反应详情

Diethyl isopropylidenemalonate (4, 50g, 0.25 mol) was refluxed with stirring with N-bromosuccinimide (44.3 g, 0.25 mol) and dibenzoyl peroxide (1.0 g, 4.1 mmol) in carbon tetrachloride (100 mL) with illumination using Kodak Ectagraphic slide projector lamp ELH (300 Watt) for 1.5 h. The reaction was completed as indicated by a negative starch-iodine test for N-bromosuccinimide. The resulting mixture was diluted with carbon tetrachloride (100 mL) and it was cooled in an ice-bath. The precipitated succinimide was filtered off and the filtrate was evaporated in vacuo at room temperature. The residual pale yellow oil of diethyl bromo-isopropylidene-malonate (5, 71.1 g) was used without purification in the Example 2.

1. customfor 1.5 h
2. temperaturewas cooled in an ice-bath
3. filtrationThe precipitated succinimide was filtered off
4. customthe filtrate was evaporated in vacuo at room temperature
5. customThe residual pale yellow oil of diethyl bromo-isopropylidene-malonate (5, 71.1 g) was used without purification in the Example 2