Jinya Koshitani

Synthesis of some 5H-benzo[a]phenoxazin-5-one derivatives

The substituted 6-bromo and 6-chloro-5H-benzo[a]phenoxazin-5-ones, prepared by condensation of substituted 2-aminophenols with 2,3-dibromo or 2,3-dichloro-1,4-naphthoquinone in methanolic potassium hydroxide solution, have been dehalogenated to substituted 5H-benzo[a]phenoxazin-5-ones in the presence of sodium hydrosulfite dissolved in aqueous pyridine under nitrogen atmosphere.

The photochemical synthesis of 6-acyl-5H-benzo[a]phenoxazin-5-ones

Abstract6-Acyl-5H-benzo[a]phenoxazin-5-ones were prepared by the photochemical reaction of 5H-benzo[a]phenoxazin-5-one with aldehydes.ZusammenfassungDie Titelverbindungen wurden mittels photochemischer Reaktion von 5H-Benzo[a]phenoxazin-5-onen mit Aldehyden hergestellt.

The dehalogenation of the halo substituted 5H-benzo[a]phenothiazin-5-ones and 3H-phenothiazin-3-ones

Abstract6-Bromo- and 6-chloro-5H-benzo[a]phenothiazin-5-ones were dehalinated to 5H-benzo[a]phenothiazin-5-one in the presence of sodium hydrosulfite (disodiumdithionite · 2H2O) dissolved in aqueous pyridine under nitrogen atmosphere.Zusammenfassung6-Brom- und 6-Chlor-5H-benzo[a]phenothiazin-5-on lassen sich in wäßrigem Pyridin in Gegenwart von Natriumdithionit unter Stickstoff zu 5H-Benzo[a]phenothiazin-3-on enthalogenieren.

Mechanism of decomposition of α,α-dimethylbenzyl hydroperoxide producing acetophenone and α,α-dimethylbenzyl alcohol in a constant proportion of 2 to 1

In the decomposition of α,α-dimethylbenzyl hydroperoxide (1) by use of copper(II) chlorocomplexes, the novel fact was found that the product ratio of acetophenone (2) to α,α-dimethylbenzyl alcohol (3) is 2 to 1. The kinetics of this result was investigated and a mechanism consistent with the experimental result is proposed.ZusammenfassungBei der Zersetzung von α,α-Dimethylbenzylhydroperoxid (1) unter Verwendung eines Kupfer(II)chlorkomplexes wurde die neue Feststellung gemacht, daß das Produktverhältnis Acetophenon (2): α,α-Dimethylbenzylalkohol (3) stets 2:1 ist. Die Kinetik der Reaktion wurde untersucht und ein Mechanismus vorgeschlagen, der mit dem experimentellen Resultat konsistent ist.

Effect of 1,3:2,4-dibenzylidene-D-sorbitol (DBS) additive on reverse osmosis properties of cellulose acetate membrane

Abstract The performance of the modified membranes prepared by adding aprotic solvent and DBS to Manjikian-named Batch 47-type casting solution was investigated. The addition of 1.5 wt-%, DBS to the casting solution made by mixing cellulose acetate, acetone, formamide, and N,N-dimethylformamide in the proportion of 5:9:2:4 by weight brought about the optimum performance of the resulting membrane. From the results obtained, it is suggested that an addition of proper amount of DBS does not affect the separation mechanism of the cellulose acetate membrane but DBS has the effect of forming a number of homogeneous pores in the membrane surface layer.