Insecticidal triffluormethyl alkane derivatives

An alkane or alkoxyalkane derivative of the formula ##STR25## in which R.sub.1 is aryl or heteroaryl or these groups substituted by C.sub.1-4 alkyl, halo-C.sub.1-4 alkyl, phenyl-C.sub.1-4 alkyl, C.sub.2-4 alkenyl, halo-C.sub.2-4 alkenyl, phenyl-C.sub.2-4 alkenyl, C.sub.2-4 alkynyl, halo-C.sub.2-4 alkynyl, phenyl-C.sub.2-4 alkynyl, C.sub.1-4 alkoxy, halo-C.sub.1-4 alkoxy, phenyl-C.sub.1-4 alkoxy, C.sub.2-4 alkenyloxy, halo-C.sub.2-4 alkenyloxy, phenyl-C.sub.2-4 alkenyloxy, C.sub.2-4 alkynyloxy, halo-C.sub.2-4 akynyloxy, phenyl-C.sub.2-4 alkynyloxy, alkylsulphonyloxy, haloalkylsulphonyloxy, arylsulphonyloxy, halo, cyano, nitro, aryloxy, haloaryloxy, C.sub.1-4 alkyl-aryloxy, or nitroaryloxy, wherein heteroaryl is benzofuranyl, benzothiophenyl, benzoxazolyl, indanyl or benzodioxanyl

• R.sub.2 is hydrogen or C.sub.1-4 alkyl,
• R.sub.3 is hydrogen, cyano or ethynyl,
• R.sub.4 is phenyl or pyridyl or these groups substituted by at least one of C.sub.1-6 alkyl, halo-C.sub.1-6 alkyl, phenyl-C.sub.1-6 alkyl, C.sub.2-6 alkyl interrupted by an O-, N- or S-atom, C.sub.2-4 alkenyl, halo-C.sub.2-4 alkenyl, phenyl-C.sub.2-4 alkenyl, C.sub.1-4 alkoxy, halo-C.sub.1-4 alkoxy, phenyl-C.sub.1-4 alkoxy, C.sub.2-4 alkenyloxy, halo-C.sub.2-4 alkenyloxy, phenyl-C.sub.2-4 alkenyloxy, C.sub.2-4 alkynyloxy, halo-C.sub.2-4 alkynyloxy, phenyl-C.sub.2-4 alkynyloxy, aryloxy, haloaryloxy, C.sub.1-4 alkylaryloxy, arylamino, haloarylamino, C.sub.1-4 alkylarylamino, aryl-N-C.sub.1-4 alkylamino, aryl-N-C.sub.1-4 acylamino, aroyl, haloaroyl, C.sub.1-4 alkylaroyl, aryl, haloaryl, C.sub.1-4 alkylaryl or halo, and
• A is CH.sub.2 or O.