英语语法分析

Synthesis of o phenylenediamine from o nitroaniline by catalytic hydrogenation at lower pressure was studied.

以邻硝基苯胺为原料，采用低压催化加氢还原技术合成邻苯二胺。

The synthesis of quinoxaline-2-carboxaldehyde from o-phenylenediamine and fructose was too expensive because of its low yield.

喹喔啉-2-甲醛的合成按前人的文献，操作麻烦、产率低、成本太高。

When the mass ratio of diamine A top -phenylenediamine reached 10 : 0 - 5 : 5, the resultant polymers were soluble in strong polar solvent.

当二胺A与对苯二胺的物质的量比例为10∶0～5∶5时，所得聚合物溶解于强极性溶剂。