Patent GB-1262491-A (GB)
Title: Cyclohexene carboxylic acids and cyclohexane carboxylic acids and derivatives thereof and process for their production
IPC: C07D309/12
Filed: 1968-11-26
Abstract: 1,262,491. Cyclohexene and cyclohexane carboxylic acid derivatives. SYNTEX CORP. 26 Nov., 1968 [11 Jan., 1968], No. 56059/68. Headings C2C and C2P. The invention comprises compounds of Formula (I):  wherein R<SP>1</SP> is methyl or ethyl; R<SP>2</SP>' is hydrogen or methyl; R<SP>3</SP> is methyl, ethyl or isopropyl; R<SP>4</SP> is hydrogen, lower alkoxy, hydroxy and the hydrolysable carboxylic esters thereof, cyclopentyloxy, cyclohexyloxy, tetrahydropyran-2<SP>1</SP>- yloxy, tetrahydrofuran-2<SP>1</SP>-yloxy, the group OSO 2 OX or the group OPO(OX) 2 , wherein X is hydrogen or an alkali metal atom; R<SP>5</SP> is hydrogen, lower alkyl, lower alkoxy, hydroxy and the hydrolysable carboxylic esters thereof, cyclopentyloxy, cyclohexyloxy, tetrahydropyran-2<SP>1</SP>-yloxy, tetrahydrofuran-2<SP>1</SP>-yloxy, the group OSO 2 OX or the group OPO(OX) 2 , wherein X is hydrogen or an alkali metal atom; R<SP>6</SP>' is hydroxymethyl or the hydrolysable carboxylic esters thereof, formyl, -COCl, -COF, -CONH 2  or the group -COOR<SP>7'</SP> in which R<SP>7</SP> is hydrogen, lower alkyl or an alkali metal atom; and Z and Z<SP>1</SP> is a carbon to carbon single bond or double bond provided that at least one of Z and Z<SP>1</SP> is a carbon to carbon single bond, provided that when R<SP>6</SP>' is -COCl or -COF, that each of R<SP>4</SP> and R<SP>5</SP> is other than the group OSO 2 OX or the group OPO(OX) 2 , provided further that when R<SP>3</SP> is ethyl, R<SP>4</SP> is lower alkoxy, R<SP>5</SP> is H and R<SP>6</SP> is -COOR<SP>7</SP>, then R<SP>2'</SP> is methyl. Lower alkyl and alkoxy are defined as having 1 to 6 carbon atoms. The invention further comprises a process for the preparation of compounds of the above formula, but wherein R<SP>1</SP> is hydrogen, methyl or ethyl and R<SP>3</SP> is hydrogen, methyl, ethyl or isopropyl and subject to only the first of the above provisos, wherein (a) to obtain a cyolohex-3-ene carboxylic acid a compound of Formula (II) or the corresponding isothiouroniun acetate is reacted with a compound of Formula (III) in an aqueous solution of a water-miscible organic solvent, followed by acid treatment to yield a compound of Formula (IV) treating said compound with an aqueous watermiscible organic solvent solution of an alkali metal hydroxide followed by carbonyl reduction in a divided electrolysis cell in an electrolyte medium comprising a mineral acid electrolyte, water and an inert water-miscible organic solvent at a current density of from about 0À01 to about 0À2 ampere per square centimeter; or (b) for preparing a cyclohexane carboxylic acid, catalytically hydrogenating the thus obtained cyclohex-3-enecarboxylic acid, or (c) for preparing a cyclohex-4-enecarboxylic acid, heating the thus obtained cyclohex-3-enecarboxylic acid with hydrogen chloride in an organic solvent; and optionally treating any one of the thus-obtained cyclohex-3-enecarboxylic acid, cyclohexanecarboxylic acid and cyclohex-4-enecarboxylic acid products by any of the following steps: (1) converting to the corresponding acid chloride by treatment with triphenylphosphine in carbon tetrachloride or with thionyl or oxalyl chloride; (2) converting to the corresponding acid fluoride with N-(2-chloro-1,1,2- trifluoroethyl)diethylamine, (3) converting to the corresponding amide by sequential treatment with thionyl chloride and anhydrous ammonia, (4) converting to the corresponding alkali metal salt by treatment with an alkali metal hydroxide or bicarbonate solution, (5) converting said alkali metal salt to the corresponding acid ester by treatment with lower alkyl iodide or bromide, (6) converting said acid ester to the corresponding hydroxymethyl compound by treatment with an aluminum hydride reagent, (7) esterifying said hydroxymethyl compound to a corresponding hydrolysable carboxylic ester of the hydroxymethyl group, (8) converting said hydroxymethyl compound to the corresponding aldehyde by treatment with chromium trioxide in pyridine, (9) converting any free ring hydroxy group to a group of the formula OSO 2 OX wherein X is hydrogen or an alkali metal, (10) converting any free ring OH groups to OPO(OX) 2  groups wherein X is H or an alkali metal atom and (11) restoring any acid and/or base labile derivatives of free OH groups which may have been removed during any of the preceding steps (1) to (10). The compounds of Formula (I) admixed with an edible bait are used as anti-fertility agents in the control of rodents.