18233-19-7

Upstream product

• 936-02-7 2-Hydroxybenzoylhydrazine 
• 78-39-7 Triethyl orthoacetate 
• 20349-50-2 N’-acetyl-2-hydroxybenzohydrazide 
• 79-24-3 Nitroethane 
• 119-36-8 methyl salicylate 
• 70203-02-0 N'-(2-phenyl-2-ethylidene)-2-hydroxybenzohydrazide 
• 96134-65-5 2-(5-Methyl-1,3,4-oxadiazol-2-yl)benzenamine 

Relevant academic research and scientific papers

Synthesis and spectral luminescence properties of 2-aryl-5-methyl-1,3,4-oxadiazoles and zinc(ii) 2-(2-hydroxyphenyl)-5-methyl-1,3,4-oxadiazole complex

2-Aryl-5-methyl-1,3,4-oxadiazoles were synthesized by reflux of equimolar amounts of acyl hydrazides with triethyl orthoacetate in o-xylene. The obtained oxadiazoles, except for 2-(2-hydroxyphenyl)-5-methyl-1,3,4-oxadiazole, luminesce with a high quantum

Electrophilic activation of nitroalkanes in efficient synthesis of 1,3,4-oxadiazoles

A novel methodology for general and chemoselective preparation of non-symmetric 1,3,4-oxadiazoles is developed. This unusual reaction proceeds via polyphosphoric acid-assisted activation of nitroalkanes towards nucleophilic attack with acylhydrazides.

METHOD FOR PREPAREING 1,3,4-OXADIAZOL UNDER SOLVENT-FREE CONDITION

The present invention relates to a synthesis method of 1,3,4-oxadiazol, comprising: 1) under a solvent-free condition and by means of a mechanical pulverization method, making a hydrazide compound react with an aldehyde compound and thereby synthesizing a N-acylhydrazone compound; and 2) under a solvent-free condition, adding an iodine-based oxidizing agent to the N-acylhydrazone compound to synthesize 1,3,4-oxadiazol via oxidative cyclization. The solventless synthesis method of 1,3,4-oxadiazol according to the present invention is easy to perform and handle, and has the advantage of synthesizing 1,3,4-oxadiazol at high selectivity and yield. Also, the solventless synthesis method of the present invention can prevent the formation of side products caused by the minute amount of water that usually remains in solvents, and can further prevent synthesized intermediates from being converted back into the starting materials by the water.COPYRIGHT KIPO 2016

Synthesis and Biological Evaluation of Some Heterocyclic Compounds from Salicylic Acid Hydrazide

Different heterocyclic compounds were prepared starting from 2-hydroxy benzohydrazide; for example, cyclization of hydrazide hydrazone 3 derived from 2-hydroxybenzohydrazide 2 with acetic anhydride or concentrated sulfuric acid gave 1,3,4-oxadiazole derivatives 4–5. On the other hand, direct cyclization of 2-hydroxy benzohydrazide 2 with one carbon cyclizing agent gave a new derivative of 1,3,4-oxadiazole 7, 8, 9, 10, 11. Heating of hydrazide hydrazone 3 with thioglycolic acid in pyridine gave thiazolidinone 12. When 2-hydroxy benzohydrazide 2 reacted with aliphatic carboxylic acids such as formic acid or acetic acid, it gave the corresponding N-formyl or N-acetyl derivatives 6. Subsequent cyclization of 6 using phosphorous pentasulphide in pyridine gave 1,3,4-thiadiazoles 13. Cyclization of 2-hydroxy benzohydrazide with ethyl acetoacetate gives pyrazolone derivative 14. Finally, when an ethanolic solution of acid hydrazide 2 was treated with ammonium thiocyanate in 35% HCl, it gave the thiosemicarbazide 15. Subsequent treatment of 15 with concentrated sulfuric acid or 10% sodium hydroxide gave 5-amino-1,3,4-thiadiazole 16 and 1,2,4-triazole 17, respectively. The structures of all newly isolated compounds were confirmed using1H NMR, IR spectra, and elemental analyses. The antimicrobial activities for all isolated compounds were examined against different microorganisms.

Excited state intramolecular proton transfer reaction and luminescent properties of the ortho-hydroxy derivatives of 2,5-diphenyl-1,3,4-oxadiazole

Luminescent properties of several ortho-hydroxy derivatives of 2,5-diphenyl-1,3,4-oxadiazole were studied in solvents of different polarity and protolytic ability and compared with the analogous derivatives of 1,3-oxazole, studied by us earlier. Evaluatio

Reinvestigation of synthetic routes to 1,3,4-benzoxadiazepin-5-ones and 1,3-benzoxazepines

Recently reported syntheses of 1,3-benzoxazepines and 1,3,4-benzoxadiazepin-5-ones were reinvestigated and found to produce, instead, 2-(2-hydroxyphenyl)-1,3,4-oxadiazoles and 5-(2-hydroxyphenyl)-1,3-oxazoles, respectively.