反应详情

With stirring 146 ml. of dicyclohexylamine were slowly added in portions to the ethyl acetate solution. The dicyclohexylamine salt of N-t-butyloxycarbonyl D-methionine began to crystallize during the addition of the amine. After addition of the amine was completed, approximately 400 ml. of petroleum ether were added to the crystallization mixture which was cooled in an ice bath for approximately 2 hours to complete crystallization. The product was filtered and washed on the filter with cold petroleum ether and was dried at 40° C. in a vacuum oven. The dried product weighed 199.5 g. (63% yield) and melted at about 136°-138° C. [α]=-12.8° (methyl alcohol).

1. customto crystallize during the addition of the amine
2. additionAfter addition of the amine
3. additionof petroleum ether were added to the crystallization mixture which
4. temperaturewas cooled in an ice bath for approximately 2 hours
5. customcrystallization
6. filtrationThe product was filtered
7. washwashed on the
8. filtrationfilter with cold petroleum ether
9. customwas dried at 40° C. in a vacuum oven
10. custom(63% yield) and melted at about 136°-138° C. [α]=-12.8° (methyl alcohol)