Patent ID: 6207846
Filing Date: 2001-03-27
Classification: C07C,C07F

Abstract:
A process for the preparation of a difluoro-vinylsilane compound of the formula ##STR11##whereinAr is phenyl, optionally substituted with any combination of from one to three halogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 haloalkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 haloalkoxy, C(O)R.sub.2 or S(0) R.sub.3 groups,1- or 2-naphthyl, optionally substituted with any combination of from one to three halogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 haloalkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 haloalkoxy, C(O)R.sub.2 or S(O),R.sub.3 groups, ora 5- or 6-membered heteroaromatic ring, optionally substituted with any combination of from one to three halogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 haloalkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 haloalkoxy, C(O)R.sub.2 or S(O),R.sub.3 groups;R and R, are each independently C.sub.1 -C.sub.4 alkyl or C.sub.3 -C.sub.5 cycloalkyl;Ar.sub.1 is phenoxyphenyl, optionally substituted with any combination of from one to five halogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 haloalkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 haloalkoxy or C(O)R.sub.4 groups,phenyl, optionally substituted with any combination of from one to five halogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 haloalkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 haloalkoxy or C(O)R.sub.4 groups,biphenyl, optionally substituted with any combination of from one to five halogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 haloalkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 haloalkoxy or C(O)R.sub.4 groups,phenoxypyridyl, optionally substituted with any combination of from one to five halogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 haloalkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 haloalkoxy or C(O)R.sub.4 groups,benzylpyridyl, optionally substituted with any combination of from one to five halogen, C.sub.1 -C.sub.4 alkyl, CQ-C.sub.4 haloalkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 haloalkoxy or C(O)R.sub.4 groups,benzylphenyl, optionally substituted with any combination of from one to five halogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 haloalkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 haloalkoxy or C(O)R.sub.4 groups,1- or 2-naphthyl, optionally substituted with any combination of from one to three halogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 haloalkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 haloalkoxy or C(O)R.sub.4 groups, ora 5- or 6-membered heteroaromatic ring, optionally substituted with any combination of from one to three halogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 haloalkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 haloalkoxy or C(O)R.sub.4 groups;n is an integer of 0, 1 or 2;R.sub.2 and R.sub.4 are each independently C.sub.1 -C.sub.4 alkyl, benzyl or phenyl; andR.sub.3 is C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 haloalkyl; and the fluorine atoms attached to the double bond are trans with respect to each other,which process comprises:(a) reacting a 3-aryl-1,1,2-trifluoro-1-propene compound of the formulaF.sub.2 C=CFCH.sub.2 Ar.sub.1wherein Ar.sub.1 is as described above with a reducing agent to form a 3-aryl-l,2-difluoro-1-propene compound of the formula ##STR12##wherein the fluorine atoms attached to the double bond are predominately trans with respect to each other;(b) reacting the 3-aryl-1,2-difluoro-1-propene compound with a lithium base to form a 3-aryl-1,2-difluoro-1-propenyllithium compound of the formula ##STR13##wherein the fluorine atoms attached to the double bond are predominately trans with respect to each other; and(c) reacting the 3-aryl-1,2-difluoro-1-propenyl-lithium compound with an arylchlorosilane compound of the formula ##STR14##wherein Ar.sub.1 R and R.sub.1 are as described above.