申请人:Bayer Aktiengesellschaft
公开号:US05591869A1
公开(公告)日:1997-01-07
Methylene compounds are preferably prepared by reducing an aluminum halide complex of the formula ##STR1## in which R.sup.1 represents a C.sub.6 -C.sub.10 -aryl radical which is optionally substituted by 1 to 4 C.sub.1 -C.sub.4 -alkyl radicals, 1 to 4 fluorine, chlorine and/or bromine atoms, one C.sub.1 -C.sub.8 -alkoxy group and/or one acetoxy group, or represents a heteroaryl radical which is optionally substituted by one C.sub.1 -C.sub.4 -alkyl radical and/or one fluorine, chlorine or bromine atom and contains 5 to 10 C atoms and one O or S atom and R.sup.2 represents a C.sub.1 -C.sub.12 -alkyl radical which is optionally substituted by 1 to 5 fluorine, chlorine and/or bromine atoms, independently of R.sup.1 represents a radical as defined for R.sup.1 and, in the case where R.sup.1 =a C.sub.6 -C.sub.10 -aryl radical which is substituted by 1 to 4 fluorine, chlorine and/or bromine atoms, also represents a furyl or thienyl radical, Y represents fluorine, chlorine or bromine, with an amineborane of the formula ##STR2## in which R.sup.3 represents C.sub.1 -C.sub.4 -alkyl and R.sup.4 represents hydrogen or C.sub.1 -C.sub.4 -alkyl and/or with sodium borohydride and/or with potassium borohydride. 2-(2,4-Dichloro-5-fluorobenzyl)thiophene is obtainable in this way for the first time.
甲烷基化合物首选通过还原具有以下结构的铝卤化物络合物来制备:
其中R.sup.1代表一个C.sub.6-C.sub.10芳基基团,该基团可选地被1至4个C.sub.1-C.sub.4烷基基团、1至4个氟、氯和/或溴原子、一个C.sub.1-C.sub.8烷氧基团和/或一个乙酰氧基团取代,或者代表一个杂芳基基团,该基团可选地被一个C.sub.1-C.sub.4烷基基团和/或一个氟、氯或溴原子取代,含有5至10个碳原子和一个氧或硫原子;R.sup.2代表一个C.sub.1-C.sub.12烷基基团,该基团可选地被1至5个氟、氯和/或溴原子取代,独立于R.sup.1代表的基团的定义,如果R.sup.1=a被1至4个氟、氯和/或溴原子取代的C.sub.6-C.sub.10芳基基团,也代表一个呋喃基或噻吩基团;Y代表氟、氯或溴,与具有以下结构的胺硼烷反应:
其中R.sup.3代表C.sub.1-C.sub.4烷基,R.sup.4代表氢或C.sub.1-C.sub.4烷基和/或与氢化钠硼或氢化钾硼反应,可以首次获得2-(2,4-二氯-5-氟苄基)噻吩。