Zi-Yi Zhang

A green route to the synthesis of azo compounds

Polyethylene glycol (PEG, average molecular weight 400) was used as an absorbent for NO2, the absorptivity was found to reach up to 97%. PEG·NO2, the resulting absorbent product, proved to be a very efficient, clean and moderate oxidant, It can convert hydrazo derivatives 1 to the corresponding azo compounds 2 for the first time. The spent PEG can be recovered and recycled after the oxidation process.

1H and 13C NMR spectroscopy of 6-aryl-substituted 3-[5-methyl-1-(4-methylphenyl)-1,2,3-triazol-4-yl]-s-triazolo[3,4-b]-1,3,4-thiadiazoles

Novel 6‐aryl‐3‐[5‐methyl‐1‐(4‐methylphenyl)‐1,2,3‐tri‐azol‐4‐yl]‐s‐triazolo[3,4‐b]‐1,3,4‐thiadiazoles were synthesized by the condensation of 3‐[5‐methyl‐1‐(4‐methylphenyl)‐1,2,3‐triazol‐4‐yl]‐4‐amino‐5‐mercapto‐s‐triazole with various aromatic carboxylic acids in the presence of phosphorus oxychloride. The compounds were characterized by MS, IR, 1H and 13C NMR spectroscopy. The measured and calculated 13C chemical shifts of the aromatic carbons were compared. Copyright

The New Synthesis of Azo Compounds by 4-Hydroxy-2,2,6,6-Tertramethyl-L-Piperidinyloxyl as the Phases Transfer Dehydrogenation Catalyst

Abstract Using 4-hydroxy-2,2,6,6-tertramethyl-l-piperidinyloxyl as the phases transfer dehydrogenation catalyst to prepare azo compounds is reported first time, ten N, 2-diaryl diazenecarboxamides were synthesized in high yield under mild condition. A possible mechanism was suggested by a nitroxide free radical which acted on substituted semicarbazides to form azo compounds.

The Improved Method of Oxidation of 4-Fluoroaniline to 4-Fluoroazobenzene

Abstract The improved method of oxidation of 4-fluoroaniline to 4-fiuoroazobenzene with K3Fe(CN)6/KOH and 2,4,6-tri-tert-butylphenol as catalyst is described for the first time in this paper. This report offers an efficient and rapid method to prepare azobenzene and a possible mechanism is also suggested.

Novel and Efficient Solid‐State Synthesis of 3‐Alkyl‐6‐Aryl‐s‐triazolo[3,4‐b]‐1,3,4‐thiadiazine Derivatives

Abstract A novel and efficient solid‐state synthesis of s‐triazolo[3,4‐b]‐1,3,4‐thiadiazine derivatives has been reported. Twelve 3‐alkyl‐6‐aryl‐s‐triazolo[3,4‐b]‐1,3,4‐thiadiazine derivatives have been synthesized in excellent yields with short reaction time.

Studies on Condensed Heterocyclic Compounds. XIII. 6-(4-Methylphenyl)-3-(1-naphthylmethylene)-s-triazolo[3,4-b][1,3,4]thiadiazole

6-(4-Methylphenyl)-3-(1-naphthylmethylene)-s-triazolo-[3,4-b][1,3,4]thiadiazole, C 21 H 16 N 4 S, was prepared by cyclization of 3-(1-naphthylmethylene)-4-amino-5-mercapto-1,2,4-triazole with p-methyl benzoic acid in the presence of phosphorus oxychloride. The structure of the compound was determined by elemental analysis, IR and 1 H NMR spectroscopy,and X-ray diffraction. The phenyl group and the heteronucleus are almost coplanar. The dihedral angle between the naphthyl group and the heteronucleus is 83.54 (6)°.

Studies on Condensed Heterocyclic Compounds Xix. 1H and 13C Nmr Spectroscopy of 6-Aryl-3-(1-P-Chlorophenyl-5-Methyl-1,2,3-Triazol-4-Yl)-S-Triazolo[3,4-B]-1,3,4-Thiadiazoles

Abstract 1H and 13C NMR spectra of eight novel 6-aryl-3-(l-p-chlorophenyl-5-methyl-1,2,3-triazol-4-yl)-s-triazolo[3,4-b]-1,3,4-thiadiazoles were measured and assigned on the basis of the additivity effects induced by the substituents. the signal intensities, data reported earlier for related compounds and two-dimensional HMBC experiment. The SCS effects of the s-triazolo[3,4-b]-1,3,4-thiadiazole nucleus on the aromatic ring were determined.