反应详情

n-Butyllithium (2.5M in hexane, 1.7 ml) was added to diisopropylamine (0.59 ml) under nitrogen in dry tetrahydrofuran (15 ml) at -78° C. This solution was stirred for 30 minutes, then a solution of the product of stage (a) above (1.0 g) in tetrahydrofuran (10 ml) was added over 20 minutes. Methyl chloroformate (0.4 g) in dry tetrahydrofuran (10 ml) was added over 15 minutes at -78° C., and the reaction mixture was allowed to warm slowly to room temperature, after which it was added to aqueous ammonium chloride solution. The mixture was extracted with ether, the extracts being washed with water, dried over magnesium sulfate, and evaporated to dryness to give 1.08 g of the desired product, identical to that of Method A above.

1. extractionThe mixture was extracted with ether
2. washthe extracts being washed with water
3. dry with materialdried over magnesium sulfate
4. customevaporated to dryness