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A kind of preparation method of 2,2-dimethyl-5-(4-chlorobenzyl) cyclopentanone

A dimethyl and chlorobenzyl technology, applied in the field of preparation of pesticide intermediates, can solve the problems of difficult operation, easy environmental pollution and high toxicity in post-processing, and achieves simple post-processing, ease of reaction, easy control, and easy operation. Effect

Active Publication Date: 2021-07-09
SHANGHAI SHISI CHEM PROD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] The problem to be solved by this invention is to provide a kind of preparation method of 2,2-dimethyl-5-(4-chlorobenzyl) cyclopentanone, to overcome 2,2-dimethyl-5- (4-Chlorobenzyl)cyclopentanone uses high-risk compound sodium hydride, highly toxic methylation steps, difficult operation, and post-processing is easy to pollute the environment during the preparation process.

Method used

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  • A kind of preparation method of 2,2-dimethyl-5-(4-chlorobenzyl) cyclopentanone
  • A kind of preparation method of 2,2-dimethyl-5-(4-chlorobenzyl) cyclopentanone
  • A kind of preparation method of 2,2-dimethyl-5-(4-chlorobenzyl) cyclopentanone

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Embodiment 1

[0032] Embodiment 1 A kind of preparation method of 2,2-dimethyl-5-(4-chlorobenzyl) cyclopentanone, concrete implementation is as follows:

[0033] 1) preparation of formula II compound

[0034] Add p-chlorobenzaldehyde (70.3g, 500mmol, 99.0%) and formula I compound 2,2-dimethyl-4-cyclopenten-1-one (60.2g, 537mmol) in the four-necked flask of 1L, then Add 500mL of methanol, stir, add DBU (40mL, 268mmol), react at room temperature for 3 hours, TLC shows that the raw material is basically converted completely, add 5% hydrochloric acid to acidify to a pH value of 3, concentrate, cool and crystallize, filter with suction, and use 50mL of the obtained solid to After rinsing with cold methanol and drying, the compound of Formula II (93.5 g, 374 mmol) was obtained as a light yellow solid with a purity of 96% and a yield of 88.1% (calculated as p-chlorobenzaldehyde).

[0035] 2) preparation of formula III compound

[0036] Add formula II compound (31.5g, 126mmol) in 1L four-necked f...

Embodiment 2

[0041]Embodiment 2 A kind of preparation method of 2,2-dimethyl-5-(4-chlorobenzyl) cyclopentanone, concrete implementation is as follows:

[0042] 1) preparation of formula II compound

[0043] Add p-chlorobenzaldehyde (70.3g, 500mmol, 99.0%) and formula I compound 2,2-dimethyl-4-cyclopenten-1-one (61.6g, 550mmol) in the four-necked flask of 1L, then Add 500mL of methanol, stir, add DBU (25mL, 167mmol), react at room temperature for 4 hours, TLC shows that the raw material is basically converted completely, add 5% hydrochloric acid to acidify to pH value 3, concentrate, cool and crystallize, suction filter, the obtained solid is washed with 50mL After rinsing with cold methanol and drying, the compound of Formula II (92.5 g, 370 mmol) was obtained as a pale yellow solid with a purity of 97% and a yield of 87.2% (calculated as p-chlorobenzaldehyde).

[0044] 2) preparation of formula III compound

[0045] Add formula II compound (31.5g, 126mmol) in 1L four-necked flask, then ...

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Abstract

The invention discloses a preparation method of 2,2-dimethyl-5-(4-chlorobenzyl) cyclopentanone, which uses p-chlorobenzaldehyde and 2,2-dimethyl-4-cyclopentanone En-1-ketone, that is, the compound of formula I, is used as the initial raw material. After aldol condensation, hydrogenation, hydroxyl removal and further hydrogenation, the compound of formula V is obtained, which is the intermediate 2,2-dimethyl-5 of metconazole ‑(4‑chlorobenzyl) cyclopentanone, compared with the prior art, the inventive method avoids the use of high-risk compound sodium hydride, avoids operations such as highly toxic methylation, and the reaction is moderate and easy to control. The target product 2, The 2-dimethyl-5-(4-chlorobenzyl) cyclopentanone has a purity greater than 95%, a total yield of over 65%, meets the requirements of green chemical industry, and is suitable for industrial production.

Description

technical field [0001] The invention belongs to the field of preparation of pesticide intermediates, in particular to a preparation method of 2,2-dimethyl-5-(4-chlorobenzyl)cyclopentanone. Background technique [0002] Meconazole is a broad-spectrum systemic fungicide used for plant pathogenic fungi. It has low toxicity to non-target organisms and has very little residue, so it can be safely applied to crops such as wheat, barley, and rye. It is mainly used to control Cereal crop leaf rust, stripe rust, powdery mildew, glume blight, Septoria, etc., has excellent activity against Septoria, leaf rust and glume blight, has both excellent protection and therapeutic effects, and also has the effect of realizing crop The effect of increasing production. 2,2-Dimethyl-5-(4-chlorobenzyl)cyclopentanone is a key intermediate for the synthesis of metconazole, and currently there is a great demand in the market. [0003] In the prior art, U.S. Patent US7166750 of Japan Kureha Chemical ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C45/62C07C49/697
CPCC07C45/45C07C45/62C07C45/66C07C49/697C07C49/747
Inventor 李海涛周琴张传好李芳詹家荣
Owner SHANGHAI SHISI CHEM PROD
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