Preparation method of cyclic tetrapolybutylene terephthalate

A technology of butylene phthalate and phthalic acid chloride, applied in the field of compound preparation, can solve the problems of low yield, complicated operation, high cost and the like, and achieve the effects of high yield, high product quality and low cost

Inactive Publication Date: 2018-08-24
EAST CHINA NORMAL UNIV +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The method has low yield, complicated operation and high cost

Method used

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  • Preparation method of cyclic tetrapolybutylene terephthalate
  • Preparation method of cyclic tetrapolybutylene terephthalate
  • Preparation method of cyclic tetrapolybutylene terephthalate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0049] 1-1. In a single-necked bottle, add 19.7g of terephthaloyl chloride into 70mL of tetrahydrofuran, add 35g of 1,4-butanediol, drop into ice water, slowly add 23g of pyridine dropwise, and gradually rise to room temperature under nitrogen protection React for 4 hours. After the reaction is complete, add dichloromethane, wash with water, dilute hydrochloric acid and saturated sodium bicarbonate solution successively, dry over anhydrous sodium sulfate, filter, and then concentrate under reduced pressure, use (V (petroleum ether) : V (ethyl acetate) = 5 ︰1) Beating to obtain 20.3 g of bis(4-hydroxy-butyl) terephthalate, compound I, with a yield of 67%.

[0050] 1 HNMR (CDCl 3 , 400MHz), δ: 8.10(s, 4H); 4.40(t, 4H, J=6.5Hz); 3.74(t, 4H, J=6.4Hz); 1.94~1.85(m, 4H); 1.78~1.70( m, 4H).

[0051] MS (ESI), m / z: 311 [M+H] + .

[0052] 1-2. In a single-necked bottle, add 19.7g of terephthaloyl chloride into 70mL of dichloromethane, add 69.9g of 1,4-butanediol, drop into ice wa...

Embodiment 2

[0059] 2-1. In a single-necked bottle, add 6.79g of compound I and 11.2g of monobenzyl terephthalate into 100mL of dichloromethane, then add 0.67g of dimethylaminopyridine and 17.5g of EDCI, and react at room temperature under nitrogen protection 10 hours. After completion of the reaction, wash with dilute hydrochloric acid and saturated sodium carbonate solution successively, dry over anhydrous sodium sulfate, filter, then concentrate under reduced pressure, heat up and reflux with methanol for beating, and obtain 9.7g of white solid after filtration: bis(4-(4-benzyl Oxy-terephthaloyloxy) butyl) terephthalate is compound II, and the yield is 65%.

[0060] 1 HNMR (CDCl 3 , 400MHz), δ: 8.07-8.00 (m, 12H); 7.39-7.26 (m, 10H); 5.31 (s, 4H); 4.36 (s, 8H); 1.89 (s, 8H).

[0061] MS (ESI), m / z: 787 [M+H] + .

[0062] 2-2. In a single-necked bottle, add 6.79g of compound I and 14g of monobenzyl terephthalate into 100mL of chloroform, then add 0.67g of dimethylaminopyridine and 1...

Embodiment 3

[0072] 3-1. In a single-necked bottle, add 7.1g of compound II into 80mL of tetrahydrofuran, add 1.42g of 10% palladium on carbon, and 0.36g of trifluoroacetic acid, and hydrogenate at room temperature and pressure for 17 hours. After evaporating the solvent to dryness, dichloromethane was added, 2.75 g of 1,8-diazabicycloundec-7-ene (DBU) was added, and palladium carbon was removed by suction filtration. After the filtrate was concentrated under reduced pressure, 1M dilute hydrochloric acid was added to precipitate a white solid. After suction filtration, the crude product was slurried with methanol to obtain 4.18 g of white solid: 4,4'-[terephthaloylbis-(oxytetramethyleneoxycarbonyl)]dibenzoic acid, compound III, with a yield of 74% .

[0073] 1 HNMR (DMSO-d 6 , 400MHz), δ: 8.06 (d, 12H, J=4.7Hz); 4.38 (s, 8H); 1.90 (s, 8H).

[0074] 3-2. In a single-necked bottle, add 7.1 g of compound II to 80 mL of methanol, add 1.42 g of 10% palladium on carbon, and 0.71 g of trifluo...

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Abstract

The invention discloses a preparation method of cyclic tetrapolybutylene terephthalate. The method comprises the steps as follows: a) an initial material, namely, terephthaloyl dichloride, reacts with1,4-butanediol under the action of an alkaline reagent, and terephthalic bis(4-hydroxyl-butyl)ester, namely, a compound I, is obtained; b) the compound I reacts with monobenzyl terephthalate under the action of a condensing agent, and bis(4-(4-benzyloxy terephthaloyl)butyl)terephthalate, namely, a compound II, is obtained; c) the compound II is dissolved in a proper solvent, a catalyst is added to reduce debenzylation under the action of palladium-carbon and hydrogen, and 4,4'-[terephthaloyl bis(oxytetramethylene oxycarbonyl)]dibenzoic acid, namely a compound III, is obtained; d) the compoundIII reacts with the compound I under the action of a condensing agent, and the target product, namely, cyclic tetrapolybutylene terephthalate, is obtained. The method is low in cost, short in synthesis route, convenient to operate, high in product quality and good in industrial application value.

Description

technical field [0001] The invention relates to the technical field of compound preparation, and relates to a preparation method of cyclic tetrapolybutylene terephthalate. Background technique [0002] Polybutylene terephthalate (PTB) is a polymer of terephthalic acid and 1,4-butanediol. PBT is a thermoplastic polyester engineering plastic with excellent performance. It has the advantages of high rigidity and hardness, good thermal stability, good chemical corrosion resistance and excellent wear resistance. It is widely used in mechanical equipment, precision instruments, textiles and other fields. Applications. [0003] During the production of PBT, some cyclic polymers with a low degree of polymerization will be produced, such as trimers, tetramers, and pentamers of cyclic butylene terephthalate (Formula 1). Although the content of these cyclic cyclic oligomers in PBT plastics is very small, its content is usually an important indicator for analyzing and detecting the qu...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D323/00
CPCC07D323/00
Inventor 罗宇周朴李晓林张玉柳朱皓庭何洋占莉杨世琼李倩康立涛
Owner EAST CHINA NORMAL UNIV
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