Abstract: Diels-Alder products obtained by reacting a haloprene with a 4-vinylpyridine, i.e., mixtures of 4-(halocyclohex-3-enyl)pyridine isomers, are reacted with a relatively strong acid, i.e., an acid having a dissociation constant of at least 1.7.times.10.sup.-5 at 25.degree. C., to form salts which are readily separated and/or reduced.

Abstract: 4-(1-Chlorovinyl)pyridines are prepared by heating an acid salt of 4-(1,2-dichloroethyl)pyridine in an inert solvent until dehydrohalogenation is effected.

Abstract: The coupling of an aminohalobenzeneacetonitrile with a benzene compound in the presence of an alkyl nitrite to form a halobiphenylacetonitrile via a diazo intermediate is improved by conducting the reaction at a temperature of about 0.degree.-15.degree. C. until diazotization of the aminohalobenzeneacetonitrile is substantially complete. Use of the low diazotization temperature leads to an increased yield of halobiphenylacetonitrile.

Abstract: An alpha-arylacrylonitrile is prepared by reacting an aryl ketone having a removable hydrogen alpha to the carbonyl group with an alkali metal cyanide and aluminum chloride, preferably in the presence of a solvent and a phase transfer catalyst. In a preferred embodiment, the aryl ketone is a tetralone, and the product is a 1-cyano-3,4-dihydronaphthalene which may then be dehydrogenated to a 1-cyanonaphthalene.

Abstract: 2-Amino-4-(4-pyridinyl)benzoic acids, such as 2-amino-4-(4-pyridinyl)benzoic acid, are prepared by treating the appropriate 4-(4-alkyl-3-nitrophenyl)pyridine with an alcoholic base, such as methanolic potassium hydroxide. The products are particularly useful in the preparation of antibacterial 1-alkyl-1,4-dihydro-4-oxo-7-pyridinyl-3-quinolinecarboxylic acids.

Abstract: Biaryl compounds are prepared by coupling an arylamine with an aromatic compound in the presence of an alkyl nitrite and about 0.04-0.6 mol of an acid having a dissociation constant of at least about 1.7.times.10.sup.-5 at 25.degree. C. and about 0.08-1.3 mols of a cuprous halide catalyst per mol of the arylamine. The invention has particular utility in the coupling with aromatic compounds of arylamines having acid-sensitive ar-substituents, e.g. flurbiprofen intermediates, such as 2-(4-amino-3-fluorobenzene)propionitrile and alkyl 2-(4-amino-3-fluorobenzene)propionates.