反应详情

A mixture of polyphosphoric acid (11.2 g) in chlorobenzene (290 mL) was heated to reflux and added, under nitrogen, dropwise in about one hour 1-chloro-4-(2,2-dimethoxy-ethylsulfanyl)-benzene (compound PRE9; 9.12 g, 39.2 mmol). The reaction mixture was then heated for one night until reaction is complete, cooled, quenched with water (150 mL) and extracted into methylene chloride (200 mL). Combined organic layer was dried over Na2SO4 and concentrated to give a crude residue that was purified by flash chromatography (silica, eluting solvent: petroleum ether) to give 2.1 g of 5-chloro-benzo[b]thiophene (limpid oil) (Yield=32%).

1. temperaturewas heated
2. temperatureto reflux
3. temperatureThe reaction mixture was then heated for one night until reaction
4. temperaturecooled
5. customquenched with water (150 mL)
6. extractionextracted into methylene chloride (200 mL)
7. dry with materialCombined organic layer was dried over Na2SO4
8. concentrationconcentrated
9. customto give a crude residue that
10. customwas purified by flash chromatography (silica, eluting solvent: petroleum ether)