反应详情

0.5 N Lithium hydroxide (4.5 ml, 2.25 mmol) was added to a solution of 3,5-dichloro-N-trifluoroacetyl-O-[(2-phenyl)-benzoxazol-7-yl]methyl-L-tyrosine methyl ester (246 mg, 0.434 mmol) in tetrahydrofuran (2 ml) at 5° C. and the mixture was reacted at 5° C. for 84 hrs. The reaction mixture was diluted with water, adjusted to pH 3-4 with 1N hydrochloric acid under ice cooling and allowed to stand at 5° C. The precipitates were collected by filtration, washed with water and then dried to give 3,5-dichloro-O-[(2-phenyl)-benzoxazol-7-yl]methyl-L-tyrosine (198 mg, 94%) as a colorless solid.

1. customthe mixture was reacted at 5° C. for 84 hrs
2. customto stand at 5° C
3. filtrationThe precipitates were collected by filtration
4. washwashed with water
5. customdried