反应详情

Magnesium turnings (3.87 g) were charged into a round bottom flask. Tetrahydrofuran (15 mL) was added to the flask. Iodine (30 mg) was added. A solution of ethyl bromide (16 g in 60 mL tetrahydrofuran) was prepared and 10 mL of this solution was slowly charged to the round bottom flask. The reaction mixture was stirred at 20° C. to 25° C. for 5 minutes and the remaining amount of ethyl bromide was added slowly over 30 minutes. The reaction mixture was heated to gentle reflux for 30 minutes and was cooled to −5° C. to −10° C. 2-Chloro-6-methylaniline (22.86 g) was added drop-wise at −5° C. to −10° C. and the temperature of the reaction mixture was slowly raised to 15° C. to 20° C. Ethyl 2-[(tert-butoxycarbonyl)amino]-1,3-thiazole-5-carboxylate (10 g) dissolved in tetrahydrofuran (60 mL) was slowly added to the reaction mixture over 30 minutes. The reaction mixture was stirred for 3 hours. The reaction mixture was poured slowly into 25% ammonium chloride solution (100 mL) with stirring. Ethyl acetate (100 mL) was added and stirred for 30 minutes, filtered, suck dried, and dried under vacuum at 40° C. to 45° C. to obtain the title compound.

1. temperatureThe reaction mixture was heated
2. temperatureto gentle reflux for 30 minutes
3. temperaturewas cooled to −5° C. to −10° C
4. temperaturethe temperature of the reaction mixture was slowly raised to 15° C. to 20° C
5. additionwas slowly added to the reaction mixture over 30 minutes
6. stirringThe reaction mixture was stirred for 3 hours
7. stirringwith stirring
8. stirringstirred for 30 minutes
9. filtrationfiltered
10. customsuck dried
11. customdried under vacuum at 40° C. to 45° C.