US 12,686,662 B2 · Use of silicon compounds in cyclization reactions

Abstract

A first aspect of the present invention provides a method for the preparation of 2-chloro-5-chloromethylpyridine, comprising: performing a cyclization reaction on 4,5-dichloro-4-methoxypentanenitrile in presence of a silicon compound and an acylamide compound to obtain 2-chloro-5-chloromethylpyridine. Another aspect of the present invention provides a method for preparation of 2-(chloromethyl)-5-(trifluoromethyl)-1,3,4-oxadiazole, comprising: performing a cyclization reaction on 1-(chloroacetyl)-2-(trifluoroacetyl)hydrazine in a presence of a silicon compound and an acylamide compound to obtain 2-(chloromethyl)-5-(trifluoromethyl)-1,3,4-oxadiazole. The silicon compound or/and acylamide compound provided by the present invention serve as cyclization reagents and have high efficiency.

Claims14

Dependent claims

A method for preparation of 4,5-dichloro-4-methoxypentanenitrile, comprising:

performing a cyclization reaction on 4,5-dichloro-4-methoxypentanenitrile in presence of a silicon compound and an acylamide compound to provide 2-chloro-5-chloromethylpyridine, wherein a reaction equation of the cycllization reaction is as follows:
wherein the silicon compound is selected from one or more of compounds having a chemical structural formula shown below:
wherein R3, R4, and R5 are each independently selected from H, Ph, C1-C4 alkyl, Cl, and Br,
Y is O or is not present,
n is selected from 0, 1, 2, 3, 4, and 5, and
X is selected from Cl and Br.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application

18/275,612Filed 27 Jan 2022

Priority

CN 202110180140.17 Feb 2021

Published

US 2024/0124401 A118 Apr 2024

Granted

21 Jul 2026

Term ends

Not estimatedThe source records don’t support an estimate.

Classification8 codes

C07D 213/61
With hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals,…:…
B01J 31/0247
Being derivatives of carboxylic or carbonic acids: imides, amides or imidates
B01J 31/0274
Containing elements other than those covered by B01J31/0201 - B01J31/0255: containing silicon
C07D 271/10
Not condensed with other rings: 1,3,4-Oxadiazoles; Hydrogenated 1,3,4-oxadiazoles

Use of silicon compounds in cyclization reactions

Life of this patent

Use of silicon compounds in cyclization reactions

Life of this patent

Abstract

Claims14