4-Methylmorpholine → rac-tert-Butyl {1-[({8-[(2,6-difluorobenzyl)oxy]-2,6-dimethylimidazo[1,2-a]pyridin-3-yl}-carbonyl)amino]-3-methylbutan-2-yl}carbamate

Participants

Reaction Steps

200 mg (0.60 mmol) of 8-[(2,6-difluorobenzyl)oxy]-2,6-dimethylimidazo[1,2-a]pyridine-3-carboxylic acid from Example 21A, 203 mg (0.63 mmol) of HATU and 0.20 ml (1.81 mmol) of 4-methylmorpholine were initially charged in DMF (3.8 ml), the mixture was stirred at RT for 20 min, 134 mg (0.66 mmol) of rac-tert-butyl (1-amino-3-methylbutan-2-yl)carbamate were added and the reaction mixture was stirred at RT overnight. Water/TFA were added and the mixture was purified by preparative RP-HPLC (acetonitrile/water gradient with addition of 0.1% TFA). The product fractions were concentrated and the residue was taken up in dichloromethane and washed twice with saturated aqueous sodium bicarbonate solution. The aqueous phase was extracted twice with dichloromethane and the combined organic phases were dried over sodium sulphate, filtered off and concentrated. This gave 262 mg (84% of theory, purity 100%) of the target compound.

Provenance & Evidence