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Please login or sign up for a free trial to access the full content. Nitrogen and Carbon Decarboxylation, Deacylation, and Dealkylation

DOI: 10.1055/sos-SD-013-01452

Brigas, A. F.Science of Synthesis, (200413897.

5-Carboxy-substituted tetrazoles can be decarboxylated on heating. Since C5-substituted tetrazoles can be oxidized to the carboxylic acid by potassium permanganate or nitric acid, e.g. the formation of 78 and 79, this provides a means of removing such substituents (Scheme 56). The decarboxylation of 2-phenyl-2H-tetrazole-5-carboxylic acid (78) has been reported to occur in 87% yield in five minutes under pressure at 150170°C.[‌211‌] A 5-acetyl or 5-formyl group can also be displaced from 1-substituted tetrazoles by treatment with alkali, potassium cyanide, or piperidine; 2-substituted acyl tetrazoles are stable. The acyl group in N-acyltetrazoles can be cleaved by nucleophiles under mild conditions. Dearylation at N2 readily occurs upon treatment of 2-(4-methoxyphenyl)tetrazole with ceric ammonium nitrate in methanol/water.[‌209‌]

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