Syntheses, characterizations and crystal structures of triorganotin(IV) derivatives with 2-mercapto-4-quinazolinone

The triorganotin(IV) derivatives of 2-mercapto-4-quinazolinone (HSqualone) of the type, R₃SnL (R = Ph 1, CH₃2, PhCH₂3, p-F-PhCH₂4, o-F-PhCH₂5, n-Bu 6), were obtained by the reaction of the R₃SnCl and HSqualone with 1:1 molar ratio in benzene. All complexes 1-6 were characterized by elemental analyses, IR, ¹H and ¹³C NMR spectroscopy and the crystal structures of complexes 1-3 were also confirmed by X-ray crystallography. The structure analyses reveal that the tin atoms of complexes 1-3 are all distorted tetrahedral geometries. Furthermore, the dimeric structures in complexes 1-3 have also been found linked by intermolecular O-H?N or N-H?O hydrogen bonding interaction. Interestingly, the dimers of complexes 2 and 3 are further linked into one-dimensional chain through intermolecular C-H?S and C-H?O weak hydrogen bonding interactions, respectively.     

Vilsmeier Reagent: An Efficient Reagent for the Transformation of 2-Aminobenzamides into Quinazolin-4(3H)-one Derivatives

Clean and easy preparation of quinazolin-4(3H)-one derivatives using 2-aminobenzamides and Vilsmeier reagent is described. 2-Aminobenzamides were converted into the corresponding quinazolinones under mild and efficient conditions, in good yields without undesirable by-products.

[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.]     

Novel Dual Use of Formamide-POCl3 Mixture for the Efficient,One-Pot Synthesis of Condensed 2H-Pyrimidin-4-amine Libraries Under Microwave Irradiation

The novel dual use of formamide-POCl₃ mixture for the incorporation of a C-N fragment to form the pyrimidine nucleus and its subsequent chlorination in an efficient, one-pot synthesis of potentially bioactive condensed 2H-pyrimidin-4-amine libraries under microwave irradiation (MWI) is reported. The one-pot microwave-assisted synthetic protocol is high-yielding, ecofriendly, rapid, and novel as well as eliminates intermittent workups. The protocol can be adapted for the library synthesis of series of a condensed pyrimidines.     

Synthesis and structure of 4-arylspirodihydro-pyranochromen-2-one derivatives

Syntheses are reported for sulfur-and nitrogen-containing derivatives of 4-arylspiro-2-benzopyranones modified at the exocyclic oxygen atom. The structure of these products was demonstrated by correlational NMR spectroscopy. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 518–527, April, 2007.     

Synthesis of 2-thioxo-1,3-thiazolidin-4-one derivatives

A series of new 2-thioxo-1,3-thiazolidin-4-one derivatives containing arylidene, arylazo, and aminomethylene fragments in position 5 of the rhodanine cycle was synthesized. Dedicated to Academician V. A. Tartakovsky on the occasion of his 75th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1564–1569, August, 2007.     

Investigation of amination in 4-chloro-2-phenylquinoline derivatives with amide solvents

Novel 4-amino-2-phenylquinoline derivatives were synthesized by reacting various 4-chloro-2-arylquinoline compounds having activated chloro group with the corresponding amide solvents at reflux for overnight. The activity of amination by the amide solvents depended on the competition between the steric and electronic effect of the N-substituents on the amino group. Their activities were shown as N,N-dimethylformamide>N,N-diethylformamide>N-methylformamide>formamide>N,N-dimethylacetamide>N,N-dimethylpropionamide. The yields for the amination products seemed proportional to the ease of the dissociation of the amides.     

Synthesis and functionalization of 4-arylamino-2-pyridone derivatives

New approaches to the synthesis of the previously unknown pyrimidine, 4-amino-2-pyridone, and 4-aminopyridine derivatives were developed based on the reactions of enaminoamides with dimethylformamide dimethyl acetal. New structural modifications of 4-amino-2-pyridone derivatives were performed. Numerous compounds of this type, which are of interest for biological studies, were prepared. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1421–1432, August, 2006.     

几种4-取代-L-脯氨酸衍生物的合成

以Boc-(4R)-羟基-(2S)-脯氨酸为原料,在NaH作用下与苄位溴代试剂发生醚化反应,合成了几种4-取代-L-脯氨酸类手性催化剂,即在(4R)-羟基-(2S)-脯氨酸的4-位上引入不同的苄氧基以期提高其催化活性和脂溶性,并通过1 H NMR、13 C NMR和HRMS对合成产物的结构进行表征,确定其为目标产物.实验结果还表明,当苯环上连有强的吸电子基团时反应很难进行,而当连有给电子基团时反应相对较容易进行且反应条件较温和.     

Synthesis of derivatives of 4-amino-2-trifluoromethylnicotinic acid

The method for the synthesis of ethyl 4-R-amino-2-trifluoromethylnicotinates from a diphenylboron complex of ethyl 2-acetyl-3-amino-4,4,4-trifluorobut-2-enoate was developed.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2221–2223, October, 2004.     

Reactions of Trifluorotriacetic Acid Lactone and Hexafluorodehydroacetic Acid with Amines: Synthesis of Trifluoromethylated 4-Pyridones and Aminoenones

Dehydroacetic acid and triacetic acid lactone are known to be versatile substrates for the synthesis of a variety of azaheterocycles. However, their fluorinated analogs were poorly described in the literature. In the present work, we have investigated reactions of trifluorotriacetic acid lactone and hexafluorodehydroacetic acid with primary amines, phenylenediamine, and phenylhydrazine. While hexafluorodehydroacetic acid reacted the same way as non-fluorinated analog giving 2,6-bis(trifluoromethyl)-4-pyridones, trifluorotriacetic acid lactone had different regioselectivity of nucleophilic attack compared to the parent structure, and corresponding 3-amino-6,6,6-trifluoro-5-oxohex-3-eneamides were formed as the products. In the case of binucleophiles, further cyclization took place, forming corresponding benzodiazepine and pyrazoles. The obtained 2,6-bis(trifluoromethyl)-4-pyridones were able to react with active methylene compounds giving fluorinated merocyanine dyes.     

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.     

2-溴-4-甲基苯酚的合成

2-溴-4-甲基苯酚是合成许多药物及广谱型香料香兰素的重要中间体。常温下,以对甲基苯酚为原料加溴易生成2,6-二溴-4-甲基苯酚,本文在原来工作的基础上,在低温下,通过溴化氧化一步直接合成了2-溴-4-甲基苯酚,产率可达93％并通过红外光谱和核磁共振谱对产物结构进行确证。反应的最佳条件是：反应温度为-5～-10℃,反应时间为4h,搅拌速度为1000r／min,对甲基苯酚与双氧水物质的量比为1：0．85。反应方程式如下：     

Synthesis and Crystal Structure of 2-Ethoxy-spiro[2H-1, 4,2-benzoxazaphosphorine-3（4H）, 1＇-Cycloheptane] 2-Oxide

1 INTRODUCTION α-Aminophosphonates are an important class of compounds since they are considered as structural analogues of the corresponding α-amino acids. Their utilities as enzyme inhibitors, antibiotics, pharma- cological agents and many other applications are well documented[1~5]. Moreover, cyclic α-amino- phosphonates, one important kind of α-aminopho- sphonates, have attracted chemists’ interests for a long time[6~11]. In order to search for potent and selec- tive herbicides a…     

Microwave promoted synthesis and antimicrobial activity of 3-thiazole substituted 2-styryl-4(3H)-quinazolinone derivatives

The present paper describes an optimized reaction condition for the microwave promoted synthesis of newer 3-thiazole substituted 2-styryl-4(3H)-quinazolinone derivatives, which in turn were prepared in good yield by the treatment of various 2-styryl benzoxazinone derivatives with various 2-aminothiazoles using co-solvent under microwave irradiation. All the compounds were characterized by various spectroscopic techniques and analytical methods. All newly synthesized compounds have been screened for their in vitro antibacterial and antifungal activities against Escherichia coli, Pseudomonas aeruginosa, Bacillus megaterium,Bacillus subtilis, and Aspergillus niger.     

Synthesis of 4-unsubstituted 2H-1,2,3-benzothiadiazine 1,1-dioxides via ortho lithiation of protected benzaldehyde derivatives

Variously substituted 2-phenyl-1,3-dioxolanes and 2-(2-bromophenyl)-1,3-dioxolanes, prepared from the corresponding benzaldehydes, were lithiated ortho to the acetal group. Reaction of the lithio derivatives with sulfur dioxide led to the lithium sulfinate salts, which gave, upon oxidative chlorination with sulfuryl chloride, the corresponding benzenesulfonyl chlorides. Then, depending on the aromatic substitution pattern of the molecule, several protocols were elaborated for the functional group transformations leading to the target compounds. Ring closure was performed with hydrazine hydrate or acetylhydrazine, in the latter case with one-pot removal of the acetyl group. The 4-unsubstituted 2H-1,2,3-benzothiadiazine 1,1-dioxides thus obtained are potential drug candidates based on their structural similarity to biologically active phthalazinones.     

2-氨基-6-三氟甲基嘧啶衍生物的合成及表征

近几年,含嘧啶结构单元的高效低毒农药层出不穷,如用作杀菌剂的嘧啶胺类、嘧啶腺类及嘧啶丙烯酸酯类,除草剂有嘧啶磺酰脲类、嘧啶水杨酸类、酰基(硫)脲类及三唑并嘧啶磺酰脲类。将含氟基团引入杂环结构是新药创制的一个发展方向,     

2-氨基-4-氟吡啶合成工艺研究

2-氨基-4-氟吡啶是制备酪氨酸激酶抑制剂、PI3K抑制剂和醛固酮合酶抑制剂等酶抑制剂的重要中间体.已报道的制备方法均存在一些缺陷,难以满足工业化生产.本文以4-氯吡啶-2-甲酰胺为原料,经酰胺脱水、卤素交换、氰基水解、霍夫曼降解等反应得到目标化合物.产物结构经1 H NMR和GC-MS确证.本文采用的合成方法简单、反...     

Synthesis and antibacterial activity of C-2(S)-substituted pleuromutilin derivatives

<正>In order to probe the effect of C-2(S)-substituted groups in the antibacterial activity,a series of novel C-2(S)-substituted pleuromutilin analogues of SB-225586 were synthesized and evaluated for their in vitro antibacterial activity.The results of antibacterial activities indicated that C-2(S)-substituted pleuromutilin derivatives retained appreciable antibacterial activity,and the 2-fluorination compounds 6a and 6b are more potent than the corresponding 2-hydroxylation analogues 7a and 7b.     

Heterocyclic derivatives of 2-amino-4-nitrophenol

Summary A new pathway for the synthesis of cyclic derivatives of 2-amino-4-nitrophenol by application of dibromoalkanes is described. This general method was used for the preparation of several heterocycles (partially saturated 1,4-benzoxazines, 1,5-benzoxazepines, 1,6-benzoxazocines). Two rotamers are present in solution of theN-formyl derivatives, the relative amounts depending on the solvent used.

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Heterozyklische Derivate von 2-Amino-4-nitrophenol

Zusammenfassung Eine neue Methode zur Herstellung heterozyklischer Derivate von 2-Amino-4-nitrophenol wird vorgestellt. Dieses allgemeine Verfahren kann zur Synthese von verschiedenen Ringsystemen (partielle gesättigte 1,4-Benzoxazine, 1,5-Benzoxazepine, 1,6-Benzoxazocine) benutzt werden. In den Lösungen derN-Formyl-Derivate können zwei Rotamere identifiziert werden. Ihre relative Menge hängt vom Lösungsmittel ab.

     

4－叔丁基－2－巯基吡啶的合成

以４－叔丁基吡啶为原料，与碘甲烷成盐后经铁氰化物氧化，在吡啶环上引入酮基，再经溴代、巯基化得标题化合物。由原料到溴代物的合成总收率达８０％。