2-hydrocarbyl-3,6-dichloropyridine compounds

DETAILED DESCRIPTION OF THE INVENTION The addition reaction of a dichloromethyl hydrocarbyl ketone with acrylonitrile according to the present process is typically carried out in an organic solvent, such as t-butanol, ethanol, dimethylformamide, dimethyl sulfoxide, acetonitrile, methylene chloride, tetrahydrofuran, toluene, and the like.
Reaction temperatures of from about 0.
degree.
to about 120.
degree.
C.
, preferably from about 40.
degree.
to about 90.
degree.
, are normally employed.
The reaction mixture is usually agitated and it is often convenient to carry out the reaction at its reflux temperature.
Suitable bases for the addition reaction are those that are capable of abstracting a proton from the dichloromethyl hydrocarbyl ketone and include alkali metal hydroxides, such as sodium hydroxide or potassium hydroxide: alkali metal alkoxides, such as potassium t-butoxide or sodium ethoxide; and trialkylamines, such as triethylamine, N,N-dimethyl-N-hexylamine, N,N,N',N'-tetramethylethylenediamine, or N-methylpyrrolidine.
When the base is an alkali metal hydroxide or alkali metal alkoxide, a quaternary ammonium salt, such as N,N,N-tricapryl-N-methylammonium chloride or N-benzyl-N,N,N-triethylammonium chloride, may be added to facilitate the reaction.
Approximately equimolar quantities of acrylonitrile and the dichloromethyl hydrocarbyl ketone or an excess of acrylonitrile can be conveniently employed in the process.
The reaction is continued until a substantial amount of the desired 1,1-dichloro-3-cyanopropyl hydrocarbyl ketone product has formed or until one of the starting materials has been substantially depleted.
The exact time will depend on the starting dichloromethyl hydrocarbyl ketone employed as well as the solvent and the reaction temperature used.
The 1,1-dichloro-3-cyanopropyl hydrocarbyl ketones of Formula II prepared in the above described procedures can be recovered using conventional means, such as distillation, extraction, chromatography, crystallization, and the like.
After recovery of the 1,1-dichloro-3-cyanopropyl hydrocarbyl ketones in a pure or partially purified form, they may be utilized in the cyclization reaction of the invention