反应详情

18.6 g (0.211 mol) of D,L-alanine and 46.6 g (0.41 mol) of triethylamine are initially charged in 300 ml of dichloromethane. at 0° C., 50.09 g (0.461 mol) of trimethylsilyl chloride are added dropwise, and the mixture is stirred at room temperature for 1 h and then at 40° C. for 1 h. The solution is cooled to −10° C., and 40 g (0.21 mol) of 2-ethyloctanoyl chloride in 50 ml of dichloromethane are added dropwise. The mixture is stirred at room temperature overnight, and 100 ml of water are then added dropwise with ice-cooling, and the mixture is stirred for another 10 minutes. The phases are separated, the aqueous phase is extracted twice with in each case 100 ml of dichloromethane and the combined organic phases are dried over sodium sulphate and evaporated under reduced pressure. The residue is recrystallized from toluene by adding n-hexane and dried at 60° C.

1. waitat 40° C. for 1 h
2. temperatureThe solution is cooled to −10° C.
3. stirringThe mixture is stirred at room temperature overnight
4. temperaturecooling
5. stirringthe mixture is stirred for another 10 minutes
6. customThe phases are separated
7. extractionthe aqueous phase is extracted twice with in each case 100 ml of dichloromethane
8. dry with materialthe combined organic phases are dried over sodium sulphate
9. customevaporated under reduced pressure
10. customThe residue is recrystallized from toluene
11. additionby adding n-hexane
12. customdried at 60° C.