反应详情

A mixture of t-butyl 4-amino-3-hydroxy-5-methyl-phenylacetate (0.38 g, Reference Example 10) in ethanol (10 mL) and o-tolylisothiocyanate (0.24 g) was stirred for 7 hours, then left to stand over night and then evaporated. The residue was dissolved in ethanol (10 mL) and the solution was treated with dicyclohexylcarbodiimide (0.36 g). This mixture was heated at reflux temperature for 2 hours and then evaporated. The residual gum was dissolved in dichloromethane (15 mL) and the solution was treated with trifluoroacetic acid (4.75 mL). After standing at room temperature for 3 hours the mixture was evaporated and the residue was dissolved in diethyl ether. This solution was extracted twice with saturated sodium bicarbonate solution and the pH of the combined aqueous extracts was adjusted to 1-2 by addition of dilute hydrochloric acid. This solution was then extracted with ethyl acetate and the extract was washed with brine, then dried and then evaporated to give the title compound (0.33 g) as a pale yellow solid.

1. waitleft
2. waitto stand over night
3. customevaporated
4. dissolutionThe residue was dissolved in ethanol (10 mL)
5. additionthe solution was treated with dicyclohexylcarbodiimide (0.36 g)
6. temperatureThis mixture was heated
7. temperatureat reflux temperature for 2 hours
8. customevaporated
9. dissolutionThe residual gum was dissolved in dichloromethane (15 mL)
10. additionthe solution was treated with trifluoroacetic acid (4.75 mL)
11. waitAfter standing at room temperature for 3 hours
12. customthe mixture was evaporated
13. dissolutionthe residue was dissolved in diethyl ether
14. extractionThis solution was extracted twice with saturated sodium bicarbonate solution
15. additionthe pH of the combined aqueous extracts was adjusted to 1-2 by addition of dilute hydrochloric acid
16. extractionThis solution was then extracted with ethyl acetate
17. washthe extract was washed with brine
18. customdried
19. customevaporated