Back to results
US 5,703,238 AGranted
Preparation of pyridine dyes
AssigneeBASF SE
InventorsErnst Schefczik, Sabine Gruttner-Merten, Peter Saling, Rudiger Sens, Helmut Reichelt
Life of this patent
Estimating the term…
Abstract
Methine or azamethine dyes are prepared on the basis of pyridine dyes by condensing an oxime- or formyl-pyridine or its tautomeric form with 5-membered aromatic heterocycles.
Claims11
A process for preparing pyridine dyes having the formula (I):
- wherein:
- X is nitrogen or CH;
- R.sup.1 is C.sub.1 -C.sub.20 -alkyl, which is unsubstituted or substituted and which is uninterrupted or interrupted by one or more oxygen atoms in ether function, said substitution being phenyl, C.sub.1 -C.sub.4 -alkylphenyl, C.sub.1 -C.sub.4 -alkoxyphenyl, halophenyl, C.sub.1 -C.sub.8 -alkanoyloxy, C.sub.1 -C.sub.8 -alkylaminocarbonyloxy or C.sub.1 -C.sub.20 -alkoxycarbonyl;
- R.sup.2 is a 5-membered aromatic heterocyclic radical;
- R.sup.3 is hydrogen, cyano, carbamoyl, carboxyl or C.sub.1 -C.sub.4 -alkoxycarbonyl;
- R.sup.4 is oxygen or a radical of the formula C(CN).sub.2, C(CN)COOL.sup.1 or C(COOL.sup.1).sub.2, where L.sup.1 is in either case C.sub.1 -C.sub.8 -alkyl, which is uninterrupted or interrupted by one or two oxygen atoms in ether function;
- and
- R.sup.5 is hydrogen or C.sub.1 -C.sub.4 -alkyl;
- which comprises condensing a pyridine compound of the formula (II):
- ##STR17## wherein X, R.sup.1, R.sup.3, R.sup.4 and R.sup.5 are each as defined above, with a 5-membered aromatic heterocycle of the formula (Ill):
- R.sup.2 --H(III),
- wherein R.sup.2 is as defined above, in an acid reaction medium at a pH of from about 0 to about 5 at from about -10.degree. to +100.degree. C.
9 more elements
Dependencies are inferred from the claim text.