Patent ID: 6576789
Filing Date: 2003-06-10
Classification: C07F,Y02P

Abstract:
A process for the preparation of a compound of the formula (I) in whichQ1 and Q2 are each OH or together are a divalent radical of the formula (Ib) Z is â€”CHO, D, â€”CH2Y or X, where D is a protected aldehyde group, Y is hydroxyl or amino, and X is cyano, COOH, COCl, CONH2 or C(OR)3, where R is C1-C5-alkyl or phenyl, and where Z is in the ortho-, meta- or para-position to the boronic acid radical; R1 to R4, independently of one another, are hydrogen, C1-C12-alkyl, C2-C12-alkenyl, C2-C12-alkynyl, C3-C12-cycloalkyl, (C1-C12-alkoxy, O-phenyl, O-benzyl, aryl, heteroaryl, fluorine, N(alkyl)2, N[Si(C1-C4-alkyl)3]2 or CF3, or R1 and R2, or R3 and R4, or R1 and R2, and R3 and R4 together form a 5- or 6-membered aliphatic or aromatic ring; said process comprising the steps of: a) reacting a compound of the formula (II) â€ƒwith magnesium in the presence of i) an anthracene compound and, optionally a transition-metal halide and, optionally, a magnesium halide; or ii) a transition-metal halide and, optionally, a magnesium halide, where the anthracene compound is a compound from the group consisting of anthracene, Mg anthracene, substituted anthracene and substituted Mg anthracene, to give an arylmagnesium chloride of the formula (III) b) reacting the compound of the formula (III) with a borate of the formula B(ORâ€²)3, in which Râ€² are identical to or different from one another and are straight-chain or branched (C1-C8)-alkyl radicals, phenyl radicals which are unsubstituted or substituted by one or two (C1-C4)-alkyl groups or (C1-C4)-alkoxy groups, and hydrolyzing the product to give a compound of the formula (IV) â€ƒin which D1 is CHO or D; Q1 and Q2 are each OH or together are a divalent radical of the formula (IVb) c) optionally oxidizing the compound of the formula (IV) or (IVb) in which D1 is CHO to give a compound of the formula (I) In which Z is X, or optionally reducing the compound of the formula (IV) or (IVb) to give a compound of the formula (I) in which Z is CH2Y.