N-ethyl pyridine methylamine hydrochloride crystal, preparation process thereof and application of N-ethyl pyridine methylamine hydrochloride crystal in preparation of tropicamide

Abstract

The invention discloses an N-ethyl pyridine methylamine hydrochloride crystal, a preparation process thereof and an application of the N-ethyl pyridine methylamine hydrochloride crystal in preparationof tropicamide. N-ethyl pyridine methylamine hydrochloride prepared from free-state N-ethyl pyridine methylamine and hydrochloric acid is diffracted by using X-ray powder, and the crystal has diffraction peaks at about 9.73 degrees, 14.61 degrees, 17.98 degrees, 18.49 degrees, 20.36 degrees, 24.63 degrees and 27.21 degrees. The preparation method comprises the following steps: dissolving N-ethylpyridine methylamine in an organic solvent, and stirring the materials at room temperature or under heating until the materials are completely dissolved, slowly adding hydrochloric acid into the solution to crystallize, and carrying out heat preservation aging, filtering and drying to obtain the tropicamide key starting material N-ethylpyridine methylamine hydrochloride crystal. The method is simple to operate and obvious in purification effect, and the salt form and crystal form prepared by crystallization are low in impurity content, purity is high, and the process is simple and convenient tooperate and beneficial to industrial production.

Description

technical field [0001] The invention relates to a hydrochloride crystal of a key starting material of tropicamide and a preparation process thereof, belonging to the technical field of medicine preparation. Background technique [0002] Tropicamide is an anticholinergic drug and a parasympathetic nerve inhibitor. In the field of ophthalmology, it is the preferred mydriatic drug for fundus examination and diagnosis, and it also has the effect of ciliary muscle anesthesia. [0003] It was first synthesized by Roche Company in 1955. In addition to being used alone, it is mostly used as a compound agent in clinics. Compared with other mydriatics, tropicamide has many advantages such as rapid mydriasis and short recovery period. [0004] Physicochemical properties of tropic amide: white crystal in powder form, bitter in taste, soluble in ethanol, chloroform and acetone, slightly soluble in water, insoluble in petroleum ether. [0005] At present, the earliest disclosed syntheti...

AI Technical Summary

Problems solved by technology

Under the trend that the current national policy has stricter and stricter requirements on raw materials, it is difficult for such low-purity N-ethylpicolylamine to meet the market demand

[0015] The oily N-ethylpicolinylamine has a high viscosity, which makes it difficult to transfer, pack, store, and transport. Moreover, the unpleasant smell that volatile organic amines emit is also extremely unfriendly to the workers in the workshop. In addition, the volatilized amines can easily form smoky urea derivative solids with carbon dioxide in the air, which can easily block the pipeline and cause unnecessary accidents when there is airflow while polluting the product. Purity, low cost, N-ethylpicolylamine that is solidified and easy to operate is very meaningful and necessary;

[0016] The commonly used purification method is crystallization, but N-ethylpicolylamine has a very low melting point and is not suitable for crystallization. Considering that N-ethylpicolylamine itself is a free base, it is solidified to form a salt of this free base with an acid an effective means of purifying and

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