反应详情

A mixture of 19 parts of 4-(phenylamino)-1-(phenylmethyl)-4-piperidinecarboxylic acid dihydrochloride, 14.4 parts of sulfuric acid and 64 parts of ethanol is stirred and refluxed for 16 hours. The solvent is decanted. The residue is dissolved in water. The aqueous solution is alkalized with ammonium hydroxide and extracted with a mixture of methylbenzene and 2,2'-oxybispropane. The combined organic layers are dried over magnesium sulfate, filtered and evaporated. The oily residue is dissolved in 200 parts of 2,2'-oxybispropane and gaseous hydrogen chloride is introduced into the solution. The precipitated hydrochloride is filtered off, washed with 2-propanol, filtered off again and dried, yielding 11.5 parts of ethyl 4-(phenylamino)-1-(phenylmethyl)-4-piperidinecarboxylate dihydrochloride; mp. 212°-214.4° C.

1. temperaturerefluxed for 16 hours
2. customThe solvent is decanted
3. dissolutionThe residue is dissolved in water
4. extractionextracted with a mixture of methylbenzene and 2,2'-oxybispropane
5. dry with materialThe combined organic layers are dried over magnesium sulfate
6. filtrationfiltered
7. customevaporated
8. dissolutionThe oily residue is dissolved in 200 parts of 2,2'-oxybispropane and gaseous hydrogen chloride
9. additionis introduced into the solution
10. filtrationThe precipitated hydrochloride is filtered off
11. washwashed with 2-propanol
12. filtrationfiltered off again
13. customdried