反应详情

温度

110 °C

A flask was charged with 3.75 g of 2,2,6,6-tetramethyl-1-(2′,4′,6′-tri-isopropylbiphenyl-2-yl)phosphinan-4-one (8.32 mmol, 1.0 equiv) and 0.16 g of p-toluenesulfonic acid monohydrate (0.84 mmol, 0.1 equiv). The atmosphere was purged with nitrogen and the flask was charged with 80 mL of nitrogen-sparged toluene. To this solution was added 4.6 mL of ethylene glycol (83 mmol, 10 equiv). The reaction flask was equipped with a Dean-Stark trap and warmed to an internal temperature of 110° C. for 2 h under nitrogen atmosphere. The distilled toluene was collected in the Dean-Stark trap. The reaction mixture was cooled to room temperature under nitrogen gas. The reaction was quenched with 1.6 mL of aqueous 10 wt % sodium carbonate solution and partitioned between 65 mL of heptane and 35 mL of water. The organic solution was washed twice with 20 mL portions of water, concentrated in vacuo with gentle heating and the residue was chased once with heptane. The concentrate was dissolved in 35 g of methanol. Seed crystals were added to induce crystallization, the solvent was removed in vacuo and 16 mL of methanol was added to the crystalline solid. The mixture was stirred overnight at room temperature and the crystalline product was isolated by filtration, washed with methanol and dried in vacuo at 50° C. to give 3.5 g of 7,7,9,9-tetramethyl-8-(2′,4′,6′-triisopropylbiphenyl-2-yl)-1,4-dioxa-8-phosphaspiro[4.5]decane (96 area % by HPLC, 82% yield).

1. customThe atmosphere was purged with nitrogen
2. additionthe flask was charged with 80 mL of nitrogen-
3. customsparged toluene
4. customThe reaction flask was equipped with a Dean-Stark trap
5. distillationThe distilled toluene was collected in the Dean-Stark trap
6. temperatureThe reaction mixture was cooled to room temperature under nitrogen gas
7. customThe reaction was quenched with 1.6 mL of aqueous 10 wt % sodium carbonate solution
8. custompartitioned between 65 mL of heptane and 35 mL of water
9. washThe organic solution was washed twice with 20 mL portions of water
10. concentrationconcentrated in vacuo
11. temperaturewith gentle heating
12. dissolutionThe concentrate was dissolved in 35 g of methanol
13. additionSeed crystals were added
14. customcrystallization
15. customthe solvent was removed in vacuo and 16 mL of methanol
16. additionwas added to the crystalline solid
17. customthe crystalline product was isolated by filtration
18. washwashed with methanol
19. customdried in vacuo at 50° C.