An improved synthesis of 3-hydroxymethylantipyrine using antipyrine as starting material

A partly new synthesis of 3-hydroxymethylantipyrine, an important metabolite of antipyrine in man and therefore frequently used as a reference substance, is described. The use of tri-n-butyltin hydride to reduce the vinyl bromide system in 3-hydroxymethyl-4-bromoantipyrine is the main improvement, since it enables the isolation of salt-free 3-hydroxymethylantipyrine in an almost quantitative yield.