Method for preparing precursor 2-chloro-2-chloromethyl-4-cyano butyraldehyde of Paichonghding intermediate

• Main Authors: AN LITAO, JIN AIPING, WU ZHONGYAN, XU QIWEN
• Format: Patent
• Language: Chinese; English
• Published: 07.11.2012
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; CHEMISTRY; CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION ORPROCESSING OF GOODS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; METALLURGY; ORGANIC CHEMISTRY; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE

The invention provides a method for preparing a precursor 2-chloro-2-chloromethyl-4-cyano butyraldehyde of a Paichonghding intermediate. The method comprises the following steps: 1) a chlorination addition reaction: introducing chlorine into an acrolein solution for reaction to generate 2, 3-dichloropropylaldehyde; and 2) a Michael addition reaction: dissolving the product obtained from the step 1) in an organic solvent for a reaction with acrylonitrile, with catalysts comprising organic or inorganic base, and tertiary butanol or salt thereof, to generate the 2-chloro-2-chloromethyl-4-cyano butyraldehyde. According to the present invention, a route comprising the first chlorination addition reaction to generate 2, 3-dichloropropylaldehyde, and the Michael addition reaction of the 2, 3-dichloropropylaldehyde with acrylonitrile to generate the 2-chloro-2-chloromethyl-4-cyano butyraldehyde is designed to improve reaction yield and reduce production cost; and appropriate solvents and catalysts are chosen to short