HCID 14500616, compound → HCID 21241960, compound

Participants

Reaction Conditions

Reaction Steps

To a stirred suspension of 2 g (50 mmol) of lithium aluminum hydride in 100 ml of anhydrous tetrahydrofuran was added dropwise, at room temperature, a solution of 12 g (46 mmol) of 1-propyl-2-(3'-aminobenzoyl)-5-ethylpyrrole in 100 ml of anhydrous tetrahydrofuran. The reaction mixture was refluxed for 15 minutes, cooled to 0° C. and the excess reagent destroyed by carefully adding ethyl acetate, saturated sodium sulfate solution and solid anhydrous sodium sulfate. The insoluble material was separated by filtration and the filtrate evaporated in vacuo, to produce 11.1 g (43 mmol) of 1-propyl-2-(3'-amino-α-hydroxybenzyl)-5-ethylpyrrole. This crude compound was dissolved in 150 ml of methanol, cooled to -10° C. and treated with 23.5 ml of glacial acetic acid and 5.1 g (80 mmol) of sodium cyanoborohydride. The reaction mixture was warmed to room temperature and stirred for 18 additional hours. It was then poured into 500 ml of saturated sodium carbonate solution and the product extracted with ethyl acetate (4×300 ml). The combined extracts were washed with water (3×300 ml), dried and evaporated in vacuo. The residue was purified by column chromatography on 500 g of silica gel, using hexane-acetone (97:3) as eluant, thus obtaining 4.8 g (47%) of the title compound, 1-propyl- 2-(3'-aminobenzyl)-5-ethylpyrrole, as an oil.

Provenance & Evidence