Dimethyl acetylenedicarboxylate → 1-(o-chlorobenzyl)-1H-1,2,3-triazole-4,5-dicarboxylic acid dimethyl ester

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Reaction Steps

A solution of 8 g (0.054 mol) of acetylene-dicarboxylic acid dimethyl ester in 25 ml of benzene is added dropwise to a solution of 8.4 g (0.05 mol) of o-chlorobenzyl azide in 50 ml of benzene that is boiling under reflux. After a further hour under reflux, the whole is diluted with 75 ml of cyclohexane and, after cooling, the substance that has crystallised out is filtered off with suction. After washing with a mixture of diethyl ether and hexane (1:1), there is obtained 1-(o-chlorobenzyl)-1H-1,2,3-triazole-4,5-dicarboxylic acid dimethyl ester having a melting point of 88°-91°.

Provenance & Evidence