Lithium Hydroxide → HCID 58919231, compound

Participants

Reaction Steps

To a room temperature solution of tert-butyl 4-(2,4-difluoro-3-(methoxycarbonyl)benzyl)piperazine-1-carboxylate (2.0 g, 5.4 mmol, 1.0 equiv) in THF (5.0 mL) was added a solution of LiOH (249 mg, 5.94 mmol, 1.1 equiv) in water (5 mL). The resulting mixture was stirred overnight. The resulting lithium carboxylate salt was concentrated in vacuo and used in the next step without purification. The lithium salt was suspended in dioxane (50 mL), and N-hydroxysuccinimide (652 mg, 5.67 mmol, 1.05 equiv) and DCC (1.28 g, 6.21 mmol, 1.15 equiv) were added as solids. After the reaction mixture was stirred for 2 days, it was charged with sodium azide (340 mg, 5.4 mmol, 1.0 equiv) and then stirred overnight. The resulting solid was filtered and washed with DCM. The organic layer was passed through a plug of silica gel and concentrated in vacuo to provide tert-butyl 4-(3-(azidocarbonyl)-2,4-difluorobenzyl)piperazine-1-carboxylate (2.52 g crude) which was taken on to the next step without purification.

Provenance & Evidence