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Cisatracurium is one of the isomers of the atracurium besylate, which is a new generation neuromuscular blocking agent. As demonstrated, the effect of the cisatracurium is three times as atracurium besylate, and it is also used as the good muscle relaxant for the general anesthesia.1R-cis-2,2’-(3,11-dioxo-4,10-dioxa-1,13-tridecame-thylene)-2-methyl-bis[6-dimethoxy-l-(3,4-dimethoxybenzyl)-1,2,3,4-tetrahydro-isoquinolinum]benzenesulfon ate(mono-benzenesulfonate salt of cisatracurim) is an important intermediate to the systhesis of the cisatracurium besylate.Based on the chemical structure of target intermediates, we utilized retrosynthetic analysis to design several synthetic routes, and carefully analyized the routes to explore a promising and convenient route. Finally, R-tetrohydronaceine N-acetyl-L-leucinate was employed as the starting material. The validation and optimization of this route was investigated in detail.The dissertation focused on the synthesis of the intermediates. The first intermed iate, cis-(R)-1-[(3,4-dimethoxyphenyl)methyl]-1,2,3,4-tetrahydro-2-[3-[(5-hydroxypentyl)o xy]-3-oxopropyl]-6,7-dimethoxy-2-methyl-isoquinolinium besylate, was obtained via six steps (dissociation, Michael reaction, Mannich reaction, hydrolysis, purification, ester ification) with an overall yield of 49%; The second intermediate, 1-[(3,4-dimethoxyp henyl)methyl]-3,4-dihydro-6,7-dimethyoxy-2(1H)-isoquinolinepropanoic acid, was obtain ed via other two steps (Michael reaction, hydrolysis) with an overall yield of 75%. And the final product of mono-benzenesulfonate salt of cisatracurim, 1R-cis-2,2’-(3,11-Dioxo-4,10-dioxa-1,13-tridecame-thylene)-2-methyl-bis[6-dimethoxy-1-(3,4-dimethoxybe nzyl)-1,2,3,4-tetrahydro-isoquinolinum]benzenesulfonate, was esterified with the two in termediates. And the resulting total yield is 36.5%after the purification by the HPL C. The investigation shows that it can be obtained with some more cis-structure of production, which has important significance in the industrialized production.
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