反应详情

A mixture of (4-phenylbutyl)phosphonic acid, diethyl ester (0.97 g., 3.6 mmole), dry benzene (10 ml.), and phosphorus pentachloride (0.75 g., 3.6 mmole) is refluxed under argon for 20 minutes. The phosphorus oxychloride and benzene are removed in vacuo, and the residue is taken up in dry tetrahydrofuran (10 ml.) and treated with N-(L-alanyl)-N-methylglycine, ethyl ester, hydrochloride (0.67 g., 3.0 mmole). The resulting suspension is cooled to 0° (ice-bath) and treated dropwise with triethylamine (1.2 ml., 3.0 eq.) in tetrahydrofuran (5 ml.) over a period of 2 minutes in an argon atmosphere. After stirring at 0° for 20 minutes the ice bath is removed and the reaction mixture is stirred for an additional 4 hours. The reaction mixture is then diluted with ethyl acetate and washed successively with 5% potassium bisulfate, saturated sodium bicarbonate, brine, dried (MgSO4), and evaporated. The residue (1.4 g.) is chromatographed on silica gel (60 g.) eluting with toluene/acetone (1:1) to give 1.0 g. of N-[N-[ethoxy(4-phenylbutyl)phosphinyl]-L-alanyl]-N-methylglycine, ethyl ester as an oil after evaporation. Tlc (toluene/acetone; 1:1) shows a single spot at Rf =0.19.

1. temperatureis refluxed under argon for 20 minutes
2. customThe phosphorus oxychloride and benzene are removed in vacuo
3. temperatureThe resulting suspension is cooled to 0° (ice-bath)
4. customis removed
5. additionThe reaction mixture is then diluted with ethyl acetate
6. washwashed successively with 5% potassium bisulfate, saturated sodium bicarbonate, brine
7. dry with materialdried (MgSO4)
8. customevaporated
9. customThe residue (1.4 g.) is chromatographed on silica gel (60 g.)
10. washeluting with toluene/acetone (1:1)
11. customto give 1.0 g
12. customof N-[N-[ethoxy(4-phenylbutyl)phosphinyl]-L-alanyl]-N-methylglycine, ethyl ester as an oil after evaporation