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来自 : 发布时间：2024-12-22

Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URLShare a linkShare onEmailFacebookTwitterLinked InRedditWechat The synthesis of an N-alkyl pyridinium salt involving the formation of an N-(2,4-dinitrophenyl)pyridinium chloride from pyridine and 2,4-dinitrochlorobenzene and subsequent treatment of the pyridinium chloride with a primary amine and 2,4-dinitroaniline as a side product is generally referred to as the Zincke reaction or Zincke synthesis of pyridinium salt. Besides the effect of primary amine, the N-(2,4-dinitrophenyl)pyridinium chloride also decomposes in the presence of a secondary amine to afford an N,N-disubstituted conjugated aldehyde and is known as Zincke aldehyde. Furthermore, dichloromethane as a solvent improves the opening of the pyridinium ring during the attack of amine for 3,4-dialkylpyridinium salt. This reaction has been modified by using 2,4-dinitrochlorobenzene and cyanogen bromide, which activates the pyridine nucleus. This reaction has been broadly applied for the detection of nicotine, nicotinic acid, nicotinamide, or trigonellin in urine. The full text of this article hosted at iucr.org is unavailable due to technical difficulties. Please check your email for instructions on resetting your password. If you do not receive an email within 10 minutes, your email address may not be registered, and you may need to create a new Wiley Online Library account. Can\'t sign in? Forgot your username? Enter your email address below and we will send you your username If the address matches an existing account you will receive an email with instructions to retrieve your username