Diisopropylethylamine → HCID 117864629, compound

Participants

Reaction Steps

A solution of 170 mg (0.366 mmol, 75% purity) of 7-[(2,6-difluorobenzyl)oxy]-5-methoxy-2-methylpyrazolo[1,5-a]pyridine-3-carboxylic acid (Example 163A) in 8 ml of tetrahydrofuran was admixed with 84 mg (0.44 mmol) of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (CAS: 25952-53-8) and 60 mg (0.44 mmol) of 1-hydroxy-7-azabenzotriazole (CAS: 39968-33-7). The solution was stirred at room temperature for 20 minutes. The reaction mixture was admixed with 0.191 ml (1.01 mmol) of N,N-diisopropylethylamine and 158 mg (0.732 mmol) of rac-(1-amino-2-methylpentan-2-yl)carbamic acid tert-butyl ester (Example 152A). The mixture was stirred at room temperature for a further 18 hours, and the reaction mixture was then concentrated under reduced pressure. The residue was partitioned between dichloromethane and water. The organic phase was removed, extracted with a saturated aqueous sodium hydrogencarbonate solution, water and aqueous sodium chloride solution, dried over sodium sulphate, filtered and concentrated under reduced pressure. The remaining residue was purified by flash chromatography using a prepacked silica gel cartridge (eluent:dichloromethane/methanol, gradient 0% to 10%), which gave 120 mg (44% yield, 73% purity) of product.

Provenance & Evidence