反应详情

温度

-5 °C

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. and a solution of 1.97 ml (12.5 mmole) diethyldiazodicarboxylate 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.

1. stirringwith stirring
2. customexothermed to +3° C
3. customThe bath was removed
4. stirringthe reaction stirred under nitrogen for 3 days
5. dissolutiondissolved in methylene chloride
6. filtrationThe diethoxycarbonylhydrazine was then filtered off
7. customthe filtrate was chromatographed on 400 ml silica
8. washeluting with a 5% isopropyl alcohol/hexane