نتایج جستجو برای: toluenesulfonic acid
تعداد نتایج: 747445 فیلتر نتایج به سال:
A convenient one-pot Mannich-type-cyclization-oxidation tandem process has been developed for the synthesis of 1,3,5-trisubstituted pyrazoles derivatives from aldehydes, hydrazines and alkynes using p-toluenesulfonic acid monohydrate (PTSA) as a multifunctional catalyst. This method provides a flexible and rapid route to 1,3,5-trisubstituted pyrazoles.
In this study an improved process for the production of 5-Methyl-1,2,4-triazolo(3,4-b) benzothiazole fungicide (IV) is described. Firstly, (2-methylphenyl) thiourea (I), 2-amino- 4-methylbenzothiazole (II) and 2-hydrazino-4-methylbenzothiazole (III) as intermediates consequently were prepared. Then IV is synthesized by the reaction of III with formic acid in the presence of p-toluenesulfonic ac...
Inexpensive and readily available sulfonic acids, p-toluenesulfonic acid, and sulfuric acid are versatile and efficient catalysts for the peracetylation of a broad spectrum of carbohydrate substrates in good yield and in a practical time frame. Three appealing features in sulfonic acid-catalyzed acetylation of free sugars were explored including (1) suppression of furanosyl acetate formation fo...
Microwave-assisted three component cyclocondensation reactions of aldehydes, amides and dienophiles in the presence of acetic anhydride and para-toluenesulfonic acid as a catalyst to afford the highly substituted cyclohexene derivatives, in relatively good yields after several minutes are reported.
Oxidation of some benzoins to benziles is reported by using p-toluenesulfonic acid as aselective oxidation catalyst under solvent-free condition in high yield. The adjacent carbonylgroup is necessary for the oxidation of hydroxyl group in these compounds. The reaction iscarried out in a sand-bath at 100 °C with minimum by-products.
Novel coumarin derivatives, 2-oxo-2H-chromenecarbaldehyde hydrazones were prepared by reaction of substituted 2-oxo-2H-chromenecarbaldehydes with N-aminoimides in ethanol in the presence of 4-toluenesulfonic acid as catalyst. The photochromic and thermochromic properties of the prepared compounds were investigated.
Herein, the data acquired regarding the preliminary and exploratory experiments conducted with potato peel as a biomass source for the direct thermochemical liquefaction is disclosed. The procedure was carried out in a 2-ethylhexanol/DEG solvent mixture at 160 °C in the presence of p-Toluenesulfonic acid. The adopted procedure afforded a bio-oil in high yield (up to 93%) after only 30 min. For ...
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