Reaction #327991

Reaction equation

1,4-Phenylene diisocyanate

triethylamine

1-methoxy-4-trifluoropropynylbenzene

4-nitrobutanoic acid methyl ester

→

trifluoromethyl isoxazole

Yield 56.5%

Solvents

toluene

Conditions

Workup

1. 1
   FiltrationThe reaction solution was filtered with celite
2. 2
   workup.DISTILLATIONthe solvent was then distilled away
3. 3
   OtherThe residue was purified by silica gel column chromatography (hexane/ethyl acetate)

Procedure

1,4-Phenylene diisocyanate (597.1 mg, 3.73 mol) and triethylamine (780 μL, 5.60 mmol) were added to a solution of 1-methoxy-4-trifluoropropynylbenzene (373.2 mg, 1.86 mmol) and 4-nitrobutanoic acid methyl ester (441.5 mg, 2.80 mmol) in toluene (10 mL). Using a microwave reactor, the obtained mixture was stirred at 150° C. for 2 hours. The reaction solution was filtered with celite, and the solvent was then distilled away. The residue was purified by silica gel column chromatography (hexane/ethyl acetate) to obtain a trifluoromethyl isoxazole compound (144.0 mg, yield: 25%).

Source