The cyclization of trifluoroacetylmethylpyridinium bromide (I) with 3-(4-trifluoromethylbenzoyl)acrylic acid (II) by means of ammonium acetate in refluxing methanol gives 2-trifluoromethyl-6-(4-trifluoromethylphenyl)isonicotinic acid (III), which by condensation with 2-bromopyridine (IV) by means of butyllithium in ethyl ether yields 2-trifluoromethyl-6-(4-trifluoromethylphenyl)4-pyridyl-2'-pyridyl ketone (V). Finally, this compound is reduced with H2 over Pt in aqueous concentrated HCl. The starting products are prepared as follows: 1) The acrylic acid (II) is obtained by condensation of maleic anhydride (VI) with 4-trifluoromethylphenylmagnesium bromide (VII) by means of ZnCl2 in refluxing ethyl ether. An alternative method is the condensation of 4-trifluoromethylacetophenone (VIII) with glyoxylic acid (IX) by means of triethylamine at 135 C. 2) The pyridinium salt (I) is prepared by bromination of 1,1,1-trifluoroacetone (X) giving 1,1,1-trifluoro-3-bromoacetone (XI), which is then condensed with pyridine.

The cyclization of trifluoroacetylmethylpyridinium bromide (I) with 3-(4-trifluoromethylbenzoyl)acrylic acid (II) by means of ammonium acetate in refluxing methanol gives 2-trifluoromethyl-6-(4-trifluoromethylphenyl)isonicotinic acid (III), which by condensation with 2-bromopyridine (IV) by means of butyllithium in ethyl ether yields 2-trifluoromethyl-6-(4-trifluoromethylphenyl)4-pyridyl-2'-pyridyl ketone (V). Finally, this compound is reduced with H2 over Pt in aqueous concentrated HCl. The starting products are prepared as follows: 1) The acrylic acid (II) is obtained by condensation of maleic anhydride (VI) with 4-trifluoromethylphenylmagnesium bromide (VII) by means of ZnCl2 in refluxing ethyl ether. An alternative method is the condensation of 4-trifluoromethylacetophenone (VIII) with glyoxylic acid (IX) by means of triethylamine at 135 C. 2) The pyridinium salt (I) is prepared by bromination of 1,1,1-trifluoroacetone (X) giving 1,1,1-trifluoro-3-bromoacetone (XI), which is then condensed with pyridine.

The cyclization of trifluoroacetylmethylpyridinium bromide (I) with 3-(4-trifluoromethylbenzoyl)acrylic acid (II) by means of ammonium acetate in refluxing methanol gives 2-trifluoromethyl-6-(4-trifluoromethylphenyl)isonicotinic acid (III), which by condensation with 2-bromopyridine (IV) by means of butyllithium in ethyl ether yields 2-trifluoromethyl-6-(4-trifluoromethylphenyl)4-pyridyl-2'-pyridyl ketone (V). Finally, this compound is reduced with H2 over Pt in aqueous concentrated HCl. The starting products are prepared as follows: 1) The acrylic acid (II) is obtained by condensation of maleic anhydride (VI) with 4-trifluoromethylphenylmagnesium bromide (VII) by means of ZnCl2 in refluxing ethyl ether. An alternative method is the condensation of 4-trifluoromethylacetophenone (VIII) with glyoxylic acid (IX) by means of triethylamine at 135 C. 2) The pyridinium salt (I) is prepared by bromination of 1,1,1-trifluoroacetone (X) giving 1,1,1-trifluoro-3-bromoacetone (XI), which is then condensed with pyridine.

The cyclization of trifluoroacetylmethylpyridinium bromide (I) with 3-(4-trifluoromethylbenzoyl)acrylic acid (II) by means of ammonium acetate in refluxing methanol gives 2-trifluoromethyl-6-(4-trifluoromethylphenyl)isonicotinic acid (III), which by condensation with 2-bromopyridine (IV) by means of butyllithium in ethyl ether yields 2-trifluoromethyl-6-(4-trifluoromethylphenyl)4-pyridyl-2'-pyridyl ketone (V). Finally, this compound is reduced with H2 over Pt in aqueous concentrated HCl. The starting products are prepared as follows: 1) The acrylic acid (II) is obtained by condensation of maleic anhydride (VI) with 4-trifluoromethylphenylmagnesium bromide (VII) by means of ZnCl2 in refluxing ethyl ether. An alternative method is the condensation of 4-trifluoromethylacetophenone (VIII) with glyoxylic acid (IX) by means of triethylamine at 135 C. 2) The pyridinium salt (I) is prepared by bromination of 1,1,1-trifluoroacetone (X) giving 1,1,1-trifluoro-3-bromoacetone (XI), which is then condensed with pyridine.

The cyclization of trifluoroacetylmethylpyridinium bromide (I) with 3-(4-trifluoromethylbenzoyl)acrylic acid (II) by means of ammonium acetate in refluxing methanol gives 2-trifluoromethyl-6-(4-trifluoromethylphenyl)isonicotinic acid (III), which by condensation with 2-bromopyridine (IV) by means of butyllithium in ethyl ether yields 2-trifluoromethyl-6-(4-trifluoromethylphenyl)4-pyridyl-2'-pyridyl ketone (V). Finally, this compound is reduced with H2 over Pt in aqueous concentrated HCl. The starting products are prepared as follows: 1) The acrylic acid (II) is obtained by condensation of maleic anhydride (VI) with 4-trifluoromethylphenylmagnesium bromide (VII) by means of ZnCl2 in refluxing ethyl ether. An alternative method is the condensation of 4-trifluoromethylacetophenone (VIII) with glyoxylic acid (IX) by means of triethylamine at 135 C. 2) The pyridinium salt (I) is prepared by bromination of 1,1,1-trifluoroacetone (X) giving 1,1,1-trifluoro-3-bromoacetone (XI), which is then condensed with pyridine.