Reaction #2254159

Reaction equation

2-(3-chloro-2-pyridyl)-N-[2,4-dichloro-6-hydroxycarbonyl-phenyl]-5-(trifluoromethyl)pyrazole-3-carboxamide

acetic anhydride

→

title compound

Yield 57.1%

6,8-dichloro-2-[2-(3-chloro-pyridin-2-yl)-5-trifluoromethyl-2H-pyrazol-3-yl]benzo[d][1,3]oxazin-4-one

Yield 57.1%

Solvents

methylene chloride

Conditions

Workup

1. 1
   FiltrationThe resulting solid was filtered
2. 2
   Washwashed with cold methylene chloride

Procedure

To a solution of 2-(3-chloro-2-pyridyl)-N-[2,4-dichloro-6-hydroxycarbonyl-phenyl]-5-(trifluoromethyl)pyrazole-3-carboxamide (18.4 g, 38.3 mmol) in methylene chloride (130 mL) was added acetic anhydride (39.4 mL, 417 mmol). The reaction was then heated to 55° C. for 2 h and then stirred for a further 16 h at room temperature. The resulting solid was filtered and washed with cold methylene chloride. Trituration with diethyl ether afforded the title compound (10.1 g, 57%).

Source