4-Hydroxybenzaldehyde → 2-(3,5-Di-t-butyl-4-hydroxyphenyl)-4-(2-(4-formylphenoxy)ethyl)-5-methyloxazole

Participants

Reaction Conditions

Reaction Steps

The compound of Step C 3.61 g (10.9 mmole), 1.53 g (12.5 mmole) 4-hydroxybenzaldehyde, and 3.29 g (12.5 mmole) triphenylphosphine were dissolved in 30 ml tetrahydrofuran with stirring, under nitrogen. The solution was chilled to −5° C. ancl a solution of 1.97 ml (12.5 mmole) diethylcliazodicarboxylate in 10 ml. tetrahydrofuran was added over 10 minutes, with stirring. The reaction exothermed to +3° C. The bath was removed and the reaction stirred under nitrogen for 3 days. The reaction was stripped, dissolved in methylene chloride and placed in the freezer. The diethoxycarbonylhydrazine was then filtered off and the filtrate was chromatographed on 400 ml silica, eluting with a 5% isopropyl alcohol/hexane. The appropriate fractions were bulked and stripped to give 3.52 g (74%) product which was used without further purification.

Provenance & Evidence