carboxylic acid from resorcinol. Reaction of 7-hydroxy-4-methylcoumarin with chloroacetone in anhydrous K2CO3 and dry acetone gave ether derivative of 7-hydroxy-4-methylcoumarin 3 which on reaction with N-bromosuccinimide in chloroform gave corresponding 3-bromo derivative 4. Cyclization of bromo derivative in 10% ethanolic KOH gave benzodifuran-2-carboxylic acid 5. This acid was converted into acid chloride using oxalyl chloride and then substituted with different amines in presence of base, triethylamine to give amide derivatives of benzodifuran-2-carboxylic acid 6. All compounds were screened for antimicrobial activity against two Gram positive bacteria Staphylococus aureus and Bacillus subtilis, two Gram negative bacteria E. coli and P. aeruginosa and one fungus Candida albicans. We have synthesized various benzodifuran amide derivatives from benzodifuran carboxylic acid which in turn has been prepared from 7-hydroxy-4-methylcoumarin by ring contraction. The antimicrobial evaluation has been carried out. [Display omitted] •Synthesis of benzodifuran carboxylic acid by ring contraction.•Synthesis of new various amides of benzodifuran carboxylic acid via acid chloride.•Investigated antimicrobial activity of synthesized amide derivatives.