反应详情

2',3'-Dichloro-4'-methoxy-2-cyclopentyl-acetophenone (51.6 g., 0.18 mole) is dissolved in dioxane (460 ml.) and paraformaldehyde (21.6 g., 0.72 mole) and concentrated sulfuric acid (9.65 g.) are added. The mixture is heated at 80°-85°C. for 20 hours. The dioxane is evaporated at reduced pressure. Water is added to the residual gum which then is extracted into ether. The ether extract is washed with water and dried over magnesium sulfate. The ether is evaporated and upon triturating the residue with hexane (5 ml.) there is obtained a solid that is crystallized from ligroin to obtain (33.3 g.), m.p. 59°-63°C. Crystallization from butyl chloride affords a sample (m.p. 66°-67.5°C.) for analysis.

1. temperatureThe mixture is heated at 80°-85°C. for 20 hours
2. customThe dioxane is evaporated at reduced pressure
3. additionWater is added to the residual gum which
4. extractionthen is extracted into ether
5. extractionThe ether extract
6. washis washed with water
7. dry with materialdried over magnesium sulfate
8. customThe ether is evaporated
9. customupon triturating the residue with hexane (5 ml.) there
10. customis obtained a solid
11. customthat is crystallized from ligroin
12. customto obtain (33.3 g.), m.p. 59°-63°C
13. customCrystallization from butyl chloride
14. customaffords a sample (m.p. 66°-67.5°C.) for analysis