Hydrochloric Acid → 2-methyl-3,4-dihydropyrazino[1,2-a]indol-1(2H)-one

Participants

Reaction Conditions

Reaction Steps

To a mixture of ethyl 1-(2-(methylamino)-2-oxoethyl)-1H-indole-2-carboxylate (0.86 g), NaBH4 (0.39 g) in 33 mL of THF stirred at 0° C. under a N2 atmosphere, a solution of Iodine (1.26 g, 10 mL THF) was added dropwise. The resulting mixture was reacted at 65° C. for 24 hr. The reaction was worked up by the addition of HCl (con., 1.5 mL) and heated at 65° C. for 4 hr. Then the mixture was neutralized by saturated NaHCO3 solution and the aqueous phase was extracted with EtOAc (2×60 mL). The combined organic phase was washed with brine, dried over Na2SO4, filtered and evaporated. The residue was purified by Combiflash (0-100% EtOAc/hexane) to afforded 208 mg of the title compound.

Provenance & Evidence