Ethylparaben → ethyl 4-[2-[1-(phenylmethyl)-4-piperidinyl]ethoxy]benzoate (Z)-2-butenedioate

Participants

Reaction Steps

To a stirred and cooled (-10° C.) mixture of 19.6 parts of triphenyl phosphine and 54 parts of tetrahydrofuran were added portionwise 13.7 parts of diethyl diazenedicarboxylate (exothermic reaction). Upon completion, stirring was continued for 15 minutes and then a solution of 16.5 parts of 1-(phenylmethyl)-4-piperidineethanol and 12.5 parts of ethyl 4-hydroxybenzoate in 54 parts of tetrahydrofuran was added dropwise at a temperature between 0° and -5° C. After complete addition, the whole was stirred overnight at room temperature and then evaporated. Water was added to the residue and the product was extracted with dichloromethane. The extract was dried, filtered and evaporated. The residue was dissolved in 2,2'-oxybispropane and allowed to crystallize. The precipitate was filtered off and the filtrate was evaporated. The residue was converted into the (Z)-2-butenedioate salt in 280 parts of 2-propanol. The salt was filtered off and dried, yielding 15 parts (42%) of ethyl 4-[2-[ 1-(phenylmethyl)-4-piperidinyl]ethoxy]benzoate (Z)-2-butenedioate(1:1); mp. 142.0° C. (int. 50).

Provenance & Evidence