Dichloromethane → HCID 58010071, compound

Participants

Reaction Steps

A round-bottomed flask was charged with 2-hydrazinyl-5-tosyl-5H-pyrrolo[2,3-b]pyrazine (2.0 g, 6.6 mmol, Step J) and DCM (40 mL) to give a brown suspension. 4-(tert-Butoxycarbonylamino)-2-ethylcyclopentanecarboxylic acid (2.0 g, 7.8 mmol, Step G), HATU (2.51 g, 6.59 mmol), and TEA (4.59 mL, 33.0 mmol) were added to the suspension and the resulting mixture was stirred at ambient temperature for about 24 h with dissolution occurring after about 2 h. Water (20 mL) was added and the layers were partitioned. The organic layer was washed with additional water (2×15 mL), brine (2×25 mL), dried over anhydrous MgSO4, filtered, and solvent was removed under reduced pressure to give a brown residue. The crude material was purified by silica gel chromatography eluting with a gradient of 0-10% MeOH/DCM. The recovered impure material was re-purified by silica gel chromatography eluting with a gradient of 0-10% MeOH/DCM. The product-containing fractions from the two columns were combined and concentrated to give tert-butyl-3-ethyl-4-(2-(5-tosyl-5H-pyrrolo[2,3-b]pyrazin-2-yl)hydrazinecarbonyl)cyclopentylcarbamate (2.45, 69%) as a brown solid: LC/MS (Table 2, Method d) Rt=1.47 min; MS m/z: 543 (M+H)+.

Provenance & Evidence