1,2-Dichloroethane → 4-[2-(4-hydroxymethyl-piperidin-1-yl)-2-oxo-ethyl]-6,6-dimethyl-morpholine-3-carboxylic acid (6-chloro-9H-beta-carbolin-8-yl)-amide

Participants

Reaction Steps

[5-(6-Chloro-9H-beta-carbolin-8-ylcarbamoyl)-2,2-dimethyl-morpholin-4-yl]-acetic acid (200 mg, 0.48 mmol) and piperidin-4-yl-methanol (111 mg, 0.96 mmol) were dissolved in pyridine (4 mL). The resulting yellow solution was stirred at room temperature for 10 min and then EDC (184 mg, 0.96 mmol) was added in a single portion. The reaction mixture was allowed to stir over night (16 h). Water (4 mL) was added and the mixture was concentrated under reduced pressure. The resulting residue was partitioned between ethyl acetate (50 mL) and 1 M aqueous potassium carbonate. The aqueous layer was back-extracted with ethyl acetate (3×50 mL) and the combined extracts were washed with water and brine, dried over sodium sulfate, filtered, and concentrated. The crude residue was purified by silica gel chromatography (methylene chloride and methanol gradient) to afford pure 4-[2-(4-hydroxymethyl-piperidin-1-yl)-2-oxo-ethyl]-6,6-dimethyl-morpholine-3-carboxylic acid (6-chloro-9H-beta-carbolin-8-yl)-amide as a yellow foam (152 mg, 62%). The bis-HCl salt was prepared by adding 2 equivalents of conc. HCl to an ethanolic solution of the freebase. Concentration, followed by ether trituration afforded the salt as a free-flowing, yellow powder.

Provenance & Evidence