Simple synthesis of condensed pyran containing compounds and their antimicrobial properties.

Reaction of various fused pyran compounds with formic acid was studied. Thus, refluxing 6-aminopyrano[2,3-c]pyrazole-5-carbonitriles 3 with formic acid afforded the corresponding 3-aryl-3-(5-hydroxy-3-methyl-1H-pyrazole-4-yl)propanoic acids 4. Whereas, reaction of formic acid with 2-amino-4H-1-benzopyran-3-carbonitriles 6 gave the corresponding quinoline-2,5(1H,6H)-diones 7. The study was also extended towards many spiro compounds possessing pyran residue. The antimicrobial properties of the prepared compounds was screened.

Synthetic approaches towards benzo[h]quinoline-3-carbonitriles.

2-Alkoxybenzo[h]quinoline-3-carbonitriles 2 were readily synthesized via Dimroth rearrangement of 2-amino-4-aryl-5,6-dihydro-4H-naphtho[1,2-b]pyran-3-carbonitriles 5 induced by ethanolic and methanolic KOH. Compounds 2 were also obtained by the reaction of 2-arylmethylidene-3,4-dihydro-1(2H)-naphthalenones 1 with malononitrile or of ylidenemalononitriles 4 with 1,2,3,4-tetrahydro-1-naphthalenone in ethanolic and methanolic KOH. The molluscicidal activity of the products towards Biomphalaria alexandrina snails was screened.

New 2 H-benz[g]indazoles of anticipated molluscicidal activity.

A facile synthetic approach towards the synthesis of 2-substituted carbamoyl (or thiocarbamoyl)-3-aryl-3,3a,4,5-tetrahydro-2 H-benz[g]indazoles 3a-r and their 2-acylating derivatives 4-6 was reported via the reaction of 2-unsubstituted-2 H-benz[g]indazoles 2 with isocyanates or their thio analogues, acid anhydrides and aliphatic or aromatic carboxylic acids. The molluscicidal activity of the products was screened.

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.

New 2-pyrazolines of anticipated molluscicidal activity.

A facile one-pot synthesis of 1-substituted carbamoyl or thiocarbamoyl-2-pyrazolines 6 is described. Also, the synthesis as well as the molluscicidal activity of 1,3,5-triaryl- (2), 1-acetyl-3,5-diaryl- (4) 2-pyrazolines are outlined.