Pyridines and pyrazolines from salicylic acid derivatives with propenone residue and their antimicrobial properties.

Reaction of the propenones 1c, d with chlorosulfonyl isocyanate followed by hydrolysis gave the corresponding carbamoyloxybenzoates 2a, b. While their reaction with ethyl isocyanate afforded the 1,3-benzoxazine-2,4-diones 3a, b. Reaction of 1a, b with aryl hydrazines gave the pyrazolines 4a, d, whereas, with hydrazine hydrate in acetic acid, the acetyl derivatives 4e, f were produced. 1c, d reacted with malononitrile and ethyl cyanoacetate affording the cyanopyridines 5 and cyanopyridones 6 respectively. The products show antimicrobial activities.