Chlorostilbene oxide

Rates of hydrolysis may be influenced by the presence of dissolved organic carbon, or organic components of soil and sediment. The magnitude of the effect is determined by the structure of the compound and by the kinetics of its association with these components. For example, whereas the neutral hydrolysis of chlorpyrifos was unaffected by sorption to sediments, the rate of alkaline hydrolysis was considerably slower (Macalady and Wolf 1985) humic acid also reduced the rate of alkaline hydrolysis of 1-octyl 2,4-dichlo-rophenoxyacetate (Perdue and Wolfe 1982). Conversely, sediment sorption had no effect on the neutral hydrolysis of 4-chlorostilbene oxide, although the rate below pH 5 where acid hydrolysis dominates was reduced (Metwally and Wolfe 1990). 

Metwally M E-S, NL Wolfe (1990) Hydrolysis of chlorostilbene oxide. II. Modelling of hydrolysis in aquifer samples and in sediment-water systems. Environ Toxicol Chem 9 963-973. 

Compounds (1) 2-phenylethylbromide, (2) 1,4-diphenylbutane, (3) phenetole, (4) nitrobenzene, (5) trans-chlorostilbene oxide, 6 = Sudan red 7B. 

Stilben-4-yl)naphthotriazoles (2) are prepared by diazotization of 4-amino-stilbene-2-sulfonic acid or 4-amino-2-cyano-4 -chlorostilbene, coupling with an ortho-coupling naphthylamine derivative, and finally, oxidation to the triazole. 

Another control experiment was done to determine the importance of water in this oxidative cleavage reaction. Water was found to be a necessary reagent for the reaction to occur since no p-hydroxybenzaldehyde was obtained when the sodium salt of chlorostilbene 5b was heated in neat nitrobenzene with or without solid sodium hydroxide and a crown ether phase transfer catalyst. Another set of controls was done to evaluate the formation of p-hydroxybenzaldehyde by a nonoxidative reaction, such as the loss of X-PI1-CH2 in a retrograde-type Aldol reaction. No p-hydroxybenzaldehyde was formed when the chlorostilbene 5b was heated at 155 °C for 5 hours in the presence of 2N NaOH but without the presence of nitrobenzene and atmospheric oxygen. Finally, in all of the above control experiments, no oxidized cleavage products were observed from the nonphenolic side of the alcohols 4 or stilbenes 5 (Dershem, S. M., et al., Holzforschung, in press). 

Thus it takes less than a minute for traits stilbene to react with the oxidizer at 0 °C producing trans stilbene oxide in higher than 90% yield. The physical constants of the oxide show a full retention of the starting material configuration. Similar results were observed with cis stilbene, which was converted to cis stilbene oxide without any trace of the trans isomer. Substituted stilbenes react as well, as evidenced by the transformation of trans 4-chlorostilbene and trans 4,4 -dinitrostilbene to the corresponding epoxides in 90% and 70% yield respectively (figure 9). 

Asymmetric derivatives can be synthesized by 4-amino-4 -nitrostilbene-2,2 -disulfonic acid however, their preparation is more expensive, and they show little advantage over the symmetrical compounds. The principal effects of structural variations are changes in solubility, substrate affinity, acid fastness, etc. The bistriazinyl brighteners are anployed principally on cellulosics such as cotton or paper. 2-(Stilben-4-yl)-naphthotriazoles (34, 35) are prepared by diazotization of 4-aminostilbene-2-sulfonic acid or 4-amino-2-cyano-4 -chlorostilbene, coupling with an orthocoupling naphthylamine derivative, and finally, oxidation to the triazole. 

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