Trimethylaluminum → 3-Methyl-5-(2-morpholin-4-yl-ethyl)-4-oxo-1,4,5,6,7,8-hexahydro-pyrrolo[3,2-c]azepine-2-carboxylic acid tert-butyl ester

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Reaction Steps

3-Methyl-5-[3-(2-morpholin-4-yl-ethylamino)-propyl]-1H-pyrrole-2,4-dicarboxylic acid 2-tert-butyl ester 4-ethyl ester 10a (2.238 g, 5.29 mmol) was dissolved in 50 ml of toluene under stirring, and added slowly with a solution of trimethyl aluminum in toluene (3.9 ml, 2 mol/L, 7.9 mmol) under an argon atmosphere. The reaction system was stirred for 30 minutes at room temperature until no white smoke was released, and refluxed for another 3 hours in an oil bath. After thin lay chromatography showed the disappearance of starting materials, the oil bath was removed, and the reaction mixture was quenched with a little water, adjusted to pH 8-10 with dilute sodium hydroxide solution (2 mol/L), added with saturated brine (50 ml) and extracted with ethyl acetate (50 ml×3). The combined organic extracts were filtered through a pad of Celite, concentrated under reduced pressure to obtain the title compound 3-methyl-5-(2-morpholin-4-yl-ethyl)-4-oxo-1,4,5,6,7,8-hexahydro-pyrrolo[3,2-c]azepine-2-carboxylic acid tert-butyl ester 10b (1.218 g, yield 61%) as a light yellow solid

Provenance & Evidence