反应详情

To a mixture of sodium hydride (50%, 9.64 g., prewashed with tetrahydrofuran to remove mineral oil) and tetrahydrofuran (120 ml.) were added dropwise with stirring first a filtered solution of N-benzyloxycarbonyl-O-benzyl-L-tyrosine (16.22 g.) in tetrahydrofuran (50 ml.), then methyl iodide (20 ml.), then tetrahydrofuran (10 ml.). The resulting mixture was stirred overnight at room temperature. Ethyl acetate (200 ml.) was added, then water (6 ml.) dropwise, and stirring was continued for one hour. Charcoal was added and the mixture was filtered. Water (70 ml.) and ether were added, affording a pale yellow solid which melted upon drying at 65° C. and resolidified upon cooling (15.72 g., m.r. 88°-90° C.). Recrystallization of the solid from ethyl acetate (12 ml., 5 ml. used for washing) afforded N-benzyloxycarbonyl-N-methyl-O-benzyl-L-tyrosine (14.13 g.; m.r. 90°-91.5° C.).

1. additionwere added dropwise
2. waitwas continued for one hour
3. filtrationthe mixture was filtered
4. additionWater (70 ml.) and ether were added
5. customaffording a pale yellow solid which
6. customupon drying at 65° C.
7. temperatureupon cooling (15.72 g., m.r. 88°-90° C.)
8. customRecrystallization of the solid from ethyl acetate (12 ml., 5 ml. used for washing)