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Method for preparing quinazoline-2-thioketone

A quinazoline and the quinazoline technology are applied in the field of preparation of organic nitrogen heterocyclic compounds, and can solve the problems of increasing the preparation cost, the complexity of the process, the unsafe reaction route, the complex reaction process, and the like, and achieve a simple preparation process. Controllable, favorable for purification, mild reaction conditions

Inactive Publication Date: 2013-08-07
SUZHOU UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] One is the reaction of aryl carbinol or aryl ketone substituted by amino group and isothiocyanate or isothiocyanate to prepare quinazoline-2-thione, such as J. Peters in the presence of hydrochloric acid, with ortho The reduction product of aminoacetophenone and KSCN were reacted at 65°C for 3 hours to prepare the product with a yield of 31% (see J. Peters, et al. Bioorg. Med. Chem. Lett. 2008.18: 262~266), But need the participation of protonic acid in this method reaction process, thereby make this reaction route exist unsafe factor, the process of reaction is complicated simultaneously; Its two is the condensation reaction (referring to J.Spindler , et al. Zeitschrift fuer Chemie. 1987.27:35~36), but the product structure of this method is limited, and the scope of application is narrow
[0005] Fukamachi first reacted acrylic acid derivatives with primary amines in methanol to obtain thiourea intermediates, and then cyclized quinazoline-2-thiones by heating at reflux temperature (see S. Fukamachi, et al. Synthesis2010.10:1593 ~1598); however, this method requires the use of more complex starting materials, which increases the cost of preparation and the complexity of the process

Method used

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  • Method for preparing quinazoline-2-thioketone
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  • Method for preparing quinazoline-2-thioketone

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] Embodiment one: catalyst [(Me 3 Si) 2 N] 3 La(μ-Cl)Li(THF) 3 Synthesis

[0035] -10°C, the n - BuLi in hexane solution (60 mmol, 2.52 M) was slowly added to the (Me 3 Si) 2 NH (60 mmol) in a 100 mL Schlenk reaction flask for 30 minutes at room temperature. The above reaction solution was added to anhydrous LaCl 3 (20 mmol) in THF (30 mL) and stirred overnight at room temperature. The solvent was removed under reduced pressure, and the obtained solid powder was extracted with hot toluene to remove LiCl, concentrated, placed at 0°C, and a large number of crystals were precipitated, which was the desired lanthanum siliconamide compound, with a yield of 85%.

[0036] Other catalysts can refer to the preparation method of Example 1.

Embodiment

[0037] Example: [(Me 3 Si) 2 N] 3 Yb( m -Cl)Li(THF) 3 Catalytic reaction of ethyl o-aminocinnamate and phenylisothiocyanate to prepare quinazoline-2-thione

[0038] In the reaction flask treated with dehydration and deoxygenation, weigh [(Me 3 Si) 2 N] 3 Yb( m -Cl)Li(THF) 3 (0.0455 g, 0.05 mmol ), added ethyl o-aminocinnamate (0.1912 g, 1 mmol ) and phenylisothiocyanate (0.1622 g, 1.2 mmol ) in sequence, stirred at 50°C for 5 hours after mixing, added water Terminate the reaction, extract three times with ethyl acetate, dry the extract with anhydrous sodium sulfate, filter, remove the solvent under reduced pressure, and finally perform flash column chromatography on a silica gel column (eluent: ethyl acetate:petroleum ether=1:10) to obtain White solid product, 80% yield.

[0039] The theoretical molecular formula of the obtained product and the main NMR test data are as follows. It can be seen from the analysis that the actual synthesized product is consistent with t...

Embodiment 3

[0042] Embodiment three: [(Me 3 Si) 2 N] 3 Sm( m -Cl)Li(THF) 3 Catalytic reaction of ethyl o-aminocinnamate and phenylisothiocyanate to prepare quinazoline-2-thione

[0043] In the reaction flask treated with dehydration and deoxygenation, weigh [(Me 3 Si) 2 N] 3 Sm( m -Cl)Li(THF) 3 (0.0445 g, 0.05 mmol ), added ethyl o-aminocinnamate (0.1912 g, 1 mmol ) and phenylisothiocyanate (0.1622 g, 1.2 mmol ) in sequence, stirred at 50°C for 5 hours after mixing, added water Terminate the reaction, extract three times with ethyl acetate, dry the extract with anhydrous sodium sulfate, filter, remove the solvent under reduced pressure, and finally perform flash column chromatography on a silica gel column (eluent: ethyl acetate:petroleum ether=1:10) to obtain White solid product, 90% yield.

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Abstract

The invention discloses a method for preparing quinazoline-2-thioketone. The method comprises the steps of: under the catalysis of silicoamino rate-earth compound [(Me3Si)2N]3Ln(mu-Cl)Li(THF)3s erving as a catalyst; and preparing the quinazoline-2-thioketone by addition reaction of catalytic o-amino ethyl cinnamate and isothiocyanate, wherein Ln represents a triad rate-earth metal ion and is one of lanthanum, neodymium, samarium or ytterbium; (Me3Si)2N represents trimethyl silicoamino; mu- represents a bridged bond; THF represents tetrahydrofuran; the chemical structural formula of the o-amino ethyl cinnamate and isothiocyanate is shown in the specification; and the general formula of the chemical structure of the isothiocyanate is RNCS. In the method, the catalyst is good in chemical selectivity, high in reactivity, mild in reaction condition and in no need of a solvent, and the yield of a target product is high.

Description

technical field [0001] The invention belongs to the technical field of preparation of organic nitrogen heterocyclic compounds, and in particular relates to a catalytic preparation method of quinazoline-2-thione. Background technique [0002] Quinazoline compounds widely exist in natural biologically active molecules and synthetic drugs, and compounds containing quinazoline-2-thione skeletons have been found to have unique physiological activities and have attracted the attention of researchers. [0003] In the prior art, the reported synthesis methods of quinazoline-2-thione mainly adopt two routes. [0004] One is the reaction of aryl carbinol or aryl ketone substituted by amino group and isothiocyanate or isothiocyanate to prepare quinazoline-2-thione, such as J. Peters in the presence of hydrochloric acid, with ortho The reduction product of aminoacetophenone and KSCN were reacted at 65°C for 3 hours to prepare the product with a yield of 31% (see J. Peters, et al. Bioor...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01J31/22C07D239/78
Inventor 徐凡花露姚志刚
Owner SUZHOU UNIV
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