21816-80-8

Upstream product

• 1199-02-6 5-phenyl-3H-[1,3,4]oxadiazol-2-one 
• 75-03-6 ethyl iodide 
• 55084-83-8 2-phenyl-4-ethoxycarbonyl-1,3,4-oxadiazol-5(4H)-one 
• 64-17-5 ethanol 
• 98407-14-8 diethyl 1-benzoylhydrazine-1,2-dicarboxylate 
• 65-85-0 benzoic acid 
• 1134-56-1 5-Phenyl-2-ethoxy-1,3,4-oxadiazole 
• 10465-97-1 N-benzoyl-N'-ethoxycarbonyl hydrazine 
• 4231-62-3 1-benzoyl-1H-benzotriazole 

Downstream Products

• 55084-91-8 2-phenyl-4-ethyl-1,3,4-oxadiazol-5(4H)-thione 

Relevant academic research and scientific papers

Application of N-Acylbenzotriazoles in the Synthesis of 5-Substituted 2-Ethoxy-1,3,4-oxadiazoles as Building Blocks toward 3,5-Disubstituted 1,3,4-Oxadiazol-2(3H)-ones

5-Substituted-2-ethoxy-1,3,4-oxadiazoles were conveniently prepared through a one-pot sequential N-acylation/dehydrative cyclization between ethyl carbazate and N-acylbenzotriazoles in the presence of Ph3P-I2 as a dehydrating agent. Subsequent treatment with a stoichiometric amount of alkyl halides (X = Cl, Br, I) enables a rapid access to a variety of 3,5-disubstituted 1,3,4-oxadiazol-2(3H)-ones in good to excellent yields.

The use of a Mitsunobu reagent for the formation of heterocycles: A simple method for the preparation of 3-alkyl-5-aryl-1,3,4-oxadiazol-2(3H)-ones from carboxylic acids

The reaction of carboxylic acids with Mitsunobu reagents, prepared by the reaction of triphenylphosphine with dialkyl azodicarboxylates, followed by heating at 180-190 °C under solvent-free conditions, afforded 3-alkyl-5-aryl-1,3,4-oxadiazol-2(3H)-ones. This facile and convenient method readily provides the 1,3,4-oxadiazolone ring systems in good yields using a one-pot protocol starting from the corresponding carboxylic acids. It was also demonstrated that the presence of a catalytic base facilitates the final ring closure forming the 1,3,4-oxadiazol-2(3H)-one.

Mitsunobu N3-alkylation of 1,3,4-oxadiazol-2(3H)-ones

The Mitsunobu reaction of 1,3,4-oxadiazol-2(3H)-ones with alcohols leads to N3-alkylated products in high yields.

Syntheses and thermal rearrangements of 2-phenyl-4-alkoxycarbonyl-1,3,4-oxadiazol-5(4H)-ones and related sulfur compounds

Syntheses of nine 2-phenyl-4-alkoxycarbonyl-1,3,4-oxadiazol-5(4H)-ones are described.On heating about 200 deg C, these compounds decarboxylate and give 2-phenyl-4-alkyl-1,3,4-oxadiazol-5(4H)-ones.Although many analogies suggest that the rearrangement proceeds through the cyclisation of a 1,5-dipole, arising from the decarboxylation of the heterocycle, no direct evidence for such a mechanism was obtained.On the contrary, the synthesis and the thermal rearrangement of four related sulfur compounds show that such a postulated intermediate cannot explain all the experimental results.