Phosgene → 5-Isocyanato-1,2,3-trimethoxybenzene

Participants

Reaction Steps

A mixture of 3,4,5-trimethoxyaniline (365 mg; 2.0 mmol) in toluene (20 ml) and phosgene (6 ml 20% in toluene; 12 mmol) was refluxed for 6 h. The solvent was removed under reduced pressure to give crude 3,4,5-trimethoxyphenylisocyanate. To the crude product was added 3(4-(6-fluoro-1,2-benzisoxazol-3-yl)-piperidine) propanol (420 mg; 1.5 mmol) in DMF (10 ml). The mixture was stirred at 100° C. for 2 h and then at room temperature for 16 h, whereupon it was taken up in ethyl acetate and water. The organic phase was washed with water and saturated sodium chloride and concentrated in vacuo. The resulting oil was taken up in acetone/ethanol (4:1, v/v) and oxalic acid (150 mg) in 2 ml acetone added to precipitate the desired product. The product was washed with ice cold ethanol giving 550 mg of the title compound. M.p. 77°-80° C. MS (70 eV): m/z 487 (9%, M+), 287 (31), 233 (40), 209 (56), 194 (45), 140 (67), 96 (100).

Provenance & Evidence