反应详情

154.7 g of 2,2,6,6-tetramethyl-4-piperidone, 160 g of piperidine and 10.0 g of p-toluenesulphonic acid monohydrate were dissolved in 200 ml of benzene. The solution was refluxed by heating for 8.5 hours, whilst the water formed in situ was removed by means of a Dean-Stark separator. The reaction mixture was then poured into a mixture of 700 ml of water, 200 ml of concentrated aqueous ammonia and 100 g of ice. The organic layer was separated, washed three times with water and then dried over magnesium sulphate. After removal of the solvent, the residue was distilled under reduced pressure, giving 46.6 g of 1,2,5,6-tetrahydro-2,2,6,6-tetramethyl-4-piperidinopyridine (bp 80° - 82° C/1 mmHg).

1. temperatureThe solution was refluxed
2. customformed in situ
3. customwas removed by means of a Dean-Stark separator
4. additionThe reaction mixture was then poured into a mixture of 700 ml of water, 200 ml of concentrated aqueous ammonia and 100 g of ice
5. customThe organic layer was separated
6. washwashed three times with water
7. dry with materialdried over magnesium sulphate
8. customAfter removal of the solvent
9. distillationthe residue was distilled under reduced pressure