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Preparation method of naphazoline hydrochloride

A technology of naphazoline hydrochloride and naphazoline, applied in directions such as organic chemistry, can solve problems such as unsatisfactory product purity and yield, and achieve the effects of good powder shape, high industrialization, and high yield and purity

Active Publication Date: 2019-07-23
GUANGDONG XIANQIANG PHARMA +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0015] In summary, the preparation of naphazoline hydrochloride using naphthalenecetonitrile as a starting material in the prior art requires strict anhydrous conditions or complex post-treatments, and the product purity and yield are not ideal. Therefore, an optimized suitable method is provided. The preparation method of naphazoline hydrochloride suitable for large-scale production is a technical problem that the prior art does not solve

Method used

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  • Preparation method of naphazoline hydrochloride
  • Preparation method of naphazoline hydrochloride
  • Preparation method of naphazoline hydrochloride

Examples

Experimental program
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Effect test

Embodiment 1

[0043] Adopt the following steps to prepare naphazoline hydrochloride:

[0044] (A) Add 1000g (6.0mol) of naphthaleneacetonitrile to the reaction kettle, add 5000ml of ethylenediamine, add CS 2 45.7g (0.6mol), heat up to 110°C, stir for 2h; cool down to room temperature, add 10L of water dropwise at a rate of 1L / min, precipitate a solid, and filter to obtain naphazoline free base.

[0045] (B) Naphazoline free base was dissolved by adding 8L of acetonitrile, and 25% hydrochloric acid was added dropwise at room temperature to adjust the pH to 2, and a solid precipitated, which was filtered to obtain 1399.3 g of naphazoline hydrochloride crude product.

[0046] (C) Add 5L of methanol to the crude product in the reaction kettle, heat to 70°C, add activated carbon after dissolving, heat up to 70°C for decolorization, filter, add 1L of acetone dropwise to the filtrate, cool the filtrate, keep warm and crystallize overnight at 25°C , centrifuged, rinsed with acetone, dried under va...

Embodiment 2

[0048] Adopt the following steps to prepare naphazoline hydrochloride:

[0049] (A) Add 1000g (6.0mol) of naphthaleneacetonitrile to the reaction kettle, add 3000ml of ethylenediamine, add Na 2 S 23.4g (0.3mol), MgCl 2 .6H 2 O 10.1g (0.05mol), heated to 90°C, stirred for 10h. Cool down to 1.5°C, add 8L of water dropwise at a rate of 0.8L / 10min, a solid precipitates, and is filtered to obtain naphazoline free base.

[0050] (B) Naphazoline free base was dissolved by adding 3L of acetone, and 5% hydrochloric acid was added dropwise at room temperature to adjust the pH to 3, and a solid precipitated, which was filtered to obtain 1450.3 g of naphazoline hydrochloride crude product.

[0051] (C) Add 4L of ethanol to the crude product in the reaction kettle, heat to 78°C, add activated carbon to decolorize after dissolving, filter, add 2L of ethanol dropwise to the filtrate at the same temperature, cool down after dropping, keep warm and crystallize overnight at 20°C, Centrifuge...

Embodiment 3

[0053] Adopt the following steps to prepare naphazoline hydrochloride:

[0054] (A) Add 1000g (6.0mol) of naphthaleneacetonitrile to the reaction kettle, add 6000ml of ethylenediamine, add 54.7g (0.72mol) of thiourea, raise the temperature to 120°C, and stir for 3h. Cool down to room temperature, add 12L of water dropwise at a rate of 1.5L / min, a solid precipitates, and is filtered to obtain naphazoline free base.

[0055] (B) Naphazoline free base was dissolved in 10 L of tetrahydrofuran, and 30% hydrochloric acid was added dropwise at room temperature to adjust the pH to 1. A solid precipitated and was filtered to obtain 1433.3 g of crude naphazoline hydrochloride.

[0056] (C) Add 12L tetrahydrofuran to the reaction kettle for the crude product, heat to 60°C, add activated carbon to decolorize after dissolving, filter, add 0.5L isopropanol dropwise to the filtrate at the same temperature, cool down the filtrate, and keep warm at 30°C for crystallization Overnight, centrifu...

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Abstract

The invention discloses a preparation method of naphazoline hydrochloride. A specific sulfur-containing catalyst CS2, Na2S or thiourea is used for synthesizing naphazoline, and a naphazoline hydrochloride product with high yield, high purity and good powder property is obtained through simple salification and recrystallization processes.

Description

technical field [0001] The invention belongs to the field of chemical synthesis. Specifically, the invention relates to an efficient and industrially scalable method for preparing naphazoline hydrochloride. [0002] technical background [0003] Naphazoline Hydrochloride (Naphazoline Hydrochloride), CAS: 550-99-2, chemical name 4,5-dihydro-2-(1-naphthylmethyl)-1H-imidazole hydrochloride 4,5-dihydro- 2-(1-naphthylmethyl)-1H-imidazolehydrochloride), the chemical structural formula is as follows: [0004] [0005] Naphazoline hydrochloride is a vasoactive drug that acts on the circulatory system. It belongs to adrenaline-like drugs and has the pharmacological activity of constricting blood vessels. It can be applied locally to relieve swelling and congestion of nasal mucosa. It is a direct-acting alpha-adrenergic agonist that constricts dilated arterioles in the nose but has no effect on beta-adrenergic receptors. After topical application, the effect can appear within 10 m...

Claims

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Application Information

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IPC IPC(8): C07D233/10
CPCC07D233/10
Inventor 黄彩逢黎万熊伟梅叶琼仙谭珍友
Owner GUANGDONG XIANQIANG PHARMA
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