The synthesis of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and its derivatives are briefly introduced, the current progresses on its development and application are also reviewed.

A new flame retardant intermediate 9, 10 - dihydro - 9 - oxa - 10 - phosphaphenanthrene - 10 - oxide (DOP) was synthesized, and the appropriate synthesis conditions were studied.

Purpose: To observe the efficacy and the side effects of oxaliplatin (oxa) in combination with vinorelbine (VRB) in the treatment of drug resistant non-small-cell lung cancer (NSCLC).