Nitrogen → 3-(4-Isocyanatophenyl)-1,4-dihydroindeno[1,2-c]pyrazole

Participants

Reaction Steps

To a solution of 4-(1,4-dihydroindeno[1,2-c]pyrazol-3-yl)benzoic acid 1 (5.8 g, 20.99 mmol) in DMF (200 mL) were added diphenylphosphoryl azide (5.22 mL, 23.09 mmol) and Et3N (3.35 mL, 23.09 mmol). The reaction mixture was heated to about 80° C., for about 4 h, until no more N2 gas evolution was observed. The off-white precipitation was filtered off and washed with EtOAc (3×5 mL) and Et2O (3×5 mL). The solid was dried under vacuum to give quantitative yield of 2 that was used in the next step without further purification. Mp 338-339° C. IR (KBr) 2132, 1723,1582,1520

Provenance & Evidence