SYNTHESIS OF 4,6-DISUBSTITUTED 5-THIOXO-1,2,4-TRIAZIN-3-ONE FROM BENZOTHIOFORMANILIDE

A method of synthesis of 4,6-disubstituted 5-thioxo-1,2,4-triazin- 3-ones from benzothioformanilides and semicarbazide is described.And six new compounds were synthesized by this method.

A Facile Synthesis of 6β-Hydroxy-7α(H)-eudesma-4-en-3-one

A stereoselective total synthesis of 6β-hydroxy-7α(H)-eudesma-4-en-3- 1startingfrom (+)-dihydrocarvone 7 has been described.

H_3PMo_(12)O_(40) catalyzed three-component one-pot synthesis of 4,6-diarylpyrimidin-2(1H)-ones under solvent-free conditions

4,6-Diarylpyrimidin-2(1H)-one derivatives have been synthesized from three-component one-pot condensation of acetophe-none derivatives,aldehydes and urea in the presence of trimethylsilyl chloride and a catalytic amount of HPMoOunder solvent-free conditions.

The First Total Synthesis of Natural 6β-Cinnamoyloxy-1α- hydroxy-5, 10-bis-epi-eudesm-4-en-3-one

The first total synthesis of natural 6β-cinnamoyloxy-1α-hydroxy-5, 10-bis-epi- eudesm-4-en-3-one （1）, a highly complex natural eudesmane, was described.

Facile synthesis of[1,2,4]triazino[4,3-b][1,2,4,5]tetrazepin derivatives by a one-pot reactions using 4-amino-3-hydrazinyl-6-methyl-1,2,4-triazin-5(4H)-one

4-Amino-3-mercapto-6-methyl-l,2,4-triazin-5（4H）-one 1 converted to 4-amino-6-methy-3-（methylthio）-1,2,4-triazin-5（4H）-one by methylation with methyl iodide.Controlled hydrazination of the resulting compound afforded 4-amino-3-hydrazinyl-6- methyl-l,2,4-triazin-5（4H）-one 2 as a building block,to the synthesis of some novel derivatives of[1,2,4]triazino- [4,3,b][1,2,4,5]tetrazepine 3-6,by the reaction with 3-chloropentane-2,4-dione,chloro acetonitrile,1,3-dichloroacetone,and methyl bromoacetate.This general synthetic procedure can be extended to the preparation of wide variety of tetrazepines using 1,2- bielectrophiles derivatives.

A Facile Synthesis of 9,10-Dimethoxybenzo[6,7]- ox-epino[3,4-<i>b</i>]quinolin-13(6<i>H</i>)-one and Its Derivatives

A concise and efficient method for the synthesis of novel 9,10-imethoxybenzo[6,7]oxepino[3,4-b]quinolin13(6H)-one and its derivatives 7a-p has been developed via the intramolecular Friedel-Crafts acylation reactions of 6,7-dimethoxy-2-(phenoxymethyl)quinoline-3-carboxylic acids 6a-p with polyphosphoric acid (PPA) as catalyst and solvent under mild conditions. The key intermediates 6a-p were prepared through the in situ formation of ethyl 6,7-dimethoxy-2-(phenoxymethyl)quinoline-3-carboxylates 5a-p followed by hydrolysis with aqueous ethanolic sodium hydroxide solution. The novel synthetic method has the advantages of good yields, easy work-up, and environmentally friendly character, which may provide a novel highly efficient process for making quinoline and related azaheterocycle libraries.

Spontaneous Changes of Solid 5,7-di-<i>tert</i>-butylspiro(2,5)octa-4,7-diene-6-one in Storage Conditions at Room Temperature

On an example of spontaneous changes 5,7-di-tert-butylspiro (2,5) octa-4,7-diene-6-one at room temperature, a new example of condensations in a solid station is opened. The single crystal of 2-(3’, 5'-di-tert-butyl-4'-hydroxy-phenyl)-ethyloxy-p-cresole is produced as result of a structure transformation 5,7-di-tert-butylspiro (2,5) octa-4,7-diene-6-one in a solid phase at room temperature except a single crystal at transformation 5,7-di-tert-butylspiro (2,5) octa-4,7-diene-6-one a new substance is formed too. Spectrums 1Н and 13С NMR differ from similar spectrums of initial compound and the single crystal. New substance represents an admixture of isomeric compounds, capable reversible to be transformed in initial 5,7-di-tert-butylspiro(2,5) octa-4,7-diene-6-one and 2-(3’, 5'-di-tert-butyl-4'-hydroxyphenyl)-ethyloxy-p-cresole.

Synthesis, Reactions and Characterization of 1,1’-(1,4-Phenylenebis(3-amino-6-methyl-1H-pyrazolo[3,4-b]pyridine-4,5-diyl))bis(ethan-1-one)

Reaction of 4,4’-(1,4-phenylene)bis(5-acetyl-6-methyl-2-thioxo-1,2-dihydropyridine-3-carbonitrile) (1) with methyl iodide afforded the 4,4’-(1,4-phenylene)bis(5-acetyl-6-methyl-2-(methylthio)nicotinonitrile) (2). The reaction of 2 with hydrazine hydrate followed by diazotization reaction af-forded the 1,1’-(1,4-phenylenebis(3-amino-6-methyl-1H-pyrazolo[3,4-b]pyridine-4,5-diyl))bis(e-than-1-one) (3) and 1,1’-(1,4-phenylenebis(3-(chlorodiazenyl)-6-methyl-1H-pyrazolo[3,4-b]-pyridine-4,5-diyl))bis(ethan-1-one) (4) respectively. On the other hand, reaction of 4 with malononitrile, 2-cyanoethanethioamide, ethyl acetoacetate, acetyl acetone, ethyl benzoylacetate, diethylmalonate, ethyl cyanoacetate and phenacylbromide aiming to build up pyrazolotriazine or pyrazole ring on the ring system of 4. Structures of all newly synthesized heterocyclic compounds in the present study were confirmed by considering the data of IR, 1H NMR, mass spectra as well as that of elemental analyses.

Quantum Chemical Studies on the Corrosion Inhibition of Mild Steel by Piperidin-4-One Derivatives in 1 M H₃PO₄

The corrosion inhibition properties of 2,6-diphenylpiperidin-4-one (DPP) (1A) and 2,6-diphenyldihydro-2H-thiopyran-4(3H)-one (DPDT) (1B) for mild steel in 1 M phosphoric acid were studied using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopic techniques. The effect of temperature on the corrosion behavior of mild steel has been examined in the temperature range 303 - 328 K. The inhibition efficiency increases with increasing inhibitor concentration but decreases with increasing temperature. Potentiodynamic polarization studies indicated the mixed nature of inhibitors. The adsorption of the inhibitors on mild steel surface obeyed the Langmuir adsorption isotherms. The density functional theory (DFT) at the B3LYP/6- 31G (d) basis set level was performed on 1A and 1B to investigate the correlation between molecular structure and the corresponding inhibition efficiency (%). The quantum chemical parameters such as EHOMO, ELUMO, the energy gap (E), hardness (η), softness (S), dipole moment (μ), electron affinity (A), ionization potential (I), the absolute electronegativity (χ), the fraction of electron transferred (N), electrophilicity index (ω), the back-donation (EBack-donation) and Mulliken population analysis have been calculated.

Synthesis,Crystal Structure and Anti-tumor Activity of Ethyl 3-(4-methoxyphenyl)-4-oxo-3,3a,4,6-tetrahydro-1H-furo[3,4-c]pyran-3a-carboxylate

The title compound（ethyl 3-（4-methoxyphenyl）-4-oxo-3,3a,4,6-tetrahydro-1H-furo[3,4-c]pyran-3a-carboxylate） has been synthesized,and its crystal structure was characterized by X-ray single-crystal diffraction.The crystal belongs to monoclinic,space group P21/n,with a = 10.124（4）,b = 11.754（4）,c = 13.792（5） ,β = 111.533（3）o,V = 1526.6（10） 3,Z = 4,C17H19O6,Mr = 319.32,Dc = 1.389 g/cm3,F（000） = 676,λ（MoKα） = 0.71073 ,μ = 0.105 mm-1,R = 0.0660 and wR = 0.2027 for 2993 observed reflections（I 2σ（I））.The compound shows potent anti-tumor activity in vitro.

Synthesis, Characterization, and Antioxidation Evaluation of Novel Spiro-5-(fluoren-9’-yl)-6-azauracil and Their <i>N</i>,<i>N</i>-Dialkyl Derivatives

In search for new antioxidant agents derived from 6-azauracil, the spiro-5-(flurin-9’-yl)-6-azauracil 3 and their N,N-disubstituted-6-azauracils 4 - 17 have been synthesized using various methods and reaction conditions. Structure of the new synthesized compounds was deduced from elemental analysis and spectral measurements, for example IR, 1H/13C NMR and mass spectroscopy. The antioxidant evaluation of the new targets showed that the activity increases in the order of 8 > 10 > 6 > 7 > 9 in comparison with 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and ascorbic acid as standards.

An efficient synthesis of novel benzo[b]pyrido[3',2':4,5]thieno[2,3-e][1,6]naphthy-ridine-8-ones

An efficient method for the synthesis of novel benzo[b]pyrido[3＇,2＇：4,5]thieno[2,3-e][l,6]naphthyridine-8-one derivatives has been developed using a Pictet-Spengler reaction between 4-（3-aminothieno[2,3-b]pyridin-2-yl）quinoline-2-ones,which could be obtained from the alkylation of4-bromomethylquinoline-2-ones with 3-cyanopyridine-2-thione followed by a Thorpe-Ziegler isomerization,and aromatic aldehydes under p-TsOH as catalysis in good yields.

An efficient regioselective sonochemical synthesis of novel 4-aryl-3-methyl-4,5-dihydro-1H-pyrazolo[3,4-b]pyridin-6(7H)-ones

An efficient ultrasound-assisted preparation of a series of novel 4-aryl-3-methyl-4,5-dihydro-l//-pyrazolo[34-b]pyridin-6（7H）ones via the reaction of 5-amino-3-methyl-1H-pyrazole,Meldrum＇s acid and various arylaldehydes using one-pot three-component approach is described.This rapid method produced the products in short reaction times（3-4 min） and excellent yields（87-95%）.

Synthesis of novel benzo[b]pyrimido[4',5':5,4]thieno[2,3-e][1,6]naphthyridine-8-ones via Pictet–Spengler cyclization

An efficient method for the synthesis of novel benzo[b]pyrimido[4′,5′：5,4]thieno[2,3e]-[1,6]naphthyridine-8-one derivatives via Pictet-Spengler cyclization is reported. The reaction of 4-（3-aminopyrimido[4,5-d]thieno-2-yl）quinoline-2-ones, which could be obtained from Thorpe-Ziegler isomerization of 4-bromomethylquinoline-2-ones and 5-cyano-1,6-dihydro-4-methyl-2-phenyl-6-thioxopyrimidine,with aromatic aldehydes in the presence of BF3·OEt2 gives pyrimidothieno[1,6]naphthyridines in good yields.

New efficient synthesis of 2,5,6-trisubstituted oxazolo[5,4-d]pyrimidi-7(6H)-ones via an oxazolyliminophosphorane

A new efficient synthesis of 2,5,6-trisubstituted oxazolo（5,4-d]pyrimidi-7（6H）-ones by consecutive azaWittig reaction was developed.The sequential three-component reaction of oxazolyliminophosphorane4,isocyanates and amines produced 2,5,6-trisubstituted oxazolo[5,4-d]pyrimidi-7（6H）-ones 7 in good overall yields in the presence of catalytic amount of EtONa.

Study on the regioselective alkylation of 2-thiopyrimidine

Aim To investigate the alkylation of 2-thiopyrimidine. Methods Treating the starting material 2-thiopyrimidine with chloromethyl ethers via a procedure of K2CO3 in DMF or with alkyl halide in CH3ONa-CH3OH at room temperature, to obtain the corresponding regioselective 2-S-allkyl pyrimidines. The products were determined by JH NMR, 2D NMR, IR and MS spectra. Results 2-S-alkyl-pyrimidines were regioselectively synthesized. Conclusion In different conditions with different alkyl halides, 2- thiouracil could be converted into the corresponding 2-S-alkylpyrimidines regioselectively.

An efficient synthesis of benzo[b]benzofurano[2,3-e]-[1,6]naphthyridine-8-ones

An efficient method for the synthesis of benzo[b]benzofurano[2,3-e][1,6]naphthyridine-8-one derivatives has been developed via Pictet-Spengler reaction of 4-（3-aminobenzofuran-2-yl）quinoline-2-ones,which could be obtained from alkylation of 4-bromomethylquinoline-2-ones with salicylonitrile and subsequent Thorpe-Ziegier isomerization,with aromatic aldehydes under p-TsOH as catalyst in good yields.

A New Halogenated Biindole and A New Apo-carotenone from Green Alga Chaetomorpha basiretorsa Setchell

A new halogenated biindole and a new apo-carotenone have been isolated from the ethanolic extract of the green alga Chaetomorpha basiretorsa Sethcell. On the basis of chemical and spectroscopic methods including 2D NMR technique, their structures have been elucidated as 4,4′-dichloro-5,5′-dibromo-7,7′-dimethoxy-2,2′-bi-1H-indole and 1′S*,4′R*-8-(4′-hydroxy-2′,6′,6′- trimethylcyclohex-2-enyl)-6-methyloct-3E,5E,7E-trien-2-one, respectively.

Reaction of 2,3-Dihydro-1,5-benzothiazepines and Phenylacetyl Chloride in the Presence of Triethylamine:A New Aspect on the Formation Mechanism of Dihydro-1,3-oxazin-4-one Derivatives

2a,4-Disubstituted 2,2a,3,4-tetrahydro-2-phenyl-1H-azeto[2,1-d][1,5]benzothiazepin-1-ones, as well as 2-substi- tuted 2,3-dihydro-3-phenylacetyl-2-styryl-benzothiazoles and 4a,6-disubstituted 3-benzyl-4a,5-dihydro-2-phenyl- 1H,6H-[1,3]oxazino[2,3-d][1,5]benzothiazepin-1-ones, were obtained from the reaction of 2,4-disubstituted 2,3-dihydro-1,5-benzothiazepines with phenylacetyl chloride in the presence of triethylamine. The mechanism for the formation of 4a,5-dihydro-1H,6H-[1,3]oxazino[2,3-d][1,5]benzothiazepin-1-ones, 2,3-dihydro-1,3-oxazin-4-one derivatives, was suggested.

Synthesis of Benzoxepinoquinolinone Derivatives

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