Para-tert.-butyl-benzaldehyde prepn. - by bromination of para-tert. butyl toluene and saponification of the resulting para-tert. butyl-benzal-bromide

摘要

In the prodn. of p-tert. -butyl-benzaldehyde and its halogenated derivs. of formula (I), opt. halogenated p-tert. butyl-toluene of formula (II) is first reacted with approx. 2 mol. Br2/mol. (II) at 40-200 degrees C, pref. 40-120 degrees C, opt. using high energy radiation or radical formers, to form an opt. halogenated p-tert. butylbenzal bromide of formula (III). (III) is then saponified with water at elevated temp. in the presence of standard saponification catalysts. In the formulae, X=H, F, Cl, Br to I. Cpds. (III) are new (I) are useful intermediates in the prodn. of pharmaceuticals, plant protection agents, dyes and aroma substances.