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Method for preparing letrozole impurity

A kind of technology of letrozole impurity and impurity, applied in the field of medicinal chemistry

Inactive Publication Date: 2013-08-14
HARBIN PHARMA GRP CO LTD GENERAL PHARMA FACTORY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0007] At present, there is no report on the preparation method of letrozole impurity in China

Method used

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  • Method for preparing letrozole impurity
  • Method for preparing letrozole impurity
  • Method for preparing letrozole impurity

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] Example 1: Step 1: Dissolve 10g of letrozole in 50ml of acetone, add 100ml of water, add 30% NaOH solution, adjust pH=10.5, liquid phase detection until the main peak disappears, the impurity C peak area percentage is 58% ;

[0024] Step 2: evaporate the acetone under reduced pressure, filter the resulting suspension to obtain a crude impurity product with a purity of 81%;

[0025] Step 3: Recrystallize the obtained impurity crude product in ethanol to obtain impurity C, about 4.9 g, with a yield of 49% and a purity of over 99%.

Embodiment 2

[0026] Example 2: Step 1: Dissolve 20g of letrozole in 100ml of acetone, add 200ml of water, add 30% sodium carbonate solution, adjust pH=11.2, liquid phase detection until the main peak disappears, impurity C peak area percentage 63 %;

[0027] Step 2: evaporate the acetone under reduced pressure, filter the resulting suspension to obtain a crude impurity product with a purity of 80%;

[0028] Step 3: Recrystallize the obtained impurity crude product in ethanol to obtain impurity C, about 10 g, with a yield of 50% and a purity of more than 99%.

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Abstract

The invention relates to a method for preparing a letrozole impurity. A reference substance is provided for quantitative and qualitative analysis of letrozole impurity detection by synthesizing the letrozole impurity. Thus, the quality standard of letrozole is improved; guidance is provided for safe medication of letrozole; and meanwhile, an effective detection foundation is provided for obtaining the letrozole drug which accords with the quality standard of USP (United States Pharmacopoeia).

Description

technical field [0001] The invention belongs to the field of medicinal chemistry, and more specifically relates to a method for preparing impurity C in the preparation process of letrozole. [0002] [0003] Background technique: [0004] Letrozole, Chinese alias: 1-[bis(4-cyanophenyl)methyl]-1,2,4-triazole; 4,4'-(1 H-1,2,4-triazole -1-ylmethylene)-bisbenzonitrile. [0005] Letrozole is a new generation of aromatase inhibitors. It is a synthetic benzyltriazole derivative. Letrozole reduces the level of estrogen by inhibiting aromatase, thereby eliminating the stimulating effect of estrogen on tumor growth. In vivo and in vitro studies have shown that letrozole can effectively inhibit the transformation of androgen into estrogen, and estrogen in postmenopausal women mainly comes from the aromatization of androgen precursors in peripheral tissues, so it is especially suitable for postmenopausal breast cancer patient. The in vivo activity of letrozole is 150-250 ti...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C255/56C07C253/30
Inventor 孙志嘉王硕冰王志强
Owner HARBIN PHARMA GRP CO LTD GENERAL PHARMA FACTORY
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