Potassium Iodide → methyl N-(2-fluoro-4-chloro-5-cyclopentyloxyphenyl)carbamate

Participants

Reaction Steps

A 10-L three-necked flask equipped with a mechanical stirrer and a Dimroth condenser was charged with methyl N-(4-chloro-2-fluoro-5-hydroxyphenyl)carbamate (1.64 kg, 7.47 mol), cyclopentyl p-toluenesulfonate (1.80 kg, 7.48 mol), potassium carbonate (1.03 kg, 7.46 mol) and potassium iodide (12.3 g, 1.0 mol %), followed by the addition of solvent acetone (7,500 mL). The mixture was heated under reflux for 4 h. After completion of the reaction, the reaction mixture was recovered and 0.5N HCl (20 L) was added with vigorous stirring. The precipitating methyl N-(4-chloro-5-cyclopentyloxy-2-fluorophenyl)carbamate as white solids (2.00 kg, 6.95 mol; yield=93.1%) was isolated by filtration and dried thoroughly. MP: 120.0°-123.0° C. 1H-NMR(CDCl3,TMS,ppm): δ1.40-2.10(8H,m), 3.77(3H,s), 4.77(1H,m), 6.82(1H,brs), 7.07(1H,d,JHF =10.5Hz), 7.83(1H,d,JHF =7.5Hz). IR (KBr disk, cm-1): 1714, 1535, 1500, 1415, 1255, 1190.

Provenance & Evidence