Box Forest Hall No. 2, Newcastle upon Tyne NE12 9TS By using the interaction with p-nitrophenol as a mechanistic probe it has been established that solutions of Nbromo-N-sodiobenzenesulphonamide (bromamine B) in dilute alkali contain two reactive brominating species, the conjugate acid (PhS0,NHBr) and hypobromous acid; formation of the latter can be suppressed by the addition of the parent sulphonamide. These solutions are fully described by a system of four equilibria: three are proton transfer reactions, for which pK, values have been obtained, and the fourth is the alkaline hydrolysis of the conjugate acid, for which an equilibrium constant has been estimated from model experiments with sodium 3 -( N -bromophenylsu1phonamido)propanesulphonate. These data have been used to establish a species distribution diagram and the predictive value of this has been tested.THE chemistry of N-chloro-N-sodiosulphonamides in aqueous solution is reasonably well understood. Recent kinetic studies have established that the reactivity of weakly alkaline solutions of N-chloro-N-sodiotoluene-9-sulphonamide (chloramine T) towards $-cresol,l succinimide,2 and sulphides 3,4 is due to the presence of the conjugate acid, +-MeC,H,SO,NHCl, and/or the disproportionation product, +-MeC,H4S0,NCl, ; hypochlorite was not implicated. Both the dissociation 6 and disproportionation G ~7 constants for N-chlorot oluene-$-sulphonamide have been measured. Surprisingly, almost no information is available on the composition and properties of corresponding solutions of the N-bromo-N-sodiosulphonamides.We are interested in the potential of N-halogenosulphonamide ion as a nucleophile in aqueous solution and have recently described the reactions of the N-chlorospecies with ethylene oxide and propanesultone.8 As essential groundwork for an extension of our nucleophilicity studies to N-bromosulphonamide ion it was decided to investigate the composition of aqueous alkaline solutions of an N-bromo-N-sodiosulphonamide using some convenient organic substrate as a kinetic probe. This work is described in the present paper. EXPERIMENTALReage&.-Reagents used mere of the highest grade commonly available. P-Nitrophenol and toluene-p-sulphonamide were crystallised from toluene and aqueous ethanol (50y0), respectively, before use. Bromamine B (1) was prepared from the sulphonamide, bromine, and aqueous sodium hydroxide by a published p r o c e d ~r e . ~ Repeated recrystallisation from dilute aqueous sodium hydroxide (10-3~) and drying in VUGUO (P,O,) gave the sesquihydrate (Found:

A rapid, efficient means of resolving mixtures of isomeric glycosides is described. The method involves chromatography on a strongly basic anionexchange resin in the hydroxide form. It has been employed for the separation of furanosides from pyranosides, a-a-mixtures of anomers, and a mixture of the methyl a-glycosides of two different hexoses.

The reaction of a series of o-, m-, and p-substituted N-methylbenzamides with hypochlorite ion to form the corresponding N-chloro-compounds, and the hydrolysis of these derivatives in aqueous alkaline solution have been examined using an automatic recording titrator on pH-stat operation. The two reactions are the halves of an equilibrium process. It is postulated that hydrolysis takes place by base-catalysed formation of an imino-hypochlorite i ntermediate followed by its rate-determining reaction with hydroxide ion. Chlorination will then proceed by the reverse of this process such that cleavage of the N-H bond is rate-determining.

No abstract

Tetra-O-benxyl-~-glucosyl Chloride and i t s Use in the Synthesis of the a-and p-Anomers of 2-O-~-Glucosylglycerol and ~-O -D -ClUCOsyl-D -YibitOl.