Reaction #417928

Reaction equation

3-(2-Trifluoromethyl-phenylmethanesulfonylmethyl)-pyridine-2-carboxylic acid methyl ester

tetrahydrofurane

HCl

→

colourless crystals

Yield 37.3%

6,6-Dioxo-7-(2-trifluoromethyl-phenyl)-5,6-dihydro-thiopyrano[4,3-b]pyridin-8-ol

Yield 37.3%

Solvents

ethylacetate cyclohexane

Conditions

Workup

1. 1
   workup.ADDITIONdiluted with methylenehloride
2. 2
   Extractionextracted
3. 3
   DryingThe organic phase was dried with sodiumsulfate
4. 4
   Concentrationconcentrated

Procedure

To a solution of 3-(2-Trifluoromethyl-phenylmethanesulfonylmethyl)-pyridine-2-carboxylic acid methyl ester (7.58 g, 19.6 mmol) in tetrahydrofurane (160 ml) potassium tert-butoxide (2.20 g, 19.57 mmol) was added at room temperature and stirring was continued for 3.5 h. 1M HCl was added, diluted with methylenehloride and extracted. The organic phase was dried with sodiumsulfate and concentrated. Chromatography over silica with ethylacetate/cyclohexane gave 2.50 g colourless crystals (7.32 mmol).

Source