(Z)-2-Chlorofumaric acid 1-[3-[6,7-dimethoxy-2(S)-methyl-1(R)-(3,4,5-trimethoxybenzyl)-1,2,3,4-tetrahydroisoquinolinium-2-yl]propyl] 4-[3-[6,7-dimethoxy-2(R)-methyl-1(S)-(3,4,5-trimethoxyphenyl)-1,2,3,4-tetrahydroisoquinolinium-2-yl]propyl] diester dichl