Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Method for producing bisbenzoxazoles

A technology of benzoxazole and conjugated double bond, which is applied in the field of preparing bisbenzoxazole and can solve problems such as undesired effects and the like

Inactive Publication Date: 2009-08-26
CLARIANT FIANCE (BVI) LTD
View PDF0 Cites 10 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the residue that these by-products leave in the product can also sometimes cause very undesired effects

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for producing bisbenzoxazoles
  • Method for producing bisbenzoxazoles
  • Method for producing bisbenzoxazoles

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0061] Example 1: Preparation of 1,4-bis-(benzoxazol-2'-yl)-naphthalene

[0062] Suspend 3.55 g (16.4 mmol) of naphthalene-1,4-dicarboxylic acid and 4.05 g (37.1 mmol) of o-aminophenol in 12.1 g of 1,2,3,4-tetralin and stir under argon Heat to 180°C for 20 minutes. The ammonium salt-containing suspension thus obtained was admixed with 0.35 g of boric acid and 0.1 g of p-toluenesulfonic acid and exposed to microwave irradiation at 300 W for 2 hours in a vessel with KPG-stirrer and water trap. A temperature of about 230° C. measured by means of an IR sensor was reached. This temperature is kept constant by evaporative cooling. The reaction mixture was then cooled to room temperature within 10 minutes, where the product crystallized out in the form of yellow needles.

[0063] HPLC of the reaction batch mixture showed complete conversion of naphthalene-1,4-dicarboxylic acid to 1,4-bis-(2"-benzoxazolyl)-naphthalene. After filtration, the crystals were washed with methanol and dr...

Embodiment 2

[0063] HPLC of the reaction batch mixture showed complete conversion of naphthalene-1,4-dicarboxylic acid to 1,4-bis-(2"-benzoxazolyl)-naphthalene. After filtration, the crystals were washed with methanol and dried After that, 1,4-bis-(benzoxazol-2'-yl)-naphthalene with a purity of more than 99.5% was obtained. Embodiment 2: Preparation of 1,4-bis-(benzoxazol-2'-yl)-naphthalene in a closed system 2'-yl)-naphthalene

[0064] 0.71 g (3.3 mmol) of naphthalene-1,4-dicarboxylic acid and 0.81 g (7.4 mmol) of o-aminophenol were suspended in 2.4 g of N-methylpyrrolidone with stirring in a pressure-resistant glass test cell. After addition of 169 μl of tetrabutoxytitanium, the ammonium-salt-containing suspension thus prepared was exposed to microwave radiation at 300 W for 15 minutes in a pressure-resistant, closed test chamber with stirring and external cooling. A temperature of about 225[deg.] C., measured by means of an IR sensor, is reached, with the pressure rising to approximate...

Embodiment 3

[0066] Example 3: Preparation of 1,2-bis-(5-methylbenzoxazol-2'-yl)-ethene

[0067] 2.3 g of fumaric acid and 5.52 g of o-amino-p-cresol were homogenized in 12.45 g of tetralin with heating and stirring. The ammonium salt-containing suspension thus prepared was admixed with 42 mg boric acid and 12 mg p-toluenesulfonic acid and exposed to microwave irradiation at 300 W for 30 minutes with stirring in an open apparatus with complete external cooling. A temperature of about 220° C. measured by means of an IR sensor was reached. The reaction mixture was then cooled to room temperature within 10 minutes. The yield of 1,2-bis-(5-methylbenzoxazol-2'-yl)-ethylene was 65% based on fumaric acid.

[0068] After filtering off, washing the crystals with methanol, extracting the remaining acid by stirring with alcoholic sodium hydroxide solution and drying, 1,2-bis-(5-methylbenzoxazole-2' with a purity of more than 98% is obtained -yl)-ethylene.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention relates to a method for producing bisbenzoxazoles that are interconnected by means of a system of conjugated double bonds, according to which o-aminophenols are reacted with dicarboxylic acids, the carboxyl groups of which are interconnected via a double bond or a system of conjugated double bonds, to form an ammonium salt, said ammonium salt being converted in the presence of dehydrogenating catalysts and solvents with a low dielectric loss into benzoxazol by means of microwave radiation.

Description

technical field [0001] Bis-benzoxazol-2-yl-substituted compounds in which two benzoxazol-2-yl groups are linked to each other by a system of conjugated double bonds have been obtained as natural, synthetic Industrial importance of dyes, UV-absorbers and optical brighteners for semi-synthetic and semi-synthetic fibers. The compounds are used, for example, as spin brighteners, as brighteners for polyolefin fibers or in textile applications. Background technique [0002] Benzoxazoles are generally prepared from 2-aminophenols by reaction with carboxylic acid derivatives by Schiff base or cyclization of 2-hydroxy-N-anilides. [0003] For example according to DE-A-2009156, 4,4'-bisbenzoxazole compounds can be prepared from 2-aminophenol and diphenylcarboxylic acid and derivatives thereof. Here, the reaction of the free dicarboxylic acid requires very long reaction times at elevated temperatures and leads to only low yields. [0004] In order to achieve commercially satisfactor...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): C07D263/62C07D263/64
CPCC07D263/62C07D413/10C07D263/64C07D413/06
Inventor M·克鲁尔A·勒施尔R·莫施豪瑟N·毕耶H·戈瑟弗尔H·里特S·施米茨
Owner CLARIANT FIANCE (BVI) LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com