GB1490582A - Heterocyclic compounds - Google Patents

Abstract

1490582 Heterocyclic compounds; dyestuffs SANDOZ Ltd 28 Nov 1974 [28 Nov 1973 16 Aug 1974] 50900/74 Heading C4P The invention comprises a compound of the formula in which R 1 signifies a divalent, mono-or binuclear aromatic radical of the carbocyclic or heterocyclic series, R 2 signifies a hydrogen atom, an unsubstituted or substituted C 1-4 alkyl, phenyl, naphthyl or mono- or binuclear heterocyclic radical which is bound through a ring carbon atom, R 3 signifies an oxygen atom or a group of the formula = N-R 5 in which R 5 has one of the significances given above for R 2 and each of the R 4 's which may be the same or different signifies a mono- or binuclear aromatic radical of the carbocyclic or heterocyclic series which is bound through a ring carbon atom, or mixtures of such compounds. The compound or mixture of compounds I is obtained by reacting a compound of formula II with a compound of formula H 2 N-R 2 (III) or a mixture of compounds of formula III in a 1 : 1 or 1 : 2 molar ratio. If a single compound of formula III is reacted with a compound of formula II in a 1 : 1 molar ratio a mixture comprising compounds where R 3 is O and compounds where R 3 is >N-R 2 is obtained. With a 2 : 1 ratio a substantially pure product where R 3 is >N-R 2 is obtained. The reaction where R 2 is other than H is carried out in anhydrous alkane acid or anhydride in the presence of an alkane acid alkali metal salt. When compound III is ammonia the reaction can be effected in an aqueous alkaline medium. Sulphonation of the products by known methods can be carried out. When sulphonic groups are present in R 4 the compounds are useful as anionic dyes. Where one or both of R 2 and R 5 are other than hydrogen and no sulpho groups are present the products are useful as disperse dyes. The compounds wherein R 2 and R 5 are hydrogen are useful as pigments for plastics, e.g. polyethylene, polystyrene, PVC, rubber or synthetic leather, coatings. lacquers, spinning solutions, printing inks, paper. The pigments can be improved by after-treatment at elevated temperature in solvents such as chlorobenzene, nitrobenzene, dimethylformamide, acetic acid, glycol or quinoline. In an example (62) a different method of preparation is used in which a compound of the formula a is heated with aniline in butanol while passing in ammonia gas. The compound obtained of formula is heated at 270‹ in diethyl phthalate to effect cyclization, giving a product of the formula