Synthesis of benzoxazole

A technology of benzoxazole diamine and synthesis method, which is applied in the field of synthesis technology of benzoxazole diamine, and can solve the problems of easy oxidation and low yield

Inactive Publication Date: 2005-02-23
HARBIN INST OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

2,6-bis(p-aminobenzene)benzo[1,2-d; 5,4-d']bisoxazole has few reports about its synthesis, and in the existing synthetic methods (such as US4087409), directly adopt 4,6-diaminoresorcinol or 4,6-diaminoresorcinol hydrochloride is used as raw material, synthesized with p-aminobenzoic acid in polyphosphoric acid, it is easily oxidized in the reaction, and the yield is low
The synthetic method that adopts at present is to form by condensation of 4,6-diaminoresorcinol hydrochloride and p-aminobenzoic acid in polyphosphoric acid, and the productive rate is 75%, and the lower reason of its productive rate is 4, Oxidation of 6-Diaminoresorcinol Hydrochloride

Method used

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  • Synthesis of benzoxazole
  • Synthesis of benzoxazole

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Experimental program
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specific Embodiment approach 1

[0009] Specific embodiment one: p-phenylene-2 ​​of the present embodiment, 2'-bis (5-aminobenzoxazole) is prepared like this: a, under inert gas protection atmosphere, phosphoric acid and P 2 o 5 Mix and configure polyphosphoric acid solution, wherein P in the solution 2 o 5 The concentration is controlled between 80% and 85%; b. Control the temperature at 60-120°C, add 2,4-diaminophenol hydrochloride and terephthalic acid reaction raw materials to the polyphosphoric acid solution, wherein the reaction raw materials account for 6~12% of solution gross weight, 2, the mol ratio of 4-diaminophenol hydrochloride and terephthalic acid is (2.1~3.0): 1; c, add molar mass then and be 5~10g of reaction raw material / mol of SnCl 2 Reductant, heat up to 140-210°C, react at this temperature for 2-4 hours to obtain the reaction product; d, the reaction product is neutralized, washed with water, suction filtered, and dried to obtain the initial product; e, the initial product is extracte...

specific Embodiment approach 2

[0010] Specific embodiment two: the p-phenylene-2 ​​of the present embodiment, 2'-bis (5-aminobenzoxazole) is prepared like this: a, under inert gas protection atmosphere, phosphoric acid and P 2 o 5 Mix and configure polyphosphoric acid solution, wherein P in the solution 2 o 5 The concentration is controlled between 82.5% and 83.5%; b. Control the temperature at 60-120°C, add 2,4-diaminophenol hydrochloride and terephthalic acid reaction raw materials to the polyphosphoric acid solution, wherein the reaction raw materials account for 6~12% of solution gross weight, 2, the mol ratio of 4-diaminophenol hydrochloride and terephthalic acid is (2.1~2.5): 1; c, add molar mass then and be 5~8g of reaction raw material / mol of SnCl 2 Reductant, heat up to 140-210°C, react at this temperature for 3-4 hours to obtain the reaction product; d, the reaction product is neutralized, washed with water, suction filtered, and dried to obtain the initial product; e, the initial product is e...

specific Embodiment approach 3

[0011] Specific embodiment three: p-phenylene-2,2'-bis(5-aminobenzoxazole) of the present embodiment is prepared in this way: a, under nitrogen protection, add 71.32g in a 500mL four-necked bottle 85% by weight phosphoric acid and 121.74g P 2 o 5 Make polyphosphoric acid solution; b, cool down to 60°C, add 20.69g (0.105mol) 2,4-diaminophenol hydrochloride and 8.31g (0.05mol) terephthalic acid into the polyphosphoric acid solution; C, then add 0.5g tin protochloride again, be warming up to 210 ℃, react at this temperature for 4 hours, obtain reaction product; d, after reaction product is neutralized by sodium carbonate aqueous solution, suction filtration, dry, obtain initial product; e The initial product was extracted with ethanol and water by Soxhlet respectively, and dried in vacuum to finally obtain bright yellow p-phenylene-2,2'-bis(5-aminobenzoxazole) powder with a yield of 98%.

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Abstract

Synthesis method for benzo oxazole diamine, which involves organic compound synthesis process. Said p-phenylene-2,2'-bis (5-aminobenzo oxazole) of the present invention is prepared as follows: a. Formulate phosphoric acid and P2O5 into ploy(phosphoric acid) solution; b. Add to the resulting solution 2,4-diamiophenol hydrochloride and terephthalic acid; c. Add then reducing agent SnCl2; d. Followed by neutralization, extraction and drying, then the primary product is obtained; e. Subject the primary products to extraction and drying to get bright yellow powder. And said 2,6-bis primary product to extraction and drying to get bright yellow powder. And said 2,6-bis primary product to extraction and drying to get bright yellow powder. And said 2,6-bis primary product to extraction and drying to get bright yellow powder. And said 2,6-bis primary product to extraction and dyring to get bright yellow powder. And said 2,6-bis (p-aminobenzyl) benzo [1,2-d; 5,4-d'] dioxazole is prepared as follows: a. Formulate phosphoric acid and P2O5 into ploy(phosphoric acid) solution; b. Add to the resulting solution 4,6-metaphenylene diamine hydrochloride and p-aminobenzoic acid.

Description

Technical field: [0001] The invention relates to a synthesis process of organic compounds, in particular to a synthesis process of benzoxazole diamine. Background technique: [0002] In polyphosphoric acid, the synthesis of benzoxazole compounds has attracted more attention since the 1960s. It has good stability under ultraviolet light irradiation and can be widely used as laser dyes in the near ultraviolet band. It can be used as a monomer for new polymers. Benzoxazolediamine contains a benzoxazole ring, which is an important intermediate in organic synthesis. Using the benzoxazole ring and amino group on it, it can react with other molecules to form an optical polymer containing a benzoxazole ring. And nonlinear optical materials, but also as laser dyes. In addition, through molecular design, introducing a benzoxazole structure into the polymer chain can endow it with the excellent properties of aromatic heterocyclic polymers. Usually p-phenylene-2,2'-bis(5-aminobenzoxa...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D498/04
Inventor 陈向群黄玉东
Owner HARBIN INST OF TECH
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