反应详情

温度

25 °C

A stirred solution of 3-methoxy-4-[3-o-tolyl-ureido]phenylacetic acid (0.282 g, prepared as described in Example 52B of International Patent Application Publication No. WO 96/22966) in anhydrous tetrahydrofuran (5 ml), under an atmosphere of argon and at 25° C., was treated with powdered molecular sieves 4 Å (0.5 g), 7-(2-ethoxycarbonyl-ethyl)-1,2,3,4-tetrahydro-quinoxaline-1-carboxylic acid tert-butyl ester (0.2 g, Reference Example 3), triethylamine (0,336 ml), O-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (0.273 g) and 4-dimethylaminopyridine (7 mg). After stirring at 25° C. for 3 hours the reaction mixture was filtered through a pad of celite and the filter pad was washed three times with ethyl acetate (10 ml). The combined filtrate and washings were washed twice with an aqueous saturated solution of ammonium chloride (20 ml), then with water (20 ml), then dried over magnesium sulphate and then evaporated under reduced pressure (2.7 kPa) at 40° C. The resulting white foamy solid (0.483 g) was subjected to flash chromatography on silica (0,040-0,063 mm) eluting with a mixture of cyclohexane and ethyl acetate (1:1, v/v) to give the title compound (0.3 g) as a white foamy solid. 1H NMR, 400 Hz, (CD3)2SO: δ1.2 (t, 3H); 1.5 (s, 9H); 2.3 (s, 3H); 2.65 (t, 2H); 2.9 (t, 2H); 3.65 (t, 2H); 3.85 (m, 7H); 4.1 (q, 2H); 6.7 (very broad s, 2H); 7.2 (m, 2H); 7.5 (very broad s, 1H); 7.65 (broad s, 1H); 7.8 (d, J=8 Hz, 1H); 8.05 (broad d, J=8 Hz, 1H); 8.5 (s, 1H); 8.6 (broad s, 1H). MS (CI, NH3): MNH4+ 648, MH+ 631.

1. filtrationwas filtered through a pad of celite
2. washthe filter pad was washed three times with ethyl acetate (10 ml)
3. washThe combined filtrate and washings were washed twice with an aqueous saturated solution of ammonium chloride (20 ml)
4. dry with materialwith water (20 ml), then dried over magnesium sulphate
5. customevaporated under reduced pressure (2.7 kPa) at 40° C
6. washeluting with a mixture of cyclohexane and ethyl acetate (1:1, v/v)