| 摘要 |
The present disclosure describes a novel, cost-effective process for preparation of a 4-oxo-1,2,3,6,7,11b-hexahydro-4H-pyrazino-[2,1-a]isoquinoline derivatives. Specifically, it discloses a process for the preparation of the anthelmintic drug praziquantel through the use of a novel intermediate, 2-[(2,2-dimethoxyethyl)benzyl amino]-N-phenethylacetamide. This present disclosure also describes a novel crystalline form of 4-oxo-1,2,3,6,7,11b-hexahydro-4H-pyrazino[2,1-a]isoquinoline. |
| 主权项 |
1. A process for the preparation of 2-[(2,2-dimethoxyethyl)amino]-N-(2-phenylethyl)acetamide, which comprises:
a) condensation of β-phenylethylamine with chloroacetyl chloride in the presence of a solvent and a base to obtain 2-chloro-N-phenethylacetamide; b) condensation of benzylamine with chloroacetaldehyde dimethylacetal in the presence of water and a base to obtain N-benzyl-2,2-dimethoxyethanamine; c) condensation of 2-chloro-N-phenethylacetamide prepared in step a) with N-benzyl-2,2-dimethoxyethanamine of formula VI prepared in step b) in the presence of water and a base to obtain 2-[(2,2-dimethoxyethyl)benzylamino]-N-phenethylacetamide; and d) reduction of 2-[(2,2-dimethoxyethyl)benzylamino]-N-phenethylacetamide using a reducing agent and a solvent in the presence of hydrogen to obtain 2-[(2,2-dimethoxyethyl)amino]-N-(2-phenylethyl)acetamide.
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