A CONVENIENT SYNTHESIS OF SUBSTITUTED QUINAZOLIN-4(3H)-ONES UNDER MICROWAVE AND SOLVENT-FREE CONDITIONS

A clean and facile synthesis of the title compounds is achieved from cyclocondensation of 2-aminobenzamides with orthoesters catalyzed by SiO ₂ /H ₂ SO ₄ in dry and microwave conditions.     

SYNTHESIS AND PROPERTIES OF SOME NEW,STABLE THIETES (THIACYCLOBUTENES)

Abstract

Simple alkyl substituted thietes are liquids which decompose at room temperature presumably via electrocyclic ring opening to give polymeric material.     

A facile one-pot synthesis of new thieno- [2,3-d]pyrimidine-2,4（1H,3H）-dione derivatives

A facile one-pot synthesis of new 3-arylthieno[2,3-d]pyrimidine-2,4(1H,3H)-diones via base-catalyzed cyclocondensation of ethyl 2-amino-4,5-dimethylthiophene-3-carboxylate with aryi isocyanates is described.     

AN UNUSUAL ADDITION AND RING-CLOSURE REACTION OF 1-(2-BROMOETHYL)-2,3-DIHYDRO- 3-PROPYL-1,3,2-BENZO-DIAZAPHOSPHORIN-4(1H)-ONE 2-OXIDE WITH CARBON DISULFIDE FOR A NEW AND CONVENIENT SYNTHESIS OF THE FUSED PHOSPHORUS HETEROCYCLIC COMPOUND

ABSTRACT

The reaction of 1-(2-bromoethyl)-2,3-dihydro-3-propyl-1,3,2-benzodiazaphosphorin-4(1H)-one 2-oxide with carbon disulfide takes an alternative pathway in the use of different bases. The sodium hydride mediated reaction leads to the formation of the tricyclic fused 1,2,3,4,4a,4b,5,6-octahydro-6-oxo-5-propyl-4-thia-3,4b,4a-thiazphosphaphenanthridine 4a-oxide via addition of H-P bond across the double bond of carbon disulfide followed by intramolecular cyclization. In the presence of triethylamine, refluxing a mixture of 1-(2-bromoethyl)-2,3-dihydro-3-propyl-1,3,2-benzodiazaphosphorin-4(1H)-one 2-oxide with carbon disulfide in benzene takes an unusual course with formation in excellent yield of the first example of fused phosphorus heterocyclic 4-[1′-(β-bromoethyl)-4′-oxo- 3′-propyl-1′,2′,3′,4′-tetrahydro-1,3,2-benzodiazaphosphorin-2′- sulfide]-1,2,3,4,4a,4b,5,6-octahydro-6-oxo-5-propyl-3,4b, 4a-thiazphosphaphenanthridine 4a,2′-dioxide, which was confirmed by spectroscopic methods, microanalyses and single crystal X-ray structure determination.     

NEW AND CONVENIENT SYNTHESIS OF (R) AND (S) OF 2-METHYL-3-OXA-5-(TERT-BUTYLDIPHENYLSILYLOXYL) METHYLPENTANOATE AND 2-METHYL-3-OXA-5- (TERT-BUTYLDIMETHYLSILYLOXYL)METHYLPENTANOATE

Abstract

(R) and (S) of 2-Methy1-3-oxa-5-(tert-butyldiphenylsilyloxyl)methy1pentanoate (4a. 6a) and (R) and (S) of 2-methy1-3-oxa-5-(tert-butyldimethylsilyloxyl)methylpentanoate (4b, 6b) were synthesized by the reaction of the preparative compounds (2a, 2b) with (R) and (S) methy1lactate (3, 4) in the presence of a silver (1) oxide catalyst (Method B). The title compounds are useful for the synthesis of different natural products such as epothilones.     

A CONVENIENT SYNTHESIS OF LONG-CHAIN 3-n-ALKYLTHIOPHENES AND 3-n- ALKYLFURANS

Abstract

The syntheses of 3-substituted long-chain furans and thiophenes by a Wittig reaction are described. ¹H-NMR and UV data of these compounds are reported.     

SYNTHESIS AND FUNGICIDAL ACTIVITIES OF 2-BENZOTHIAZOLYLTHIO-SUBSTITUTED 4H-IMIDAZOL-4-ONES AND 4(3H)-QUINAZOLINONES

4H-Imidazol-4-ones 4 or 4(3H)-quinazolinones 8 were synthesized by base catalytic reactions of 2-mercaptobenzothiazole with carbodiimides 2 or 6, respectively, which were obtained via aza-Wittig reaction of iminophosphorane 1 or 5 with aromatic isocyanates. 4 and 8 exhibited fungicidal activity.     

A CONVENIENT AND GENERAL SYNTHESIS OF A NOVEL HETEROCYCLIC SYSTEM; 5H-[1,3,4]THIADIAZOLO[2,3-d] [1,2,4]TRIAZIN-5-ONES

Abstract

5H-[1,3,4]Thiadiazolo[2,3-d][1,2,4]triazin-5-ones were synthesized by cyclocondensation of 4-amino-5-mercapto-1,2,4-triazin-3-ones with a variety of carboxylic acids in the presence of phosphorus oxychloride.     

SYNTHESIS OF 6,7-METHYLENEDIOXY-3-THIA-1(2H,4H)ACRIDONE AND THE RELATED THIA-ACRIDINE-PUSED HETEROCYCLIC COMPOUNDS

6,7-Methylenedioxy-3-thia-1(2H,4H)acridone and the related acridine-fused quinolines and pyridines,andalso their flavylium-perchlorates were synthesized.The structures of all these compounds prepared are characterizedby elemental analysis.IR and H-NMR spectra.     

A PRACTICAL AND CONVENIENT SYNTHESIS OF METHYL 5-FORMYL-3-METHOXYBENZOATE

A practical and convenient synthesis of methyl 5-formyl-3-methoxybenzoate starting from 3-hydroxy-5-(methoxycarbonyl)benzoate in 65% overall yield is described. Ethyl 5-formyl-3-methoxybenzoate was also prepared in the similar manner.     

SYNTHESIS OF SALICYLTHIOAMIDES AND 4 H-1, 3, 2 BENZOXAZAPHOSPHORIN-DERIVATIVES

Abstract

Recent studies have shown that the dimer of p-methoxyphenylthionophosphinesulfide, 1, is a very superior thiation reagent, as ketones, amides, and esters are in most cases quantitatively converted to their thio-analogues.     

膦桥多核银络合物[Ag_4(dppe)_3(NO_3)_4]的合成与结构

膦桥过渡金属络合物和簇合物由于独特的结构特性和催化性能而引起人们的重视,许多这类的化合物已被合成和表征,但相应的银化合物的研究则较少。近年来,我们利用双齿膦配体dppm(Pb_2pCH_2PPh_2)和dppe(Ph_2PCH_2CH_2PPh_2)合成了一系列新型的膦配体银络合物。这些双齿膦配体结合硝酸根、氯离子和吡啶等配体以多种方式与银原子配位,呈现了丰富的配位结构特征。本文报导另一个新的dppe多核银络合物的合成与晶体结构测定的结果,讨论了其特殊的结构特征。     

SYNTHESIS AND STRUCTURE OF [Et4N]2[MoCu3S4(S2CNC5H10)3].DMF——A NEW CLUSTER OF Mo-Cu-S SYSTEM

<正> INTRODUCTION. In recent years, the di-, tri- and tetranuclear mixed metal Mo-Cu-S clusters have been extensively studied with [MoS_4]~(2-) core skeleton unchanged So far in the literatures, the ligands involved in the Mo-Cu-S system are all monodentate, no multidental ligands have been found     

Synthesis and properties of 3-cyano-4-(4-cyanophenyl)-1,4-dihydropyridine-2(3H)-thiones

Piperidinium 3-cyano-4-(4-cyanophenyl)-1,4-dihydropyridine-2(3H)-thiolates were obtained by the condensation of 1,3-dicarbonyl compounds, 4-cyanobenzaldehyde, and cyanothioacetamide in the presence of an equimolar amount of piperidine. The acidification of these thiolates gave the corresponding 1,4-dihydropyridine-2(3H)-thiones and pyridine-2(1H)-thione. Alkylation of 1,4-dihydropyridine-2-thiolates or the reaction mixture of the three-carbon condensation using iodacetamide gave 2-carbamoylmethylthio-1,4,5,6-tetrahydro- or 1,4-dihydropyridines, which were characterized by their conversion to 4,7-dihydrothieno[2,3-b]pyridines.Latvian Institute of Organic Synthesis, LV-1006, Riga, LatviaTranslated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 794–798, June, 2000.     

SYNTHESIS AND STRUCTURE OF A NOVEL MONONUCLEAR TUNGSTEN (VI) CITRATO COMPLEX, (NH4)3[Li(H2O)3WO3(C6 H4O7)]

Abstract

The first mononuclear tungsten-citrato complex, (NH₄)₃[Li (H₂O)₃WO₃(C₆H₄O₇)] (1), has been prepared by the reaction of ammonium tetrathio tungstate and lithium citrate in CH₃OH-H₂O solution at pH 8.2. There are two crystallographically independent anions in the asymmetric crystallographic unit. The crystal structure of the title compound (triclinic, space group P1, a = 6.901(1), b = 15.136(3), c = 16.107(3) Å, α = 75.85(3), β = 89.89(3), γ = 89.97(3), V = 1631.4(6) ų, R = 0.068, R _W = 0.1674 for 3878 reflections with I > 2σ(I)), reveals that in the compound a tungsten atom is coordinated to a fully deprotonated citrate as a tridentate ligand and three terminal oxygen atoms to form a distorted coordination octahedron.     

CONVENIENT SYNTHESIS OF 2-(2-PHENYLETHYL)BENZOIC ACID: A KEY INTERMEDIATE IN THE SYNTHESIS OF DIBENZOSUBERONE

A convenient and improved synthesis of 2-(2-phenylethyl) benzoicacid, a key intermediate in the synthesis of dibenzosuberone is described.     

Crystal Structure of (1R,4R;1S,4S)2-Amino-3-Cyano-1,4-Diphenyl-2-Cyclopentene-1-ol

1INTRODUCTIONIntheearly1970'sthreegroupsofinvestigatorsL,~,'foundthatlow-valenttita-nium,preparedbythereactionofstrongreducingagentswithtitaniumtrichlorideortitaniumtetrachlorideintetrahydrofuran,canabstractoxygenfromketonesoraldehydes,leadingtotheforma-tionofolefins.Theinterestinthereactioninducedbylow--valenttitaniumreagentsisincreasingandalargenumberoffunctionalgroupscanbereduceds4-6).Recent-ly,wefoundthatthetitlecompoundisObtainedbycy-cllzatlonreactionof(3--oxo-1,3-diphenyl)propyl-pro…     

SYNTHESIS AND CRYSTAL STRUCTURE OF A NEW BINUCLEAR SIL-VER COMPLEX, [Ag_2(Py)_6(dppe)](C1O_4)_2

<正> The crystal of the title complex, Ag2Cl2P2O8N6C56H54 ,Mr= 1287. 6, belongs to triclinic system. Space group P1 with dimensions; a=10. 535(1), b= 10. 722 (3),c=12.948(2)A;α=81.25(2)°,β=81.20(1)°, γ=86.45(2)°, V=1427. 4 A3, Z= 1 ,DC= 1. 49g/cm3,F(000) = 656. 0, Mo Ka ratiation, λ=0.7107A μ = 2. 6cm-1 , The final R for 4672 reflections is 0. 043. There is a center of inversion in the molecule.     

Crystal Structure of Trans-2-Amino-3-Cyano-4-(3',4'-Methylenedioxyphenyl)-1-Phenyl-2-Cyclopentene-r-1-ol

1INTRODUCTIONIntheearlyseventiesthreegroupsofinvestigators('--"establishedthatlow--va-lenttitanium,preparedbythereactionofstrongreducingagentsontitaniumtrichlo-rideortitaniumtetrachlorideintetrahydrofuran,canabstractoxygenfromketonesoraldehydes,leadingtotheformationofolefins.Anincreasinginterestinthereac-tioninducedbylow--valenttitaniumreagentsisobservedandalargenumberoffunc-tionalgroupscanbereducedt4--6).However,thereactionoflow-valenttitaniumreagentwith4,4--dicyano--1,3--diaryl--l-butano…     

New,simple, and efficient method for the synthesis of N-substituted 4-trifluoromethyl-5-(alkan-1-ol)-pyridin-2(1H)-imines

A new, simple, and efficient method for the synthesis a novel series of 1-substituted 4-(trifluoromethyl)-5-(alkan-1-ol)-pyridin-2(1H)-imines from the reaction of 3-(5,6-dihydro-4H-pyran-3-yl)-4,4,4-trifluorobut-2-enenitrile and 3-(4,5-dihydrofuran-3-yl)-4,4,4-trifluorobut-2-enenitrile with primary amines – is described. The products were obtained in 29–82% yield.