反应详情

To 80 ml of a pyridine solution containing 10.7 g (37 mmol) of N-carbobenzoxydopamine obtained in Synthetic Example 1-(1) was added dropwise 9.9 g (93 mmol) of isobutyryl chloride at 5° to 10° C. After stirring at room temperature for 12 hours, the mixture was allowed to react at 35° to 40° C. for 3 hours. Then, the reaction mixture was poured into ice and a sodium carbonate solution and stirred at room temperature for 30 minutes. The mixture was extracted with diethyl ether and the resulting extract was dried over anhydrous magnesium sulfate. The solvent was distilled and the thus-obtained crude crystals were recrystallized from diisopropyl ether/petroleum ether (1:2 by volume) to obtain 11.9 g (yield: 74.7%) of the desired compound in the form of white cyrstals (m.p. 44°-46° C.).

1. customto react at 35° to 40° C. for 3 hours
2. additionThen, the reaction mixture was poured into ice
3. extractionThe mixture was extracted with diethyl ether
4. extractionthe resulting extract
5. dry with materialwas dried over anhydrous magnesium sulfate
6. distillationThe solvent was distilled
7. customthe thus-obtained crude crystals
8. customwere recrystallized from diisopropyl ether/petroleum ether (1:2 by volume)