2-Dimethylaminopyridine → HCID 178499660, compound

Participants

Reaction Steps

To a solution of 8.2 mg (0.025 mmol) of 6-cyclohexyl-5-furan-2-yl-7-oxo-4,7-dihydro-pyrazolo[1,5-a]pyrimidine-2-carboxylic acid in 2 mL of dimethylformamide (DMF) was added 0.009 mL (0.05 mmol) of diisopropylethylamine (DIEA), a few crystals of dimethylaminopyridine (DMAP cat), 7 mg (0.027 mmol) of L-tryptophan methyl ester hydrochloride, followed by 11 mg (0.03 mmol) of HATU, and the resulting mixture was stirred at rt overnight. The reaction mixture was diluted with ethyl acetate, washed with 0.1 N sodium hydroxide solution (2 times) and brine. The separated organic layer was dried over sodium sulfate and concentrated to give a residue which was purified via reverse-phase chromatography (Gilson) to afford desired 2-[(6-cyclohexyl-5-furan-2-yl-7-oxo-4,7-dihydro-pyrazolo[1,5-a]pyrimidine-2-carbonyl)-amino]-3-(1H-indol-2-yl)-propionic acid methyl ester (606). This compound was then converted to 2-[(6-cyclohexyl-5-furan-2-yl-7-oxo-4,7-dihydro-pyrazolo[1,5-a]pyrimidine-2-carbonyl)-amino]-3-(1H-indol-2-yl)-propionic acid (599) via the well known LiOH saponification protocol (39% yield over 2 steps); LC-MS calcd. for C28H27N5O5 [M++H]+: 514.2; found: 514.2.

Provenance & Evidence