8-chloro-2,3-dihydrothiochromen-4-one

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 8-chloro-2,3-dihydro-4H-1-benzothiopyran-4-one (10 g) in benzene (125 ml) was added dropwise to a mixture of ethyl formate (7.46 g) and sodium methoxide (5.44 g) in benzene (40 ml) with ice cooling and stirring over a period of 10 minutes. After being stirred for 1 hour at room temperature, 10% hydrochloric acid was added to the reaction mixture. The aqueous layer was separated and extracted with ethyl acetate. The combined organic layers were washed with water, dried over magnesium sulfate, and evaporated in vacuo. The residue was recrystallized from a mixture of ethyl acetate and n-hexane to give 8-chloro-2,3-dihydro-3-hydroxymethylene-4H-1-benzothiopyran-4-one (10.13 g). After being stirred for 1 hour at room temperature The aqueous layer was separated extracted with ethyl acetate The combined organic layers were washed with water dried over magnesium sulfate evaporated in vacuo The residue was recrystallized from a mixture of ethyl acetate and n-hexane

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 8-chloro-2,3-dihydro-4H-1-benzothiopyran-4-one (10 g) in benzene (125 ml) was added dropwise to a mixture of ethyl formate (7.46 g) and sodium methoxide (5.44 g) in benzene (40 ml) with ice cooling and stirring over a period of 10 minutes. After being stirred for 1 hour at room temperature, 10% hydrochloric acid was added to the reaction mixture. The aqueous layer was separated and extracted with ethyl acetate. The combined organic layers were washed with water, dried over magnesium sulfate, and evaporated in vacuo. The residue was recrystallized from a mixture of ethyl acetate and n-hexane to give 8-chloro-2,3-dihydro-3-hydroxymethylene-4H-1-benzothiopyran-4-one (10.13 g). After being stirred for 1 hour at room temperature The aqueous layer was separated extracted with ethyl acetate The combined organic layers were washed with water dried over magnesium sulfate evaporated in vacuo The residue was recrystallized from a mixture of ethyl acetate and n-hexane