Patent GB-826146-A (GB)
Title: Derivatives of cyclodiene carboxylic acids
IPC: C08G63/06
Filed: 1956-03-20
Abstract: Carboxylated derivatives of bicycloheptene are obtained by mixing a dicarboxylic acid of a dimer or mixed dimer of a compound or compounds selected from cyclopentadiene and its homologues, or an ester of such an acid, with an unsaturated dienophilic compound as defined below and heating the mixture at a temperature sufficient to depolymerize the dimer and to effect reaction between the resulting monomer and the dienophilic compound.  The invention also comprises an adduct of a monocarboxylated cyclopentadiene and an unsaturated dienophilic compound.  The unsaturated dienophilic compound is defined as a compound which contains a reactive double bond and which is capable of being used in the Diels-Alder reaction.  The dienophilic compounds may be unsaturated aliphatic alcohols, ketones, or aldehydes, conjugated dienes or other reactive unsaturated hydrocarbons, e.g. vinyl substituted hydrocarbons, unsaturated nitriles, unsaturated triglycerides, chlorinated derivatives, e.g. chloroprene, vinyl chloride and vinylidene chloride, and unsaturated dienophilic carboxylated compounds such as acids, esters or acid anhydrides, e.g. maleic acid, itaconic acid and their anhydrides, aconitic acid or unsaturated monocarboxylic acids, e.g. methacrylic acid, crotonic acid or sorbic acid.  The dicarboxylic dimer compound may be dicyclopentadiene dicarboxylic acid, the dicarboxylated dimer of methyl (or ethyl) cyclopentadiene, or the mixed dimer of cyclopentadiene carboxylic acid and methyl cyclopentadiene carboxylic acid and the corresponding alkyl esters, e.g. the dimethyl ester of dicyclopentadiene dicarboxylic acid.  The dienophilic compound may have the formula R1.CH=C(R2)(R3), in which R1 is hydrogen or an alkyl or aryl radical, R2 is hydrogen, carboxyl, carbalkoxyl, formyl, alkanoyl, cyano, chlorine or aryl, and R3 is hydrogen, carboxyl, carboxyalkyl, carboxyalkenyl, carboxyalkadienyl, aryl, alkyl, or alkenyl and the product from reacting such compound and maleic anhydride, respectively, with dicyclopentadiene dicarboxylic acid would be derivatives of bicyclo-(2,2,1)-heptene-5 of the formulae <FORM:0826146/IV (b)/1> and <FORM:0826146/IV (b)/2> respectively. Suitable reaction temperatures are 75 DEG  to 250 DEG  C. and reduced, atmospheric, or elevated pressures may be employed. The reaction can be carried out batchwise or in a continuous manner and may be suitably controlled by carrying it out in the presence of a refluxing inert diluent medium.  Specified reactions are the reaction of acrolein with the dimethyl ester of dicyclopentadiene dicarboxylic acid to produce the corresponding carboxylated bicycloheptene derivative which may be hydrogenated to form the corresponding carbmethoxy - bicyclo - (2,2,1) - heptan - 2 - methylol compound, and the reaction of dicyclopentadiene dicarboxylic acid with crotonaldehyde, styrene, isoprene and the elaeostearic acid glyceride present in tung oil to give the corresponding carboxylated bicycloheptene derivatives.  Some of the products on chlorination yield chlorinated carboxylated derivatives which can be used as pesticides either as such or as their alkyl esters or in the form of their salts with copper, mercury or lead.  Polycarboxylic acid products which are formed from carboxylated dienophilic compounds may be esterified, e.g. with butyl or octyl alcohol or with glycols (see Group IV (a)).  Examples are given (1) for the reaction of dicyclopentadiene dicarboxylic acid with maleic anhydride in the presence of xylene to form a tricarboxylic acid anhydride which may be used to form alkyd resins (see Group IV (a)) and a lactone dibasic acid which results if some water is present to effect hydration at the double bond of the tricarboxylic acid followed by inner esterification, and (2) for the reaction of dicyclopentadiene dicarboxylic acid with aconitic acid to form a tetracarboxylic acid product and a lactone tribasic acid which results if water is present.  The lactones can also be obtained by carrying out the reactions in the absence of water and then treating the products with water in a separate step.  Adducts containing an aldehyde group can be oxidized to an acid or reduced to form an unsaturated or saturated alcohol.ALSO:A tricarboxylic acid anhydride derivative of bicycloheptene obtained by heating a mixture of maleic anhydride with dicyclopentadiene dicarboxylic acid (see Group IV (b)) may be used in preparing alkyd-type resins, e.g. by treating with ethylene glycol in the presence of xylene at a temperature rising from 150 DEG  to 190 DEG  C.  A mixture of propylene glycol and ethylene glycol may also be used and modified resin products may be obtained by the addition of monohydric alcohols.  Polyurethane plastics may be obtained by reacting the polyesters with m-toluene diisocyanate.  Lactones obtained by hydration followed by inner esterification of polycarboxylic derivatives of bicycloheptene obtained by reacting dicyclopentadiene dicarboxylic acid with a polycarboxylic dienophilic compound may also be used either alone or in admixture with the polycarboxylic derivatives to form resins by heating with glycols. Polycarboxylic derivatives of bicycloheptene obtained by reacting dicyclopentadiene dicarboxylic acid (or homologue thereof) with a carboxylated dienophilic compound may also be esterified with ethylene glycol to form alkyd resins.