反应详情

温度

40 °C

95% Sodium hydride (40.85 g, 1.6 moles) was placed into a 3 L flask under argon and THF (1.2 L) at −10° C. was added. Dry tetraethylene glycol (500.0 g, 2.57 moles) was added slowly. The pot temperature was maintained below 15° C. during the addition. Once the NaH had reacted, a homogeneous solution resulted. 18C6 (3.9 g) and dimethyl-acetamide (DMAC, 500 mL) was added. Chloroisodurene (TMB-Cl, 98.6 g, 0.58 mole) dissolved in THF (500 mL) was added to pot over about 4 h. The reaction mixture was stirred for about 17 h at about 40° C. under argon. The reaction was monitored by tlc on silica gel plates, eluting with 10% MeOH/CH2Cl2 vs TMB-Cl. The reaction was complete; the TMB-Cl was consumed. The solvent was removed in vacuo; the resulting oil was extracted with CH2Cl2 (700 mL) and water (300 mL). The CH2Cl2 layer was separated, dried over MgSO4, filtered through fluted filter paper and concentrated in vacuo to leave an oil. A column was prepared with 600 g of silica gel and hexane as needed. The crude product was placed onto column with hexane and a minimum of t-butylmethyl ether (TBME, 100 mL) to make a clean transfer. The column was eluted with hexane (4 L) and then as follows: (2 L) 10% TBME/hexane; (2 L) 20% TBME/hexane; (4 L) TBME/hexane; (3 L) 40% TBME/hexane, and (2 L) TBME. Like fractions containing product were combined and concentrated in vacuo to give 140.2 g (73%). The product was characterized by nmr. 1H NMR[400 MHz, DMSO(d6)] □6.81 (s, 2H), 4.56 (t, 1H), 4.45 (s, 2H), 3.57-3.45 (m, 14H), 3.41 (t, 2H), 2.28 (s, 6H), 2.22 (s, 3H).

1. temperatureThe pot temperature was maintained below 15° C. during the addition
2. customa homogeneous solution resulted
3. additionwas added to pot over about 4 h
4. washeluting with 10% MeOH/CH2Cl2 vs TMB-Cl
5. customthe TMB-Cl was consumed
6. customThe solvent was removed in vacuo
7. extractionthe resulting oil was extracted with CH2Cl2 (700 mL) and water (300 mL)
8. customThe CH2Cl2 layer was separated
9. dry with materialdried over MgSO4
10. filtrationfiltered
11. filtrationthrough fluted filter paper
12. concentrationconcentrated in vacuo
13. customto leave an oil
14. washThe column was eluted with hexane (4 L)
15. additionLike fractions containing product
16. concentrationconcentrated in vacuo
17. customto give 140.2 g (73%)