PURPOSE: To industrially advantageously obtain the title compound useful as an antiallergic agent having a purity sufficiently permissible as the raw material for medicine by reacting (A) 3-(1H-tetrazol-5-yl)aniline with (B) dibutyl oxalate in the presence of an acid.
CONSTITUTION: (A) 3-(1H-Tetrazol-5-yl)aniline is reacted with (B) dibutyl oxalate in the presence of (C) an acid, preferably hydrochloric acid, sulfuric acid or mixture thereof or one or more kinds of organic acids selected from oxalic acid, malonic acid, pyruvic acid and oxaloacetic acid, preferably at an amount of the ingredient B 5-10 times the ingredient A and an amount of the ingredient C 0.05-1.0 times, especially 0.3-0.4 times by mole based on the ingredient A at 80-100°C for 12-20hr and then the reaction product is purified, preferably by absorbing agent, especially an active alumina to provide butyl 3'-(1H- tetrazol-5-yl)oxanylate (tazanolast) with a high purity, high yield and good reproducibility.
OTAKE YASUHIRO (JP)
SAWAKI SHOHEI (JP)
GOTO MASAYOSHI (JP)
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