Trimethylaluminum → (S)-5-(2-hydroxy-3-morpholin-4-yl-propyl)-3-methyl-5,6,7,8-tetrahydro-1H-pyrrolo[3,2-c]azepin-4-one

Participants

Reaction Steps

(S)-5-[3-(2-Hydroxy-3-morpholin-4-yl-propylamino)-propyl]-3-methyl-1H-pyrrole-2 and 4-dicarboxylic acid 2-tert-butyl ester 4-ethyl ester 78d (580 mg, 1.28 mmol) were dissolved in 6 ml of toluene under an argon atmosphere, the reaction mixture was cooled in an ice-water bath, meanwhile a solution of trimethylaluminum in toluene (1.9 ml, 2 mol/L, 3.84 mmol) was added to the solution. Upon the completion of the addition, the ice-water bath was removed, and the reaction solution was heated to reflux for 24 hours. After thin lay chromatography showed the disappearance of starting materials, the reaction was stopped. The reaction solution was concentrated under reduced pressure to remove the reaction solvent, added with 20 ml hydrochloric acid (6 mol/L) and stirred for 20 minutes, adjusted to about pH 12 with sodium hydroxide solution (12 mol/L) in an ice-water bath. The resulting mixture was extracted with dichloromethane (50 ml×2), the combined organic phase was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography to obtain the title compound (S)-5-(2-hydroxy-3-morpholin-4-yl-propyl)-3-methyl-5,6,7,8-tetrahydro-1H-pyrrolo[3,2-c]azepin-4-one 78e (300 mg, yield 57.6%) as a white solid.

Provenance & Evidence