反应详情

Into a round bottom flask was placed XVI (2.0 g), and formaldehyde (37% w/v in water, 20 mL) and formic acid (95-97% w/v, 45 mL), both a 0° C., were added. The mixture then was refluxed under nitrogen for 8 hr. The cooled reaction mixture was basified with aqueous sodium hydroxide (50% w/v) to pH 8-9, and the solution extracted with chloroform (5×25 mL). The combined organic liquors were dried over anhydrous sodium sulfate, filtered and evaporated; and the resulting oil distilled under reduced pressure to afford XVII as a clear odorless oil (b.p. 107° C. at 3 mm Hg, 92% yield).

1. customInto a round bottom flask was placed
2. temperatureThe mixture then was refluxed under nitrogen for 8 hr
3. customThe cooled reaction mixture
4. extractionthe solution extracted with chloroform (5×25 mL)
5. dry with materialThe combined organic liquors were dried over anhydrous sodium sulfate
6. filtrationfiltered
7. customevaporated
8. distillationand the resulting oil distilled under reduced pressure