Dinitrations occurred at two ortho-positions or both ortho- and para-positions to the hydroxy group with longer reaction time than mononitration.
随着反应时间的延长，有羟基邻位和对位双硝基化以及羟基两个邻位双硝基化产物生成。
2
For isomerization of o-xylene the improvement in para-selectivity has not been observed, because the reaction is not mainly controlled by the diffusion of the reaction products.
但对邻二甲苯异构化反应，由于反应不是单纯由反应产物扩散控制，它们的对位选择性并无明显改善。
3
Under optimum reaction conditions, esterification degree of para-hydroxybenzoate chitosan ester was 130%, and yield reached 80%.