Qandil, A.M., Synthesis and Spectroscopic Analysis of Novel 1H-Benzo[d]imidazolylphenylsulfonylpiperazines. Pharmaceuticals 2012, 5, 460-468

Abstract

We have found the following errors in the title of this article which was recently published in Pharmaceuticals [1]

Convenient Synthesis and Characterization of Novel 4-[2-Ethoxy-5-(4-Methyl-1-Piperazinesulphonyl)Benzamido]-3-Isobutyl-1-Methyl-1H-Pyrazole-5-Carboxamide: Key Precursor for Isobutyl Sildenafil

“…The intermediate 12 was synthesized from commercially available 2-ethoxybenzoic acid in five-step chemical transformations with high yield. In this method, 2-ethoxybenzoic acid methyl ester 9 was chlorosulfonated at the contrapositon of the ethoxyl group using chlorosulfonic acid (HSO3Cl) in the presence of SOCl2 to ensure maximum conversion [14]. For simplicity and efficiency, the intermediate sulfonyl chloride was dissolved in CH2Cl2 and was coupled to N-methyl piperazine with excess amounts of (CH3CH2)3N.…”