探针分子3-乙基-十一烷的合成

Synthesis of Probe Molecule 3-Ethylicundecane

针对SAPO-11的一维十元环直孔道结构,设计了具有特殊分子结构的长链烷烃3-乙基-十一烷。3-乙基-十一烷与目前常用的长直链探针分子相比,具有能卡在SAPO-11分子筛孔口的特点,因此可以作为特殊的长链探针分子,结合直链探针分子,对SAPO-11负载催化剂在长链正构烷烃异构化反应中的孔口催化机理进行研究。3-乙基-十一烷的合成按以下三步完成:(1)溴辛烷与镁反应生成格氏试剂,格氏试剂进一步与3-戊酮加成并水解生成3-乙基-3-十一醇;(2)3-乙基-3-十一醇在脱水剂硫酸的作用下脱水生成3-乙基-2-十一烯/3-乙基-3-十一烯;(3)3-乙基-2-十一烯/3-乙基-3-十一烯通过催化加氢反应生成3-乙基-十一烷。对于合成产物,结合红外、质谱和核磁这3种分析手段确定其正确性,并对后两步的合成条件进行了研究,确定出了适宜的合成条件。

In allusion to the molecular sieve of SAPO-11 with unidimensional 10-rings pore channel,3-ethylicundecane was selected as probe molecule for its special molecular structure.Compared to the common long straight-chain structure alkanes,3-ethylicundecane had the character of being locked near the pore of SAPO-11.Thus,it was appropriate to be the probe molecules to study the mechanism of pore mouth catalysis,used with common high alkanes,in the isomerization reaction of high n-alkanes on the catalysts loaded on SAPO-11.The synthetical route of 3-ethylicundecane was confirmed as followed： first,the corresponding alcohol was synthesized by hydrolyzing the products which were obtained with Grignard reagent and ketone;second,the purified alcohol was dehydrated to synthesize the corresponding alkene;the last,the purified alkene was hydrogenated to synthesize 3-ethylicundecane.The products were analyzed by infrared spectroscopy and mass spectrometry.Combining the two analytical tools ensured that the 3-ethylicundecane was synthesized inerrably.The synthetic conditions of the latter two steps were studied and the appropriate conditions were confirmed.