In 2022,Zhou, Yin; Gao, Cheng-Feng; Ma, Hai; Nie, Jing; Ma, Jun-An; Zhang, Fa-Guang published an article in Chemistry – An Asian Journal. The title of the article was 《Quadruple Functionalized Pyrazole Pharmacophores by One-pot Regioselective [3+2] Cycloaddition of Fluorinated Nitrile Imines and Dicyanoalkenes》.Formula: C4H5ClO3 The author mentioned the following in the article:
A quadruple functionalization approach for the modular construction of fully substituted N1-aryl 3-di/trifluoro-methyl-4/5-cyanopyrazole pharmacophores from readily available hydrazonyl chlorides and dicyanoalkenes was presented. The realization of this [3+2] cycloaddition reaction hinges upon the employment of N-aryl di/trifluoromethyl nitrile imines as the 1,3-dipoles to bypass external synthetic steps and dicyanoalkenes as the dipolarophiles to tune the regioselectivity. This one-pot strategy offered access to a divergent library of cyano analogs of prevalent 3-di/trifluoromethyl pyrazole pharmacophores, among which several compounds have shown potent inhibitory activity towards cyclooxygenase 2 (COX-2) compared with marketed drug Celecoxib. The experimental process involved the reaction of Ethyl oxalyl monochloride(cas: 4755-77-5Formula: C4H5ClO3)
Ethyl oxalyl monochloride(cas: 4755-77-5) belongs to acyl chlorides. In the laboratory, acyl chlorides are generally prepared by treating carboxylic acids with thionyl chloride (SOCl2). The reaction is catalyzed by dimethylformamide and other additives.Formula: C4H5ClO3
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