Preparation of Pimobendan Key Intermediate

A technology of nitrophenyl and methyl, applied in the field of preparation of key intermediates of pimobendan, can solve problems such as being unfavorable to industrialized production

A technology of nitrophenyl and methyl, applied in the field of preparation of key intermediates of pimobendan, can solve problems such as being unfavorable to industrialized production

CN105968054BActive Publication Date: 2018-09-14WISDOM PHARM CO LTD
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  • Preparation of Pimobendan Key Intermediate
  • Preparation of Pimobendan Key Intermediate
  • Preparation of Pimobendan Key Intermediate

Examples

Experimental program
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Effect test

Embodiment

[0021] 1. Preparation of N-(2-nitro-4-propionylphenyl)acetamide (formula I)

[0022] h 2 SO 4 (200mL) and nitric acid (600mL) were mixed and cooled to below 0°C, then N-(4-propionylphenyl)acetamide (200g, 1.05mol) was added in batches, and the internal temperature of the system was kept below 0 °C for 5 hours. The reaction solution was slowly poured into a mixture of ice water (2000 g) and dichloromethane (2000 mL), stirred for 30 min, and the organic phase was separated after the ice completely turned into water. The aqueous phase was extracted with dichloromethane (800 mL). The organic phases were combined and washed twice with saturated brine (2×2000 mL). After the solvent was removed under reduced pressure, the residue was recrystallized from heptane / ethyl acetate to obtain a pale yellow solid (192 g, 77%).

[0023] 2. Preparation of N-(4-(2-bromopropionyl)-2-nitrophenyl)acetamide (formula II)

[0024] N-(2-nitro-4-propionylphenyl)acetamide (150g, 0.63mol) was added t...

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Abstract

The invention relates to a preparation technology of a pimobendan key intermediate 6-(4-amino-3-nitro phenyl)-5-methyl-4, 5-dihydrogen pyridazine-3(2H)-ketone (formula V). The preparation technology is short in synthesis route and simple in operation, thus having large industrial production prospect. The chemical reaction formula is shown in the description.

Description

technical field [0001] The invention relates to the preparation of a key intermediate of pimobendan-6-(4-amino-3-nitrophenyl)-5-methyl-4,5-dihydropyridazin-3(2H)-one. Background technique [0002] Pimobendan (Pimobendan, UD-CG115BS, Acardi, CAS: 74150-27-9) was developed by Boehringer Ingelheim, Germany, and was first listed in Japan in 1994 as a cardiotonic drug with vasodilation. Phosphodiesterase inhibitors are mainly used clinically for the treatment of heart failure. The mechanism of action of this drug is different from that of traditional cardiotonic drugs, and its positive inotropic effect is mainly attributed to the enhancement of the effect of cardiac contractile proteins on Ca 2+ Sensitivity and inhibitory effect on phosphodiesterase III (PDEIII), it is the first calcium sensitizer drug on the market. The chemical name of this product is: 4,5-dihydro-6-[2-(4-methoxyphenyl)-1H-benzimidazol-5-yl]-5-methyl-3(2H)- Pyridazinone has the following chemical structural ...

Claims

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Application Information

Patent Timeline
14 Sep 2018
Publication
CN105968054B
IPC
C07D237/04
CPC
C07D237/04
Inventors
邹平; 邱小龙