1. Field of the Invention
The present invention relates to a process for the preparation of certain benzyl alcohol derivatives which can be used as or suitably converted into intermediates used in the preparation of biologically, especially insecticidally, active compounds.
It has been found that compounds of the general formula: ##STR1## wherein n is 0 or 1 and X represents an oxygen or a sulphur atom or an alkylene group; Z and Z.sup.1 each represents independently hydrogen or one or more halogen, alkyl, alkenyl, haloalkyl, alkoxy, aryl, cyano or nitro groups, can be prepared in almost quantitative yields by reacting the corresponding benzaldehyde derivative with a ketocyanohydrin in an inert organic solvent in the presence of an organic base.
Thus, the present invention relates to a process for the preparation of alpha-cyano benzylalcohol derivatives of the general formula (I) by reacting a benzaldehyde derivative of the general formula: ##STR2## with a ketocyanohydrin of the general formula: ##STR3## in an inert organic solvent in the presence of an organic base, in which formulae n, X, Z and Z.sup.1 are as hereinbefore defined and R.sup.1 and R.sup.2 each represents a substituted or unsubstituted hydrocarbyl group, or R.sup.1 and R.sup.2 together represent an alkylene group.
The process according to the present invention relates in particular to the preparation of meta-aryloxy-alpha cyano benzyl alcohol derivatives, especially to meta-phenoxy-alpha cyano benzyl alcohol, by reacting the corresponding meta-aryloxy benzaldehyde, especially metaphenoxy benzaldehyde, with a ketocyanohydrin, especially acetone cyanohydrin, in an organic solvent in the presence of an organic base.