C([O:3][C:4](=O)[CH:5]([NH:7][C:8]([NH:10][C:11]1[CH:16]=[CH:15][CH:14]=[C:13]([CH2:17][C:18]2[C:27]3[CH2:26][CH2:25][CH2:24][CH2:23][C:22]=3[C:21](=[O:28])[NH:20][N:19]=2)[CH:12]=1)=[O:9])[CH3:6])C.[OH-].[Na+]>CC(N(C)C)=O>[CH3:6][CH:5]1[NH:7][C:8](=[O:9])[N:10]([C:11]2[CH:16]=[CH:15][CH:14]=[C:13]([CH2:17][C:18]3[C:27]4[CH2:26][CH2:25][CH2:24][CH2:23][C:22]=4[C:21](=[O:28])[NH:20][N:19]=3)[CH:12]=2)[C:4]1=[O:3]To a solution of 2-{3-[3-(4-oxo-3,4,5,6,7,8-hexahydro-phthalazin-1-ylmethyl)-phenyl]-ureido}-propionic acid ethyl ester (5) (0.715 g, 1.80 mmol) in dry DMA (2 ml) was added finely powdered sodium hydroxide (71 mg, 1.80 mmol). The reaction mixture was then immersed in a preheated oil bath at 50° C. and heated for 10 minutes before being quenched by addition of HCl (1N, 0.5 ml). The reaction mixture was then concentrated to dryness in vacuo. The crude oil was subjected to flash chromatography eluent 4:1, hexane:ethyl acetate (Rf=0.18, neat ethyl acetate). Main peak in LC-MS, (0.25 g, 95% purity); 1H NMR (300 MHz, D6 DMSδ ppm 12.61 (s, 1H), 8.41 (s, 1H), 7.40 (dd, J=11.46, 4.58 Hz, 1H), 7.29-7.12 (m, 2H), 4.32-4.15 (m, 1H), 3.94 (s, 2H), 2.46 (m, 4H), 1.61 (s, 4H), 1.34 (d, J=6.94 Hz, 3H). M/z (LC-MS, ESP), RT=3.04 mins (M+H 353.2).
Wird geladen…