25380-15-8Relevant articles and documents
Screening of natural deep eutectic solvents for green synthesis of 2-methyl-3-substituted quinazolinones and microwave-assisted synthesis of 3-aryl quinazolinones in ethanol
Komar, Mario,Konjarevi?, Anastazija,Molnar, Maja
, (2020/07/13)
In this study, two fast and efficient protocols for green synthesis of 3-substituted quinazolinones were perfomed. A synthesis of 2-methyl-3-substituted quinazolinones was performed in natural deep eutectic solvents, while 3-aryl quinazolinones were obtained by using microwave assisted synthesis. Benzoxazinone, which was used as an intermediate in the synthesis of 2-methyl-3-substituted quinazolinones, was prepared conventionally from anthranilic acid and acetic anhydride. In order to find the most appropriate synthetic path, twenty natural deep eutectic solvents were applied as a solvent in these syntheses. Choline chloride:urea (1: 2) was found to be the most efficient solvent and was further used in the synthesis of 2-methyl quinazolinone derivatives (2–12). 3-Aryl quinazolinones (13–17), on the other hand, were synthesized in one-pot microwave-assisted reaction of anthranilic acid, different amines and trimethyl orthoformate. All compounds were synthesized in good to excellent yields, characterized by LC-MS/MS spectrometry and 1H- and 13C-NMR spectroscopy.
Synthetic method of nitrogenous heterocyclic compound
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Paragraph 0035; 0036; 0037, (2016/10/27)
The invention discloses a synthetic method of a nitrogenous heterocyclic compound, comprising: dissolving o-nitro aromatic hydrocarbon in triethylamine-methane acid mixture, adding Pd/c catalyst, irradiating with microwave at 130-180 DEG C for 5-10 min, and reacting to obtain a corresponding nitrogenous heterocyclic compound; the o-nitro aromatic hydrocarbon is o-nitro benzoyl amine or o-nitro aminobenzene.The o-nitro aromatic hydrocarbon is used as a starting material, the material is converted in the triethylamine-methane acid azeotropic mixture under microwave irradiation into a product by means of palladium catalytic transfer hydrogenation reduction and cyclic condensation, the method is efficient, environment-friendly and applicable to diversified substrates, and no side reaction occurs during the generation of the product.The reaction product is extracted with an organic reagent to remove the catalyst in the reaction system, and the nitrogenous heterocyclic compound pure product is obtained by rotary evaporation; separation and purification by column chromatography is not required.
Building heterocyclic systems with RC(OR)2+ carbocations in recyclable bronsted acidic ionic liquids: Facile synthesis of 1-substituted 1H-1,2,3,4-tetrazoles, benzazoles and other ring systems with CH(OEt)3 and EtC(OEt)3 in [EtNH 3][NO3] and [PMIM(SO3H)][OTf]
Aridoss, Gopalakrishnan,Laali, Kenneth K.
experimental part, p. 2827 - 2835 (2011/06/23)
1-Aryl/alkyl-1H-1,2,3,4-tetrazoles can conveniently be synthesized in one-pot reactions from the corresponding amines by reaction with TMSN 3 and CH(OEt)3 using the readily available, recyclable, Bronsted acidic ionic liquids [EtNH3][NO3] IL-1 and [PMIM(SO3H)][OTf] IL-2 under mild conditions in high yields. Based on comparative reactions, whereas both ILs are excellent promoters, reactions are completed with shorter reaction times and in higher yields with IL-2. Among 24 examples provided, identical products were obtained via the two ILs, except in the case of 2-aminobenzoic acid where tetrazole was formed with IL-2 and 2-ethylquinazolin-4(3H)-one was formed with IL-1. By leaving out TMS-N 3 from the reaction, the in-situ formed CH(OEt)2 + and EtC(OEt)2+ (via their corresponding orthoesters) react under sonication with o-phenylenediamine bearing various substituents, o-aminothiophenol and o-aminophenol to form a wide array of benzazoles (benzimidazole, benzothiazole and benzoxazole) and quinazolin-4(3H)-one in high yields (18 examples). The two ILs reacted differently in reaction with 2-aminobenzamide, whereas quinazolin-4(3H)one was formed with IL-2/CH(OEt)3, the "unexpected" N-ethylquinazolin-4(3H)one was isolated with IL-1/CH(OEt)3. The latter was also formed from 2-aminobenzoic acid in IL-1/CH(OEt)3. Mechanistic implications are addressed. The reported protocols enable rapid assembly of a host of heterocyclic systems in high yields with the added advantage of recycling and re-use of the ILs.
