- Sulfur/DABCO Promoted Reductive Coupling/Annulation Cascade Reaction between o -Hydroxy/Amino Nitrobenzenes and Benzaldehydes
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Sulfur/DABCO was found to be an efficient reagent in promoting- the reductive coupling/annulation of o -nitrophenols or o -nitroanilines with benzaldehydes. This method represents a simple, straightforward, and green approach to the construction of benz-oxazoles and benzimidazoles.
- Dang, Minh-Huy Dinh,Nguyen, Linh Ho Thuy,Tran, Phuong Hoang
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supporting information
p. 1687 - 1694
(2020/05/25)
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- Some Reactions of 3,1-Benzoxathian-4-ones
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3,1-Benzoxathian-4-ones (II) have been thiated with Lawesson reagent (I) and also with P4S10 to give a mixture of IV, V and VI.These thianones (II) react too with Grignard reagents to give 4-alkyl/aryl-2-phenyl-3,1-benzoxathian-4-ols (VIII), and with alkoxides and mercaptides to give bis(2-substituted phenyl) disulphides (IX). 2-Phenyl-1, 3-benzodithiane-4-thione (Vc) reacts with primary amines and hydrazines to give the imino and hydrazono derivatives (X).The reactions of Vc with diphenyl diazomethane, diazofluorene and copper-bronze have also been studied.
- El-Barbary, A. A.,Hammouda, H. A.,El-Borai, M.
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p. 770 - 773
(2007/10/02)
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- STUDIES ON ORGANOPHOSPHORUS COMPOUNDS-XXXVI SIMPLE NEW ROUTES TO PHOSPHORINS FROM 2-HYDROXY-, 2-MERCAPTO-, AND 2-AMINOBENZOIC ACIDS AND THEIR DERIVATIVES
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2-Hydroxybenzoic acid heated with 2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4-disulfide, 1, gave 2-(p-methoxyphenyl)-4H-1,3,2-benzoxathiaphosphorin-4-one 2-sulfide, 3, and its thio analogue, 4, while its ethyl or phenyl esters gave 4 as the sole product. 2-Mercaptobenzoic acid and its ethyl ester when heated with 1 produced 3H-1,2-benzodithiole-3-one, 8, 3H-1,2-benzidithiole-3-thione, 9, and 2-(p-methoxyphenyl)-4H-1,3,2-benzodithia-phosphorin-4-one 2-sulfide, 10.The reaction of 2-aminobenzoic acid with 1 gave 1,2-dihydro-2-(p-methoxyphenyl)-4H-3,1,2-benzoxaphosphorin-4-one 2-sulfide, 12.Reactions of 1 with methyl 2-aminobenzoate and 2-aminobenzamides are described.Mechanistic considerations for the formation of the heterocyclic phosphorus compounds are presented.
- El-Barbary, A. A.,Lawesson, S.-O.
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p. 2641 - 2646
(2007/10/02)
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- 1,1'2,2'-Tetrathiafulvalenes, III. - Syhthesis, Properties, and Reactions of 3,3'-Bi(3H-1,2-dithiolylidenes)(1,1',2,2'-Tetrathiafulvalenes)
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1,1',2,2'-tetrathiafulvalenes 1 can be prepared by different methods from the cations of 1,2-dithiolylium salts 4 which are either unsubstituted or appropriate substituted in 3-position (instead of 3-Cl also H or SCH3).The structure of 1 is substantiated by chemical arguments.IR and 13C-NMR spectra support the absence of thioxo groups. - Like the 1,1',3,3'-isomers 2 the 1,1',2,2'-tetrathiafulvalenes are disposed to stepwise donation of electrons with formation of the radical cation and dication salts 25 or 11, respectively, as well as to the formation of charge transfer complexes with tetracyanoethylene, tetracyanoquinodimethane, and 2,3-dichloro-5,6-dicyanobenzoquinone.Tris(triphenylphosphine)rhodium(I) chloride and tetrakis(triphenylphosphine)platinum(O) yield complexes with 1a. - Thermolysis of 1 produces thienothiophenes 6.Partial desulfuration of 1a, for example, is also feasible with oxidizing agents like lead(IV) acetate.Selenium dioxide, however, gives the corresponding thienofuran 41.The reaction with trialkyl phosphites yields a disulfide - probably the 2,2'-bi(2H-thietylidene) 38 - the thermolysis of which gives the thienothiophene 6a. - Compounds 1a and 1c do not react with dimethyl acetylenedicarboxylate, isothiocyanate, several 1,3-dipoles (azides), and also not with elementary sulfur, however, 1e forms with sulfur the 3H-1,2-dithiol-3-thione 5e (X = S).
- Behringer, Hans,Meinetsberger, Eike
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p. 1928 - 1959
(2007/10/02)
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- STUDIES ON ORGANOPHOSPHORUS COMPOUNDS. THIATION OF 3,1-BENZOXATHIAN-4-ONES. NEW ROUTES TO 1,2-BENZISOTHIAZOLE-3(2H)-THIONES AND 3H-1,2-BENZODITHIOL-3-IMINES
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3,1-Benzoxathian-4-ones, 2, when heated with 2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4-disulfide, 1, or with P4S10 give one or more of the following products: 3,1-benzoxathian-4-thione, 3, 1,3-benzodithian-4-one, 4, 1,3-benzodithian-4-thion
- El-Barbary, A. A.,Clausen, K.,Lawesson, S.-O.
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p. 3309 - 3316
(2007/10/02)
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