反应详情

L-tyrosine 1 (181.2 g, 1.0 mol) was suspended in methanol (1268 g), and thionyl chloride (428.3 g, 3.6 mol) was added dropwise thereto at 40° C. over 2 hrs. After further keeping at 40° C. for 3 hrs, the reaction mass was concentrated to about one third of the volume under reduced pressure. To the concentrate mass was added dropwise toluene (1268 g) at 40° C. over 1.5 hrs. After keeping at 0° C. for 1 hr, precipitates were filtered and dried under reduced pressure to give L-tyrosine methyl ester hydrochloride 2 (208.7 g, yield 90.1%) as white crystals.

1. waitAfter further keeping at 40° C. for 3 hrs
2. concentrationthe reaction mass was concentrated to about one third of the volume under reduced pressure
3. additionTo the concentrate mass was added dropwise toluene (1268 g) at 40° C. over 1.5 hrs
4. waitAfter keeping at 0° C. for 1 hr
5. customprecipitates
6. filtrationwere filtered
7. customdried under reduced pressure