Preparation method of pramipexole hydrochloride

Abstract

The invention discloses a preparation method of pramipexole hydrochloride. The method comprises the following steps: protecting an amino group of aminocyclohexanol by means of condensation of propionyl chloride to obtain p-propionyl cyclohexanol; then, carrying out catalytic oxidation to obtain p-propionyl cyclohexanone; carrying out oxidative bromination and Hantzsch condensation to obtain 2-amino-6-propionylamino-4, 5, 6, 7-tetrahydrobenzothiazole; then, reducing by using diisobutylaluminum hydride to obtain 2-amino-6-propylamino-4, 5, 6, 7-tetrahydrobenzothiazole; finally, carrying out L-(+)-tartaric acid separation and salification to obtain the pramipexole hydrochloride. The preparation method, provided by the invention, of pramipexole hydrochloride is low in price of raw materials, easy in obtaining of the raw materials, convenient and simple to operate, novel in route, environmentally-friendly and high in yield; the prepared pramipexole hydrochloride is good in purity.

Description

technical field [0001] The invention relates to the technical field of pharmaceutical preparations, in particular to a preparation method of pramipexole hydrochloride. Background technique [0002] Pramipexole hydrochloride is a new generation non-ergot alkaloid dopamine D2 receptor agonist, chemical name (S)-2-amino-4,5,6,7-tetrahydro-6-propylaminobenzothiazole dihydrochloride Salt-hydrate, which was approved by the US FDA in 1997, is currently the first-line drug for the treatment of Parkinson's disease. In 2007, it was launched in my country under the trade name "Senfulo". Global sales exceeded 1 billion US dollars that year, and the patent period has expired, and major domestic pharmaceutical companies are competing to imitate it. Therefore, the green, environmentally friendly, simple, practical, cheap and easy-to-control process has broad market prospects. [0003] The synthetic technique about pramipexole hydrochloride mainly includes following several at present. [...

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Problems solved by technology

[0015] This route seems to be a very perfect route. Its materials are cheap and easy to obtain, and the reaction yield is high. However, this route has been repeated many times, and the reports in the literature have not been repeated. It may be related to the stability of the substrate.

[0016] Known by above-mentioned total number, at present about the synthetic route of pramipexole hydrochloride or because of using the big metal oxidizing agent of environmental pollution, or have used the reduction reagent that exists toxicity big and explosive danger, or because route is long, yield is low, or because route Difficulty in achieving repetition and other reasons lead to difficulties in the industrial production of pramipexole hydrochloride, so the development of cheap and easy-to-get raw materials, green environmental protection, high yield, and good purity of pramipexole hydrochloride synthesis process route has broad prospects

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