26925-60-0

Upstream product

• 590-28-3 potassium cyanate 
• 74467-03-1 N-hydroxy-2-methylbenzenecarboximidoyl chloride 
• 81478-70-8 C₁₂H₁₄N₂O₃ 
• 104849-77-6 C₁₁H₁₄N₂O₃ 
• 40312-14-9 N'-hydroxy-2-methylbenzamidine 
• 40312-14-9 (Z)-N'-hydroxy-2-methylbenzamidine 
• 1885-14-9 phenyl chloroformate 
• 616-38-6 carbonic acid dimethyl ester 
• 541-41-3 chloroformic acid ethyl ester 
• 1583263-85-7 2-methyl-5-[(3-(2-tolyl)-1,2,4-oxadiazol-5-yl)(dinitro)methyl]-2H-tetrazole 

Relevant academic research and scientific papers

Copper-Catalyzed Selective N-Arylation of Oxadiazolones by Diaryliodonium Salts

Here, we report the method for copper-catalyzed N-arylation of diverse oxadiazolones by diaryliodonium salts under mild conditions in high yields (up to 92%) using available CuI as a catalyst. The developed method allows utilizing both symmetric and unsymmetric diaryliodonium salts bearing auxiliary groups such as 2,4,6-trimethoxyphenyl (TMP). We found that the steric effects in aryl moieties determined the chemoselectivity of N- and O-arylation of the 1,2,4-oxadiazol-5(4H)-ones. Mesityl-substituted diaryliodonium salts demonstrated the high potential as a selective arylation reagent. The structural study suggests that steric accessibility of N-atom in 1,2,4-oxadiazol-5(4H)-ones impact to arylation with sterically hindered diaryliodonium salts. The synthetic application of proposed method was also demonstrated on selective arylation of 1,3,4-oxadiazol-2(3H)-ones and 1,2,4-oxadiazole-5-thiol. (Figure presented.).

Green synthesis method of oxadiazole derivatives

The invention relates to the field of organic chemistry, overcomes disadvantages in the synthesis of oxadiazole derivatives in the prior art, and provides a green synthesis method of the oxadiazole derivatives. The method comprises the following specific steps: (1) adding a basic reagent, dropwise adding a carbonylation reagent, stirring evenly, and back-flowing at 100 DEG C, wherein water is usedas a solvent, N-hydroxybenzamidine or substituted N-hydroxybenzamidine is used as a raw material, the reaction time is 1-5 hours; and (2) after the reaction is finished, cooling, standing, adjustingpH to 3-4 with 1 mol/L diluted HCl acidification reaction solution, performing suction filtration, collecting filter cakes, washing the filter cakes with water, and performing vacuum drying to finallyobtain the oxadiazole derivative. N-hydroxybenzamidine or substituted N-hydroxybenzamidine and a carbonylation reagent are used as the raw materials, under the action of the basic reagent, the oxadiazole derivatives can be synthesized in one step in water, and the two steps of esterification and cyclization are simplified to one step, thus greatly shortening the reaction time and increasing the reaction yield. The method has the advantages of being mild in reaction conditions, convenient to separate and purify, green and environmentally friendly.

Rh(II)-Catalyzed Transannulation of 1,2,4-Oxadiazole Derivatives with 1-Sulfonyl-1,2,3-triazoles: Regioselective Synthesis of 5-Sulfonamidoimidazoles

An effective method for the synthesis of fully substituted 5-sulfonamidoimidazoles by Rh(II)-catalyzed transannulation of 1,2,4-oxadiazole derivatives with N-sulfonyl-1,2,3-triazoles is reported. The reaction works well with both aromatic 1,2,4-oxadiazoles and 1,2,4-oxadiazol-5-ones providing a flexible approach to N-(alkoxy/amino)carbonyl- and N-alkyl-substituted imidazoles. Both the disclosed reactions are completely regioselective and provide the first examples of a carbenoid-mediated transformation of N,N,O-heterocycles.

Synthesis of 2-(2-methyltetrazol-5-yl)-2,2-dinitroacetonitrile and its reaction with substituted nitrile N-oxides

A procedure of synthesis of 2-(2-methyltetrazol-5-yl)-2,2- dinitroacetonitrile has been developed and its reaction with substituted nitrile N-oxides has been investigated, proceeding by the mechanism of 1,3-dipolar cycloaddition and affording 2-methyl-5-[(1,2,4-oxadiazol-5-yl)(dinitro)methyl]- 2H-tetrazoles. The latter react with KOH in ethanol forming the potassium salt of 2-methyltetrazol-5-yldinitromethane and substituted 5-hydroxy-1,2,4- oxadiazoles.

Heterocycles from Nitrile Oxides. 3. 1,2,4-Oxadiazol-5(4H)-ones

The reaction of nitrile oxides with potassium cyanate gives 3-aryl-1,2,4-oxadiazol-5(4H)-ones (5).These heterocycles are also obtained by cyclization of the corresponding O-carbethoxyamidoximes (7) with sodium ethoxide.

Cyclization of O-Acetoacetylbenzamide Oxime Derivatives

O-Acetoacetylbenzamide oxime derivatives (2) were prepared from benzamide oxime derivatives (1) and diketene at low temperature in almost quantitative yields.Cyclization of 2 in the presence of a strong base proceeded with elimination of acetone to afford 3-aryl-1,2,4-oxadiazolin-5-one derivatives (4) in 77-95percent yields.However, in the cases of the o-, m-, and p-nitrobenzamide oxime derivatives (2f-h), the reaction proceeded with dehydration even in the presence of a strong base to afford 5-acetonyl-3-aryl-1,2,4-oxadiazole derivatives (3f-h) in moderate yields.Possible mechanisms of these cyclization are discussed.