Patent GB-1389987-A (GB)
Title: Hydroxy-benzoylcarboxylic acid esters
IPC: C07C62/38
Filed: 1973-08-16
Abstract: 1389987 Hydroxybenzoylcarbonylic acid esters; acids CIBA-GEIGY AG 16 Aug 1973 [17 Aug 1972] 38668/73 Heading C2C [Also in Division C3] The invention comprises novel compounds of the Formula I in which n denotes 1, 2, 3 or 4; R 1  and R 2  are independently primary or secondary C 1-5  alkyl groups or a C 6-8  cycloalkyl group; R 3  is H or CH 3  ; A denotes H, C 1-18  alkyl thio, C 3-21  alkoxycarbonylalkylthio or, if n = 1 and B denotes H A may represent a group of Formula IA B denotes hydrogen or A and B together denote an additional direct bond, or, together with the carbon atoms to which they are attached form a C 5-7  saturated carbocyclic ring, D 1  and D 2  together denote a group = 0 or, If A and B denote hydrogen D 1  and D 2  together form a group of Formula IB X denotes a C 1-18  straight chain, branched or cyclic alkyl group, C 7-9  aralkyl group, C 3-20  thiaalkyl, C 4-18  oxaalkylene or C 4-18  thiaalkylene in which the oxygen atom of the carbonyl group in Formula I is not attached to a carbon atom which is attached to the oxygen or sulphur atom of said oxaalkylene thiaalkyl or thiaalkylene groups, C 2-18  alkylene or a 3 valent C 3-10  hydrocarbon radical or 4-valent C 4-10  hydrocarbon radical in either of which not more than one bond to the carboxyl groups leads from the same carbon atom, or are of the groups IC to IG wherein m 1  and m 2  are 1, 2 or 3. The compounds of Formula I may be prepared in various ways: (a) When D 1  and D 2  together represent =0 by reacting n moles of a carboxylic acid of Formula II with one mole of a hydroxy compound of Formula III in the presence of an acid catalyst. (b) By reacting one mole of a compound of Formula IV with n moles of a mercaptan of formula in which A is alkylthio, or if n = 1 with half a mole of H 2 S to produce compounds in which A denotes a group of formula IH (c) When D 1  and D 2  together denote the group of Formula IIB by reacting one mole of a compound of Formula VI with n moles of ethanedithiol in the presence of an acid catalyst. 3 - (4 - Hydroxy - 3,5 - dialkylbenzoyl)- acrylic acids in which the alkyl groups are CH 3 , iso-C 3 H 7  or sec-C 4 H 9  are prepared by reacting maleic anhydride with the corresponding 2,6- dialkyl phenol in the presence of AlCl 3 . 3 - (4 - Hydroxy - 3,5 - dialkylbenzoyl)- propionic acids in which the alkyl groups are CH 3 , iso C 3 H 7  or sec-C 4 H 9  are prepared by reduction of the corresponding acrylic acids (above) with Zn and acetic acid. 2 - (4 - Hydroxy - 3,5 - dimethylbenzoyl)- hexahydrobenzoic acid is prepared by reacting 2,6-dimethylphenol with hexahydrophthalic anhydride in the presence of AlCl 3 . 2 - Alkylthio - 3 - (4 - hydroxy - 3,5 - dialkylbenzoyl)-propionic acids in which the alkyl thio groups are octyl thio, dodecylthio or butylthio and the alkyl groups attached to be benzene ring are CH 3  or iso-C 3 H 7  are prepared by reaction of the corresponding acrylic acid with the appropriate mercaptan. The novel compounds of Formula I have application as stabilizers for a variety of organic materials especially polymers and in particular polyolefins.