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Abstract

The invention relates to a process for the preparation of chromenes of the general Formula V ##STR1## (wherein R.sup.1 and R.sup.2 are hydrogen, optionally halogeno substituted C.sub.1-6 alkyl or aryl; R.sup.3 and R.sup.7 stand for hydrogen, halogen or C.sub.1-6 alkyl; R.sup.4 represents C.sub.1-8 alkyl, aryl, aralkyl or a group containing a carbonyl group; R.sup.5 and R.sup.6 stand for C.sub.1-10 alkyl, aryl, amino, hydroxyalkyl, alkoxyalkenyl, alkylmercaptoalkyl, acyl, carboxy or an ester group or a halogen atom; n is 0 or 1) which comprises (a) for the preparation of compounds, in which R.sup.5 and R.sup.6 stand for different groups, reacting a compound of the general Formula I ##STR2## with an approximately equimolar, preferably 0.8-1.5 molar amount of a reactant of the general Formula R.sup.5 --X-related to the amount of the compound of the general Formula I (wherein R.sup.5 has the same meaning as stated above X is halogen) and reacting the O-monosubstituted compound of the general Formula III ##STR3## (wherein R.sup.1 -R.sup.6 and n are as stated above) obtained with a 1.1-1.5 molar amount of a compound of the general Formula III (wherein R.sup.6 and X are as stated above); or (b) for the preparation of compounds, in which R.sup.5 and R.sup.6 stand for the same group, reacting a chromanone of the general Formula I (wherein R.sup.1 -R.sup.4 and m have the meaning as stated above) with a 2-3 molar amount of a compound of the general Formula R.sup.5 --X-related to the amount of the compound of the general Formula I (wherein R.sup.5 and X are as stated above), preferably in the presence of a base, a catalyst and a solvent, and thereafter reducing the O-substituted chromanone derivative of the general Formula III thus obtained (wherein R.sup.1 -R.sup.6 and n are as stated above) and dehydrating the chromanol derivative of the general Formula IV ##STR4## thus obtained (wherein R.sup.1 -R.sup.6 and n are as stated above) in acidic-aqueous medium. The compounds of the general Formula V are partly new and useful for the preparation of pesticides.

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First Claim