反应详情

A solution of 1,3-benzodioxole-4-carbaldehyde (96 mg, 0.64 mmol) in ethanol (2 mL) and acetic acid (0.2 mL) at room temperature was treated with tert-butyl-1-piperazine carboxylate (2.5 eq, 1.60 mmol, 297 mg) and stirred for 5 minutes. Sodium cyanoborohydride (0.95 eq, 0.60 mmol, 38 mg) was added portionwise and the reaction then stirred for 16 h. Concentration in vacuo and preparative tlc purification (CH2Cl2-MeOH, 95:5) gave the product (131 mg, 62%) as a colourless oil; δH (500 MHz, CDCl3) 1.47 and 1.48 (2 s, 9H, C(CH3)3), 1.99 (s, br, 1H, piperazine NCHAHA), 2.44 (t, J=4.7 Hz, 2H, piperazine NCH2), 2.54-2.63 (m, 1H, piperazine NCHAHA), 3.45 (t, J=4.9 Hz, 4H, piperazine N(CH2)2), 3.55 (s, 1H, NCHAHA), 4.70 (s, 1H, NCHAHA), 5.97 (s, 1H, OCHAHB), 5.99 (s, 1H, OCHAHB), 6.75-6.96 (m, 3H, phenyl H-4, H-5, H-6);

1. customthe reaction
2. stirringthen stirred for 16 h
3. concentrationConcentration
4. customin vacuo and preparative tlc purification (CH2Cl2-MeOH, 95:5)