Formaldehyde → (4-Benzotriazol-1-yl-piperidin-1-yl)-(7-chloro-2-methyl-1,2,3,4-tetrahydro-pyrazino[1,2-a]indol-10-yl)-methanone

Participants

Reaction Conditions

Reaction Steps

A mixture of 0.20 g (0.41 mmol) (4-benzotriazol-1-yl-piperidin-1-yl)-[6-chloro-1-(2-methylamino-ethyl)-1H-indol-3-yl]-methanone hydrochloride, 0.057 ml (0.41 mmol) triethylamine and 0.10 g (3.3 mmol) paraformaldehyde in 4 ml methanol was heated at reflux for 7 h. After cooling to 0° C. 0. were added 052 g (0.82 mmol) sodium cyanoborohydride. The cooling bath was removed and the reaction mixture was stirred at room temperature for 16 h. Quenching with 1 M aqueous sodium hydroxide solution was followed by extraction with two portions of ethyl acetate. The combined organic extracts were dried over sodium sulfate and concentrated in vacuo. Flash chromatography gave 0.040 g (22%) (4-benzotriazol-1-yl-piperidin-1-yl)-[6-chloro-1-(2-dimethylamino-ethyl)-1H-indol-3-yl]-methanone as a white solid (ES-MS m/e (%): 451 (M+H+, 100)) and 0.11 g (60%) (4-benzotriazol-1-yl-piperidin-1-yl)-(7-chloro-2-methyl-1,2,3,4-tetrahydro-pyrazino[1,2-a]indol-10-yl)-methanone as a white solid (ES-MS m/e (%): 449 (M+H+, 100)).

Provenance & Evidence