Synthesis of [1,3]dithiole and spiro[1,3]dithiole thiopyran derivatives of the [1,2]dithiolo[1,4]thiazine ring system

We report the synthesis of some new polysulfur-nitrogen heterocycles by cycloaddition reactions to readily available tricyclic condensed 1,2-dithiole-3-thiones. Thus, treatment of bis[1,2]dithiolopyrrole ketothione 1 with diacyl acetylenes gave the bis-aducts 2a-d. On the other hand, cycloaddition of bis[1,2]dithiolo[1,4]thiazine ketothione 3 with 1 equiv of acyl or diacyl acetylenes gave [1,3]dithiolylidenyl[1,2]dithiolo[1,4]thiazines 4a-f in fair to high yields. Catalysis by scandium triflate was used in the reactions that implied the less reactive dipolarophiles. Treatment of 3 with 2 equiv of DBA gave the bis-aduct 5a, and reaction of 4c with DMAD gave the mixed bis-adduct 5b. Cyclic voltammetry of selected examples showed irreversible processes that were influenced by the electrochemical activity of peripheral groups bonded to the heterocyclic system.     

Synthesis of highly branched sulfur-nitrogen heterocycles by cascade cycloadditions of [1,2]dithiolo[1,4]thiazines and [1,2]dithiolopyrroles

We report the synthesis of some new polysulfur-nitrogen heterocycles by cascade cycloadditions to readily available polycyclic 1,2-dithiole-3-thiones. Thus, treatment of bis[1,2]dithiolopyrrole dithione 1 with dimethyl acetylenedicarboxylate (DMAD) or dibenzoylacetylene (DBA) gave the 1:4 adducts 2a,b and 3a. On the other hand, cycloaddition of bis[1,2]dithiolo[1,4]thiazine dithiones 4a-d with the same dipolarophiles gave the 1:2, 1:3, or 1:4 adducts 5a-c, 6a, 7a, 8a, 9a, and 10a,c,d selectively in fair to high yields. Reaction conditions were crucial for achievement of selectivity in thermal reactions. Catalysis by scandium triflate was used in the reaction of 4a and 2 equiv of DMAD. Treatment of the [1,2]dithiolo[1,4]thiazine dithione 11 with DBA gave the 1:2, 1:3 (two isomers), and 1:4 adducts 12-14 and 15a-d selectively. Cyclic voltammetry of selected examples showed irreversible processes that were not influenced by peripheral groups bonded to the heterocyclic system.     

Novel heterocycles. 9. Synthesis of the benzofuro[2,3-c][1,2]thiazine ring system

The treatment of 2-coumaranone with the Vilsmeier reagent affords three products: 2-chloro-3-benzofurancarboxaldehyde ( 3 ), 3-dimethylaminomethylene-2-(3H)benzofuranone ( 4 ), and 3-dimethylaminomethylene-2,3-dihydro-2-oxo-6-benzofurancarboxaldehyde ( 5 ). Both 4 and 5 are isolated as a mixture of E and Z isomers. The reaction of 3 with the anion of N-methylmethanesulfonamide affords the title compound 1-methyl-1H-benzofuro[2,3-c][1,2]-thiazine 2,2-dioxide ( 6 ). Spectral data is also discussed.     

Synthesis and properties of some derivatives of 2-thionoindeno [1,2-d]-pyrimidine and indeno [1,2-d] [3,1] thiazine

Derivatives of 2-thiono-5-oxo-2,3,4,5-tetrahydroindeno[1,2-d] pyrimidine and 5-oxo-1,2,4,5-tetrahydroindeno [1,2-d] [3,1] thiazine are formed in the cyclocondensation of 2-arylideneindan-1,3-diones with thiourea and N-monomethylthiourea, while only derivatives of indeno [1,2-d]-pyrimidine are formed in the reaction with N,N-di-methylthiourea. S- and N(₃)-Alkylation occur in the alkylation of 2-thiono-4-pheny1-5-oxo-2,3,4,5-tetrahydroindeno[1,2-d]pyrimidine, while only the N-methyl derivative is formed in the alkylation of 2,5-dioxo-4-phenyl-1,2,4,5-tetrahydroindeno [1,2-d] [3,1]thiazine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1136–1141, August, 1988.     

Heterocycles containing nitrogen and sulfur. Part 49. Synthesis of derivatives of new heterocyclic systems: 1,2-Dioxocyclopenta(hexa)[g]oxazolidino-[3,2-f] pyrimido[4,5-b][1,4]thiazine, 1,2-dioxocyclopenta(hexa)-[g] imidazolidino[3,2-f]pyrimido[4,5-b][1,4]thiazine, and 1,2-oxazino[5,4-g]pyrimidino[4,5-b][1,4]thiazine

The reaction of 4-methoxy-5-amino-6-mercaptopyrimidine with 2-oxo-1-chlorocyclopentyl(hexyl)glyoxalate esters gave derivatives of the previously unknown tetracyclic systems 1,2-dioxocyclopenta (hexa)[g]oxazolidino[3,2-f]pyrimido[4,5-b][1,4]thiazines, which are transformed by ammonium acetate into derivatives of 1,2-dioxocyclopenta(hexa) [g]imidazolidino[3,2-f]pyrimido[4,5-b]-[1,4] thiazines. Derivatives of the new tricyclic 1-oxazino [5,4-g]pyrimido[4,5-b][1,4]thiazine system were obrtained by reaction of 6-carbethoxy-7-acetylpyrimido [4,5-b] [1,4] thiazines with hydroxylamine.     

Selective synthesis of bis[1,2]dithiolo[1,4]thiazines from 4-isopropylamino-5-chloro-1,2-dithiole-3-ones

Reaction of 4-isopropylamino-5-chloro-1,2-dithiole-3-ones 3 and S₂Cl₂ in acetonitrile gave selectively 3-oxo-bis[1,2]dithiolo[1,4]thiazine-5-thiones 1 by the addition of triethylamine and bis[1,2]dithiolo[1,4]thiazine-3,5-diones 5 under the action of formic acid. 3,5-Diones 5 were also obtained by intramolecular cyclization of N,N-bis(5-chloro-3-oxo[1,2]dithiol-4-yl)amines 6 with S₂Cl₂ in the presence of Et₃N.     

Synthesis of some pyrazolo[4,3-e][1,2]- and thiazolo[4,5-e][1,2]thiazine 1,1-dioxide derivatives

The synthesis of various 2-methylpyrazolo[4,3-e]- and thiazolo[4,5-e][1,2]thiazine 1,1-dioxide derivatives is described.     

Novel benzo[e][1,2]thiazine derivatives, synthesis and reactions

New benzo[e][1,2]thiazine derivatives are described. The synthetic route to N-alkyl benzothiazinones, involving protection-deprotection steps is developed and their reactivity is investigated. Novel β-aminovinylketones, hydroxymethylene ketones and pyrazolobenzothiazines are obtained.     

Cyanine dyes from naphtho [1,2-6]thiazolo[3,2-d][1,4]thiazine

Deeply colored cyanine dyes have been synthesized from the previously unknown 3-methyl-12H-naphtho[1,2-b]thiazolo[3,2-d][1,4]thiazinium salts. It is assumed that the deep color of the new cyanines is connected with the conversion of the nonaromatic 1,4-thiazine ring in the dye molecule into an aromatic thiazine ring with three double bonds in a six-membered ring.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1282–1284, September, 1973.     

Synthesis of 5H-5-oxobenzimidazo[2,1-b]pyrido[3,2-e][1,3]thiazine,A novel ring system

Reaction between 2-chloronicotinic acid chloride and 2-mercaptobenzimidazole afforded 5H-5-oxobenzimidazo[2,1-b]pyrido[3,2-e][1,3]thiazine, a novel heterocyclic ring system. The assigned structure was confirmed by means of mass spectrometry.     

6,7,8,9-Tetrahydrodipyrimido[4,5-b][4′,5′-e][1,4]thiazine derivatives. Synthesis and structure

The reaction of 5-amino-6-mercaptopyrimidines with 1,3-dimethyl-5-nitro-6-chlorouiracil in the presence of bases results in derivatives of 6,7,8,9-tetrahydrodipyrimido[4,5-b][4,5-e][1,4]-thiazine. If the 5-amino-6-mercaptopyrimdine contains a free or alkyl-substituted amino group at the 4-position, the tetrahydrodipyramidothiazines formed exist in a free radical form. The structure of the compounds formed has been established by spectral methods.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 258–264, February, 1989.     

Synthesis,reactions, and antimicrobial evaluations of new benzo[e][1,3]thiazine derivatives

4H-Spiro[benzo[d][1,3]oxathiine-2,1′-cyclohexan]-4-one undergoes aminolysis with certain aromatic amines to give the respective 4-benzenesulfonamide, Ethyl benzoate, and 4-acetylphenyl of 4-oxospirobenzo[e][1,3]thiazine derivatives. The Schiff bases prepared by reacting Ethyl benzoate derivative 2a with aldehydes, undergoes cyclocondensation with thioglycolic acid yielding p-methoxyphenyl and 2-(thiophen-2-yl) thiazolidinone derivatives. Treatment of the benzoate derivative with hydrazine hydrate afforded the corresponding benzohydrazide derivative which upon reaction with phenyl isocyanate and phenyl isothiocyanate afforded the urea and thiourea derivatives. New pyrimidine, pyridone, and imino pyridine derivatives of 4-oxospirobenzo[e][1,3]thiazine were also successfully prepared by reacting 2b or 2c with the appropriate organic reagents. Structural elucidations for the new products were based upon compatible microanalytical and spectroscopic measurements. Besides, their biological screening indicated that they possess potent antimicrobial activity in comparison with reference drugs.     

Synthesis and in vitro cytotoxic evaluation of new derivatives of pyrido[1,2-a]benzimidazolic ring system: the pyrido[1',2':1,2]imidazo[4,5-h]quinazolines

Access to the original series of pyrido[1',2':1,2]imidazo[4,5-h]quinazoline was developed from a 1,3-dicarbonyl unit with some "N-C-N" bisnucleophilic reagents and the derivatives obtained were evaluated for in vitro cytotoxic activities against HL60 and A2780 cells. All compounds exhibited cytotoxic activities on resistant cell lines (MDR+; HL60R and A2780R) with no resistance phenomena.     

Studies of pyridazine compounds. XXVI. The synthesis of Pyridazino[4,5-b]pyrrolo[1,2-d][1,4]oxazines and a pyridazino[4,5-b]pyrrolo[1,2-d][1,4]thiazine

The tricyclic oxazines 3 and 5 were obtained by ring closure of (2-hydroxymethyl-1-pyrrolidinyl)-3(2H)-pyridazinones 2d,e,g , respectively, prepared from 4,5-dichloro-3(2H)-pyridazinones with L-prolinol. The synthesis of the thiazine analogue 4a was achieved by treatment of 2d with thionyl chloride and the subsequent reaction with sodium sulfide. The structures of the compounds were supported by spectroscopic evidence.     

New derivatives and ring systems of annulated pyrrolobenzo[1,4]diazepines

(S)-11-Thioxo-2,3,11,11a-tetrahydro-1H-benzo[e]pyrrolo[1,2-a][1,4]diazepine-5(10H)-one was subsequently reacted with amino acid esters and base to give new 6:7:5:5, 6:7:5:6, and 6:5:7:7 ring systems. The 6:7:5:5 ring system, (S)-11,12,13,13a-tetrahydro-2H-benzo[e]imidazo[2,1-c]pyrrolo[1,2-a][1,4]diazepine-3,9-dione, exhibits a considerable CH-acidity at position 2, which was exploited in Knoevenagel reactions, a Wittig reaction, enol ester formations, and methylations.     

以水作溶剂微波法合成1,4-二氢苯并咪唑并[1,2-a]嘧啶类衍生物

以芳香醛、2-氨基苯并咪唑和丙二腈为原料,用传统法和微波辐射法三组分一锅煮法合成1,4-二氢苯并咪唑并[1,2-a]嘧啶类化合物。反应均在无催化剂条件下以水作反应溶剂进行。结果表明,采用微波辐射优于常规方法,三组分摩尔比n(2-氨基苯并咪唑)∶n(丙二腈)∶n(取代苯甲醛)=1∶1.1∶1,辐射功率400 W,时间为6～8 min时,1,4-二氢苯并咪唑并[1,2-a]嘧啶的收率在85%以上,反应速率比常规加热条件下提高70倍。通过荧光发射光谱研究证实,该系列化合物具有明显的荧光性质,其荧光发射峰位于480～550 nm。