3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylic acid → 3-(3-chloro-1H-pyrazol-1-yl)pyridine

HRID 57084

Reaktionsgleichung

Reaktionsgleichung von HRID 57084
[Cl:1][C:2]1[CH:6]=[C:5](C(O)=O)[N:4]([C:10]2[CH:11]=[N:12][CH:13]=[CH:14][CH:15]=2)[N:3]=1>[Cu]=O.CN(C)C=O>[Cl:1][C:2]1[CH:6]=[CH:5][N:4]([C:10]2[CH:11]=[N:12][CH:13]=[CH:14][CH:15]=2)[N:3]=1

Komponenten

4

Versuchsvorschrift

In step d of Scheme 2, 3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylic acid (6e) is decarboxylated in the presence of copper (II) oxide in polar solvents such as N,N-dimethylformamide at temperatures from about 80° C. to about 140° C. to yield 3-(3-chloro-1H-pyrazol-1-yl)pyridine (5b). It was surprisingly discovered that this decarboxylation only occurs in the presence of copper (II) oxide. Several known decarboxylation agents from the literature such as, for example, hydrochloric acid (See alternate synthetic route, Example 14), sulfuric acid, and palladium (II) trifluoroacetate/trifluoroacetic acid (Pd(TFA)2/TFA) (See “CE-5”) did not yield the desired product.

Quellen und Nachweise

ORD-Eintrag
ord-1a23c4ccebed4846af0dbda241626759
Quelldatensatz
uspto-grants-2016_09
Patentnummer
US09434712B2

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