反应详情

Step I (I): To a solution of methyl 2-(5-bromo-1H-indol-3-yl)acetate ( 268 mg, 1.0 mmol) and tert-butyl isocyanate (149 mg, 1.5 mmol) in dichloromethane was added boron trifluoride diethyl etherate dropwise at −5° C. under nitrogen. The mixture was stirred from −5° C. to rt and at rt overnight. 100 mL of EtOAc was added, and the resulting solution was washed with 0.1 N HCl and water. The organic layer was dried over Na2SO4, and the solvents was removed to give 340 mg of the crude methyl 2-(5-bromo-2-(tert-butylcarbamoyl)-1H-indol-3-yl)acetate (yield 92.6%). MS (ESI) (M+H)+=369.05. 1H NMR (500 MHz, CDCl3) δ ppm 1.51 (s, 9 H) 3.74 (s, 3 H) 3.86 (s, 2 H) 7.26 (d, J=8.55 Hz, 1 H) 7.35 (dd, J=8.55, 1.83 Hz, 1 H) 7.79 (d, J=1.53 Hz, 1 H) 8.01 (s, 1 H) 9.17 (s, 1 H).

1. washthe resulting solution was washed with 0.1 N HCl and water
2. dry with materialThe organic layer was dried over Na2SO4
3. customthe solvents was removed