PROCESS FOR PREPARING ACID ESTERS OF 4-PIPERIDINOL DERIVATIVES AND THEIR USE AS STABILIZERS

摘要

1390252 Piperidine compounds; borates SANKYO CO Ltd 31 Jan 1972 [29 Jan 1971] 27221/74 Divided out of 1390251 Headings C2B C2C and C2P [Also in Division C3] Piperidine compounds of general Formula I wherein R1 and R2 may be the same or different, and each represents an alkyl group having from 1 to 4 carbon atoms; or R1 and R2, together with the carbon atom to which they are attached, constitute a saturated alicyclic group or a group of the formula X represents a hydrogen atom, an oxygen free radical, or an alkyl group having from 1 to 4 carbon atoms; = 1, 2, 3 or 4; and when n = 1 R 3 represents an acyl group derived from an aliphatic or aromatic monocarboxylic acid; when n =2 R3 represents a diacyl group derived from an aliphatic or aromatic dicarboxylic acid, or a carbonyl group; when n = 3 R3 represents a triacyl group derived from an aliphatic or aromatic tricarboxylic acid, or a trivalent group derived by removal of three hydroxyl groups from phosphoric acid, phosphorous acid or boric acid; and when n =4 R3 represents a tetraacyl group derived from an aromatic tetracarboxylic acid, or a tetravalent group derived by removal of four hydroxyl groups from orthosilicic acid; or a salt thereof, are prepared by reacting a 4- piperidinol derivative of formula with an ester of formula in the presence of an alcoholysis catalyst (wherein R1, R2, R3, X and n have the meanings already given, and R4 represents C 1 -C 3 alkyl) and, if appropriate, salifying the reaction product.