4-(Benzyloxy)-1-(5-methyl-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indol-7-yl)pyridin-2(1H)-one (75 mg, 0.16 mmol) was dissolved in a mixture of CH2Cl2 (1 mL) and sat. NaHCO3 solution (1 mL) and chloroacetyl chloride (28 mg, 0.25 mmol) was added. The reaction mixture was vigorously stirred for 1 h then the phases were separated. The aqueous phase was extracted with CH2Cl2 and the combined organic extracts were dried over Na2SO4, filtered and concentrated to dryness providing the title compound (74 mg, 97%) as a beige solid which was a mixture of rotamers: ESI MS m/z 462 [M+H]+.
