The bromination of 4 benzyloxy-3-nitroacetophenone (I) with Br2 in CHCl3 gives 4-benzyloxy-3-nitro-alpha-bromoacetophenone (II), which is then condensed with N-benzyl-N-(1-methyl-2-(p-methoxyphenyl)ethyl]-amine (III) in butanone at 80 C yielding 4-benzyloxy-3-nitro-alpha-[N-benzyl-N-[1-methyl-2-(p-methoxyphenyl)ethyl]amino]acetophenone (IV). The reduction of the carbonyl group of (IV) with NaBH4 in ethanol affords the corresponding nitro alcohol (V), which is reduced again with Fe and HCl in ethanol - water to the amino alcohol (VI). The formylation of (VI) with formic acid in acetic anhydride gives 4-benzyloxy-3-formyl-amino-alpha-[N-benzyl-N-[1-methyl-2-(p-methoxyphenyl)ethyl]aminomethyl]benzyl alcohol (VII), which is finally debenzylated with H2 over Pd/C in ethanol and treated with fumaric acid (A).
By reduction of a mixture of 1-(3-formylamino-4-hydroxyphenyl)-2-aminoethanol (VIII) and 1-(4-methoxyphenyl)-2-propanone (IX) with H2 over Pt in ethanol, followed by a treatment with fumaric acid (A).