반응 #5632
ord-b21f5d35f68c4e3ead3485ab0ba70fbb
반응 조건
후처리
- 1기타A five neck five liter round bottom flask equipped with a mechanical stirrer
- 2기타two condensers, and a dropping funnel is purged with nitrogen
- 3온도is slowly heated
- 4온도to reflux under a slow nitrogen
- 5기타purge
- 6기타a white material precipitates
- 7온도in increasing amounts as the refluxing
- 8기타The reaction mixture is quenched with one liter of water
- 9workup.ADDITIONthen poured into 4 liters of water
- 10여과filtered under reduced pressure
- 11온도in warm (50°-70° C.) water
- 12여과filtered again
- 13세척washed with several portions of boiling water
- 14기타It is then dried in a vacuum oven at 120° C.
- 15기타310 grams of crude white product is recovered
- 16workup.ADDITIONThe product is treated with 8 liters of boiling ethanol
- 17여과filtered
- 18기타to remove oligomers
- 19기타The filtrate yields a total of 134 grams (41% Yield
- 20기타A final crystallization form 1.1 liters
실험 절차
A five neck five liter round bottom flask equipped with a mechanical stirrer, two condensers, and a dropping funnel is 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 is slowly heated to reflux under a slow nitrogen purge. A solution of 184 grams (2.7 moles) 85% KOH pellets in 184 grams water is added dropwise under a nitrogen blanket over a period of 75 minutes. After about one third of the KOH has been added, the slurry has converted to a tea colored solution; then, after most of the KOH has been added, a white material precipitates in increasing amounts as the refluxing is continued an additional 90 minutes. The reaction mixture is quenched with one liter of water then poured into 4 liters of water. The water slurry is acidified with 30% sulfuric acid and filtered under reduced pressure. The filter cake is slurried in warm (50°-70° C.) water, filtered again and washed with several portions of boiling water. It is then dried in a vacuum oven at 120° C. and 310 grams of crude white product is recovered. The product is treated with 8 liters of boiling ethanol and filtered to remove oligomers. The filtrate yields a total of 134 grams (41% Yield based on the dibromide) of white, shiny, "mica-like" crystals more than 95% pure by HPLC peak area nd GPC analysis. A final crystallization form 1.1 liters boiling ethanol gives product more than 99% 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 is 30/70 (by volume) methanol/dimethylformamide (DMF) shows a maximum absorption at 297 nm and in 30/70 (by volume) 1.0N KOH in methanol/DMF at 315 nm.