反应详情

温度

80 °C

The crude 2-bromo-6-ethoxycarbonylbenzothiazole (1.90 g, 6.64 mmol) from Step 2 was suspended in absolute ethanol (35 mL) and treated with potassium hydrogen sulfide (0.96 g, 13.3 mmol). The mixture was placed under a nitrogen atmosphere, stirred, and heated in an oil bath at 80° C. The benzothiazole starting material gradually went into solution. After heating for 30 minutes, the mixture was cooled in an ice bath, treated with 1N hydrochloric acid (13.5 mL), and evaporated under vacuum. The residue was partitioned between ethyl acetate (100 mL) and water (100 mL) and the aqueous phase extracted with more ethyl acetate (50 mL). The combined ethyl acetate solution was washed with brine (50 mL), dried over sodium sulfate, filtered and evaporated under vacuum to a yellow-tan solid (1.56 g). This material was triturated with diethyl ether and dried under vacuum to provide 6-ethoxycarbonyl-2-mercaptobenzothiazole (1.14 g) as a pale tan powder.

1. temperatureAfter heating for 30 minutes
2. temperaturethe mixture was cooled in an ice bath
3. customevaporated under vacuum
4. customThe residue was partitioned between ethyl acetate (100 mL) and water (100 mL)
5. extractionthe aqueous phase extracted with more ethyl acetate (50 mL)
6. washThe combined ethyl acetate solution was washed with brine (50 mL)
7. dry with materialdried over sodium sulfate
8. filtrationfiltered
9. customevaporated under vacuum to a yellow-tan solid (1.56 g)
10. customThis material was triturated with diethyl ether
11. customdried under vacuum