C([N-]C(C)C)(C)C.[Li+].C([Li])CCC.C(NC(C)C)(C)C.[CH3:21][O:22][C:23]1[CH:30]=[C:29]([O:31][CH3:32])[CH:28]=[CH:27][C:24]=1[CH:25]=[O:26].[CH3:33][N:34]([CH3:37])[CH:35]=[S:36]>CCCCCC.C1COCC1>[CH3:33][N:34]([CH3:37])[C:35](=[S:36])[CH:25]([C:24]1[CH:27]=[CH:28][C:29]([O:31][CH3:32])=[CH:30][C:23]=1[O:22][CH3:21])[OH:26]A 110 mL THF solution of lithium diisopropylamide (LDA) ( 80 mmol) was generated from a 1.6 M hexane solution of n-butyllithium (50 mL, 80 mmol) and diisopropylamine ( 11.2 mL, 80 mmol) at -10° C., then cooled to -78° C. A 50 mL solution of 2,4-dimethoxybenzaldehyde (12 g, 72 mmol) and N,N-dimethylthioformamide (6.8 mL, 80 mmol) was cooled to 0° C. and added to the -78° C. LDA solution at a rate keeping the temperature less than -70° C. The reaction mixture was stirred at -75° C. for 2.5 hours, allowed to warm to 0° C., quenched with saturated aqueous NH4Cl, and extracted with EtOAc three times. The EtOAc extracts were combined, washed with brine, dried (Na2SO4), concentrated, triturated with Et2O/ pet. ether, filtered, and dried in vacuo to give 8.4 g(46% yield) of product: mp 139-140° C.; 1H NMR (CDCl3) d 3.05 (s, 3H, NCH3), 3.50 (s, 3H, NCH3), 3.80 (s, 3H, OCH3), 3.89 (s, 3H, OCH3), 5.19-5.21 (d, 1H, J=7 Hz, OH), 5.72-5.74 (d, 1H, J=7 Hz, CH), 6.43-6.47 (m, 2H, ArH), 7.24(s, 1H, ArH); MS(FD) 255(M+). Anal. Calcd for C12H17NO3S: C, 56.45; H, 6.71; N, 5.49. Found: C, 56.64; H, 6.49; N, 5.59.
読み込み中…
