Process for the preparation of 4-trifluoromethyl-2(1H)-pyridinone

1. A process for the preparation of 4-trifluoromethyl-2(1H)-pyridinone (I),

which comprises:

i) contacting either a 4-alkoxy-1,1,1-trifluorobut-3-en-2-one of the formula

in which R represents C 1 -C 4 alkyl, or a 4,4-dialkoxy-1,1,1-trifluorobutan-2-one of the formula

in which R is as previously defined, with a trialkyl phosphonoacetate of the formula:

in which R is as previously defined, in the presence of a base and an alcohol or glycol solvent to provide a mixture of condensation products of the formula

in which R is as previously defined;

and

ii) cyclizing the mixture of condensation products to provide 4-trifluoromethyl-2(1H)-pyridinone.

2. The process of claim 1 in which the mixture of condensation products is cyclized by reacting with an ammonium salt of an organic acid and/or with a mineral acid and/or with formamide.

3. The process of claim 2 in which the ammonium salt of an organic acid is ammonium formate or ammonium acetate.

4. The process of claim 1 in which the mixture of condensation products is cyclized by reacting with an unsubstituted amide and methoxide to form a mixture of amides which is subsequently cyclized with acid.

5. The process of claim 1 in which the mixture of condensation products is cyclized by reacting with an acid and water to form the lactone which is subsequently reacted with ammonia.

6. The process of claim 1 in which the mixture of condensation products is cyclized by reacting with an organic anhydride and pyridinium p-toluenesulfonate (PPTS) to form a mixture of dieneoates which is subsequently cyclized by reacting with an ammonium salt of an organic acid (R′ represents alkyl or aryl) or a mineral acid or with formamide or by reacting with an unsubstituted amide and methoxide to form a mixture of amides which is subsequently cyclized with acid.