- HIGH-TEMPERATURE ORGANIC SYNTHESIS. XXVII. REACTIONS OF ALKANETHIONES WITH THE CHLORINE DERIVATIVES OF BENZENE, THIOPHENE, AND NAPHTHALENE
-
Alkanethiols react effectively with chlorobenzene, its derivatives, 1-chloronaphthalene, and 2-chlorothiophene at 600-660 deg C with the preferential formation of the corresponding aromatic or heteroatomic thiols.Ethanethiol is most reactive.When it is used instead of hydrogen sulfide in reactions with chlorobenzene or its 4-substituted derivatives, the yield of the aromatic thiols, from which the phenylthiyl radicals are generated with greater difficulty, increases more sharply than the yield of the thiophenols, which generate the more stable 4-XC6H4S radicals.The side products of the reactions are the corresponding diaryl sulfides, thiophene, benzothiophene, and toluene.
- Voronkov, M. G.,Deryagina, E. N.,Sukhomazova, E. N.
-
p. 755 - 760
(2007/10/02)
-
- An increased internal rotational barrier in thiophenol caused by meta substituents
-
The twofold internal barriers to rotation about the C-S bond in 3,5-diX-thiophenols were determined in solution from long-range spin-spin coupling constants.They are 3.4, 4.85, 5.3, 6.45, and 7.25 +/- 10percent kJ/mol for X = H, CH3, OCH3, F, and Cl, respectively.In 3,5-dichloro-4-hydroxythiophenol, V2 is -0.8 kJ/mol as compared to -1.9 kJ/mol in 4-methoxythiophenol.The para substituent here dominates.The observed barriers are in rough agreement with arguments based on perturbation molecular orbital theory and with MO calculations of changes in the barrier caused by substituents.The computed values appear as nearly pure twofold barriers with very small fourfold components.
- Schaefer, Ted,Baleja, James D.,Penner, Glenn H.
-
p. 2471 - 2475
(2007/10/02)
-
- SYNTHESIS AND CONFIGURATIONAL STUDIES OF ARYL CYCLOPROPYL SULFONES
-
The cycloaddition of arylthiocarbenes to styrene gave stereospecifically cis-1-(arylthio)-2-phenylcyclopropanes, which were subsequently oxidized to the corresponding sulfones.The cyclopropanation of α,β-unsaturated sulfones with dimethylsulfonium methylide yielded stereoselectively trans-1-(arylsulfonyl)-2-arylcyclopropanes.The configurational assignments of these compounds have been arrived at on the basis of IR and PMR spectral data.Chemical shifts for ring protons and other substituents reveal that all the substituents tend to cause protons cis to them to appear at higher fields than those trans to them.This has been used as a criterion to distinguish between cis and trans aryl cyclopropyl sulfones.
- Reddy, D. Bhaskar,Balaji, T.,Reddy, B. Venkataramana
-
p. 297 - 306
(2007/10/02)
-
- Cephalosporin displacement reaction
-
The present invention is directed to a process for the displacement of the acetoxy group of a cephalosporanic acid by a sulfur nucleophile, in an organic solvent and under essentially anhydrous conditions.
- -
-
-
- 2-Substituted-5-trifluoromethyl-1,3,4-thiadiazoles
-
2-Substituted-5-trifluoromethyl-1,3,4-thiadiazoles of the formula STR1 in which R is substituted alkyl, phenyl monosubstituted in the o- or m- position, polysubstituted phenyl, substituted phenylalkyl, phenylalkenyl, substituted phenylalkenyl, an optionally substituted 5-membered or 6-membered heterocyclic radical with 1 to 4 hetero-atoms selected from N and S atoms, optionally substituted benzimidazolyl or benzthiazolyl, optionally substituted naphthyl, quinolyl, cyano or one of the groups STR2 wherein R1 and R2 conjointly are a trimethylene, tetramethylene or pentamethylene group, X is oxygen or sulfur, R' and R" each independently is alkyl or, together with the nitrogen atom and optionally further hetero-atoms selected from O and N atoms, form an optionally substituted 6-membered or 7-membered ring, and N is 0, 1 or 2, Which possess fungicidal, bactericidal, arthropodicidal and insecticidal properties.
- -
-
-