Selective dehalogenation

Abstract

An improved process for removal of halogen from the pyrimidine ring only of a compound of the formula ##SPC1## Wherein At least one of X is chlorine or bromine, the remainder hydrogen; .[.or lower alkyl.]. Q is chlorine or fluorine; and N is an integer from 1 to 5. The dehalogenation process yields an α-halophenyl-α-phenyl-5-pyrinidylmethane of 95 percent or higher purity, which compound is useful as an intermediate in the preparation of the corresponding α-halophenyl-α-phenyl-5-pyrinidylmethanol, useful as an agricultural fungicide.

I claim: 
     
       1. The process of selectively dehalogenating the pyrimidyl ring of a compound of the formula ##SPC4## wherein   at least one of X is chlorine or bromine, the remainder hydrogen; .[.or lower alkyl.].   Q is chlorine or fluorine; and   n is an integer from 1 to 5,   by contacting the compound with hydrogen in the presence of Raney nickel catalyst,   in methanol as the solvent,   in the presence of a hydrogen halide acceptor selected from the group consisting of tri(C 1  -C 4  alkylamines and pyridine, at a temperature within the range of from about ambient room temperature to about 60°C., at a hydrogen pressure of from about 14 pounds per square inch to about 60 pounds per square inch.   
     
     
       2. The process of claim 1 wherein the hydrogen halide acceptor is triethylamine. 
     
     
       3. The process of claim 1 wherein the compound contacted is 2,4-dichloro-5-(2,4-dichlorobenzhydryl)pyrimidine. 
     
     
       4. The process of claim 1 wherein the compound contacted is 4,6-dichloro-5-(2,4-dichlorobenzhydryl)pyrimidine.