Sodium Carbonate → N-[[1-[(2,3-dihydro-1,4-benzodioxin-2-yl)methyl]-4-piperidinyl]methyl]-5,6,7-trimethoxy-2-benzothiazolamine (E)-2-butenedioate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 2.8 parts of 2,3-dihydro-1,4-benzodioxin-2-methanol methanesulfonate (ester), 3.4 parts of 5,6,7-trimethoxy-N-(4-piperidinylmethyl)-2-benzothiazolamine, 3 parts of sodium carbonate and 67.5 parts of N,N-dimethylacetamide was stirred overnight at about 75° C. Water was added. The product was extracted with 4-methyl-2-pentanone. The extract was dried, filtered and evaporated. The residue was purified by column chromatography over silica gel using a mixture of trichloromethane and methanol (97:3 by volume) as eluent. The pure fractions were collected and the eluent was evaporated. The residue was converted into the (E)-2-butenedioate salt in ethanol and 2-propanone. The salt was filtered off and dried, yielding 3.2 parts (48.5%) of N-[[1-[(2,3-dihydro-1,4-benzodioxin-2-yl)methyl]-4-piperidinyl]methyl]-5,6,7-trimethoxy-2-benzothiazolamine (E)-2-butenedioate(2:3); mp. 171.6° C. (compound 26).

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