Ethyl bromopyruvate → Ethyl oxazole-4-carboxylate
反応式
C(OC(=O)C[C@H]([NH:20][C:21](N)=[O:22])CC1C=CC(C2C=CC=CC=2)=CC=1)C.Br[CH2:26][C:27](=O)[C:28]([O:30][CH2:31][CH3:32])=[O:29]>CCO>[CH2:31]([O:30][C:28]([C:27]1[N:20]=[CH:21][O:22][CH:26]=1)=[O:29])[CH3:32]参加物
4
実験手順
To a suspension of (R)-4-biphenyl-4-yl-3-ureido-butyric acid ethyl ester (169 mg, 0.518 mmol) in EtOH (5 ml) at ice bath is added ethyl bromopyruvate (0.098 ml, 0.777 mmol). The reaction is warmed up slowly to room temperature and stirred at reflux overnight. The reaction is concentrated and the residue is taken up in EtOAc and H2O. The combined organic layer is washed with brine and dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to give 2-(R)-1-biphenyl-4-ylmethyl-2-ethoxycarbonyl-ethylamino)-oxazole-4-carboxylic acid ethyl ester. HPLC retention time=1.42 minutes (condition B); MS (m+1)=423.