To an ice-cooled flask containing a solution of 10.5 gm (0.065 mole) of p-methoxyformanilide in 37.1 gm (0.47 mole) of pyridine and 13.0 ml (0.16 mole) of chloroform is added dropwise at 0°C 6.12 gm (0.040 mole) of phosphorus oxychloride. The solution is stirred for 1? hr at room temperature and then added to 55 ml of ice-water. The water layer is extracted with two 10-ml portions of chloroform; the combined chloroform layer is dried and distilled under reduced pressure, to afford 3.5 gm (40%), b.p. 767C (1.0 mm Hg), IR 2137 c m " 1 (R—NC).