反应详情

To a mixture of 4-hydroxy-2-methylbenzaldehyde (5.0 g, 37 mmol) and dimethylamine hydrochloride (12 g, 147 mmol) in DCM (200 mL), triethylamine (10 mL, 73 mmol) was added. Sodium triacetoxyborohydride (9.3 g, 44 mmol) was added in portions and the reaction mixture was stirred at rt over night. Water (20 mL) was added and the solution was concentrated by evaporation. THF (100 mL) and aqueous NaHCO3 (sat., 30 mL) was added and the two phases were separated. NaCl (3-4 g) was added to the aqueous phase and it was extracted twice with THF (50 mL). The combined solutions were evaporated. EtOAc (150 mL) was added to the residue and the two phases were separated. The organic phase was dried (Na2SO4) and evaporated to dryness. There was obtained 5.8 g (96%) of 20A as an oil. 1H NMR (600 MHz, DMSO-d6): δ 2.08 (s, 6H), 2.21 (s, 3H), 3.19 (s, 2H), 6.49 (d, 1H), 6.54 (s, 1H), 6.92 (d, 1H).

1. additionwas added
2. concentrationthe solution was concentrated by evaporation
3. additionTHF (100 mL) and aqueous NaHCO3 (sat., 30 mL) was added
4. customthe two phases were separated
5. additionNaCl (3-4 g) was added to the aqueous phase and it
6. extractionwas extracted twice with THF (50 mL)
7. customThe combined solutions were evaporated
8. additionEtOAc (150 mL) was added to the residue
9. customthe two phases were separated
10. dry with materialThe organic phase was dried (Na2SO4)
11. customevaporated to dryness