Koon Ha Park

2-ARYLBENZOXAZOLES FROM PHENOLIC SCHIFF'S BASES BY THIANTHRENE CATION RADICAL

Abstract 2-Arylbenzoxazoles 2 have been made in 91–97% yields from phenolic Schiffs bases 1 by thianthrene cation radical perchlorate (Th +. ClO 4 − ) in the presence of 2,6-di- tert -butyl-4-methylpyridine.

One step synthesis of 4-ethoxy-1,2,3,4-tetrahydroquinoline from nitroarene and ethanol: A TiO2 mediated photocatalytic reaction

Abstract 4-Ethoxy-1,2,3,4-tetrahydroquinoline is formed in a one pot reaction from a heterogeneous solution of nitroarene, ethanol, and TiO 2 by UV light ( λ =350 nm).

Introduction of N‐Containing Heterocycles into Pyrazole by Nucleophilic Aromatic Substitution

Abstract The nucleophilic aromatic substitution on 5‐chloropyrazoles activated by the electron‐withdrawing formyl group offers a useful method to introduce a wide range of N‐containing heterocycles into them. The rate of reaction was greatly affected by the electronic nature of the N‐1 substitution.

s-Triazolo[3,4-α]Phthalazines From 1-Phthalazinylhydrazones by Thianthrene Cation Radical Perchlorate

Abstract 1-Phthalazinylhydrazones 4 gave i,-triazolo[3,4-a]phthalazines 5 in 94-98% yields by thianthrene cation radical perchlorate (Th+′C104 -).

Novel photocatalytic product from m-nitrocinnamic acid and alcohol mediated by TiO2

Abstract New heterocycles 6 having a skeleton of 7-membered lactone and a 1,2,3,4-tetrahydroquinoline were obtained from TiO2 suspended alcoholic solution of trans m-nitrocinnamic acid 4 by uv (350 nm) irradiation. Highly functionalized products 6 are believed to be formed through 4-alkoxy-1,2,3,4-tetrahydroquinolines 5.

A Convenient Dediazoniation of Arenediazonium Tetrafluoroborates: Triethylamine Effects on Competitive Ionic and Radical Dediazoniation

Abstract Triethylamine was very efficient in the dediazoniation of arenediazonium salt. The major product depended on the comparative molar ratio (r) of triethylamine to benzenediazonium salt. When r 1.

INDIRECT OXIDATIVE DEAMINATION OF BENZYLAMINES TO BENZALDEHYDES

Abstract Treatment of N-benzylarenesulfonamide (1) with potassium superoxide yields benzaldehyde (2) and arenesulfonamide (3).

[9, 9]-Sigmatropic shifts in acid-catalyzed benzidine-type rearrangements

Each of the three new hydrazobenzenes consisting of a hydrazobenzene conjugated with a 5-membered heterocyclic ring (furan or thiophene) at its two para positions, prepared from corresponding azo precursors, was used in the acid-catalyzed benzidine rearrangements. Both rearrangement and disproportionation occurred and product structures were characterized by spectroscopic data such as NMR, MS, and with CHN analysis. We confirm the largest [9, 9]-sigmatropic benzidine-type rearrangement in each case as a prominent pathway accompanied by disproportionation.