4-Methylmorpholine → HCID 86717977, compound

Participants

Reaction Steps

45 mg of 8-[(2,6-difluorobenzyl)oxy]-6-fluoro-2-methylimidazo[1,2-a]pyridine-3-carboxylic acid Example 11A, 0.13 mmol, 1 equivalent), 65 mg of (benzotriazol-1-yloxy)bisdimethylaminomethylium fluoroborate (TBTU, 0.2 mmol, 1.5 equivalents) and 54 mg of 4-methylmorpholine (0.54 mmol, 4 equivalents) were initially charged in 0.9 ml of DMF. After 10 min at RT, 24 mg of 1,2-diamino-2-methylpropane (0.27 mmol, 2 equivalents) were added and the mixture was stirred at RT overnight. Another 22 mg equivalents of TBTU (0.07 mmol, 0.5 equivalents) and 12 mg of 1,2-diamino-2-methylpropane (0.13 mmol, 1 equivalent) were added and the reaction was stirred at RT for 2 h. Water was added and the reaction solution was purified by preparative HPLC (RP18 column, mobile phase: acetonitrile/water gradient with addition of 0.1% TFA). 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. The mixture was filtered and concentrated and the crude product obtained was purified by thick-layer chromatography (mobile phase: dichloromethane/2 N ammonia in methanol: 10:0.5). This gave 31 mg of the title compound (55% of theory; purity 98%).

Provenance & Evidence