反应详情

A suspension of 22.1 g of the crude hydrochloride salt prepared in Example 2 in a mixture of 30 ml of concentrated hydrochloric acid and 30 ml acetic acid was cooled to 0°-5°. A solution of 6.2 g of sodium nitrite in 15 ml water was added dropwise at 0°-5°. The thick suspension was diluted with 19 ml of concentrated hydrochloric acid to facilitate stirring and 1.0 g of sodium nitrite was added; stirring was continued for 1 hour. The suspension of the diazonium salt was added portionwise at 0°-5° to a stirred mixture of 80 ml of acetic acid, 25 ml of sulfur dioxide and 1.6 g of copper (II) chloride dihydrate. The resulting pale green suspension was allowed to warm to ambient temperature and stirred for 4.5 hours. The yellow-green solution was poured into 1000 ml of cold water and the aqueous mixture extracted three times with 1-chlorobutane. The combined organic solution was washed three times with water and saturated sodium bicarbonate solution, then dried over magnesium sulfate, and filtered. Evaporation of the solvent in vacuo gave 9.8 g of 1,3-dihydrobenzo[c]furan-4-sulfonyl chloride as a yellow oil which crystallized on cooling and scratching, m.p. 40°-43°.

1. temperaturewas cooled to 0°-5°
2. stirringstirring
3. stirringstirred for 4.5 hours
4. extractionthe aqueous mixture extracted three times with 1-chlorobutane
5. washThe combined organic solution was washed three times with water and saturated sodium bicarbonate solution
6. dry with materialdried over magnesium sulfate
7. filtrationfiltered
8. customEvaporation of the solvent in vacuo