16105-56-9

Upstream product

• 110921-61-4 O-ethyl 3-hydroxy-3-phenyl-2-propenethioate 
• 94-02-0 ethyl 3-oxo-3-phenylpropionate 
• 1155802-72-4 3-ethoxy-4-iodo-5-phenyl-1H-pyrazole 
• 98-80-6 phenylboronic acid 
• 1207432-08-3 Ethyl 5-ethoxy-3-phenyl-1H-pyrazole-4-carboxylate 
• 1207432-08-3 ethyl 3-ethoxy-5-phenyl-1H-pyrazole-4-carboxylate 

Downstream Products

• 1147771-09-2 1-(4-chlorophenyl)-3-ethoxy-5-phenyl-1H-pyrazole 
• 1147771-12-7 1-(4-chlorophenyl)-5-ethoxy-3-phenyl-1H-pyrazole 
• 1155802-72-4 3-ethoxy-4-iodo-5-phenyl-1H-pyrazole 
• 1223597-16-7 2-(3-ethoxy-5-phenyl-1H-pyrazol-1-yl)pyridine 
• 1223597-28-1 2-(5-ethoxy-3-phenyl-1H-pyrazol-1-yl)pyridine 
• 1338378-38-3 4-chloro-3-ethoxy-5-phenyl-1H-pyrazole 
• 1231307-78-0 4-bromo-3-ethoxy-5-phenyl-1H-pyrazole 
• 27412-71-1 5-phenyl-1H-pyrazol-3(2H)-one 

Relevant academic research and scientific papers

DMF-catalyzed direct and regioselective C-H functionalization: Electrophilic/nucleophilic 4-halogenation of 3-oxypyrazoles

A novel, straightforward, and highly regioselective 4-chlorination of 3-oxypyrazole derivatives in boiling thionyl chloride (SOCl2) in the presence of catalytic N,N-dimethylformamide (DMF) has been developed. This reaction likely proceeds through a DMF-catalyzed electrophilic/nucleophilic chlorination mechanism and involves electrophilic attack by SOCl2 and nucleophilic substitution by Cl- as the key steps. Based on this mechanism, the corresponding 4-bromination and 4-iodination of 3-oxypyrazoles have also been achieved in good yield by adding Br- and I -, respectively, to the reaction system. This halogenation method enables quick access to many original 4-halo-3-oxypyrazole series. A novel DMF-catalyzed electrophilic/nucleophilic 4-halogenation of 3-oxypyrazole derivatives has been developed. This halogenation procedure provides quick access to many novel 4-halo-3-oxypyrazole series.

5-Iodo-3-ethoxypyrazoles: An entry point to new chemical entities

Our program, which has focused on the preparation of new pyrazole derivatives, has led us to report here an original and simplified preparation of ethyl 3-ethoxy-lW-pyrazole-4-carboxylate. This is based on the reaction of hydrazine monohydrochloride and diethyl 2-(ethoxymethylene)malonate. Further transformations of this key compound allowed the preparation of the two possible iodinated isomers, namely, 3-ethoxy-4-iodo- and 3-ethoxy-5-iodo-1H-pyrazole. These compounds have opened the way to a quick access to many original pyrazole series. As an illustration, we report here on the selectivity of N-arylation, by using the Lam and Cham method, the C4- and C5-arylation of some of these 3-ethoxy-pyrazole derivatives by using the Suzuki-Miyaura reaction, and C5-benzylation reactions by means of the Negishi reaction. This was followed by hydrolysis of the ethoxy group, which led to the corresponding pyrazol-3-one derivatives. As a conclusion of this work, we conducted an investigation into the regiochemistry of the condensation between diethyl 2-(ethoxymethylene) malonate and the hydrochloride salts of methyl, benzyl, or phenyl hydrazine.

Alkoxypyrazoles and the process for their preparation

The present invention relates to a alkoxypyrazoles preparation process, and new alkoxypyrazole compounds.

Alkoxypyrazoles and the process for their preparation

The present invention relates to a process for the preparation of alkoxypyrazoles and new alkoxypyrazole compounds.

4-Arylation of 3-alkoxypyrazoles

Following the study of the alkoxypyrazoles nitrogen's reactivity toward arylation or alkylation reactions, we report here our results on the introduction of various aryl groups on carbon 4 position of 3-alkoxypyrazoles. This was achieved from the correspo

An improved preparation of 3-alkoxypyrazoles

The condensation between alkyl acetoacetates and hydrazines constitutes the very well-known Knorr synthetic method leading to pyrazol-3/5-ones. However, contemporary reports describe an alternate reaction pathway leading to low yields of 3/5-alkoxypyrazoles using hydrazine salts. No general method for the selective synthesis of 3-alkoxypyrazoles has been reported to date, hence we focused on this side reaction in an attempt to turn it into the main transformation. Depending on the starting material, various 3-alkoxypyrazoles (methoxy, ethoxy, benzyloxy, isopropoxy, allyloxy) were obtained in up to 56% yield. Georg Thieme Verlag Stuttgart.

Synthesis of 3-ethoxyisoxazole derivatives and 3-ethoxy-1H-pyrazole derivatives from β-oxo thionoesters

3-Ethoxyisoxazoles and 3-ethoxy-1H-pyrazoles were obtained in high yields from β-oxo thionoesters. The reaction of the ethyl β-oxo thionoesters with hydroxylamine hydrochloride in the presence of triethylamine at room temperature for 2 h gave the ethyl 3-oxopropiohydroximates and their hemiacetals, which were easily converted to the 3-ethoxyisoxazoles by refluxing for 3 h at pH 3-5. On the other hand, the reaction of the ethyl β-oxo thionoesters with hydrazine derivatives in the presence of triethylamine for 3-8 h at room temperature directly yielded the 3-ethoxy-1H-pyrazoles.