Chloromethyleniminium salts

N -Cyanocarbamimides (112) may be condensed with chloromethyleniminium salts in a similar way (equation 58). Yields are good to excellent, and reaction conditions are mild (Table 12) (81S907). The synthesis provides an easy route to 4-aIkoxy-2-chloro-l,3,5-triazines (113) and the-corresponding mercapto derivatives. 

REACTIONS OF AROMATIC COMPOUNDS WITH CHLOROMETHYLENIMINIUM SALTS... 

Enol ethers represented by the general structure (81 Scheme 6) and their vinylogs react with salt (1) to give iminium salts (82). Enol ethers (81) are often prepared in situ by treating acetals or ketals (83) with salt (1). Acetals (83) react with an excess of chloromethyleniminium salt (1) to provide iminium salts (82 R = H, = alkyl or phenyl) that are hydrolyzed under basic conditions to afford 3-dimethyl-aminoacrolein derivatives (84 48-89%). Synthetically useful vinylamidinium salts (85 R = H) can be prepared by 0-methylation of compounds (84) followed by treatment with dimethylamine. Ketals (83 R = Et) similarly yield iminium salts (82 R = Et, R = alkyl or phenyl, R = alkyl) from which either p-ethoxyacrolein derivatives (86 R = Et 59-92%) are isolated after basic hydrolysis or vinylamidinium... 

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