反应详情

To a solution of 180 g of paraformaldehyde in methanol (500 ml) were slowly added under ice-cooling 230 ml of a 40% solution of methylamine in methanol and 17 ml of acetic acid. After adding dropwise a solution of 250 ml of 3,5-dimethylcyclohexanone in methanol (1 l) thereinto, the resulting mixture was heated under reflux for 5 hours. Then the reaction mixture was cooled to room temperature and the solvent was distilled off under reduced pressure. The residue was acidified by adding dilute hydrochloric acid and then extracted with ethyl acetate. The aqueous layer was made basic by adding sodium hydroxide and then extracted with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate and the solvent was distilled off under reduced pressure. Then the residue was distilled under reduced pressure (100-110° C./1 mmHg) to thereby give 79 g of crude (6R*,8R*)-3,6,8-trimethyl-3-azabicyclo[3.3.1]nonan-9-one as a pale yellow oily substance.

1. temperaturethe resulting mixture was heated
2. temperatureunder reflux for 5 hours
3. distillationthe solvent was distilled off under reduced pressure
4. additionby adding dilute hydrochloric acid
5. extractionextracted with ethyl acetate
6. additionby adding sodium hydroxide
7. extractionextracted with ethyl acetate
8. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
9. distillationthe solvent was distilled off under reduced pressure
10. distillationThen the residue was distilled under reduced pressure (100-110° C./1 mmHg)