Synthesis of 2,3-Dihydroquinazoline-4(1H)-ones

An efficient, inexpensive, and heterogeneous catalyst, [Al(H₂PO₄)₃], was applied in a three-component, one-pot cyclocondensation reaction of isatoic anhydride with primary amines (or ammonium salts) and aldehydes to afford the corresponding quinazolinone derivatives in excellent yields. Reactions occurred under thermal solvent-free conditions. It was found that this solid acidic catalyst could be easily recovered and reused for at least three cycles without any loss of activity.     

2-芳基-2,3-二氢4(1H)-喹唑啉酮类化合物的合成

在NaHSO4催化下,以苯甲醛和邻氨基苯甲酰胺为底物,在室温下合成了一系列2-芳基-2,3-二氢-4(1H)-喹唑啉酮类化合物,该反应产率高、操作简单、并且避免使用有毒的金属催化剂.     

6-(3-氨基苯基)-4, 5-二氢哒嗪-3(2H)-酮的合成

以苯、丁二酸酐为原料,经傅克酰基化,硝化,与水合肼反应三步反应合成6-(3-氨基苯基)-4,5-二氢哒嗪-3(2H)-酮(1),总收率为58.3%。由3-(3-硝基苯甲酰基)丙酸(3)合成化合物1的过程中,在雷尼镍(Raney Ni)的催化下与水合肼反应,一步完成了苯环上硝基的还原和成环。重点考察了该步反应的物料配比、反应时间对产率的影响。结果表明,水合肼与化合物3的摩尔比11.7∶1,回流反应4 h,产率为82.7%。     

Synthesis and Anti-HIV-1 Activity of 2-[2-(3,5-Dimethylphenoxy)ethylthio]pyrimidin-4(3H)-ones

New 2-[2-(3,5-dimethylphenoxy)ethyl]thio derivatives of pyrimidin-4(3H)-one containing various substituents at positions 5 and 6 of the pyrimidine ring were synthesized. It was shown that alkylation of 2-thiouracils with 1-bromo-2-(3,5-dimethylphenoxy)ethane in DMF takes place exclusively at the sulfur atom. The obtained 6-benzyl and 6-(2,6-difluorobenzyl) derivatives have clearly defined virus-inhibiting properties with respect to type 1 human immunodeficiency virus in vitro and suppress its reproduction by 50% at concentrations of 1.3 and 11.2 mM respectively.     

Highly efficient synthesis of 2,3-dihydroquinazolin-4(1H)-ones catalyzed by heteropoly acids in water

<正>Heteropoly acids efficiently catalyzed the cyclocondensation reaction of anthranilamide with aldehydes in water at ambient temperature and afforded the corresponding 2,3-dihydro-4(1H)-quinazolinones compounds in good to excellent yields.This method provides mild reaction conditions and clean reaction profiles,using a small quantity of catalyst and a simple workup procedure.     

Synthesis of 2,3-dihydroquinazolin-4(1H)-ones catalyzed by α-chymotrypsin

We discovered that α-chymotrypsin has a promiscuous ability to catalyze the cyclocondensation of aromatic and aliphatic aldehydes with 2-aminobenzamides to afford the corresponding 2,3-dihydroquinazolin-4(1H)-ones successfully in high yields (90%-98%) under alcohol solvent. The catalytic activity of α-chymotrypsin was evaluated through investigating the temperature, the enzyme loading and the ratio of substrates in the enzyme-catalyzed reactions. The present method proves to be efficient and environmentally friendly in terms of short reaction time, high yield, green catalyst and the clean products obtained without further purification processes.     

New route to 2-arylthieno[2,3-d]pyrimidin-4(3H)-ones and isolation of the unoxidized intermediates

Abstract  A new route to the synthesis of 2-arylthieno[2,3-d]pyrimidin-4(3H)-ones has been developed through heterocyclization of 2-amino-4,5-dimethylthiophene-3-carboxamide with aromatic aldehydes in boiling glacial acetic acid followed by air oxidation. The unoxidized intermediates, 2-aryl-2,3-dihydrothieno[2,3-d]pyrimidin-4(1H)-ones, are isolated when the reactions are carried out either at room temperature or under a nitrogen atmosphere. Graphical Abstract        

Chelating Group Enabled Palladium-Catalyzed Regiodivergent Carbonylative Synthesis of 2,3-Dihydroquinolin-4(1H)-ones

A new procedure on palladium-catalyzed carbonylative cyclization of N-(2-pyridyl)sulfonyl (N-SO₂Py)-2-iodoanilines with terminal alkenes has been developed for the rapid construction of dihydroquinolin-4(1H)-one scaffolds. Enabled by the chelating group and using benzene-1,3,5-triyl triformate (TFBen) as the CO source, both aromatic and aliphatic alkenes were smoothly transformed into the corresponding 2,3-dihydroquinolin-4(1H)-ones in good yields with excellent regioselectivities. Notably, the reaction of aromatic alkenes produces 2-aryl-2,3-dihydroquinolin-4(1H)-ones, while 3-alkyl-2,3-dihydroquinolin-4(1H)-ones were obtained when aliphatic alkenes were used. This protocol has been applied in the synthesis of antitumor agent A as well.     

Quinoxaline-2,3(1H,4H)-dithione: Synthesis and reactions

Quinoxaline-2,3(1H,4H)-dithione can be synthesized efficiently through the thionation of quinoxaline-2,3(1H,4H)-dione with phosphorous pentasulfide. It can also be obtained by reaction of 2,3-dichloroquinoxaline with thiourea or sodium hydrogen sulfide. The most common reactions of quinoxaline-2,3(1H,4H)-dithione involve deprotonation and electrophilic attack at the sulfur atoms to give various substituted derivatives and poly-fused heterocyclic ring systems. The current review aims to provide a survey of the developments in quinoxaline-2,3(1H,4H)-dithione chemistry until 2016.     

4-羟基-2(1H)-吡啶酮-3-甲酰胺类冬青生菌素类似物的合成与生物活性

以反式-4-羟基肉桂酸为起始原料,经乙酰化、酰基叠氮、curtius重排、加成和环合等6步反应合成了4-羟基-2(1 H)-吡啶酮-3-甲酰胺类冬青生菌素类似物,总收率17%.随后用滤纸片扩散法对该化合物的抑菌性能进行了初步研究.实验表明,该化合物对于白色念珠菌具有较好的抑制作用,对于酵母菌抑制作用较弱,对大肠杆菌和金黄色葡萄球菌基本无抑制作用.     

One-Pot Synthesis of Novel 2-(Thiazol-2-yl)-4,5-dihydropyridazin-3(2H)-one Derivatives Catalyzed by Activated KSF

A series of 2-(thiazol-2-yl)-4,5-dihydropyridazin-3(2H)-one derivatives were synthesized by one-pot multicomponent cyclocondensation of ketoacid, thiosemicarbazide, and phenacyl bromide using catalytical amount of KSF in EtOH under reflux. The straightforward synthesis, presence of two important class of heterocyclic rings in the individual molecule, easy workup of the products, rapid reaction, mild conditions, and good to excellent yields are notable features of this protocol.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]     

2-羟基-4-磺酰氨基苯-3-(4-硝基苯)-三氮烯的合成及与镍的显色反应

合成了新的三氮烯试剂2 羟基4 磺酰氨基苯3 (4 硝基苯) 三氮烯(HSNPT) ,并研究了在TritonX 1 0 0表面活性剂存在下与镍的显色反应。在pH 1 0～1 2. 0的Na2 B4 O7 NaOH缓冲溶液中,试剂与镍形成配合比为3∶1型淡黄色配合物。配合物最大负吸收峰位于λ=5 40nm处,表观摩尔吸光系数1 .1 8×1 0 5L·mol- 1·cm- 1。Ni2 +的质量浓度在0～480 μg/L范围内符合比尔定律。用拟定方法测定合金钢样品中的微量镍,结果满意。     

Vitamin B12:An efficient type catalyst for the one-pot synthesis of 3,4,5-trisubstituted furan-2(5H)-ones and N-aryl-3-aminodihydropyrrol-2-one-4-carboxylates

Vitamin B12 was applied as catalyst for the one-pot three-component synthesis of 3,4,5-trisubstituted furan-2(5H)-ones from the condensation between aldehydes, amines and dialkylacetylendicarboxylates at ambient temperature in EtOH. In addition, N-aryl-3-aminodihydropyrrol-2-one-4-carboxylates were synthesised using mentioned catalyst at ambient temperature in EtOH from condensation between formaldehyde, amines, and dialkylacetylenedicarboxylates. This methodology has number of advantages such as:use of green and nonhazardous catalyst, clean work up, short reaction times, high yields and no need to column chromatography.     

Simple and Efficient Synthesis of 2-Aryl-2,3-Dihydroquinolin-4(1H)-ones Using Silica Chloride as a New Catalyst Under Solvent-Free Conditions

A mild, efficient, and high-yielding method for the synthesis of 2-aryl-2,3-dihydroquinolin-4(1H)-ones from their corresponding 2-amino chalcones using silica chloride (SiO₂Cl) under solvent-free conditions is described. A series of 2-aryl-2,3-dihydroquinolin-4(1H)-ones containing both electron-donating and electron-withdrawing substituents were synthesized.     

One-Pot Synthesis of 4-Aminoquinazolines by Hexamethyldisilazane-Mediated Reaction of Quinazolin-4(3H)-ones with Amines

Hexamethyldisilazane-mediated reaction of quinazolin-4(3H)-ones with primary amines led to facile formation of 4-aminoquinazolines through tandem silylation and substitution in a single pot. Excellent yields of the products (83–97%) and environmental friendliness (avoiding the use of chlorination reagents) are the advantages of this method.      

Ionic liquid promoted synthesis of 3-(2′-benzothiazolo)-2,3-dihydroquinazolin-4(1H)-ones

3-(2′-Benzothiazolo)-2,3-dihydroquinazolin-4(1H)-ones have been synthesized in high yields in the presence of 1-butyl-3-methylimidazolium bromide [bmim]Br as an ionic liquid; the reaction work-up is simple and the ionic liquid can be easily separated from the product and reused.