反应详情

A solution of 2,2-dimethyl-3-(2-thienyl)propanoic acid (11.2 g, 0.06 mole), diphenylphosphorylazide (16.7 g, 0.06 mole) (Aldrich Chemical Company), and triethylamine (6.14 g, 0.06 mole) in t-butanol (100 mL) was heated at reflux for 5 hrs. The solution was poured into water (300 mL) and the crude material extracted with ether. The combined extracts were washed with brine, dried (MgSO4) and evaporated to 11.9 g of an oil. This oil was added to a mixture of ethylene glycol (50 mL), H2O (20 drops) and KOH (10 g). The mixture was heated at reflux for 5 hr, cooled to 25°, diluted with H2O (300 mL) and acidified to pH 1 with conc HCl. Acid insoluble material was removed by washing with ether. The aqueous solution was then made basic with 50% NaOH solution and the product was extracted with ether. The ether extracts were combined, washed with brine, dried (MgSO4) and concentrated in vacuo to 6.9 g (74%) of product. The NMR spectrum is consistent with the structure of this intermediate compound.

1. temperatureat reflux for 5 hrs
2. extractionthe crude material extracted with ether
3. washThe combined extracts were washed with brine
4. dry with materialdried (MgSO4)
5. customevaporated to 11.9 g of an oil
6. additionThis oil was added to a mixture of ethylene glycol (50 mL), H2O (20 drops) and KOH (10 g)
7. temperatureThe mixture was heated
8. temperatureat reflux for 5 hr
9. temperaturecooled to 25°
10. additiondiluted with H2O (300 mL)
11. customAcid insoluble material was removed
12. washby washing with ether
13. extractionthe product was extracted with ether
14. washwashed with brine
15. dry with materialdried (MgSO4)
16. concentrationconcentrated in vacuo to 6.9 g (74%) of product