反应详情

温度

21 °C

To a mixture of compound 5B (5.00 g, 20.86 mmol) in 1,4-dioxane (27 mL) and water (27 mL) was added NBS (4.08 g, 22.9 mmol) at −10 to 0° C. The slurry was warmed and stirred at 20-22° C. for 3 h. Thiourea (1.60 g, 21 mmol) was added and the mixture heated to 80° C. After 2 h, the resulting solution was cooled to 20-22° and conc. ammonium hydroxide (4.2 mL) was added dropwise. The resulting slurry was concentrated under vacuum to about half volume and cooled to 0-5° C. The solid was collected by vacuum filtration, washed with cold water (10 mL), and dried to give 5.3 g (94.9% yield) of 2-amino-N-(2-chloro-6-methylphenyl)thiazole-5-carboxamide. 1H NMR (400 MHz, DMSO-d6) δ δ 2.19 (s, 3H), 7.09-7.29 (m, 2H, J=7.5), 7.29-7.43 (d, 1H, J=7.5), 7.61 (s, 2H), 7.85 (s, 1H), 9.63 (s, 1H); 13C NMR (125 MHz, DMSO-d6) δ: 18.18, 120.63, 126.84, 127.90, 128.86, 132.41, 133.63, 138.76, 142.88, 159.45, 172.02.

1. temperatureThe slurry was warmed
2. temperaturethe mixture heated to 80° C
3. waitAfter 2 h
4. temperaturethe resulting solution was cooled to 20-22°
5. concentrationThe resulting slurry was concentrated under vacuum to about half volume
6. temperaturecooled to 0-5° C
7. filtrationThe solid was collected by vacuum filtration
8. washwashed with cold water (10 mL)
9. customdried