نتایج جستجو برای: toluenesulfonic acid

تعداد نتایج: 747445  

Journal: :Organic & biomolecular chemistry 2012
Pei Liu Ying-Ming Pan Yan-Li Xu Heng-Shan Wang

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.

Journal: :Journal of the Serbian Chemical Society 2001

Abbas Ahmadi, Babak Nahri-Niknafs

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...

Journal: :Carbohydrate research 2008
Chin-Sheng Chao Min-Chun Chen Shih-Che Lin Kwok-Kong T Mong

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...

Ahmad Shaabani, Peiman Mirzaei

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.

Abdul Hossein Abdul Hossein Dabbagh Nader Noroozi Pesyan,

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.

Journal: :Molecules 2009
Radoslav Flasík Henrieta Stankovicová Anton Gáplovský Jana Donovalová

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.

2016
Patrícia Ventura João Carlos Moura Bordado Maria Margarida Mateus Rui Galhano dos Santos

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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