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Method for preparing polysubstituted 2-naphthol

A multi-substitution, naphthol technology, applied in pharmaceutical and chemical intermediates and related chemical fields, can solve the problems of difficult synthesis of raw materials and many reaction steps, and achieve the effect of environmental friendliness and short synthesis route

Active Publication Date: 2014-04-02
DALIAN UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Kozlowski et al. used polysubstituted phenylacetic acid as a raw material to first generate the corresponding acid chloride, then reacted with diethyl malonate, and finally undergo cationic cyclization to obtain polysubstituted 2-naphthol (see: Org.Lett.2007, 9, 385-388; Adv.Synth.Catal.2007, 349, 583-594; Angew.Chem.Int.Ed.2008, 47, 6877-6880; J.Org.Chem.2010, 75, 16-29. ), but this method has many reaction steps and needs strong acid and strong base to proceed smoothly
In summary, most of the above-mentioned methods for obtaining substituted 2-naphthols by intramolecular ring formation currently reported have disadvantages such as difficult synthesis of raw materials and many reaction steps.

Method used

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  • Method for preparing polysubstituted 2-naphthol
  • Method for preparing polysubstituted 2-naphthol
  • Method for preparing polysubstituted 2-naphthol

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0054]

[0055] Add Pd(Ph 3 P) 4 (555mg, 0.48mmol, 2mol%), o-bromobenzyl bromide (1a, 5.7g, 24mmol), 1,4-dioxane (96mL), tributylallyltin (7.9g, 24mmol), and Then connect to a CO constant pressure device, put it into an 80°C oil bath and heat and stir for 12h (during which the CO pressure is kept constant at 0.2MPa). Cool to room temperature, release excess gas, remove the solvent under reduced pressure, perform direct silica gel column chromatography, elute sequentially with petroleum ether, petroleum ether: ethyl acetate = 20:1, spin dry, and dissolve the obtained product in 20 mL Ethyl acetate was passed through a layer of basic alumina to obtain 2a (4.4g of light yellow liquid, yield 76%, Z / E=20 / 80, GC ratio), and further separation by silica gel column chromatography can obtain Z and E formula respectively configuration product. 2a-Z formula, pale yellow liquid: 1 H NMR (400MHz, CDCl 3 )δ7.57(dd, J=8.0, 0.8Hz, 1H), 7.30-7.21(m, 2H), 7.15-7.11(m, 1H), 6.30-6.21(m, ...

Embodiment 2

[0058]

[0059] Add Pd(Ph 3 P) 4 (555mg, 0.48mmol, 2mol%), 1-bromo-2-naphthylbenzyl bromide (1b, 7.6g, 24mmol), toluene (96mL), tributylallyltin (7.9g, 24mmol), and then connect To the CO constant pressure device, put it into an 80°C oil bath to heat and stir for 12h (during which the CO pressure was kept constant at 0.4MPa). Cool to room temperature, release excess gas, remove the solvent under reduced pressure, perform direct silica gel column chromatography, elute sequentially with petroleum ether, petroleum ether: ethyl acetate = 20:1, spin dry, and dissolve the obtained product in 20 mL Ethyl acetate was passed through a layer of basic alumina to obtain 2a (4.4g of light yellow liquid, yield 63%, Z / E=25 / 75, GC ratio), and further separation by silica gel column chromatography can obtain Z and E respectively configuration product. 2b-Z, pale yellow solid: 1 H NMR (400MHz, CDCl 3 )δ8.31(d, J=8.5Hz, 1H), 7.83-7.77(m, 2H), 7.61-7.49(m, 2H), 7.33(d, J=8.4Hz, 1H), 6.29-...

Embodiment 3

[0062]

[0063] Add Pd(Ph 3 P) 4 (555mg, 0.48mmol, 2mol%), 2-bromo-4methylbenzyl bromide (1c, 6.7g, 24mmol), MeCN (96mL), tributylallyltin (7.9g, 24mmol), and then ligated To the CO constant pressure device, put it into an 80°C oil bath to heat and stir for 24h (during which the CO pressure was kept constant at 0.3MPa). Cool to room temperature, release excess gas, remove the solvent under reduced pressure, perform direct silica gel column chromatography, elute sequentially with petroleum ether, petroleum ether: ethyl acetate = 20:1, spin dry, and dissolve the obtained product in 20 mL Ethyl acetate was passed through a layer of basic alumina to obtain 2c (4.6g of light yellow liquid, yield 76%, Z / E=21 / 79, GC ratio), and further separation by silica gel column chromatography can obtain Z and E formula respectively configuration product. 2c-Z, pale yellow liquid: 1 H NMR (400MHz, CDCl 3 )δ7.41(s, 1H), 7.17-7.01(m, 2H), 6.35-6.15(m, 2H), 3.86(s, 2H), 2.32(s, 3H), 2.12(d,...

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Abstract

The invention belongs to the field of fine chemical and relates to a pharmaceutical and chemical intermediate and a related chemical technology, in particular to a method for preparing polysubstituted 2-naphthol by synthesizing o-halogen benzyl ketene from o-halogen benzyl halide, tributyl allyl tin and carbon monoxide which are used as raw materials and then carrying out intramolecular Heck reaction. The method for preparing the polysubstituted 2-naphthol is characterized in that the o-halogen benzyl halide, the tributyl allyl tin and, the carbon monoxide and aryl bromide are used as raw materials and the zero-valent or divalent palladium is used as catalyst to carrying out the intramolecular Heck reaction in an organic solvent. The invention mainly provides a novel method for preparing the polysubstituted 2-naphthol, and the novel method has the advantages of good functional group compatibility, a wide range of substrates, environment friendliness, and a single reaction product without isomers, etc.

Description

technical field [0001] The invention relates to the field of pharmaceutical and chemical intermediates and related chemical technologies, and relates to a method for preparing multi-substituted 2-naphthols. Background technique [0002] 2-Naphthol, also known as β-naphthol, is an important organic chemical raw material and pharmaceutical synthesis intermediate. There are more than 130 kinds of dyes and pigments directly synthesized from it, and more than 20 dye intermediates. It is also widely used in medicine, pesticides, rubber additives, spices, leather tanning, textile printing and dyeing additives, and mineral processing agents. [0003] Intramolecular ring formation is one of the important methods for the synthesis of multi-substituted 2-naphthols, but the early reactions were mostly carried out under the conditions of strong acid and strong base, which required stoichiometric additives to promote the reaction, or required higher reaction temperatures, And the substra...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07B41/02C07C37/07C07C39/14C07C39/12C07C41/26C07C43/23
Inventor 包明冯秀娟于晓强戴耀江华
Owner DALIAN UNIV OF TECH
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