反应详情

温度

30 °C

To a stirred mixture of 35 parts of ethyl 3-hydroxy-4,4-dimethoxy-1-piperidinecarboxylate and 144 parts of N,N-dimethylformamide were added portionwise 8.2 parts of sodium hydride dispersion 50%: exothermic reaction (temp. roses to 30° C.; cooling in a water-bath was necessary to keep the temperature below 30° C.). The whole was stirred for 1.50 hours at about 30° C. and then it is cooled to room temperature. 24.1 Parts of iodomethane were added dropwise (strong exothermic reaction) while the temperature was kept below 30° C. Upon completion, stirring was continued over week-end at room temperature. The reaction mixture was poured onto water and the product was extracted with 4-methyl-2-pentanone. The extract was washed with water, dried, filtered and evaporated, yielding 35.9 parts (95.7%) of ethyl 3,4,4-trimethoxy-1-piperidinecarboxylate as an oily residue (intermediate 64).

1. customexothermic reaction (temp
2. customto 30° C.
3. temperaturecooling in a water-bath
4. customthe temperature below 30° C.
5. temperatureit is cooled to room temperature
6. custom(strong exothermic reaction) while the temperature
7. customwas kept below 30° C
8. stirringUpon completion, stirring
9. waitwas continued over week-end at room temperature
10. additionThe reaction mixture was poured onto water
11. extractionthe product was extracted with 4-methyl-2-pentanone
12. washThe extract was washed with water
13. customdried
14. filtrationfiltered
15. customevaporated