New isochromans. 1. Synthesis and antimicrobial activity of 4-substituted (±)-1h-spiro[benzo[c]pyran-3(4H), 1′-cyclohexane]-1-ones

✍ Scribed by Milen G. Bogdanov; Mariana D. Palamareva; Blagovesta T. Gocheva; Darina B. Dimitrova

• Publisher: Journal of Heterocyclic Chemistry
• Year: 2007
• Tongue: English
• Weight: 333 KB
• Volume: 44
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570440325

✦ Synopsis

Abstract

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The reaction between homophthalic anhydride and cyclohexanone was examined both in the presence of DMAP or BF~3~·Et~2~O complex as a catalyst. The latter yielded (±)‐1‐oxo‐1__H__‐spiro[benzo[c]pyran‐3(4__H__), 1′‐cyclohexane]‐4‐carboxylic acid (3) in a higher yield (82 %). A series of new (±)‐4‐(N,N‐disubstituted‐1‐carbamoyl)‐1__H__‐spiro[benzo[c]pyran‐3(4__H__),1′‐cyclohexane]‐1‐ones (5a‐h) were synthesized from the parent acid 3 by a two‐step reaction. Differentiating microbial screening was performed for most of the synthesized compounds against twelve microorganisms belonging to different taxonomic groups. The spiro acid 3 was active against all bacterial strains with MIC ≥ 20 μg/ml against B. subtillis and P. vulgaris. E. coli was the most sensitive strain to the antibacterial effect of the tested compounds.