Cl.[N+:2]([C:5]1[CH:6]=[C:7]2[C:11](=[CH:12][CH:13]=1)[CH2:10][CH:9](N)[CH2:8]2)([O-:4])=[O:3].C=O.[C:17]([BH3-])#[N:18].[Na+].[CH3:21]C(O)=O>ClCCCl>[CH3:21][N:18]([CH3:17])[CH:9]1[CH2:8][C:7]2[C:11](=[CH:12][CH:13]=[C:5]([N+:2]([O-:4])=[O:3])[CH:6]=2)[CH2:10]1(5-Nitro-2,3-dihydro-1H-inden-2-yl)amine hydrochloride (5.52 g, 26 mmol), paraformaldehyde (4.1 g, 128 mmol), sodium cyanoborohydride (8.1 g, 128 mmol), and HOAc (7.4 mL, 128 mmol) were combined in DCE (200 mL) and the suspension was heated to reflux for 15 h. The reaction was cooled and quenched with saturated aqueous NaHCO3. The organic layer was separated, washed with brine and dried with MgSO4 and concentrated to an oil. The crude material was purified by silica gel flash column chromatography (0-100% (90% DCM/9% MeOH/1% NH4OH)/DCM) to yield 2.7 g (52%) of a yellow oil that crystallized while stored on the bench top. 1H NMR (400 MHz, CDCl3) δ 8.07 (m, 2H), 7.36 (d, J=8.1 Hz, 1H), 4.13 (m, 1H), 3.34 (m, 4H), 2.74 (s, 6H).
読み込み中…
