Sodium hydride → tert-butyl 2-cyclohexyl-2-oxoethyl(5-tosyl-5H-pyrrolo[2,3-b]pyrazin-2-yl)carbamate

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Reaction Conditions

Reaction Steps

NaH (60% in mineral oil, 0.020 g, 0.49 mmol) was added to dry DMF (3 mL). The suspension was cooled to about 0° C. and a solution of tert-butyl 5-tosyl-5H-pyrrolo[2,3-b]pyrazin-2-ylcarbamate (0.19 g, 0.489 mmol, Example #8, Step A) in dry DMF (2 mL) was added drop-wise. The reaction mixture was allowed to warm to ambient temperature and 2-bromo-1-cyclohexylethanone (0.10 g, 0.49 mmol, 3B PharmaChem) was added. The reaction mixture was stirred for about 2 h and then concentrated under reduced pressure. Purification by silica gel flash chromatography eluting with 100% heptane for 10 min and a gradient of 10-20% EtOAc in heptane over 20 min yielded tert-butyl 2-cyclohexyl-2-oxoethyl(5-tosyl-5H-pyrrolo[2,3-b]pyrazin-2-yl)carbamate as a yellow amorphous solid (0.080 g, 32%): LC/MS (Table 2, Method a) Rt=3.13 min; MS m/z: 513 (M+H)+.

Provenance & Evidence