反应详情

A five neck five liter round bottom flask equipped with a mechanical stirrer, two condensers, and a dropping funnel was purged with nitrogen then charged under a nitrogen blanket with 1.1 kg (10.0 moles) hydroquinone, 350 grams deionized water, and 272.0 grams (1.0 moles) 1,8-dibromooctane. The reaction mass becomes a stirable slurry as it was slowly heated to reflux under a slow nitrogen purge. A solution of 184 grams (2.7 moles) 85 percent KOH pellets in 184 grams water was added dropwise under a nitrogen blanket over a period of 75 minutes. After about one third of the KOH had been added, the slurry had converted to a tea colored solution; then, after most of the KOH had been added, a white material precipitates in increasing amounts as the refluxing was continued an additional 90 minutes. The reaction mixture was quenched with one liter of water then poured into 4 liters of water. The water slurry was acidified with 30 percent sulfuric acid and filtered under reduced pressure. The filter cake was slurried in warm (50°-70° C.) water, filtered again and washed with several portions of boiling water. It was then dried in a vacuum oven at 120° C. and 310 grams of crude white product was recovered. The product was treated with 8 liters of boiling ethanol and filtered to remove oligomers. The filtrate yields a total of 134 grams (41 percent Yield based on the dibromide) of white, shiny, "mica-like" crystals more than 95 percent pure by HPLC peak area and GPC analysis. A final crystallization from 1.1 liters boiling ethanol gives product more than 99 percent pure by HPLC peak area (m.p. 151°-153.5° C.) for use in preparation of the copolymer epoxy resin, examples 12, 14, 15, 23 and 24. The ultraviolet absorption spectrum in 30/70 (by volume) methanol/dimethylformamide (DMF) showed a maximum absorption at 297 nm and in 30/70 (by volume) 1.0N KOH in methanol/DMF at 315 nm.

1. customA five neck five liter round bottom flask equipped with a mechanical stirrer
2. customtwo condensers, and a dropping funnel was purged with nitrogen
3. temperaturewas slowly heated
4. temperatureto reflux under a slow nitrogen
5. custompurge
6. customa white material precipitates
7. temperaturein increasing amounts as the refluxing
8. customThe reaction mixture was quenched with one liter of water
9. additionthen poured into 4 liters of water
10. filtrationfiltered under reduced pressure
11. temperaturein warm (50°-70° C.) water
12. filtrationfiltered again
13. washwashed with several portions of boiling water
14. customIt was then dried in a vacuum oven at 120° C.
15. custom310 grams of crude white product was recovered
16. additionThe product was treated with 8 liters of boiling ethanol
17. filtrationfiltered
18. customto remove oligomers
19. customThe filtrate yields a total of 134 grams (41 percent
20. customYield
21. customA final crystallization from 1.1 liters