# US 5,703,238 A · Preparation of pyridine dyes

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- Number: US 5,703,238 A
- Document ID: US5703238A
- Status: Granted
- Kind: A
- Application number: 08/682,626
- Filed: 1996-07-30
- Granted: 1997-12-30
- Earliest claimed: 1994-02-02
- Assignees: BASF SE
- Inventors: Ernst Schefczik; Sabine Gruttner-Merten; Peter Saling; Rudiger Sens; Helmut Reichelt
- Web page: https://patentgrep.com/patent/US5703238A

## CPC

- C07D 471/04: Ortho-condensed systems
- C09B 55/009: {Azomethine dyes, the C-atom of the group -C=N- being part of a ring (Image)}
- C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08)
- C09B: ORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES {, e.g. PIGMENTS}; MORDANTS; LAKES (fermentation or enzyme using processes to synthesise a desired chemical compound C12P)

## 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.

## Claims

### Claim 1

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.

### Claim 2 (depends on 1)

The process of claim 1, wherein R.sup.5 is methyl.

### Claim 3 (depends on 1)

The process of claim 1, wherein R.sup.3 is cyano.

### Claim 4 (depends on 1)

The process of claim 1, wherein R.sup.4 is oxygen.

### Claim 5 (depends on 1)

The process of claim 1, wherein X is nitrogen.

### Claim 6 (depends on 1)

The process of claim 1, wherein R.sup.2 is a radical of pyrrole, thiazole, thiophene or indole series.

### Claim 7 (depends on 1)

The process of claim 1, wherein the condensation is carried out at from about 20.degree. to 80.degree. C.

### Claim 8 (depends on 1)

The process of claim 1, wherein R.sup.2 is selected from the group consisting of ##STR18## wherein: n is 0 or 1,
L.sup.4 and L.sup.5 are indentical or different and each is independently of the other hydrogen or else with the exception of hydroxyl the abovementioned radical R.sup.1 or together with the nitrogen atom bonding them together a 5- or 6-membered saturated heterocyclic radical with or without further hetero atoms,
L.sup.6 is hydrogen, halogen, C.sub.1 -C.sub.8 -alkyl, substituted or unsubstituted phenyl, substituted or unsubstituted benzyl, cyclohexyl, thienyl, hydroxyl or mono-C.sub.1 -C.sub.8 -alkylamino,
L.sup.7 and L.sup.8 are each independently of the other hydrogen, hydroxyl, unsubstituted or phenyl- or C.sub.1 -C.sub.4 -alkylphenyl-substituted C.sub.1 -C.sub.8 -alkyl, unsubstituted or phenyl- or C.sub.1 -C.sub.4 -alkylphenyl-substituted C.sub.1 -C.sub.8 -alkoxy, C.sub.1 -C.sub.8 -alkanoylamino, C.sub.1 -C.sub.8 -alkylsulfonylamino or C.sub.1 -C.sub.8 -mono- or dialkylaminosulfonylamino,
L.sup.9 is cyano, carbamoyl, mono- or di(C.sub.1 -C.sub.8 -alkyl) carbamoyl, C.sub.1 -C.sub.8 -alkoxycarbonyl or substituted or unsubstituted phenyl, and
L.sup.10 is halogen, hydrogen, C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy, C.sub.1 -C.sub.4 -alkylthio, substituted or unsubstituted phenyl or thienyl.

### Claim 9 (depends on 7)

The process of claim 7, wherein the condensation is carried out at from 30.degree. to 70.degree. C.

### Claim 10 (depends on 1)

The process of claim 1, wherein the condensation is carried out at a pH of from about 1 to 3.

### Claim 11 (depends on 10)

The process of claim 10, wherein the condensation is carried out at a pH of about 2.