221641-33-4

Basic information

• Product Name: 5-azido-4-formyl-3-(4-chlorobenzyl)-1-phenylpyrazole
• Synonyms: 5-azido-4-formyl-3-(4-chlorobenzyl)-1-phenylpyrazole
• CAS NO: 221641-33-4
• Molecular Weight: 337.768
• Mol File: 221641-33-4.mol
• Article Data: 1

Chemical Properties

• CAS DataBase Reference: 5-azido-4-formyl-3-(4-chlorobenzyl)-1-phenylpyrazole(CAS DataBase Reference)
• NIST Chemistry Reference: 5-azido-4-formyl-3-(4-chlorobenzyl)-1-phenylpyrazole(221641-33-4)
• EPA Substance Registry System: 5-azido-4-formyl-3-(4-chlorobenzyl)-1-phenylpyrazole(221641-33-4)

Safety Data

• Hazardous Substances Data: 221641-33-4(Hazardous Substances Data)

Upstream product

• 25026-34-0 4-chlorophenacetyl chloride 
• 1035695-08-9 5-[2-(4-chlorophenyl)-1-hydroxyethylidene]-2,2-dimethyl-1,3-dioxane-4,6-dione 
• 221641-13-0 3-(4-chlorobenzyl)-1-phenyl-5-pyrazolone 
• 62088-10-2 4-(4-chloro-phenyl)-3-oxobutyric acid ethyl ester 
• 1878-66-6 4-chlorophenylacetic Acid 
• 221641-23-2 5-chloro-3-(4-chlorobenzyl)-4-formyl-1-phenylpyrazole 

Relevant articles and documents

A pyrazole to furan rearrangement. Thermolysis of 5-Azido-4-formylpyrazoles

5-Azido-3-benzyl-4-formyl-1-phenylpyrazoles 1a-c extrude dinitrogen upon heating in toluene to give the corresponding nitrenes, which immediately rearrange via a new ring-opening ring-closure reaction to produce an equimolar mixture of 4-cyano-2-phenyl-3-phenylazofurans 2a-c and 3-benzyl-4-cyano-1-phenylpyrazoles 3a-c. The formation of the 4-cyano-2-phenyl-3-phenylazofurans 2a-c is the first example in the pyrazole series of a nitrene rearrangement, in which the parent heterocyclic system of the product differs from that of the starting material. The isolation of equimolar amounts of the two products points to the fact that their formation occurs by two mechanistically interconnected pathways, between which the exchange of a redox equivalent takes place. Evidence for the existence of two mechanistically interlinked pathways is presented, and the insight into the stoechiometry of the reaction is taken advantage of to optimize the reaction with respect to either of the two products 2 or 3. Thus, it is demonstrated how one can bias the two pathways using external reagents, thereby changing the product distribution ratio 2:3 from 1:1 in the unbiased case, to 1:4 in one direction, and to better than 20:1 in the other direction.