tert-Butanol → tert-butyl 6-bromo-8-carbamoyl-9H-carbazol-2-ylcarbamate

Participants

Reaction Conditions

Reaction Steps

6-Bromo-8-carbamoyl-9H-carbazole-2-carboxylic acid 58D (20 g, 60.0 mmol) was mixed with molecular sieve 4A (20 g, 60.0 mmol) in dioxane (500 mL). To the mixture was added Et3N (20.67 mL, 148 mmol) and diphenyl phosphorazidate (32.1 mL, 148 mmol). The mixture was stirred at 55° C. for 2 hrs. tBuOH (57.4 mL, 600 mmol) was added to the mixture and stirred at 80° C. for 16 hrs. The mixture was diluted with 500 ml MeOH, 500 ml CH2Cl2, and filtered through CELITE®. The filtrate was concentrated to dryness. 100 ml MeOH was added, light brown solid was formed and collected by filtration to give 11.2 g titled product. MS (ESI) m/z 402.1 (M−H)−.

Provenance & Evidence