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EP0435149A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Method of producing 3-dibutylamino-6-methyl-7-anilinofluoran

Assignee: Yamamoto Chemicals Inc
•
Filing: 1990-12-19
•
Granted: —
•
Expires: 2010-12-19
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Abstract

Abstract A method of producing a high melting point 3-dibutylamino-6-methyl-7-anilinofluoran characterized by peaks at diffraction angle (2ϑ) of 6.9°,11.0°, 18.5° and 18.9° in X-ray diffractiometry using Cu-Kα ray and having a melting point in the range of 179-186°C, which comprises: condensing 2-(4-dibutylamino-2-hydroxy-benzoyl)benzoic acid with 4-methoxy-2-methyldiphenylamine in the presence of concentrated sulfuric acid to provide a phthalide at a temperature in the range of 0-50°C , neutralizing the phthalide, and then subjecting the phthalide to ring closure reaction using an alkali in an amount of 0.5-15 mols per mol of the compound used in smaller amounts of 2-(4-dibutylamino-2-hydroxybenzoyl)benzoic acid and 4-methoxy-2-methyldiphenylamine at a temperature of not less than 50°C in the presence or absence of an organic solvent.

Inventors

  • 👤 Hiroaki C/O Yamamoto Chemicals Inc. Harada
  • 👤 Yasuhisa C/O Yamamoto Chemicals Inc. Iwasaki

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-10-23 14:17
CPC Classifications
C; C07; C07D; C07D493/00; C07D493/02; C07D493/10; C09; C09B; C09B11/00; C09B11/04; C09B11/10; C09B11/24

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 116 words
A method of producing a high melting point 3-dibutylamino-6-methyl-7-anilinofluoran characterized by peaks at diffraction angle (2ϑ) of 6.9°,11.0°, 18.5° and 18.9° in X-ray diffractiometry using Cu-Kα ray and having a melting point in the range of 179-186°C , which comprises: condensing 2-(4-dibutylamino-2-hydroxybenzoyl)benzoic acid with 4-methoxy-2-methyldiphenylamine in the presence of concentrated sulfuric acid to provide a phthalide at a temperature in the range of 0-50°C, neutralizing the phthalide, and then subjecting the phthalide to ring closure reaction using an alkali in an amount of 0.5-15 mols per mol of the compound used in smaller amounts of 2-(4-dibutylamino-2-hydroxybenzoyl)benzoic acid and 4-methoxy-2-methyldiphenylamine at a temperature of not less than 50°C in the presence or absence of an organic solvent.
Claim 2
Dependent Claim 41 words
The method as claimed in claim 1 wherein the ring closure reaction is carrid out in the presence of an organic solvent which is insoluble or only slightly soluble in water and has a boiling point of not less than 60°C.
Claim 3
Dependent Claim 30 words
The method as claimed in claim 2 wherein the organic solvent is an aromatic hydrocarbon, a halogenated aromatic hydrocarbon, a halogenated aliphatic hydrocarbon, an aliphatic hydrocarbon or an alicyclic hydrocarbon.
Claim 4
Dependent Claim 17 words
The method as claimed in claim 2 wherein the organic solvent is amyl alcohol or octyl alcohol.
Claim 5
Dependent Claim 32 words
The method as claimed in claim 1 wherein the alkali is used in an amount of 2-10 mols per mol of the compound used in smaller amounts of 2-(4-dibutylamino-2-hydroxybenzoyl)benzoic acid and 4-methoxy-2-methyldiphenylamine.

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