反应详情

A mixture of 4-hydroxy-3-methylbenzaldehyde (3.27 g, 24 mmol) and 1-methylpiperazine (2.7 g, 27.0 mmol) in dichloroethane (100 mL) was stirred at rt for 30 min. Sodium triacetoxyborohydride (6.2 g, 29 mmol) was added in portions and the reaction mixture was stirred at rt over night. A further portion of 1-methylpiperazine was added and stirring was continued for 24 h. Aqueous NaHCO3 (sat.) was added, the phases were separated and the aqueous phase was saturated with sodium chloride and extracted with DCM twice. The combined organic solutions were dried (MgSO4) and evaporated and the residue was purified by column chromatography on SiO2 using 0-20% MeOH in EtOAc:MeOH 95:5 as eluent. There was obtained 3.50 g (66%) of 9A as a solid. 1H NMR (500 MHz, CDCl3): δ 2.21 (2, 3H), 2.29 (s, 3H), 2.32-2.72 (bm, 8H), 3.42 (s, 2H), 6.55 (d, 1H), 6.90 (d, 1H), 7.02 (s, 1H).

1. stirringthe reaction mixture was stirred at rt over night
2. stirringstirring
3. waitwas continued for 24 h
4. customthe phases were separated
5. extractionextracted with DCM twice
6. dry with materialThe combined organic solutions were dried (MgSO4)
7. customevaporated
8. customthe residue was purified by column chromatography on SiO2 using 0-20% MeOH in EtOAc:MeOH 95:5 as eluent