Trifluoroacetic acid → HCID 67068319, compound

Participants

Reaction Steps

To a solution of (9H-fluoren-9-yl)methyl 3-(2-(tert-butoxycarbonyl(5-tosyl-5H-pyrrolo[2,3-b]pyrazin-2-yl)amino)acetyl)-4-methylpiperidine-1-carboxylate (0.627 g, 0.836 mmol, prepared using W from Preparation #20, LL, Z from Example #8, Step A) in DCM (10 mL) was added TFA (1.50 mL, 19.5 mmol) and the resulting mixture was stirred at ambient temperature under nitrogen for about 1 h. The solution was concentrated and the residue was partitioned between saturated aqueous NaHCO3 (25 mL) and EtOAc (25 mL). The organic phase was washed with brine (20 mL), dried over anhydrous MgSO4, filtered, and concentrated to yield crude (9H-fluoren-9-yl)methyl 4-methyl-3-(2-(5-tosyl-5H-pyrrolo[2,3-b]pyrazin-2-ylamino)acetyl)-piperidine-1-carboxylate as an amorphous brown solid. The crude material was added to 1,4-dioxane (5 mL), Lawesson's reagent (0.203 g, 0.502 mmol) was added, and the resulting suspension was heated at about 80° C. for about 20 min. The solvent was removed under reduced pressure and the residue was purified by silica gel chromatography eluting with a gradient of 0 to 1.5% MeOH/DCM to give (9H-fluoren-9-yl)methyl 4-methyl-3-(3-tosyl-3H-imidazo[1,2-a]pyrrolo[2,3-e]pyrazin-8-yl)piperidine-1-carboxylate as an off-white solid (0.21 g, 40%): LC/MS (Table 2, Method a) Rt=2.68 min; MS m/z: 632 (M+H)+.

Provenance & Evidence