(2-Fluorobenzyl)hydrazine → ethyl 5-amino-1-(2-fluorobenzyl)-1H-pyrazole-3-carboxylate

HRID 2120563Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 2120563
[C:1]([CH2:3][C:4](=O)[C:5]([O:7][CH2:8][CH3:9])=[O:6])#[N:2].[F:11][C:12]1[CH:20]=[CH:19][CH:18]=[CH:17][C:13]=1[CH2:14][NH:15][NH2:16]>O1CCOCC1>[NH2:2][C:1]1[N:15]([CH2:14][C:13]2[CH:17]=[CH:18][CH:19]=[CH:20][C:12]=2[F:11])[N:16]=[C:4]([C:5]([O:7][CH2:8][CH3:9])=[O:6])[CH:3]=1

Komponenten

4

Versuchsvorschrift

The compound of the formula (II) is obtainable in a multi-stage synthesis from the sodium salts of ethyl cyanopyruvate, which is known from the literature (Borsche and Manteuffel, Liebigs. Ann. Chem. 1934, 512, 97). By reaction thereof with 2-fluorobenzylhydrazine with heating and under a protective gas atmosphere in an inert solvent such as dioxane, ethyl 5-amino-1-(2-fluorobenzyl)pyrazole-3-carboxylate is obtained, which cyclizes by means of reaction with dimethylaminoacrolein in the acidic medium under a protective gas atmosphere and with heating to give the corresponding pyridine derivative. This pyridine derivative, ethyl 1-(2-fluorobenzyl)-1H-pyrazolo[3,4-b]pyridine-3-carboxylate, is converted by means of a multi-stage sequence, consisting of conversion of the ester into the corresponding amide using ammonia, dehydration using a dehydrating agent such as trifluoroacetic anhydride to give the corresponding nitrite derivative, reaction of the nitrile derivative with sodium ethoxide and final reaction with ammonium chloride, into the compound of the formula (II).

Aufarbeitung

  1. customBy reaction

Quellen und Nachweise

ORD-Eintrag
ord-98993f203a1d4501b26cf6aa687d083e
Quelldatensatz
uspto-grants-2004_02
Patentnummer
US06693102B2

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