Method for preparing lorazepam

The technology of lorazepam and crystallization is applied in the field of preparation of benzodiazepine drugs lorazepam, and can solve the problems of affecting the long-term storage and transportation of preparations, being unstable when exposed to light, and being low in oral bioavailability of the drug.
CN110776473APending Publication Date: 2020-02-11HUNAN DONGTING PHARMA
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
HUNAN DONGTING PHARMA
Publication Date
2020-02-11

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Abstract

The invention relates to a method for preparing lorazepam. The method comprises the following steps: subjecting a ketone substrate as shown in a formula I, glacial acetic acid, potassium acetate, potassium persulfate and iodine to a reaction under heating and stirring conditions to obtain an acetoxy substrate as shown in a formula II; dropwise adding a sodium hydroxide solution into a mixture of ethanol and the acetoxy substance as shown in the formula II, carrying out stirring to realize a complete reaction, performing filtering to obtain a filter cake, and reacting the filter cake with ethylacetate and a citric acid solution to obtain a crude lorazepam product; and crystallizing the crude lorazepam product by using ethanol and ethyl acetate in sequence. The invention further relates tothe pharmaceutical application of larazepam prepared by using the method. The larazepam is particularly used for treating or preventing anxiety, epilepsy, convulsion, sedation and hypnosis. The methoddisclosed by the invention has excellent technical effects as described in the specification.
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Description

technical field

[0001] The invention belongs to the technical field of medicine, and relates to a preparation method of benzodiazepine drug lorazepam. It also relates to lorazepam prepared by the method, and its use in drugs with anxiolytic, antiepileptic, anticonvulsant and sedative hypnotic effects. Background technique

[0002] Loarzepam, molecular formula C15H10Cl2N2O2, molecular weight 321.16, chemical name: 7-chloro-5-(2-chlorophenyl)-1,3-dihydro-3-hydroxy-2H-1,4-benzo Diazepin-2-one, its chemical structural formula is:

[0003]

[0004] Lorazepam is white or off-white crystalline powder; odorless; lorazepam is slightly soluble in ethanol and almost insoluble in water.

[0005] Lorazepam, also known as lorazepam, lorazepam and lorazepam, belongs to benzodiazepine (BZD) drugs. It acts on the GABAa regulatory site in the nerve center, strengthens the inhibitory function of GABA, activates chloride ion channels, and produces a powerful anti-anxiety effect. It has re...

Claims

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