135641-71-3

Upstream product

• 95827-00-2 1-(4-chlorophenyl)but-3-en-1-one 
• 1623809-09-5 C₁₂H₁₃ClN₂O₂ 
• 104-88-1 4-chlorobenzaldehyde 
• 14506-33-3 1-(4-chlorophenyl)but-3-en-1-ol 
• 135641-68-8 c-4-p-chlorobenzoyloxy-3-p-chlorophenyl-r-3-methoxycarbonyl-4,5-dihydro-3H-pyrazole 

Relevant academic research and scientific papers

Copper-Catalyzed Aerobic Cyclization of β,γ-Unsaturated Hydrazones with Concomitant CC Bond Cleavage

A Cu-catalyzed aerobic oxidative cyclization of β,γ-unsaturated hydrazones for the preparation of pyrazole derivatives has been developed. The hydrazonyl radical promoted the cyclization, along with a concomitant CC bond cleavage of β,γ-unsaturated hydrazones. This process has been verified via several control experiments, including a radical-trapping study, an 18O-labeling method, and the identification of the possible byproducts. The advantages of this reaction include operational simplicity, a broad reaction scope, and a mild selective reaction process.

Effect of Electron-withdrawing Groups on the Thermal Ring Opening of 3H-Pyrazoles to Diazoalkenes

3-Cyano-3H-pyrazoles, bearing a cyano, a p-chlorophenyl, or a p-chlorobenzyl group at C-3, generated from elimination reaction of the corresponding dihydropyrazoles with a leaving group such as a chlorine or p-chlorobenzoyloxy group, gave diazolkene derivatives, resulting from the ring-opening of the 3H-pyrazoles.However, 3-methoxycarbonyl-3H-pyrazoles bearing a methoxycarbonyl, a p-chlorophenyl, or p-chlorobenzyl group at C-3, prepared in a similar manner, gave mainly 1-methoxycarbonyl-1H-pyrazole derivatives, resulting from migration of the 3-methoxycarbonyl group to the adjacent nitrogen within the generated 3H-pyrazoles.Treatment of 3H-pyrazoles (8a and 29b) and 5-substituted 1-methoxycarbonyl-1H-pyrazoles (10a and 31b) with triethylamine gave 3-substituted 1-methoxycarbonyl-1H-pyrazoles, resulting from migration of the methoxycarbonyl group to the remote nitrogen.