反应详情

5-(2-Formyl-3-hydroxyphenoxy)pentanoic acid (595 mg, 2.5 mM) was dissolved in dry dichloromethane (7.5 ml) under nitrogen with stirring and immersed in a cooling bath kept at -10° C. To this solution was added dropwise from a syringe triethylamine (0.35 ml, 2.5 mM). After 5 minutes was then similarly added ethyl chloroformate (0.25 ml, 2.5 mM). After 15 minutes was then similarly added diethylamine (0.26 ml, 2.5 mM). The reaction mixture was stirred at -10° C. (10 minutes) and then allowed to warm to 10°-15° C. After diluting with ether (50 ml) and water the aqueous layer was removed and the organic phase washed with dilute sodium bicarbonate solution and then quickly extracted with 2 N sodium hydroxide solution (1×25 ml). The layers were separated and the aqueous phase immediately acidified with dilute hydrochloric acid and extracted with ether/ethyl acetate. The combined extracts were washed with dilute sodium bicarbonate solution, water, dried (sodium sulphate) and evaporated. The oily residue was chromatographed on a short column of kieselgel G (40 g) eluting with chloroform-methanol (95:5) to give N,N-diethyl 5-(2-formyl-3-hydroxyphenoxy)pentanamide as a colourless oil, homogeneous by chromatography (chloroform:methanol, 95:5; Rf 0.35) and having NMR, IR and UV spectra consistent with the assigned structure.

1. customimmersed in a cooling bath
2. customkept at -10° C
3. waitAfter 15 minutes was
4. stirringThe reaction mixture was stirred at -10° C. (10 minutes)
5. temperatureto warm to 10°-15° C
6. customwas removed
7. washthe organic phase washed with dilute sodium bicarbonate solution
8. extractionquickly extracted with 2 N sodium hydroxide solution (1×25 ml)
9. customThe layers were separated
10. extractionextracted with ether/ethyl acetate
11. washThe combined extracts were washed with dilute sodium bicarbonate solution, water
12. dry with materialdried (sodium sulphate)
13. customevaporated
14. customThe oily residue was chromatographed on a short column of kieselgel G (40 g)
15. washeluting with chloroform-methanol (95:5)