阻燃剂DOPO的中间体CDOP的合成工艺改进

Improved Procedure for the Synthesis of 6-Chloro-dibenzo Oxaphosphorine,an Important Intermediate of a Flame Retardant DOPO

6-氯-(6氢)-二苯并-(c,e)-氧磷杂己环(CDOP)是阻燃剂9,10-二氢-9氧杂-10-膦杂菲-10-氧化物(DOPO)制备中最重要的中间体,而常规的CDOP合成过程中,原料邻苯基苯酚(OPP)和三氯化磷(PCl3)之间的酯化反应除了生成单酯(邻苯基苯氧基二氯化磷,CC),还有少量二酯(氯代亚磷酸二邻苯基苯酯,OPPC)和三酯(亚磷酸三邻苯基苯酯,TOPP),导致后续酰基化反应产物CDOP中含有杂质6-苯氧基-(6氢)-二苯并-(c,e)-氧磷杂己环(PDOP)和TOPP。为了除去杂质,本文提出了一种简便的改进工艺,即在酰基化反应过程中额外滴加PCl3,利用酯交换反应除去PDOP和TOPP,直接得到高纯度的CDOP。

6-chloro-dibenzo[c.e][1,2]oxaphosphorine（CDOP）is an important intermediate to prepare a versatile flame retardant,9,10-dihydro-9-oxa-10-phosphaphen-anthrene-10-oxide（DOPO）.Conventional synthesis of CDOP involves esterification of o-phenylphenol（OPP）and phosphorus trichloride（PCl3）to give a monoester（o-phenylphenoxy phosphorus dichloride（CC））.However,two byproducts,diester（o-phenylphenoxy phosphorus chloride（OPPC））and trimester（tri（o-phenylphenyl）phosphite（TOPP））are generated in the meantime,resulting in the subsequent acylation product CDOP containing impurities 6-phenoxy-（6-hydrogen）-dibenzo-（c,e）-oxyphenylcyclohexane（PDOP）and TOPP.In order to remove the impurities,this paper presented a simple improved process,that is,additional PCl3 was dropped in the acylation process to eliminate PDOP and TOPP by transesterification with PCl3,and to obtain CDOP with high purity.