The kinetics and mechanism of addition of bulky alcohols to dimethyl ketene and to p-nitrophenyl isocyanate in iso-octane and carbon tetrachloride solutions

We report on the kinetics of addition of pentan-3-ol to p-nitrophenyl isocyanate and to dimethyl ketene in iso-octane, of t-butyl alcohol to the isocyanate in iso-octane, and of pentan-3-ol to the isocyanate in carbon tetrachloride. The extent of self-association of the alcohols in iso-octane has also been examined. For all the additions, our results are compatible with a mechanism that involves slow attack by both alcohol monomers and trimers, the latter being the more reactive. Conclusions from previous work with pentan-3-ol are not supported.