Ethyl orthoformate → (5-Tetrazol-1-yl)-valeric acid ethyl ester

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Reaction Steps

13 g of sodium azide and 59 ml of triethyl orthoformate are added to a solution of 13.4 g of 5-amino-valeric acid ethyl ester hydrochloride in 89 ml of acetic acid and the whole is stirred for 6 hours at 100°. The reaction mixture is cooled and partitioned betwen ethyl acetate and water. The organic phase is washed several times with saturated sodium bicarbonate solution and once with brine and, after drying over sodium sulphate, is concentrated. After purification by chromatography over silica gel (eluant: toluene/ethyl acetate 4:1 to 7:3), the pure title compound is obtained. Rf (toluene/ethyl acetate 1:1); 0.32.

Provenance & Evidence