反应详情

Concentrated sulfuric acid (8.8 ml) was added over 5 min to a stirred mixture of 5-bromo-2,3 -dihydrobenzofuran-7-carboxylic acid (0.55 g, 2.3 mmol) in chloroform (27 ml) at 45° C. Sodium azide (0.737 g, 11.3 mmol) was then added portion-wise over 0.5 h and the temperature was maintained for a further 1 h after which time the mixture was poured onto ice (100 g) and extracted with chloroform (2×50 ml). The aqueous phase was basified to pH 12 with 40% sodium hydroxide solution and extracted with chloroform (2×50 ml). The extract was dried (Na2SO4), concentrated, and the residue purified by column chromatography over silica gel eluting with a gradient of acetone/toluene to give the title compound (D14) as a solid (63 mg, 13%), MH+ 214/216.

1. temperaturethe temperature was maintained for a further 1 h after which time the mixture
2. additionwas poured onto ice (100 g)
3. extractionextracted with chloroform (2×50 ml)
4. extractionextracted with chloroform (2×50 ml)
5. dry with materialThe extract was dried (Na2SO4)
6. concentrationconcentrated
7. customthe residue purified by column chromatography over silica gel eluting with a gradient of acetone/toluene