| 摘要 |
Novel N-(dialkylamino), N-(1-pyrrolidy), N-(1-piperidyl) or N-(4-morpholinoyl) derivatives of fumaramic acid or a C-alkyl fumaramic acid are prepared by the isomerization of a strong acid salt of the corresponding N-[disubstituted amino]-maleamic acid. The invention also includes the salts and esters of such substituted fumaramic acids, and the salts of the esters, The esters may be prepared by esterifying the appropriate N-substituted fumaramic acid with the selected alcohol, or directly from a maleamic acid or maleimide component by performing the isomerization in an alcoholic medium. The isomerization reaction is carried out in an inert medium, particularly glacial acetic acid or acetonitrile. Isomerization catalyst, e.g. hydrohalic acids, iodine and aluminium chloride may be employed. N-(dimethylamino)-fumaramic acid hydrochloride is prepared by reacting maleic anhydride, 1,1-dimethyl-hydrazine and anhydrous HCl (Example VII). |
