1-(2-Methoxyphenyl)piperazine → isoquinolin-N-oxide

Reaction equation

COC1C=C(C=CC=1OC)C[C:7]1[C:16]2[C:11](=[CH:12][C:13](OC)=[C:14](OC)[CH:15]=2)[CH:10]=[CH:9][N+:8]=1[O-:21].CN(C)C=O.COC1C=CC=CC=1N1CCNCC1>C(N(CC)CC)C>[CH:7]1[C:16]2[C:11](=[CH:12][CH:13]=[CH:14][CH:15]=2)[CH:10]=[CH:9][N+:8]=1[O-:21]

Participants

Procedure

A mixture of 2.5g 4-chloromethyl-1-(3,4-dimethoxybenzyl-6,7-dimethoxyisoquinoline 2-oxide, 35 ml dimethylformamide, 1.8 triethylamine and 1.29 g 1-(2-methoxyphenyl)piperazine was stirred and heated under nitrogen at 50° for 7 hours. After evaporation of the solvent, the residue was partitioned between methylene chloride and water. The methylene chloride solution was washed with water and dried. After removal of the solvent in vacuo, the residue (3.5 g) was crystallized from methylene chloride/ethyl acetate to yield 3.05 g of yellow, hygroscopic crystals of 1-(3,4)-dimethoxybenzyl)-6,7-dimethoxy-4-{]4'-(2-methoxyphenyl)-1'-piperazinyl]methyl} isoquinoline 2-oxide, mp 128°-129° (dec.).