The synthesis and some reactions of thiophene sulfides

The reaction of some electrophilic reagents (bromine, acetyl chloride, and acetic anhydride) and of butyllithium on the zinc chelate of 2-mercapto-3-thenylidenecyclohexylamine (IIIa) is examined. Bromination and acetylation of IIIa lead to fission of the chelate ring and the formation of a complex of thienoisothiazolium bromide with ZnBr₂ (VIII), and the corresponding dimienodithiocine (X). Butyllithium combines with the C=N double bond of the chelate ring (IIIa), with the formation of the chelate XIII.For part XVI, see [16].     

The synthesis and some reactions of pentafluoroethyl vinyl ketone

The title compound has been prepared in a four step synthesis starting from acrolein. Both its dimerization, which yields a 3.4-dihydropyranyl derivative, and the uncatalyzed addition of ethanol across the CCbond take place at 20°, reflecting the high reactivity of this α,β-unsaturated ketone.     

Pyridazines. IV. The synthesis and some reactions of acetylpyridazines

Two 3-acetylpyridazines have been prepared. N-Oxidation of 3-acetylpyridazine ( 6 ) gave only 3-acetylpyridazine 1-oxide ( 7 ). During the N-oxidation of 3-acetyl-6-methoxypyridazine ( 10 ), three primary products, namely, 3-acetyl-6-methoxypyridazine 1-oxide ( 12 ), 3-acetyl-6-methoxy-pyridazine 2-oxide ( 13 ), 3-acetylpyridazin-6-one ( 14 ) and an artifact, 3-methoxypyridazine 1-oxide ( 15 ) were obtained. Furthermore, it has been shown that 3-methoxypyridazine 1-oxide ( 15 ) can be obtained in quantitative yield by treatment of 3-acetyl-6-methoxypyridazine 2-oxide ( 13 ) with dilute sodium hydroxide solution at room temperature. This represents a novel deacylation reaction. Nitration of 3-acetylpyridazine 1-oxide, ( 7 ) gave 3,4-bis(3′-pyridazinoyl)furoxan 1′,1′-dioxide ( 19 ) rather than a simple nitration product. 3-Acetyl-pyridazine ( 6 ) and 3-acetyl-6-methoxypyridazine ( 10 ) also gave furoxans ( 22 and 23 ) upon nitration.     

Facile synthesis and reactions of some olefin-substituted acetylacetonate complexes

Synthesis of transition metal complexes of olefin-substituted acetylacetones has been effected by reaction of nonaqueous solutions of substituted acetylacetones with the metal salt in the presence of Zn or Mg. 3-Allylacetylacetonates of Be(II), Cu(II), Ni(II), Fe(III), Co(II), Pd(II) and Zn(II) have thus been synthesized in quantitative yields. 3-Propylideneacetylacetone, which exists mainly in the keto form, afforded the corresponding 3-propenylacetylacetonates in which 3-propylideneacetylacetone has rearranged to 3-propenylacetylacetone which has a greater probability of existing in the enol form, thus making its reaction with metal ions favorable. Metal–metal exchange reactions of transition metal salts with olefin-substituted Zn or Mg acetylacetonates provide yet another route for the synthesis of transition metal olefin-substituted acetylacetonates. The homogeneous catalytic hydrogenation of the olefin moiety in olefin-substituted metal acetylacetonates could be achieved by a Pt/Sn catalyst.     

A study of the synthesis and some reactions of perimidines

A study of the preparation of perimidines from 1,8-diaminonaphthalene and carbonyl compounds is presented. The optimum conditions for the reaction of the above diamine with carboxylic acids and esters, acid chlorides, anhydrides and aldehydes are defined. The chemical behavior and a number of previously unreported reactions of perimidines are presented. The latter include N-alkylations, reductions, oxidations and acylations.     

The synthesis and some reactions of 2,3-substituted 1-phenylbenzo[f]quinoline

A series of 2,3-substituted 1-phenylbenzo[f]quinolines was synthesized by the Friedlander condensation of 1-benzoyl-2-naphthylamine with β-keto esters. Some chemical transformations of these compounds and the preparation of 13H-benzo[f]indeno[2,1-c]quinoline-13-one and its 9-methyl derivative are described.     

Selenopheno [3,2-c]pyrylium salts synthesis and some reactions

A method has been developed for the synthesis of selenopheno[3,2-c]pyrylium salts by the acylation of 2-acetonyl derivatives of selenophene homologs, and their reactions with nucleophilic reagents have been investigated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1212–1215, September, 1973.     

A synthesis and some reactions of 2-thiocyanato-2-ethylenic carbonyl compounds

A synthesis of 2-thiocyanato-2-ethylenic carbonyl compounds was achieved by the reaction of epoxy ketones with Ph₃P(SCN)₂ (TPPT). Some useful transformations of 2-thiocyanato-2-cyclohexenone to 2,3-disubstituted cyclohexanones and iminothiazolines are described.     

Palladium-catalysed cross-coupling reactions in the synthesis of some high polarizability materials

Liquid crystal materials of high optical anisotropy consist of moieties of high electron density in conjugation with each other along the molecular length. Such structures are conducive to convergent synthesis methods. Here we report the synthesis of a range of novel materials by the strategic use of palladium-catalysed cross-coupling methods. In addition to the traditional use of bromide and iodide leaving groups, invaluable use of the triflate leaving group and the importance of selective cross-coupling methods using both arylboronic acids and alkynylzinc chloride derivatives is illustrated. This systematic methodology allows the separate synthesis of the appropriate sub-units that can be efficiently coupled together to provide high overall product yields.     

Palladium-catalysed cross-coupling reactions in the synthesis of some high polarizability materials

Abstract

Liquid crystal materials of high optical anisotropy consist of moieties of high electron density in conjugation with each other along the molecular length. Such structures are conducive to convergent synthesis methods. Here we report the synthesis of a range of novel materials by the strategic use of palladium-catalysed cross-coupling methods. In addition to the traditional use of bromide and iodide leaving groups, invaluable use of the triflate leaving group and the importance of selective cross-coupling methods using both arylboronic acids and alkynylzinc chloride derivatives is illustrated. This systematic methodology allows the separate synthesis of the appropriate sub-units that can be efficiently coupled together to provide high overall product yields.     

A study of the synthesis and some reactions of 3-phenyl-1,4-benzothiazines

Condensation of o-aminothiophenol with 2-bromoacetophenone yields 3-phenyI-1,4-benzo-thiazine hydrobromide, which upon treatment with alkali gave a mixture of 3-phenyl-2H-1,4-benzothiazine (VIIa) and 3-phenyl-4H-1,4-benzothiazine (VIIb). Catalytic hydrogenation led to rearrangement of the benzothiazine (VIIa) to 2-phenyl-2-methyl-2,3-dihydrobenzothiazole (X), while reduction with lithium aluminium hydride resulted in 3-phenyl-2,3-dihydro-4H-1,4-benzothiazine (XVI). The latter was transferred to 3-phenyl-4-aminoalkyl-2,3-dihydro-4H-1,4-benzothiazines (XVII and XVIII).     

The generation and reactions of some diaryl-dihalomethylcarbonium ions

Previously unknown diaryl-dihalomethylcarbonium ions, formed in high yield from the respective alkenes in trifluoromethanesulfonic acid (triflic acid) undergo facile rapid equilibration of aryl groups in triflic acid with a second added aryl component.     

Glycosylidene Carbenes Part 12. A new synthesis and some reactions of spirooxiranes

The diazirine 1 , upon thermolysis or photolysis in either acetone or cyclohexanone, at different concentrations, yield the spiro epoxides 2 and 3 , and 4 and 5 , respectively (Scheme 1). Yield of 2 and 3 depended both on the temperature and the concentration, and correlated inversely with the yield of the major by-product, the enol-derived glycoside 6 . Other by-product were the benzyloxglycal 7 and the lactone azines 8 . ZnCl₂-Promoted methanolysis of 2 under mild condition yielded mixture of the uloside 9 and 10 (1.2:1); similarly, 4 yielded 11 and 12 (1.8:1; Scheme 2). More strongly acidic conditions converted 11 into 12 , evidencing that ZnCl₂-promoted methanolysis proceeds under kinetic control, which is rationalized. The diazirine 13 , upon thermolysis of Photolysis in either acetone of cyclohexanone, yielded the α-D -configurated spiro epoxides 14 and 16 , and the α-D -configurated dihydrooxazoles 15 and 17 , respectively (Scheme 3), which are either formed by ring-opening of ß-D -epoxides, by competitive interception of the initially formed, hypothetical addition products of the intermediate carbene to the ketones. The glycosylidene carbenes, derived from 1 or 13 are not very reactive towards ketones, yields are good only when sterically unhindered ketones are used in large excess.     

Silylamines in organic synthesis: preparation and some reactions of N,C-dilithiosilylamines

The dimetallation of some olefinic and aromatic N-trimethylsilylamines has been examined. Treatment with a two molar proportion of n-butyllithium gives organodimetallic reagents, which react with trimethylchlorosilane to give N,N,C-tris(trimethylsilyl)amines in 45 to 65% yields. The dianonic reagent obtained from (trimethylsilyl)(allyl)amine reacts with benzoyl chloride, N,N-dimethylformamide, ethyl-2-furylcarboxylate, and benzil to give substituted pyrroles and pyridines.