638-02-8Relevant articles and documents
MECHANISM OF RECYCLIZATION OF FURANS TO THIOPHENES AND SELENOPHENES UNDER ACID-CATALYSIS CONDITIONS. 2. KINETIC INVESTIGATIONS OF THE REACTION OF 2,5-DIALKYLFURANS WITH HYDROGEN SULFIDE AND HYDROGEN SELENIDE IN AN ANHYDROUS MEDIUM
Voronin, S. P.,Gubina, T. I.,Trushin, S. A.,Markushina, I. A.,Kharchenko, V. G.
, p. 1216 - 1220 (1989)
The effect of the concentration of the acidic component on the rates of recyclization of 2,5-dialkylfurans to thiophenes and selenophenes was studied.On the basis of the direct correlation of log k on (H0)I and the isotope effect of the solvent it was established that the reaction proceeds via a mechanism of specific acid catalysis.It was shown that the rates of the reactions with the participation of hydrogen sulfide and hydrogen selenide coincide at equal acidities and temperatures.A scheme for the mechanism of the reaction that includes a step involving the formation of the doubly protonated form of the substrate is proposed.
Study of the mechanism of recyclization of furans into thiophenes and selenophenes in conditions of acid catalysis. 6. Experiments with labeled atoms. Quantum chemical calculations of intermediates of recyclization and hydrolysis
Gubina,Pankratov,Labunskaya,Voronin,Kharchenko
, p. 903 - 909 (1997)
The reaction of 2-methyl-5-R-furans (R = Me, Bu, 2,2-pentyl-2-methylpentyl) with H218O was investigated. Furans and the corresponding 2,5-alkanediones containing the 18O isotope were obtained. The general characteristics of the recyclization and isotope exchange reactions were established. A kinetic study of recyclization of 2,5-dimethylfuran with 16O and 18O into 2,5-dimethylthiophene was conducted. A reverse kinetic isotope effect was found. The schemes of the mechanisms of these processes were refined based on the experimental data and quantum-chemical calculations of the recyclization and hydrolysis intermediates. 1998 Plenum Publishing Corporation.
Catalytic Synthesis of Methylthiophenes
Mashkina,Khairulina
, p. 1794 - 1797 (2019/03/26)
The gas-phase reaction of dimethyl disulfide with thiophene over Co/HZSM-5 catalyst in a helium medium under atmospheric pressure at 250–350°C gave a mixture of mono-, di-, tri-, and tetramethylthiophenes with an overall selectivity of 94–96%.
Reaction of dimethyl disulfide with thiophene catalyzed by zeolite
Mashkina,Khairulina
, p. 217 - 220 (2015/04/14)
Reaction of dimethyl disulfide with thiophene under the action of highly siliceous zeolite at 180-350°C and contact time 0.6-14 s resulted in formation of thioalkylation products, 2-(methylsulfanyl)- and 2,5-bis(methylsulfanyl)thiophenes and also alkylate
Investigation of the aroma-active compounds formed in the maillard reaction between glutathione and reducing sugars
Lee, Sang Mi,Jo, Ye-Jin,Kim, Young-Suk
experimental part, p. 3116 - 3124 (2011/08/05)
Aroma-active compounds formed during the thermal reaction between glutathione (GSH) and reducing sugars were analyzed by gas chromatography-mass spectrometry (GC-MS) and GC-olfactometry (GC-O) with aroma extract dilution analysis (AEDA). Application of AEDA to glutathione Maillard reaction products (GSH MRPs) led to the identification of 19 aroma-active compounds in the thermal reaction of glutathione with glucose or fructose. In addition, the carbohydrate module labeling (CAMOLA) approach was also employed to elucidate the formation pathways for selected target sulfur aroma compounds, such as 5-methylthiophene-2-carbaldehyde and 3-methylthiophene-2-carbaldehyde, which have not been reported previously. The intact carbon skeleton of glucose via 3-deoxyhexosone is incorporated into 5-methylthiophene-2-carbaldehyde with the hydrogen sulfide of GSH. On the other hand, the formation of 3-methylthiophene2-carbaldehyde may occur via the recombination of a C-4 sugar fragment and mercaptoacetaldehyde.