Phosphorus oxychloride → 2,4-Difluoro-1-(isocyano(tosyl)methyl)benzene

Participants

Reaction Conditions

Reaction Steps

To a solution of N-((2,4-difluorophenyl)(tosyl)methyl)formamide (7.31 g, 22.5 mmol) in DME (100 mL) at about −10° C. was added phosphorus oxychloride (Fluka, 6.28 mL, 67.4 mmol) followed by dropwise addition of TEA (15.7 mL, 112 mmol) in DME (10 mL). The reaction mixture was stirred at about −5° C. for about 3 h. The reaction mixture was poured into ice-cold water (250 mL) and extracted with EtOAc (3×50 mL). The organic layer was dried with MgSO4, filtered and concentrated in vacuo. The crude material was purified by silica gel chromatography using heptane/EtOAc (gradient; 1:0 to 1:1) to give the title compound (1.38 g, 20.0%), as a yellow solid. LC/MS (Table 1, Method a) Rt=2.96 min; MS m/z: 306.1 (M−H)−.

Provenance & Evidence