反应详情

The cyclization reaction may be conveniently conducted in a batch reaction or in a continuous fashion in a coil reactor. In a typical reaction, 2,2,4-trichloro-4-cyanobutanoyl chloride is diluted with the desired solvent in a closed pressure vessel, and the vessel is pressurized with anhydrous HCl to the desired pressure. The reaction mixture is stirred at the appropriate temperature until the reaction is completed, usually from about one to about three hours. The reaction vessel is vented and the product, 3,3,5,6-tetrachloro-3,4-dihydropyridin-2-one, can be isolated by conventional procedures. For example, evaporation of the solvent provides a crude solid product which can be slurried with an aliphatic hydrocarbon, such as hexane, and which can then be isolated by filtration. Product so obtained is sufficiently pure after drying to be used in the subsequent aromatization. Alternatively, the crude reaction mixture can be used directly, immediately after venting and removal of the HCl.

1. customThe cyclization reaction
2. custommay be conveniently conducted in a batch reaction or in a continuous fashion in a coil reactor
3. waitis completed, usually from about one to about three hours