- High-temperature reaction of SiO2 with methanol: Nucleophilic assistance of some N-unsubstituted benzazoles
-
SiO2-containing materials (quartz, Pyrex glass, silica gel, and H-Y zeolite) react slowly with methanol at 350 C under both supercritical and gas-phase conditions. The amount of SiO2 reacted with supercritical methanol depends on the kind of the material and is varied from 0.05 wt% for quartz sand to 4.0 wt% for wide-porous silica gel for 5 h of the reaction. The main products of the reaction are methyl orthosilicates, mainly tetramethyl orthosilicate. N-Unsubstituted 1H-indole, 1H-benzimidazole, and 1H-indazole additives considerably increase the amount of reacted SiO2-containing material. Noteworthy, quartz sand solubility is increased ca 14-fold when indole is used at the same reaction conditions. These benzazoles provide a nucleophilic assistance to the reaction between SiO2 and methanol. During the assistance, the azole ring is methylated by methanol, and the participation of SiO2-surface or tetramethyl orthosilicate molecule facilitates the alkylation reaction of benzazole used.
- Chibiryaev, Andrey M.,Kozhevnikov, Ivan V.,Martyanov, Oleg N.
-
p. 159 - 167
(2013/06/26)
-
- Synthesis of 1H-indazoles by reductive cyclization of o-nitro-ketoximes
-
ortho-Nitro-ketoximes are converted to 1H-indazoles upon reaction with carbon monoxide with [Cp*Fe(CO)2]2 as catalyst.
- O'Dell, David K.,Nicholas, Kenneth M.
-
p. 373 - 382
(2007/10/03)
-
- Reactions of Tetrasulfur Tetranitride with Alkyl Aryl Ketoximes: Synthesis of 3-Aryl- and 3-Alkyl-4-aryl-1,2,5-thiadiazoles
-
Tetrasulfur tetranitride (S4N4) was treated with various alkyl aryl ketoximes having two hydrogens at the α-carbon atom to the oxime functionality in p-dioxane at reflux to give 3-substituted and 3,4-disubstituted 1,2,5-thiadiazoles in moderate yields.Rea
- Cho, Jaeeock,Kim, Kyongtae
-
p. 2345 - 2350
(2007/10/02)
-