2-HYDROXY-3-ARYLOXYPROPYL OR 2-HYDROXY-2-BENZOFURANYL ETHYL TERTIARY AMINE HAVING AN ANTI-HYPERGLYCAEMIC AND/OR ANTI-OBESITY ACTIVITY

Abstract: A compound of formula (A): wherein X¹ represents a 2-hydroxy-3-aryloxypropyl radical un­ substituted or substituted in the aryl moiety or a 2-hydroxy­ 2-benzofuranylethyl group; and X² represents a 2-hydroxy-3-aryloxypropyl or 2-hydroxy-­ 2-arylethyl radical unsubstituted or substituted in the aryl moiety or a 2-hydroxy-2-benzofuranylethyl group; and X³ represents a 2- or 3-arylpropyl or 2-aryloxyethyl radical substituted in the aryl moiety and unsubstituted or methyl-substituted in the aryl chain; or a compound of formula (A) wherein one of the -CHOH - moieties in any one of the 2-hydroxyethyl or 2-hydroxypropyl moieties is present as a carbonyl group and/or a compound of formula (A) wherein up to two of the aforementioned -CHOH- moieties may be present in the form of a pharmaceutically acceptable in-vivo hydrolysable ester; or a pharmaceutically acceptable salt thereof; a process for preparing such compounds and pharmaceutical compositions containing them and their use in medicine and agriculture.

Description: The invention relates to tertiary amines which have anti-hyperglycaemic and/or anti-obesity activity, to processes for their preparation; pharmaceutical compositions containing them and their use in agriculture. Tertiary amines having anti-hyperglycaemic and/or anti-obesity activity are already known. For example, EP 101069 A discloses certain phenylethanolamine derivatives with anti-obesity and hypoglycaemic activity; the nitrogen atom of these is substituted by a 2-hydroxyphenethyl radical, by one phenalkyl or thienylalkyl radical, and by a further 2-hydroxyphenethyl radical or by a 2-hydroxyalkyl radical. EP 140243 A also discloses certain tertiary amines having anti-hyperglycaemic and/or anti-obesity activity. The disclosures of EP 140243 A are relevant to the invention only in so far as is dictated by Article 54(3) of the European Patent Convention. We have now discovered a group of pharmacologically active tertiary amines which are aryloxypropanolamine derivatives, the hydroxy group being on the carbon atom β to the nitrogen atom. The compounds have potent anti-obesity and anti-hyperglycaemic activity coupled with low cardiac stimulation activity. Accordingly, the present invention provides a compound of the general formula (I): or a pharmaceutically acceptable salt thereof, in which R¹ represents a 2-hydroxy-2-(benzofuran-2-yl)ethyl group or a radical of the general formula (a) or (b): R² represents a hydrogen atom or a methyl group, D represents either a benzofuran-2-yl moiety or a radical of general formula (c): R³ represents a hydrogen atom or a CH₂CONH₂ group, and where there are two R³s in the compound these are the same or different, provided that there is a maximum of one CH₂CONH₂ group in the compound, R⁴ represents a radical -(CH₂) a COOH, -O(CH₂) b COOH, or -C(R⁸)=C(R⁹)COOH or an ester or an amide, lower alkylamide, di-lower alkylamide or saturated 5- or 6-membered ring amide derivative of one of these groups, or -SO₂NR¹⁰R¹¹, -(CH₂) a CH₂X, or -O(CH₂) b CH₂X in which a represents zero or an integer from 1 to 6, b represents an integer from 1 to 6, R⁸ and R⁹, which may be the same or different, each represents a hydrogen atom or a methyl group, R¹⁰ and R¹¹, which may be the same or different, each represents a hydrogen atom or a lower alkyl radical or, together with the nitrogen atom to which they are attached, form a saturated 5- or 6- membered ring, and x represents a hydrogen atom or a lower alkyl radical, a hydroxy group or an ester thereof,a lower alkoxy radical, an unsubstituted or substituted benzyloxy radical or a (lower alkyl)carbonyl radical, or a radical NR¹⁰R¹¹ in which R¹⁰ and R¹¹ have the meanings given above, R⁴, represents a hydrogen or a halogen atom or a lower alkyl or lower alkoxy radical, a CF₃ group or a hydroxy group or an ester thereof, R⁵ represents a hydrogen or halogen atom, a hydroxy or hydroxymethyl group or an ester of either of these groups, or a group CF₃, NH₂, NHR¹², NHCOOR¹², or CH₂SO₂R¹² in which R¹² represents a lower alkyl radical, R⁶ represents a hydrogen or halogen atom, or a hydroxy group or an ester thereof, R⁷ represents a hydrogen or halogen atom, n represents 1 or 2, m represents 0 or 1, provided that n + m = 1 or 2, and Q¹ represents a hydrogen atom and Q² represents a hydroxy group or a pharmaceutically acceptable in - vivo hydrolysable ester thereof, or Q¹ and Q² together represent an oxo group,the two Q¹Q² pairs in the compound being the same or different, provided there is a maximum of one Q¹Q² oxo group in the compound; with the proviso that when R¹ represents a radical of the abovementioned formula (a), wherein R³ and Q¹ each represent a hydrogen atom and Q² represents a hydroxy group or a pharmaceutically acceptable in-vivo hydrolysable ester thereof, or R¹ represents a radical of the abovementioned formula (b) wherein R⁵ represents a hydrogen or halogen atom or a trifluoromethyl group and R⁶, R⁷ and Q¹ each represent a hydrogen atom and Q² represents a hydroxy group or an in-vivo hydrolysable ester thereof; and R² represents a hydrogen atom or a methyl group; and D represents a radical of the abovementioned formula (c) wherein R³ represents a hydrogen atom; Q¹ represents a hydrogen atom and Q² represents a hydroxy group or an in-vivo hydrolysable ester thereof; R⁴ represents a para substituent on the phenyl ring, relative to the -(O) m - moiety, and represents either a radical -(CH₂) a CO₂H, -C(R⁸)=C(R⁹)CO₂H, or an ester or amide, lower alkylamide or di- lower alkylamide of one of these groups; or -SO₂NR¹⁰R¹¹; -(CH₂) a CH₂X, wherein X represents hydroxy or a (lower alkyl)carbonyl radical; -O(CH₂) b CH₂X wherein X represents hydroxy, lower alkoxy or an unsubstituted benzyloxy group; and a represents zero or an integer from 1 to 6; and b represents an integer from 1 to 6; and R⁸ represents a hydrogen atom or a methyl group; and R⁹, R¹⁰ and R¹¹ each represents a hydrogen atom; and n represents 1 or 2 and m represents zero; then R⁴, does not represent a hydrogen atom. The compounds of the general formula (I) have, depending on the meaning of Q¹, Q² and R², up to three asymmetric carbon atoms, marked with asterisks in the formula. These compounds may, therefore, exist in up to eight stereoisomeric forms. Also, when R⁴ represents a -C(R⁸)=C(R⁹)COOH radical, geometrical isomers are possible. The present invention encompasses all stereoisomers and geometrical isomers of the compounds of the general formula (I) whether free from other isomers or admixed with other isomers in any proportion, and thus includes, for instance, racemic mixtures of enantiomers. When used herein in connection with alkyl and alkoxy radicals, or with alkanols, the term ''lower'' indicates that the radical or compound has from 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms. The alkyl radical or the alkyl moiety in the alkoxy radical or alkanol compound may be straight- or branched-chain, e.g. a methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or a tert.-butyl group. The radical Q¹ shown in the general formula (I) is preferably a hydrogen atom, and Q² preferably a hydroxy group or ester thereof. Similarly, in each of the radicals (a) and (b) represented by R¹ preferably Q¹ represents a hydrogen atom and Q² represents a hydroxy group or a pharmaceutically acceptable in - vivo hydrolysable ester thereof. Suitably in - vivo hydrolysable esters of hydroxy groups are those used conventionally in the art, preferably they are esters of lower alkyl carboxylic acids. Preferably each radical represented by Q² is a free hydroxy group. Thus, there should especially be mentioned compounds of the general formula (I)': or a pharmaceutically acceptable salt thereof, in which R¹ represents a 2-hydroxy-2-(benzofuran-2-yl) ethyl group or a radical of the general formula (a') or (b'): and R²,R³,R⁴,R⁴,,R⁵,R⁶,R⁷, m and n are as defined in relation to formula (I); and D represents a benzofuran-2-yl moiety or a radical of formula (c) as defined in relation to formula (I). More especially, there should be mentioned compounds of the general formula (I) or (I') in which m represents zero. Preferably R² in general formulae (I) or (I') represents a methyl group. Preferably in the moiety or each moiety of the formula R³ represents a hydrogen atom. Preferably, in the moiety of the formula R⁴ is in the para position. Preferably also R⁴, represents a hydrogen atom. Thus, especially, there should be mentioned compounds of the general formula (I') in which the moiety is In each of the general formulae (I) and (I'), R⁴ may represent, for example, a radical of the formula -(CH₂) a COOH, or an ester or amide derivative thereof mentioned above. Preferably a represents zero. R⁴ may also represent, for example, a radical of the formula -O(CH₂) b COOH or an ester or amide derivative thereof mentioned above. Preferably b represents 1. R⁴ may further represent, for example, a radical of the formula -C(R⁸)=(R⁹)COOH or an ester or amide derivative thereof mentioned above. Each of R⁸ and R⁹ preferably represents a hydrogen atom. An ester derivative of one of the carboxy- containing R⁴ groups is, for example, a lower alkyl ester, e.g. a methyl or ethyl ester. An amide derivative of one of the carboxy containing R⁴ groups is a CONR¹⁰R¹¹ group in which R¹⁰ and R¹¹ have the meanings given above. R⁴ may furthermore represent a radical of the formula -SO₂NR¹⁰R¹¹, -(CH₂) a CH₂NR¹⁰R¹¹ or -O(CH₂) b CH₂NR¹⁰R¹¹. In the various radicals mentioned above, each of R¹⁰ and R¹¹ may represent a lower alkyl radical, especially a methyl group, or a hydrogen atom. When NR¹⁰R¹¹ forms a saturated 5- or 6-membered ring this may, if desired, contain a further hetero atom. Preferably, NR¹⁰R¹¹ represents a 1-pyrrolidinyl or 1-piperidyl group, or, especially, in the case of an -O(CH₂) b CH₂NR¹⁰R¹¹ radical, a 1-piperazinyl or a 4-morpholinyl radical. Other possibilities for R⁴ are other radicals of the formulae -(CH₂) a CH₂X or -O(CH₂) b CH₂X, preferably CH₂X where X has the meaning given above, or -O(CH₂) b CH₂OH, especially -O(CH₂)₂OH. Preferably, however, R⁴ represents a carboxy-containing radical or an ester or amide derivative thereof. More preferably, R⁴ represents a carboxy group or a radical -OCH₂CO₂H or an ester or amide thereof. Preferred esters are the methyl and ethyl esters. R¹ may represent a 2-hydroxy-2-(benzofuran-2-yl)ethyl group or a moiety of the formula wherein R³, R⁶ and R⁷ are as defined in relation to formula (I) and R⁵ represents a hydrogen or halogen atom, a hydroxy or hydroxymethyl group or an ester of either of these groups, or a group NH₂ or NHR¹² in which R¹² represents a lower alkyl radical. When there are two of the radicals (a') in the molecule, these may be the same or different, provided that at least one R³ represents a hydrogen atom. In the radical of the formula (b'), a halogen atom represented by R⁶ and/or R⁷ is preferably a chlorine atom, and in the radical R⁵ a lower alkyl radical R¹² is preferably a methyl group. An ester of a hydroxy or hydroxy-containing group represented by R⁵ or R⁶ is an ester of, for example, an aromatic or lower alkyl carboxylic acid. Preferably, however, the moiety of the formula (b) is one of the following groups: In a particularly preferred aspect the present invention provides a compound selected from the group consisting of: methyl 4-[(R)-2-[bis-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]benzoate; methyl 4-[(R)-2-[bis-[(R)-2-hydroxy-3-phenoxypropyl]amino]propyl]benzoate; N-methyl 4-[(R)-2-[bis-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]benzamide; methyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl] -N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl] benzoate; methyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl] -N-[(R)-2-hydroxy-3-phenoxypropyl]amino]propyl] benzoate; N-methyl 4-[(R)-2-[N'-[(R)-2-hydroxy -2-phenethyl]-N'-[(S)-2-hydroxy-3-phenoxypropyl] amino]propyl]benzamide; N-methyl 4-[(R)-2-[N'-[(R)-2-hydroxy-2-phenethyl]-N'-[(R)-2-hydroxy-3-phenoxypropyl] amino]propyl] benzamide; 4-[2-[N-[2-(3-chlorophenyl)-2-hydroxyethyl]-N-[2-hydroxy-3-phenoxypropyl]amino]propyl] phenoxyacetamide; methyl 4-[2-[N-[2-hydroxy-2-[4-hydroxy-3-hydroxymethylphenyl]ethyl]-N-[2-hydroxy-3-phenoxypropyl]amino]propyl]benzoate; methyl 4-[(R)-2-[N-[2-[4-amino-3,5-dichlorophenyl]-2-hydroxyethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]benzoate; methyl 4-[2-[N-[2-(3-chlorophenyl)-2-hydroxyethyl]-N-[2-hydroxy-3-(4-carboxamidomethyl) phenoxypropyl]amino]propyl]phenoxyacetate; 4-[(R)-3-[N-(R)-2-hydroxy-2-phenethyl-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]butyl]benzamide; 4-[(R)-2-[bis-[(S)-2-hydroxy-3-phenoxypropyl] amino]propyl]phenoxyacetamide; ethyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl] phenoxyacetate; 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[(S) -2-hydroxy-3-phenoxypropyl]amino]propyl] phenoxyacetamide; ethyl 4-[(R)-2-bis-[(S)-2-hydroxy-3-phenoxypropyl] amino]propyl]phenoxyacetate; ethyl 4-[(R)-2-[N-[(R)-2-(3-chlorophenyl) -2-hydroxyethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl] phenoxyacetate; 4-[(R)-2-[N-[(R)-2-(3-chlorophenyl) -2-hydroxyethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino] propyl]phenoxyacetamide; 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl] phenoxyethylamine; ethyl 4-[(R)-3-[N-[(R)-2-hydroxy-2-phenethyl] -N-[(S)-2-hydroxy-3-phenoxypropyl]amino]butyl] phenoxyacetate; 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl] -N-[(S)-2- hydroxy-3-phenoxypropyl]amino]propyl] phenoxyethanol; ethyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl] -N-[(R)-2-hydroxy-3-phenoxypropyl]amino]propyl] phenoxyacetate; methyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl] -N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl] phenoxyacetate; 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl] -N-[(S)-2-hydroxy-3-phenoxypropyl]amino] propoxy] phenoxyacetamide; ethyl 4-[(R)-2-[N-[2-(2-benzofuranyl) -2-hydroxyethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl] amino]propyl]phenoxyacetate ethyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl] -N-[2-(2-benzofuranyl)-2-hydroxyethyl]amino] propyl] phenoxyacetate; 4-[(R)-2-[N-[(R)-2-hydroxy-2-(4-hydroxyphenyl) ethyl]-N-[(R)-2-hydroxy-3-phenoxypropyl] amino]propyl]phenoxyacetamide; methyl 4-[2-[N-[2-(4-amino-3,5-dichlorophenyl) -2- hydroxy-ethyl]-N-[2-hydroxy-3-phenoxypropyl] amino] propyl]phenoxyacetate; and 4-[2-[N-[2-(4-amino-3,5-dichlorophenyl) -2-hydroxyethyl]-N-[2-hydroxy-3-phenoxypropyl] amino]propyl] phenoxyacetamide; or a pharmaceutically acceptable salt thereof. The absolute configuration of any compound of the general formula (I) may be determined by conventional x-ray crystallographic techniques. Suitably, the ''**'' asymmetric carbon has the R-configuration. Suitably the ''****'' asymmetric carbon has the R-configuration. When R¹ is a radical of formula (a) and R₂ is methyl and Q¹ is hydrogen, a favoured enantiomer is that wherein the asymmetic carbons have the following configurations: When R¹ is a radical of formula (b) and R² is methyl and Q¹is hydrogen, a favoured enantiomer is that wherein the asymmetric carbons have the following configurations: The pharmaceutically acceptable salts of compounds of the general formula (I) may be acid addition salts; salt formation is possible for example with the nitrogen atom shown in the formula (I). Salts may also be formed, for example, with carboxy groups. Internal salts should also be mentioned. The hydrates of the pharmaceutically acceptable salts are also encompassed in the present invention. Acid addition salts may be, for example, salts with inorganic acids such, for example, as hydrochloric acid, hydrobromic acid, orthophosphoric acid or sulphuric acid, or organic acids such, for example, as methanesulphonic acid, toluenesulphonic acid, acetic acid, propionic acid, lactic acid, citric acid, fumaric acid, malic acid, succinic acid, salicylic acid or acetylsalicylic acid. Salts formed with carboxy groups may be, for example alkali metal, e.g. sodium or potassium, or ammonium salts or alkaline earth metal salts, e.g. calcium or magnesium salts. The invention also provides a process A for the preparation of a compound of the general formula (I) or a pharmaceutically acceptable salt thereof, which comprises reacting a compound of the general formula (II): in which R², D, R⁴, R⁴', n , m , Q¹ and Q² are as defined in relation to formula (I) with (i) a compound of the general formula in which R represents a benzofuran-2-yl moiety or a group of the general formula in which R³, R⁵, R⁶ and R⁷ are as defined in relation to formula (I), or (ii) a compound of the general formula (IV): in which R is as defined in relation to formula (III) and z represents a leaving group, or an ester thereof, and, if desired, converting a resulting compound of the general formula (I) into another compound of the general formula (I) and/or preparing a pharmaceutically acceptable salt thereof. The present invention also provides a process B for the preparation of a compound of the general formula (I) in which there is one oxo group represented by Q¹ + Q², or a pharmaceuticaly acceptable salt thereof, which comprises reacting a compound of the general formula (II), provided that Q¹ and Q² do not represent an oxo group, with a compound of the general formula RCOCH₂Z (v) in which R and Z are as defined in relation to formula (III) and, if desired, converting the resulting compound of the general formula (VI): in which R, R², D, R⁴, R⁴,, n , m , Q¹ and Q² are as defined in relation to formula (I) and provided that Q¹ and Q² do not represent an oxo group, into another compound of the general formula (VI) (or I), or into a pharmaceutically acceptable salt thereof. A leaving group Z is any group that will, under the reaction conditions, cleave from the starting material thus promoting reaction at a specified site. Suitable examples of such groups are halogen atoms, mesyloxy groups and tosyloxy groups. Preferably in compounds of formula (C) and (IV) Z represents a tosyloxy group, and in compounds of formula (D) and (V) Z represents a bromine atom. A starting material of the general formula (II) may be prepared, for example, by reacting a compound of the general formula (VII)a or (VII)b: in which D is as defined in relation to formula (I), and Z is as defined in relation to formula (V), with a compound of the general formula (VIII): in which R², R⁴, R⁴', n and m are as defined in relation to formula (I). Compounds of formulae (III), (IV), (V), (VII), (a and b), and (VIII) are either known compounds or can be prepared from known compounds by known processes or processes analogous to known processes. The invention also provides a process C for the preparation of a compound of the general formula (I) or a pharmaceutically acceptable salt thereof, which comprises reacting a compound of the general formula (IX): in which R², R⁴, R⁴,, n , m , Q¹ and Q² are as defined in relation to formula (I) and R is as defined in relation to formula (III), with the hereinbefore defined compound of the general formula (VII)a or (VII)b providing that if Q¹ and Q² together represent a carbonyl group then compound (IX) is reacted with compound (VII)a and, if desired, converting a resulting compound of the general formula (I) into another compound of the general formula (I) and/or into a pharmaceutically acceptable salt thereof. Starting materials of the general formula (IX) are described, for example, in EP 0023385 and may be prepared, for example, by reacting a compound of the hereinbefore defined general formulae (III) and (VIII) or (V) and (VIII). The reaction between compounds of the general formulae (II) and (III), (III) and (VIII), (VII)a and (VIII), (IX) and (VII)a, or (X) and (VIII) is advantageously carried out in a protic solvent, e.g. a lower alkanol having at least 2 carbon atoms, at reflux, preferably in ethanol. Reaction between compounds of the general formulae (II) and (IV) is advantageously carried out in dimethyl sulphoxide, for example at a temperature in the range of from 30 to 80°C, e.g. about 50°C and advantageously for a period of time of 1 to 4 days, e.g. about 3 days. The reaction between the compounds of the general formulae (II) and (V) or (V) and (VIII) is advantageously carried out in butanone or acetonitrile at reflux, if desired in the presence of a base. The invention also provides a process D for the preparation of a compound of the general formula (I) or a pharmaceutically acceptable salt thereof, which comprises reacting a compound of the general formula (II): (i) with a compound of the general formula (X): R-CO CHO (X) in which R, is as defined in relation to formula (III) and subsequently treating with a reducing agent, or (ii) with a compound of the general formula (XI): in which R, is as defined in relation to formula (III), and subsequently reducing the resulting hydroxyamide, and, if desired, converting a resulting compound of the general formula (I) into another compound of the general formula (I) and/or into a pharmaceutically acceptable salt thereof. In method (i) above, the reduction may be carried out, for example, with sodium cyanoborohydride; in method (ii), the reaction of compounds of the general formulae (II) and (XI) may be carried out in the presence, for example, of dicyclohexyl carbodiimide or other suitable condensing agent, and the subsequent reduction may be carried out, for example, with lithium aluminium hydride or a borane reducing agent, for example borane methyl sulphide complex. The invention also provides a process (E) for the preparation of a compound of the general formula (I) or a pharmaceutically acceptable salt thereof, which comprises reacting a compound of the general formula (XII): in which D, Q¹ and Q² are as defined in relation to formula (I) and R is as defined in relation to formula (III), (i) with a compound of the general formula (XIII): in which R², R⁴, R⁴', n and m are as defined in relation to formula (I) and Z¹ represents a leaving group and Z² represents a hydrogen atom, or (ii) with a compound of the general formula (XIII) in which R², R⁴, R⁴,, n and m are as defined in relation to formula (I) and Z¹ and Z² together represent an oxo group; and if necessary treating with a reducing agent, and, if desired, converting a resulting compound of the general formula (I) into another compound of the general formula (I) and/or into a pharmaceutically acceptable salt thereof. Reaction of compounds of the general formulae (XII) and (XIII) is advantageously carried out, in the case where Z¹ represents a leaving group, for example one of those mentioned above, more especially a tosyloxy group or bromine atom, in dimethyl sulphoxide or methanol, for example at a suitable temperature in the range of from 30 to 80°C, e.g. about 50°C and advantageously for a period of time of 1 to 4 days, e.g. about 3 days. In the case where Z¹and Z² together represent an oxo group, the subsequent reduction is, for example, with sodium cyanoborohydride. A compound of the general formula (I) may, if desired, be converted into another compound of the general formula (I) by a method known per se . For example, an acid may be converted into an ester, an ester may be converted into an acid, amide or alcohol, or an alcohol into an ester thereof, or a phenoxyacetate converted into a phenoxyacetamide and the phenoxyamide optionally further converted into the phenoxyethylamine. Also, for example, a compound of the general formula (VI) or a salt thereof may be reduced to form a compound of the general formula (I). Thus, the invention also provides for a process F for the preparation of a compound of the general formula (I) or a pharmaceutically acceptable salt thereof, which comprises reducing a compound of the general formula (VI) in which R, R², D, R⁴, R⁴,, n , m , Q¹ and Q² are as defined in relation to formula (I), or a salt thereof, and, if desired, converting a resulting compound of the general formula (I) into another compound of the general formula (I) and/or into a pharmaceutically acceptable salt thereof. The reduction of the compound of the general formula (VI) is advantageously carried out with sodium borohydride and preferably in a lower alkanol. The salts of compounds of the general formula (I) may be produced, for example, by treating a compound of general formula (I) with the appropriate acid or base. Compounds of the general formula (I) and pharmaceutically acceptable salts thereof, produced by the above processes, may be recovered by conventional methods. Compounds of the general formula (I) may be separated into diastereoisomeric pairs of enantiomers by, for example, fractional crystallisation from a suitable solvent, for example methanol or ethyl acetate or a mixture thereof. The pair of enantiomers thus obtained may be separated into individual stereoisomers by conventional means, for example by the use of an optically active acid as a resolving agent. Suitable optically active acids which may be used as resolving agents are described in 'Topics in Stereochemistry', Vol. 6, Wiley Interscience, 1971, Allinger, N.L. and Eliel, W.L. Eds. Alternatively, any enantiomer of a compound of the general formula (I) may be obtained by stereospecific synthesis using optically pure starting materials of known configuration. For example, reaction of one enantiomer of a compound of the general formula (VII)a or (III) with one enantiomer of a compound of the general formula (VIII) gives a compound of a general formula (II) or (IX) respectively as a single enantiomer. The enantiomer may then be further reacted with a single enantiomer, for example the enantiomer of compound of the general formula (II) with one enantiomer of a compound of the general formula (III) or the enantiomer of compound of the general formula (IX) with one enantiomer of a compound of the general formula (VII)a, to produce a single enantiomer of the general formula (I). As previously indicated, the compounds of the present invention have valuable pharmacological properties. The present invention also provides a compound of the general formula (I) or a pharmaceutically acceptable salt thereof for use as an active therapeutic substance. In one aspect, the present invention provides a compound of the general formula (I) or a pharmaceutically acceptable salt thereof for use in the treatment of obesity in human or non-human animals. The present invention further provides a compound of the general formula (I), or a pharmaceutically acceptable salt thereof, for use in the treatment of hyperglycaemia in human or non-human animals. A compound of the general formula (I) or a pharmaceutically acceptable salt thereof may be administered per se or, preferably, as a pharmaceutical composition also comprising a pharmaceutically acceptable carrier. Accordingly, the present invention also provides a pharmaceutical composition comprising a compound of the general formula (I) or a pharmaceutically acceptable salt thereof with a pharmaceutically acceptable carrier therefor. As used herein the term ''pharmaceutically acceptable'' embraces compounds, compositions and ingredients for both human and veterinary use: for example the term ''pharmaceutically acceptable salt'' embraces a veterinarily acceptable salt. The composition may, if desired, be in the form of a pack accompanied by written or printed instructions for use. Usually the pharmaceutical compositions of the present invention will be adapted for oral administration, although compositions for administration by other routes, such as by injection, are also envisaged. Particularly suitable compositions for oral administration are unit dosage forms such as tablets and capsules. Other fixed unit dosage forms, such as powders presented in sachets, may also be used. In accordance with conventional pharmaceutical practice the carrier may comprise a diluent, filler, disintegrant, wetting agent, lubricant, colourant, flavourant or other conventional adjuvant. Typical carriers include, for example, microcrystalline cellulose, starch, sodium starch glycollate, polyvinylpyrrolidone, magnesium stearate, sodium lauryl sulphate or sucrose. Most suitably the composition will be formulated in unit dose form. Such unit dose will normally contain an amount of the active ingredient in the range of from 0.1 to 1000 mg, more usually 0.1 to 500 mg, and more especially 0.1 to 250 mg. Conveniently, the active ingredient may be administered as a pharmaceutical composition hereinbefore defined, and this forms a particular aspect of the present invention. In treating hyperglycaemic or obese humans the compound of the general formula (I) or pharmaceutically acceptable salt thereof may be taken in doses, such as those described above, one to six times a day in a manner such that the total daily dose for a 70 kg adult will generally be in the range of from 0.1 to 6000 mg, and more usually about 1 to 1500 mg. In treating hyperglycaemic or obese non-human animals, especially dogs, the active ingredient may be administered by mouth, usually once or twice a day and in an amount in the range of from about 0.025 mg/kg to 25 mg/kg, for example 0.1 mg/kg to 20 mg/kg. In a further aspect the present invention also provides a method for improving the weight gain and/or improving the feed utilisation efficiency and/or increasing lean body mass of livestock, which method comprises the administration to livestock of an effective non-toxic amount of a compound of formula (I) or a veterinarily acceptable salt thereof. Whilst the compounds of formula (I) and the veterinarily acceptable salts thereof may be administered to any livestock in the abovementioned method, they are particularly suitable for improving the weight gain and/or feed utilisation efficiency and/or lean body mass in poultry, especially turkeys and chickens, cattle, pigs and sheep. In the preceding method the compounds of formula (I) and veterinarily acceptable salts thereof will normally be administered orally although non-oral modes of administration, for example injection or implantation, are also envisaged. Suitably the compounds are administered in the feed-stuff or drinking water provided for the livestock. Conveniently these are administered in the feed-stuff at from 10⁻³ ppm - 500ppm of total daily fed intake, more usually 0.01ppm to 250ppm, suitably less than 100ppm. The particular formulations used will of course depend upon the mode of administration but will be those used conventionally in the mode of administration chosen. For administration in feed-stuff the drugs are conveniently formulated as a premix in association with a suitable carrier. Suitable carriers are inert conventional agents such as powdered starch. Other conventional feed-stuff premix carriers may also be employed. No toxicological effects are indicated when a compound of formula (I) or a pharmaceutically acceptable salt thereof is administered in any of the abovementioned dosage ranges. The following Examples illustrate the invention. EXAMPLE 1 Methyl 4-[(R)-2-[bis-[(S)-2-hydroxy-3-phenoxypropyl]amino] propyl]benzoate A mixture of methyl 4-[(R)-2-aminopropyl]benzoate (0.2 g) and (S)-phenoxymethyloxirane (0.28 g) was heated under reflux in ethanol for 43h. The solvent was evaporated and the residue chromatographed on alumina. Elution with chloroform gave methyl 4-[(R)-2-[bis-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]benzoate, m.p. 63-66°C (ether-petrol), [α] 25 / D (MeOH) = -13.5°. ¹H nmr (CDCl₃), ppm 1.09 (3H,d), 2.64-2.86 (5H,m), 2.89-2.97 (1H,m), 3.11 (2H, disappears on D₂O), 3.13-3.21 (1H,m), 3.90 (3H,s), 3.94 (6H,s), 6.87-7.01 (6H,m), 7.26-7.33 (6H,m), 7.97 (2H,d). ¹³C nmr (d₆-DMSO), ppm 15.31, 51.89, 53.74, 58.35, 67.75, 70.16, 114.32, 120.32, 127.09, 129.01, 129.35, 129.44, 146.57, 158.64, 166.17. EXAMPLE 2 Methyl 4-[(R)-2-[bis-[(R)-2-hydroxy-3-phenoxypropyl]amino] propyl]benzoate, fumarate A mixture of methyl 4-[(R)-2-aminopropyl]benzoate (0.16 g) and (R)-phenoxymethyloxirane (0.224 g) was heated under reflux in ethanol for 76h. The solvent was evaporated and the residue chromatographed on kieselgel. Elution with chloroform gave an oil which was converted to methyl 4-[(R)-2-[bis-[(R)-2-hydroxy-3-phenoxypropyl]amino]propyl] benzoate, fumarate, m.p. 44-50°C. ¹H nmr (d₆-DMSO), ppm 0.97 (3H,d), 2.44-2.81 (6H,m), 3.15 (1H,q), 3.2-3.5 (2H, broad, disappears with D₂O), 3.55-3:9 (6H,m), 3.76 (3H,s), 6.63 (2H,s), 6.73 (4H,d), 6.88 (2H,t), 7.16-7.27 (6H,m), 7.71 (2H,d). ¹³C nmr (d₆-DMSO), ppm 13.54, 51.94, 52.78, 57.47, 67.47, 70.19, 114.27, 114.58, 120.35, 127.18, 129.01, 129.33, 129.40, 129.59, 134.07, 146.57, 158.65, 166.03, 166.15. EXAMPLE 3 N-Methyl 4-[(R)-2-[biS-[(S)-2-hydroxy-3-phenoxypropyl] amino]propyl]benzamide, fumarate The compound of Example 1 was dissolved in methanolic methylamine and heated in an autoclave at 100°C for 20h. The solvent was evaporated and the residue chromatographed on kieselgel. Elution with methanol-chloroform (2:98) and treatment with fumaric acid gave N-methyl 4-[(R)-2-[bis-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]benzamide, fumarate as a semi-solid. ¹H nmr (d₆-DMSO), ppm 0.85 (3H,d), 2.60-2.85 (5H,m), 2.77 (3H,d, collapses to singlet on D₂O), 2.95 (1H,m), 3.04 (1H,m), 3.84-3.95 (6H, m), 6.63 (2H,s), 6.86-6.93 (6H,m), 7.21-7.27 (6H,m), 7.72 (2H,d), 8.29 (1H, disappears with D₂O). ¹³C nmr (d₆-DMSO), ppm 15.31, 26.16, 37.86, 53.75, 58.57, 67.53, 70.18, 114.45, 120.50, 127.07, 129.07, 129.51, 132.07, 134.07, 143.73, 158.71, 166.03, 166.63. EXAMPLE 4 Methyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl)-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]benzoate, hydro chloride, monohydrate A mixture of methyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl] amino]propyl]benzoate (0.73 g) and (S)-phenoxymethyloxirane (0.35 g) was heated under reflux in ethanol for 48h. The solvent was evaporated and the residue chromatographed on kieselgel. Elution with chloroform gave an oil which was treated with ethereal hydrogen chloride to give methyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]benzoate, hydrochloride, monohydrate, m.p. 90-95°C (ethylacetate/ether), [α] 25 / D(MeOH) -96.3°. ¹H nmr (d₆-DMSO), ppm 1.21+1.24 (3H, two doublets), 3.01 (1H,t), 3.2-3.8 (4H,m), 3.85 (3H,s), 4.02-4.2 (4H,m), 4.56 (1H, broad), 5.28 (1H, broad), 6.19 (1H, disappears with D₂O), 6.40 (1H, disappears with D₂O), 6.98 (2H,d), 7.29-7.56 (10H,m), 7.93 (2H,d), 9.08+9.17 (1H, two broad singlets, disappear with D₂O). ¹³C nmr (d₆-DMSO), free base, ppm 14.63, 51.87, 53.19, 58.04, 59.58, 67.53, 69.96, 70.99, 114.35, 120.29, 126.07, 126.74, 127.09, 127.79, 128.97, 129.33, 129.44, 144.11, 146.51, 158.61, 166.17. EXAMPLE 5 Methyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[(R)-2-hydroxy-3-phenoxypropyl]amino]propyl]benzoate hydro chloride Methyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[(R)-2-hydroxy-3-phenoxypropyl]amino]propyl]benzoate hydrochloride, m.p. 70-75°C (ether/methanol), [α] 25 / D (MEOH) = -48.1° was prepared in an identical manner to the compound described in Example 4 but replacing (S)-phenoxymethyloxirane by its (R) enantiomer. ¹H nmr (d₆-DMSO), free base, ppm 0.84 (3H,d), 2.5-2.87 (5H,m), 3.02 (1H,q), 3.68-3.87 (4H,m), 3.81 (3H,s), 4.56 (1H,t), 4.77 (1H,d, disappears on D₂O), 4.86 (1H,d, disappears on D₂O), 6.84 (2H,d), 6.86 (1H,dd), 7.19-7.36 (9H,m), 7.79 (2H,d). ¹³C nmr (d₆-DMSO), free base, ppm 14.06, 52.01, 53.53, 58.09, 59,86, 68.10, 70.23, 71.40, 114,45, 120.43, 126.23, 126.97, 127.21, 128.02, 129.07, 129.47, 144.12, 146,54, 158.73, 166.34. EXAMPLE 6 N-Methyl 4-[(R)-2-[N'-[(R)-2-hydroxy-2-phenethyl]-N'-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]benzamide Methyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]benzoate (0.4 g) was dissolved in methanolic methylamine and heated at 100°C in an autoclave for 18h. The solvent was evaporated and the residue was chromatographed on kieselgel. Elution with methanol-chloroform (4:96) gave N-methyl 4-[(R)-2-[N'-[(R)-2-hydroxy-2-phenethyl]-N'-[(S)-2-hydroxy-3-phenoxypropyl] amino]propyl]benzamide, m.p. 52-58°C (ether-hexane), [α] 25 / D (MeOH) = -59.6°. ¹H nmr (d₆-DMSO), ppm 0.80 (3H,d), 2.4-2.73 (5H,m), 2.78 (3H,d, collapses to singlet on D₂O), 2.87-3.04 (2H,m), 3.78-3.87 (3H,m), 4.56 (1H,t), 4.83 (1H,d, disappears on D₂O), 4.95 (1H,d, disappears on D₂O), 6.88 (2H,d), 6.90 (1H,dd), 7.18-7.35 (9H, m), 7.73 (2H,d), 8.3 (1H,q, disappears with D₂O). EXAMPLE 7 N-Methyl 4-[(R)-2-[N'-[(R)-2-hydroxy-2-phenethyl]-N'-[(R)-2-hydroxy-3-phenoxypropyl]amino]propyl]benzamide N-methyl 4-[(R)-2-N'-[(R)-2-hydroxy-2-phenethyl]-N'-[(R)-2-hydroxy-3-phenoxypropyl]amino]propyl]benzamide, m.p. 52-58°C (ether-hexane), [α] 25 / D(MeOH) = -76.4° was prepared in an analogous manner to the compound of Example 6 but using the (RRR) enantiomer. ¹H nmr (d₆-DMSO), ppm 0.81 (3H,d), 2.45-2.84 (6H,m), 2.76 (3H,d, collapses to singlet on D₂O), 2.96 (1H,g), 3.72-3.92 (3H,m), 4.56 (1H,t), 4.80 (1H,d, disappears with D₂O), 4.86 (1H,d, disappears with D₂O), 6.87 (2H,d), 6.92 (1H,dd), 7.17-7.34 (9H,m), 7.69 (2H,d), 8.26 (1H,q, disappears with D₂O). EXAMPLE 8 4-[2-[N-[2-(3-Chlorophenyl)-2-hydroxyethyl]-N-[2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyacetamide, hydro chloride A mixture of (R*,R*)-(±)-methyl 4-[N[2-(3-chlorophenyl)-2-hydroxyethyl]aminopropyl]phenoxyacetate (0.94 g) and phenoxymethyloxirane (0.37 g) was heated under reflux in ethanol (100 ml) for 4 days. The solvent was evaporated and the residue chromatographed on kieselgel. Elution with chloroform gave an oil which was dissolved in methanolic ammonia and allowed to stand at ambient temperature for 18h. The solvent was evaporated and the residue chromatographed on kieselgel. Elution with methanol-chloroform (1:99) and treatment of the product with ethereal hydrogen chloride gave 4-[2-[N-[2-(3-chlorophenyl) -2-hydroxyethyl]-N-[2-hydroxy-3-phenoxypropyl]amino]propyl]3 phenoxyacetamide, hydrochloride, m.p. 177-185°C (ether-methanol). ¹H nmr (CDCl₃), free base, ppm 0.98 (3H,d), 2.3-3.2 (8H,m), 3.3-4.1 (4H,m), 4.25 (2H,s), 4.5 (1H,m), 6.4 (2H, broad), 6.7-7.4 (13H,m). EXAMPLE 9 Methyl 4-[2-[N-[2-hydroxy-2-[4-hydroxy-3-hydroxymethyl phenyl]ethyl]-N-[2-hydroxy-3-phenoxypropyl]amino]propyl] benzoate A mixture of (R*,R*)-(±)-methyl 4-[N-[-2-hydroxy-2-[4-hydroxy-3-hydroxymethylphenyl]ethyl]aminopropyl]benzoate (2.0 g) and phenoxymethyloxirane (0.84 g) was heated under reflux in ethanol (100 ml) for 45h. The solvent was evaporated and the residue chromatographed on kieselgel. Elution with methanol-chloroform (4:96) gave after trituration with ether-petrol methyl 4-[2-[N-[2-hydroxy-2-[4-hydroxy-3-hydroxymethylphenyl]ethyl]-N-[2-hydroxy-3-phenoxypropyl]amino]propyl]benzoate, m.p. 38-50°C. ¹H nmr (d₆-DMSO), ppm 0.83+0.85 (3H, two doublets), 2.5-3.1 (8H,m), 3.7=3.9 (2H,m, + 3H, two singlets), 4.46 (2H,d, collapses to singlet on D₂O, + 1H, m), [4.69 (1H,d), 4.82 (1H,d) , 4.89 (1H,t), all disappear with D₂O], 6.69 (2H,d), 6.8-7.0 (4H, m), 7.2-7.4 (5H,m), 7.75-7.86 (2H,dd), 9.13 (1H, s, disappears with D₂O). EXAMPLE 10 Methyl 4-[(R)-2-(N-[2-[4-amino-3,5-dichlorophenyl]-2-hydroxyethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino] propyl]benzoate (4-Amino-3,5-dichloro)phenacyl bromide (0.41 g) in acetonitrile (20 ml) was added dropwise to a stirred solution of methyl 4-[(R)-2-[(S)-2-hydroxy-3-phenoxypropyl]amino propyl]benzoate (0.5 g) and triethylamine (0.5 g) in acetonitrile (80 ml) under reflux. The mixture was stirred and heated under reflux for 20h. The solvent was evaporated, chloroform added and triethylamine hydrobromide filtered off. The residue was chromatographed on kieselgel. Elution with chloroform gave the aminoacetophenone which was reduced with sodium borohydride in methanol at ambient temperature. The solvent was evaporated, the residue partitioned between ethyl acetate and water and the organic layer dried and evaporated. The residue was chromatographed on kieselgel. Elution with chloroform gave methyl 4-[(R)-2-[N-[2-[4-amino-3,5-dichlorophenyl]-2-hydroxyethyl] -N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]benzoate, m.p. 40-49°C (ether-hexane). ¹H nmr (d₆-DMSO), ppm 0.79 + 0.84 (3H, 2 doublets), 2.4-2.85 (5H,m), 2.86-2.93 (1H,m), 3.70-4.0 (4H, m + 3H, s), 4.41 (1H,m), 4.68-4.79 (1H, 2 doublets, disappears with D₂O), 4.96 + 5.1 (1H, 2 doublets, disappears with D₂O), 5.3 (2H, s, disappears with D₂O), 6.83-6.93 (3H,m), 7.13-7.34 (6H,m), 7.80-7.84 (2H,m). EXAMPLE 11 Methyl 4-[2-[N-[2-(3-chlorophenyl)-2-hydroxyethyl]-N-[2-hydroxy-3-(4-carboxamidomethyl)phenoxypropyl]amino]propyl] phenoxyacetate, hydrochloride A mixture of (R * ,R * )-(±)-Methyl 4-[N-[2-hydroxy-(3-chloro) phenethyl]aminopropyl]phenoxyacetate (from 4.59 g of hydrochloride salt) and 4-(carboxamidomethyl)phenoxymethyloxirane (2.07 g) was heated under reflux in methanol containing triethylamine (5 ml) for 36h. The solvent was evaporated and the residue chromatographed on kieselgel. Elution with methanol-dichloromethane (15:85) gave an oil which was converted to methyl 4-[2-[N-[2-(3-chlorophenyl)-2-hydroxyethyl]-N-[2-hydroxy-3-(4-carboxamidomethyl) phenoxypropyl]amino]propyl]phenoxyacetate, hydrochloride, m.p. 82-93°C. ¹H nmr (d₆-DMSO), ppm 1.2 (3H, broad), 2.3-3.6 ( 8H, broad), 3.7 (3H,s), 4.0 (3H, broad), 4.58 (1H, broad), 4.8 (2H,s), 5.3 (1H, broad), 6.1-6.8 (2H + 2H, broad, disappears with D₂O), 6.9-7.1 (4H,m), 7.2-7.7 (8H,m), 8.7-9.5 (1H, broad, disappears with D₂O). EXAMPLE 12 4-[(R)-3-[N-(R)-2-Hydroxy-2-phenethyl-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]butyl]benzamide A mixture of 4-[(R)-3-[N-(R)-2-hydroxy-2-phenethyl]amino] butyl]benzamide (0.2 g) and (S)-phenoxymethyloxirane was heated under reflux in ethanol for 4 days. The solvent was evaporated and the residue chromatographed on kieselgel. Elution with methanol-chloroform (2:98) gave 4-[(R)-3-[N-(R)-2-hydroxy-2-phenethyl-N-[(S)-2-hydroxy-3-phenoxypropyl] amino]butyl]benzamide, m.p. 95.5-97°C (ethyl acetate diisopropyl ether), [α] 25 / D (MeOH) -46.1°. ¹H nmr (d₆-DMSO), ppm 0.91 (3H,d), 1.4-1.6 (1H,m), 1.65-1.85 (1H,m), 2.5-2.69 (5H,m), 2.7-2.91 (2H,m), 3.8-4.0 (3H,m), 4.58 (1H,t), 4.98 (1H,s, disappears with D₂O), 5.15 (1H,s, disappears with D₂O), 6.85-6.95 (3H,m), 7.1-7.4 (9H,m), 7.78 (2H,d), 7.86 (2H,s, disappears with D₂O). EXAMPLE 13 4-[(R)-2-[Bis-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl] phenoxyacetamide, hydrochloride A mixture Of 4-[(R)-2-aminopropyl]phenoxyacetamide (0.19 g) and (S)-phenoxymethyl oxirane (0.28 g) was heated under reflux in ethanol for 48 hours. The solvent was evaporated and the residue chromatographed on silica. Elution with methanol-chloroform (3:97) gave an oil which was treated with ethereal hydrogen chloride to give 4-[(R)-2-[Bis-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyacetamide, hydrochloride, m.p. 79-82°, [α] 25 / D(MeOH) -56.4°. ¹H nmr (d₆-DMSO), ppm 1.15-1.26 (3H,m); 2.72-2.87 (1H,m); 3.20-3.38 (2H,m); 3.42-3.65 (3H,m); 3.82-4.10 (5H,m); 4.32-4.53 (4H,m); 6.00-6.18 (2H, m, replaceable by D₂O); 6.85-7.06 (8H,m); 7.20-7.50 (8H,m, replaceable by D₂O); 8.78 (1H,s, replaceable by D₂O). EXAMPLE 14 Ethyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyacetate, hydrochloride A mixture of ethyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl] amino]propyl]phenoxyacetate (0.43 g) and (S)-phenoxymethyl oxirane (0.18 g) was heated under reflux in ethanol for 72 hours. The solvent was evaporated and the residue chromatographed on silica. Elution with chloroform gave an oil which was treated with ethereal hydrogen chloride to give ethyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyacetate, hydrochloride, m.p. 48-52°, [α] 25 / D (MeOH) -78.7°. ¹H nmr (d₆-DMSO), ppm 1.12-1.27 (6H,m); 2.80-2.93 (1H,m); 3.15-3.65 (5H,m); 3.85-4.10 (3H,m); 4.17 (2H,q); 4.45 (1H,m); 4.75 (2H,s); 5.18 (1H,m); 6.14 (1H, m, replaceable by D₂O); 6.40 (1H, m, replaceable by D₂O); 6.85-7.03 (5H,m); 7.22-7.55 (9H,m); 8.58 (1H, broad, replaceable by D₂O). EXAMPLE 15 4-[(R)-2-[N-[(R)-2-Hydroxy-2-phenethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyacetamide, hydrochloride, hemihydrate A mixture of 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]amino] propyl]phenoxyacetamide (1.1 g) and (S)-phenoxymethyl oxirane (0.55 g) was heated under reflux for 72 hours in ethanol. The solvent was evaporated and the residual oil was chromatographed on silica. Elution with methanol-chloroform (2:98) gave a gum which was treated with ethereal hydrogen chloride to give 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl] phenoxyacetamide, hydrochloride, hemihydrate, m.p. 85-89°, (ethyl acetate-ether). ¹H nmr (d₆-DMSO), ppm 1.13-1.30 (3H,m); 2.77-2.92 (1H,m); 3.12-3.68 (5H,m); 3.82-4.10 (3H,m); 5.11-5.28 (1H,m); 6.10-6.20 (1H,m, disappears with D₂O); 6.32-6.45 (1H,m, replaceable by D₂O); 6.86-7.05 (5H,m); 7.20-7.55 (12H, m, 3H replaceable by D₂O); 8.66 (1H, broad, replaceable by D₂O). EXAMPLE 16 Ethyl 4-[(R)-2-[bis-[(S)-2-hydroxy-3-phenoxypropyl]amino] propyl]phenoxyacetate, hydrochloride, hemihydrate Ethyl 4-[(R)-2-[bis[(S)-2-hydroxy-3-phenoxypropyl]amino] propyl]phenoxyacetate, hydrochloride, hemihydrate was prepared by an analogous procedure to that described in Example 13 but replacing 4-[(R)-2-aminopropyl]phenoxyacetamide by methyl 4-(R)-2-aminopropyl]phenoxyacetate. ¹H nmr (d₆=DMSO), ppm 1.15-1.26 (6H,m); 2.72-2.86 (1H,m); 3.09-3.20 (1H,m); 3.25-3.40 (1H,m); 3.45-3.66 (3H,m); 3.82-4.08 (5H,m); 4.13 (2H,q); 4.44 (2H,m); 4.74 (2H,s); 6.08 (2H,m, replaceable by D₂O); 6.83-7.00 (9H,m, 1H replaceable by D₂O); 7.22-7.37 (6H,m); 8.80 (1H, broad; replaceable by D₂O). EXAMPLE 17 Ethyl 4-[(R)-2-[N-[(R)-2-(3-chlorophenyl)-2-hydroxyethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyacetate , hemifumarate Ethyl 4-[(R)-2-[N-[(R)-2-(3-chlorophenyl)-2-hydroxyethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyacetate, hemifumarate, m.p. 48-52°, was prepared by an analogous procedure to that described in Example 14 but replacing ethyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]amino]propyl] phenoxyacetate by ethyl 4-[(R)-2-[N-[(R)-2-(3-chlorophenyl)-2-hydroxyethyl]amino]propyl]phenoxyacetate. ¹H nmr (d₆-DMSO), ppm 0.77 (3H,d); 1.20 (3H,t); 2.30-2.40 (1H,m); 2.56-3.00 (6H, m); 4.72-4.88 (3H,m); 4.16 (2H,q); 4.61 (1H,t); 4.70 (2H,s); 6.62 (1H,s); 6.80 (2H,s); 6.85-6.94 (3H,m); 7.08 (2H,d); 7.20-7.40 (6H,m). EXAMPLE 18 4-[(R)-2-[N-[(R)-2-(3-Chlorophenyl)-2-hydroxyethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyacetamide , hydrochloride, hemihydrate 4-[(R)-2-[N-[(R)-2-(3-Chlorophenyl)-2-hydroxyethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyacetamide, hydrochloride, hemihydrate- [α] 25 / D(MeoH)-77.4°, was prepared by an analogous procedure to that described in Example 15 but replacing 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]amino] propyl]phenoxyacetamide by 4-[(R)-2-[N-[(R)-2-(3-chlorophenyl) -2-hydroxyethyl]amino]propyl]phenoxyacetamide. ¹H nmr (d₆-DMSO), ppm 1.15-1.27 (3H,m); 2.79-2.92 (1H,m); 3.12-3.65 (5H,m); 3.82-4.10 (3H,m); 4.40 (2H,s); 4.47 (1H,m); 5.21 (1H,m); 6.14 (1H,m, replaceable by D₂O); 6.50 (1H,m, replaceable by D₂O); 6.90-7.03 (5H,m); 7.22-7.58 (11H, m, 3H replaceable by D₂O); 8.45-8.68 (1H, broad, replaceable by D₂O). EXAMPLE 19 4-[(R)-2-[N-[(R)-2-Hydroxy-2-phenethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyethylamine, dihydhrochloride , hydrate Borane methyl sulphide complex (0.32 g) in dry tetrahydrofuran (5 ml) was added in a dropwise manner, under a nitrogen atmosphere, to a stirred solution of 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]-amino]propyl]phenoxyacetamide (1 g) in dry tetrahydrofuran (30 ml). The reaction mixture was stirred and heated under reflux for 17 hours, cooled, treated with methanol (2.5 ml) and heated for a further hour. Hydrogen chloride was bubbled through the cooled solution. The solvent was evaporated and the residual oil was partitioned between 2N sodium hydroxide solution and dichloromethane. The organic layer was washed with water, dried (MgSO₄) and evaporated, to an oil which was purified by column chromatography on silica. Elution with methanol-chloroform (6:94) gave a colourless oil which was treated with ethereal hydrogen chloride to give 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyethylamine, dihydrochloride, hydrate as a crystalline solid, m.p. 99-103° (methanol-ethylacetate). ¹H nmr (d₆-DMSO), ppm 1.14-1.20 (3H,m); 2.45-2.60 (4H,m); 2.81 (1H,m); 3.15-3.68 (4H,m); 3.85-4.30 (6H,m, 2H replaceable by D₂O); 4.54 (1H, m); 5.29 (1H,m); 6.20 (1H,m, replaceable by D₂O); 6.43 (1H, m, replaceable by D₂O); 6.90-7.08 (5H,m); 7.25-7.55 (9H,m); 8.40 (1H,s, replaceable by D₂O); 9.12 (1H, broad, replaceable by D₂O); 13.70 (1H, broad, replaceable by D₂O]. EXAMPLE 20 Ethyl 4-[(R)-3-[N-[(R)-2-hydroxy-2-phenethyl]-N-[[S)-2-hydroxy-3-phenoxypropyl]amino]butyl]phenoxyacetate , hydrochloride Ethyl 4-[(R)-3-[N-[(R)-2-hydroxy-2-phenethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]butyl]phenoxyacetate, hydrochloride was prepared by an analogous procedure to that described in Example 14 but replacing ethyl 4-[(R)-2-[N-[(R)--2-hydroxy-2-phenethyl]amino]propyl]phenoxyacetate by ethyl 4-[(R)-3-[N-[(R)-2-hydroxy-2-phenethyl]amino]butyl]phenoxyacetate. ¹H nmr (d₆-DMSO), ppm 1.21 (3H,t); 1.36 (3H,m); 1.88 (1H,m); 2.11 (1H,m); 2.68 (2H,m); 3.21-3.93 (5H,m); 4.03 (2H,m); 4.16 (2H,q); 4.45 (1H,m); 4.73 (2H,s); 5.16 (1H,m); 6.30 (1H,m, replaceable by D₂O); 6.53 (1H,m, replaceable by D₂O); 6.82-7.06 (5H,m); 7.13-7.52 (9H,m); 8.33 (1H, broad, replaceable by D₂O). EXAMPLE 21 4-[(R)-2-[N-[[R)-2-Hydroxy-2-phenethyl]-N-[(S)-2-hydroxy 3-phenoxypropyl]amino]propyl]phenoxyethanol, hydrochloride , hemihydrate 4-[(R)-2-[N-[(R)-2-Hydroxy-2-phenethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyethanol, hydrochloride, hemihydrate, m.p. 68-73°, was prepared by an analogous procedure to that described in Example 14 but replacing ethyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]amino]propyl] phenoxyacetate by 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl] amino]propyl]phenoxyethanol. ¹H nmr (d₆-DMSO), ppm 1.20 (3H,m); 2.83 (1H,m); 3.12-3.63 (5H,m); 4.00 (2H,m); 3.81-4.09 (5H,m); 4.46 (1H,m); 4.80 (1H, broad, replaceable by D₂O); 5.18 (1H,m); 6.14 (1H, m, replaceable by D₂O); 6.37 (1H, m, replaceable by D₂O); 6.85-7.01 (5H, m); 7.20-7.52 (9H,m); 8.56 (1H, broad, replaceable by D₂O). EXAMPLE 22 Ethyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[(R)-2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyacetate, hydrochloride Ethyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[(R)-2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyacetate, hydrochloride, m.p. 49-52°, was prepared by an analogous procedure to that described in Example 14 but replacing (S)-phenoxymethyloxirane by (R)-phenoxymethyloxirane. ¹H nmr (d₆-DMSO), ppm 1.12-1.27 (6H,m); 2.78 (1H,m); 3.22-3.70 (5H,m); 4.01 (3H, m); 4.17 (2H,q); 4.52 (1H,m); 4.75 (2H,s); 5.22 (1H,m); 5.96 (1H, m, replaceable by D₂O); 6.39 (1H, m, replaceable by D₂O); 6.85-7.02 (5H,m); 7.20-7.55 (9H,m); 9.30 (1H, broad, replaceable by D₂O). EXAMPLE 23 Methyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyacetate, hydrochloride, hemihydrate A mixture of methyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl] amino]propyl]phenoxyacetate (0.85 g) and (S)-phenoxymethyl oxirane (0.37 g) was heated under reflux in methanol (50 ml) for 52 hours. The solvent was evaporated and the residue chromatographed on silica. Elution with chloroform gave an oil which was treated with ethereal hydrogen chloride to give methyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyacetate hydrochloride hemihydrate, m.p. 58-62°. ¹H nmr (d₆-DMSO), ppm 1.25 (3H,m); 2.85 (1H,m); 3.20-3.68 (5H,m); 3.70 (3H,s); 3.80-4.13 (3H,m); 4.49 (1H,m); 4.75 (2H,s); 5.23 (1H,m); 6.16 (1H,m, replaceable by D₂O); 6.39 (1H,m, replaceable by D₂O); 6.88-7.02 (5H,m); 7.25-7.55 (10H,m, 1H replaceable by D₂O); 8.80 (1H, broad, replaceable by D₂O). EXAMPLE 24 4-[(R)-2-[N-[(R)-2-Hydroxy-2-phenethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propoxy]phenoxyacetamide, hydro chloride 4-[(R)-2-[N-[(R)-2-Hydroxy-2-phenethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propoxy]phenoxyacetamide, hydrochloride, m.p. 81-86° (ethyl acetate-ether), was prepared by an analogous procedure to that described in Example 14 but replacing ethyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl] amino]propyl]phenoxyacetate by 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]amino]propoxy]phenoxyacetamide. ¹H nmr (d₆-DMSO), ppm 1.75 (3H,m); 3.25-3.75 (3H,m); 3.90-4.50 (9H,m); 5.14 (1H, m); 6.20-6.65 (2H, m, replaceable by D₂O); 6.80-7.15 (7H, m); 7.20-7.60 (9H,m, 2H replaceable by D₂O); 8.20 (1H, broad, replaceable by D₂O). EXAMPLE 25 Ethyl 4-[(R)-2-[N-[2-(2-benzofuranyl)-2-hydroxyethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyacetate , hydrochloride Ethyl 4-[(R)-2-[N-[2-(2-benzofuranyl)-2-hydroxyethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyacetate, hydrochloride, m.p. 56-60°, was prepared by an analogous procedure to that described in Example 14 but replacing ethyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]amino]propyl] phenoxyacetate by ethyl 4-[(R)-2-[N-[2-(2-benzofuranyl)-2-hydroxyethyl]amino]propyl]phenoxyacetate. ¹H nmr (d₆-DMSO), ppm 1.11-1.27 (6H,m); 2.70-2.88 (1H,m); 3.25-3.81 (5H,m): 3.91-4.09 (3H,m); 4.16 (2H,q); 4.52 (1H,m); 4.75 (2H,s); 5.48 (1H,m); 6.12 (1H, broad, replaceable by D₂O); 6.70 (1H, broad, replaceable by D₂O); 6.82-7.03 (6H,m); 7.18-7.38 (6H, m); 7.52-7.70 (2H,m); 9.50 (1H, broad, replaceable by D₂O). EXAMPLE 26 Ethyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[2-(2-benzofuranyl)-2-hydroxyethyl]amino]propyl]phenoxyacetate hydrochloride Ethyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[2-(2-benzofuranyl)-2-hydroxyethyl]amino]propyl]phenoxyacetate hydrochloride, m.p. 65-70°, was prepared by an analogous procedure to that described in Example 14 but replacing (S)-phenoxymethyloxirane by 2-benzofuranyloxirane. ¹H nmr (d₆-DMSO), ppm 1.15-1.28 (6H,m); 2.75-2.92 (1H,m); 3.30-3.55 (3H,m); 3.75 (2H,m); 4.03 (1H,m); 4.16 (2H,q); 4.75 (2H,s); 5.30 (1H,m); 5.53 (1H,m); 6.40 (1H, m, replaceable by D₂O); 6.70 (1H, broad, replaceable by D₂O); 6.85-7.00 (3H,m); 7.20-7.70 (11H,m); 9.44 (1H, broad, replaceable by D₂O). EXAMPLE 27 4-[(R)-2-[N-[(R)-2-Hydroxy-2-(4-hydroxyphenyl)-ethyl]-N-[(R) - 2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyacetamide A solution of 4-[(R)-2-[N-[(R)-2-(4-benzyloxyphenyl)-2-hydroxyethyl]-N-[(R)-2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyacetamide (0.1 g) in ethyl acetate (60 ml) was hydrogenated at ambient temperature and pressure over 10% palladium on carbon until the theoretical amount of hydrogen was absorbed. The mixture was filtered through celite, evaporated and the residual oil chromatographed on silica. Elution with methanol/chloroform (2:98) gave 4-[(R)-2-[N-[(R)-2-hydroxy-2-(4-hydroxyphenyl)ethyl]-N-[(R)-2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyacetamide as a colourless oil. ¹H nmr (CDCl₃), ppm 1.04 (3H,d); 2.50-2.95 (6H,m); 3.15 (1H,m); 3.70-4.12 (3H, m); 4.32-4.60 (6H, m, 3H replaceable by D₂O); 5.95 (1H, broad, replaceable by D₂O); 6.48 (1H, broad, replaceable by D₂O); 6.75-7.29 (13H,m). EXAMPLE 28 Methyl 4-[2-[N-[2-(4-amino-3,5-dichlorophenyl)-2-hydroxy ethyl]-N-[2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxy acetate, hemifumarate A mixture of methyl 4-[2-[N-[2-(4-amino-3,5-dichlorophenyl)-2-hydroxyethyl]amino]propyl]phenoxyacetate (1.0 g) and phenoxymethyloxirane (0.35 g) gas heated under reflux in methanol (80 ml) for 40 hours. The solvent was evaporated and the residue chromatographed on silica. Elution with chloroform gave a colourless oil which was treated with a methanolic solution of fumaric acid to give methyl 4-[2-[N-[2-(4-amino-3,5-dichlorophenyl)-2-hydroxyethyl]-N-[2-hydroxy -3-phenoxypropyl]amino]propyl]phenoxyacetate, hemifumarate as a white solid, m.p. 65-72° (ether). ¹H nmr (d₆-DMSO), ppm 0.76 (3H,m); 2.25-2.95 (7H,m); 3.15-4.00 (8H,m, 2H replaceable by D₂O); 4.44 (1H,m); 4.70 (2H,m); 5.29 (2H,s, replaceable by D₂O); 6.62 (1H,s); 6.75-7.31 (11H,m). EXAMPLE 29 4-[2-[N-[2-(4-Amino-3,5-dichlorophenyl)-2-hydroxyethyl]-N-[2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyacetamide A mixture of 4-[2-[N-[2-(4-amino-3,5-dichlorophenyl)-2-hydroxyethyl]amino]propyl]phenoxyacetamide (0.54 g) and phenoxymethyloxirane (0.2 g) in ethanol (50 ml) was heated under reflux for 48 hours. The solvent was evaporated and the residue chromatographed on silica. Elution with methanol/chloroform (2:98) gave 4-[2-[N-[2-(4-amino-3,5-dichlorophenyl)-2-hydroxyethyl]-N-[2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyacetamide as a white solid, m.p. 50-60°. ¹H nmr (d₆-DMSO), ppm 0.74-0.87 (3H,m); 2.33 (1H,m); 2.50-2.95 (6H,m); 3.65-3.97 (3H,m); 4.31-4.44 (3H,m); 4.70-5.15 (2H,m, replaceable by D₂O); 5.28 (2H,m, replaceable by D₂O); 6.75-7.45 (13H,m, 2H replaceable by D₂O). The following examples X1 - X14 illustrate the preparation of starting materials. EXAMPLE X1 Ethyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]amino]propyl] phenoxyacetate A solution of (R)-phenyloxirane (1.77 g) in ethanol (10 ml) was added dropwise, to a stirred, refluxing solution of methyl 4-[(R)-2-aminopropyl]phenoxyacetate (3.29 g) in ethanol (80 ml). The resulting solution was heated under reflux for 52 hours. The solvent was evaporated and the residual oil was chromatographed on silica gel. Elution with methanol-chloroform (3:97) gave ethyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]amino]propyl]phenoxyacetate as a colourless oil. ¹H nmr (CDCl₃), ppm 1.00 (3H,d); 1.25 (3H,t); 2.32-3.00 (7H, m, 2H replaceable by D₂O); 4.22 (2H,q); 4.35-4.70 (2H,s + 1H, m); 6.65-7.30 (9H,m). EXAMPLE X2 Ethyl 4-[(R)-2-[N-[(R)-2-(3-chlorophenyl)-2-hydroxyethyl] amino]propyl]phenoxyacetate Ethyl 4-[(R)-2-[N-[(R)-2-(3-chlorophenyl)-2-hydroxyethyl] amino]propyl]phenoxyacetate was prepared by an analogous procedure to that described in Example X1 but replacing (R)-phenyloxirane by (R)-3-chlorophenyloxirane. ¹H nmr (CDCl₃), ppm 1.00 (3H,d); 1.22 (3H,t); 2.35-3.20 (7H,m, 2H replaceable by D₂O) 4.25 (2H,q); 4.40-4.70 (2H,s + 1H,m); 6.65-7.40 (8H,m). EXAMPLE X3 4-[[R)-2-[N-[(R)-2-Hydroxy-2-phenethyl]amino]propyl]phenoxy acetamide Ammonia gas was bubbled into a solution of ethyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]amino]propyl]phenoxyacetate (1.45 g) in methanol (50 ml). The resulting solution was allowed to stand for 18 hours and evaporated to give 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]amino]propyl]phenoxyacetamide as a white solid. ¹H nmr (CDCl₃), ppm 1.05 (3H,d); 2.30-3.00 (7H, m, 2H replaceable by D₂O); 4.30 (2H,s); 4.55 (1H,t); 6.60-7.40 (11H, m, 2H replaceable by D₂O). EXAMPLE X4 4-[(R)-2-[N-[(R)-2-(3-Chlorophenyl)-2-hydroxyethyl]amino] propyl]phenoxyacetamide 4-[(R)-2-[N-[(R)-2-(3-Chlorophenyl)-2-hydroxyethyl]amino] propyl]phenoxyacetamide was prepared by an analogous procedure to that described in Example X1 but replacing ethyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]amino]propyl]phenoxyacetate by ethyl 4-[(R)-2-[N-[(R)-2-(3-chlorophenyl)-2-hydroxyethyl]amino]propyl]phenoxyacetate. ¹H nmr (CDCl₃), ppm 1.05 (3H,d); 2.30-3.00 (7H, m, 2H replaceable by D₂O); 4.40-4.90 (2H,s + 1H,m); 6.80-7.50 (10H, m, 2H replaceable by D₂O). EXAMPLE X5 Ethyl 4-[(R)-2-[N-[2-(2-benzofuranyl)-2-hydroxyethyl]amino] propyl]phenoxyacetate The title compound was prepared by an analogous procedure to that described in Example X1 but replacing (R)-phenyloxirane by 2-benzofuranyl oxirane. ¹H nmr (CDCl₃), ppm 1.00 (3H,d); 1.30 (3H,t); 2.35-3.50 (7H, m, 2H replaceable by D₂O); 4.20 (2H,q); 4.40 (2H,s); 4.75 (1H,m); 6.40-7.50 (9H,m). EXAMPLE X6 Ethyl 4-[(R)-3-[N-[(R)-2-hydroxy-2-phenethyl]amino]butyl] phenoxyacetate Ethyl 4-[(R)-3-[N-[(R)-2-hydroxy-2-phenethyl]amino]butyl] phenoxyacetate was prepared by an analogous procedure to that described in Example X1 but replacing methyl 4-[(R)-2-aminopropyl]phenoxyacetate by methyl 4-[(R)-3-aminobutyl]phenoxyacetate. ¹H nmr (CDCl₃), ppm 1.10 (3H,d); 1.30 (3H,t); 1.70 (2H,m); 2.35-3.00 (5H,m); 3.68 (2H, m, replaceable by D₂O); 4.25 (2H,q); 4.50-4.85 (2H,s + 1H,m); 6.70-7.40 (9H,m). EXAMPLE X7 Methyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]amino]propyl] phenoxyacetate A mixture of (R)-phenyloxirane (0.86 g) and methyl 4-[(R)-2-aminopropyl]phenoxyacetate (1.6 g) in dimethylsulphoxide (40 ml) was stirred and heated at 95°C for 24 hours. The reaction mixture was poured into water (100 ml) and extracted into chloroform. The organic layer was washed with water, dried (MgSO₄) and evaporated to an oil which was chromatographed on silica. Elution with methanol-chloroform (4:96) gave methyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]amino]propyl]phenoxyacetate as an oil. ¹H nmr (CDCl₃), ppm 1.00 (3H,d); 2.35-3.00 (7H, m, 2H replaceable by D₂O); 3.70 (3H,s); 4.35-4.65 (2H,s + 1H,m); 6.65-7.30 (9H,m). EXAMPLE X8 4-[(R)-2-[N-[(R)-2-Hydroxy-2-phenethyl]amino]propyl]phenoxy ethanol Dicyclohexylcarbodiimide (1.1 g) in dry dimethyl formamide was added to a stirred solution of 1-hydroxybenzotriazole (0.73 g), (R)-mandelic acid (0.82 g) and methyl 4-[(R)-2-aminopropyl]phenoxyacetate (1.2 g) in dry dimethyl formamide at 0°. The mixture was allowed to stand at ambient temperature for 20 hours. The solvent was evaporated, the residue taken up in ethyl acetate and filtered. The filtrate was washed successively with sodium carbonate solution, 2N hydrochloric acid, sodium carbonate, water (x 2), dried (MgSO₄), filtered and evaporated to a gum which was chromatographed on silica. Elution with chloroform gave N-[(4-carbomethoxymethoxyphenyl)-2-(R)-propyl]-(R)-mandelamide. ¹H nmr (CDCl₃), ppm 0.98 (3H,d); 2.50 (2H,d); 3.70 (1H,s, replaceable by D₂O); 4.20 (1H,m); 4.45 (2H,s); 4.65 (1H,s + 1H,s, replaceable by D₂O); 6.40-7.20 (9H,m). Borane dimethyl sulphide (1.15 g) was added under nitrogen to a stirred solution of the above material (1.36 g) in dry tetrahydrofuran and the mixture was heated under reflux for 22 hours. The solution was cooled, methanol (3 ml) added and the solution stirred and heated under reflux for one hour. Dry hydrogen chloride was bubbled through the cooled solution, the solvent was evaporated and the residue was partitioned between 2N sodium hydroxide and ethyl acetate. The organic layer was separated, dried (MgSO₄) and evaporated to give an oil which was chromatographed on silica. Elution with methanol-chloroform (2:98) gave 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]amino]propyl]phenoxyethanol as a colourless oil. ¹H nmr (CDCl₃), ppm 1.05 (3H,d); 2.50-3.00 (8H, m, 3H replaceable by D₂O); 3.80-4.15 (4H,m); 4.60 (1H,m); 6.70-7.20 (4H,q); 7.30 (5H, s). EXAMPLE X9 Methyl 4-[(R)-2-aminopropyl]phenoxyacetate hydrochloride A mixture of d-(+)-α-methylbenzylamine (5.23 g) and methyl 4-acetonylphenoxyacetate (9.6 g) in dry benzene was heated under reflux with azeotropic removal of water for 5 hours. The solvent was evaporated, the residue taken up in methanol and hydrogenated over Raney Nickel at 60 psi and ambient temperature for 48 hours. The reaction mixture was filtered through Celite and evaporated to an oil which was dissolved in ether and treated with hydrogen chloride until no further solid precipitated. The solid was filtered and recrystallised from ether-benzene to give methyl 4-[(R)-2-[(R)-1-phenethylamino]propyl]phenoxyacetate hydrochloride as a white solid, m.p. 168-173°. ¹H nmr (CDCl₃), free base, ppm 0.90 (3H,d); 1.30 (3H,d); 1.58 (1H,s, replaceable by D₂O); 2.40-2.90 (3H,m); 3.60-4.00 (3H,s plus 1H,m); 4.50 (2H,s); 6.60-7.00 (4H,q); 7.20 (5H,s). A methanolic solution of this hydrochloride (3.3 g) was hydrogenated over 10% palladium on carbon at 50 psi and 50° for 8 hours. The mixture was filtered, evaporated and the residue recrystallised from ethylacetate to give methyl 4-[(R)-2-aminopropyl]phenoxyacetate hydrochloride, m.p. 147°, [α] 25 / D (H₂O) -13.6°. ¹H nmr (d₆-DMSO) , ppm 1.20 (3H,d); 2.65-3.50 (3H,m); 3.72 (3H,s); 4.78 (2H,s); 6.83-7.30 (4H,q); 8.30 (3H, broad, replaceable by D₂O). EXAMPLE X10 Methyl 4-[(R)-3-aminobutyl]phenoxyacetate hydrochloride Methyl 4-[(R)-3-aminobutyl]phenoxyacetate hydrochloride, m.p. 112-116°, [α] 25 / D (MeOH) + 6.2° was prepared by an analogous procedure to that described in Example X9, but replacing methyl 4-acetonyl phenoxyacetate by methyl 4-[3-oxobutyl]phenoxyacetate. ¹H nmr (d₆-DMSO), ppm 1.22 (3H,d); 1.80 (2H,m); 2.57 (2H,m); 3.00-3.58 (3H,m, 2H replaceable by D₂O); 3.70 (3H,s); 4.78 (2H,s); 6.83-7.25 (4H,q); 8.20 (1H, broad, replaceable by D₂O). EXAMPLE X11 4-[(R)-2-Aminopropoxy]phenoxyacetamide hydrochloride 4-[(R)-2-Aminopropoxy]phenoxyacetamide hydrochloride, m.p. 187-190°, [α] 25 / D (MeOH) -14.7° was prepared by an analogous procedure to that described in Example X9, but replacing methyl 4-acetonylphenoxyacetate by 4-acetonyloxyphenoxyacetamide. ¹H nmr (d₆-DMSO), ppm 1.32 (3H,d); 3.53 (1H,m); 4.08 (2H,m); 4.38 (2H,s); 7.00 (4H,s); 7.50 (2H, broad, replaceable by D₂O); 8.33 (3H, broad, replaceable by D₂O). EXAMPLE X12 Ethyl 4-[(R)-2-[N-[(R)-2-(4-benzyloxyphenyl)-2-hydroxy ethyl]amino]propyl]phenoxyacetamide Ethyl 4-[(R)-2-[N-[(R)-2-(4-benzyloxyphenyl)-2-hydroxyethyl]amino]propyl]phenoxyacetamide was prepared by an analogous procedure to that described in Example X7 but replacing (R)-phenyloxirane by (R)-(4-benzyloxy)phenyloxirane. ¹H nmr (CDCl₃), ppm 1.10 (3H,d); 2.60-2.85 (7H,m); 3.83 (3H,s); 4.60 (2H,s + 1H,m); 5.10 (2H,s); 6`75-7.35 (13H,m). EXAMPLE X13 4-[(R)-2-[N-(R)-2-(4-Benzyloxyphenyl)-2-hydroxyethyl]amino] propyl]phenoxyacetamide 4-[(R)-2-[N-(R)-2-(4-Benzyloxyphenyl)-2-hydroxyethyl]amino] propyl]phenoxyacetamide was prepared from ethyl 4-[(R)-2-[N-[(R)-2-(4-benzyloxy)phenyl-2-hydroxyethyl]amino]propyl] phenoxyacetate by an analogous procedure to that described in Example X3. ¹H nmr (CDCl₃), ppm 1.02 (3H,d); 2.55-3.15 (7H,m); 4.55-4.80 (2H,s + 1H,m); 5.15 (2H,s); 6.80-7.50 (15H,m, 2H replaceable by D₂O). EXAMPLE X14 4-[(R)-2-[N-[(R)-2-(4-Benzyloxyphenyl)-2-hydroxyethyl]-N-[(R)-2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyacetamide 4-[(R)-2-[N-[(R)-2-(4-Benzyloxyphenyl)-2-hydroxyethyl]-N-[(R)-2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyacetamide was prepared from (R)-phenoxymethyloxirane and 4-[(R)-2-[N-[(R)-2-(4-benzyloxyphenyl)-2-hydroxyethyl]amino]propyl]-phenoxyacetamide by the method described in Example 14. ¹H nmr (CDCl₃), ppm, free base. 1.05 (3H,d); 2.40-3.10 (9H,m, 2H replaceable by D₂O); 3.62-4.10 (3H,m); 4.32-4.70 (2H,s plus 1H,m); 5.08 (2H,s); 6.71-7.40 (20H,m, 2H replaceable by D₂O). Demonstration of Effectiveness of Compounds a) Anti-Obesity Activity Female BALB/c mice were trained to feed on powdered oxoid for 1 week. They were then housed in threes and the compound under study was added to the diet for 3 days. Food was removed at 09.00h and the mice were killed at 11.00h. The parametrial fat pads were weighed as pairs. The result is a mean of 9 values. b) Effect on Energy Expenditure of Mice The effect of the compounds on the energy expenditure of mice was demonstrated by means of the following procedure: Female CD1 mice each weighing approximately 24 g were given food and water ad lib before and during the experiment. The compounds were dissolved in water and these solutions were administered orally to each of 12 mice. A further 12 mice were dosed orally with water. The mice were placed in groups of threes in boxes through which air was drawn and the oxygen content of the air leaving the boxes was measured. The energy expenditure of the mice was calculated for 3 and 21 hours after dosing from the volume of air leaving the boxes and its oxygen content, following the principles described by J.B. de V. Weir, J. Physiol. (London) 109 , 1-9 (1949). The results are expressed as a percentage of the rate of energy expenditure of the mice dosed with water. c) Effect on Energy Expenditure of Rats The effect of the compounds on the energy expenditure of rats was demonstrated by means of the following procedure: Male Sprague-Dawley rats each weighing between 170-200 g were deprived of food for 16 hours before, and during the experiment. Water was provided ad lib at all times. The compounds were administered orally in water to 3 or 4 rats. A further 4 rats were dosed orally with water. The rats were placed in boxes through which air was drawn and the oxygen content of the air leaving the boxes was measured. The energy expenditure of the rats was calculated for 3 hours and for 21 hours after dozing from the volume of air leaving the boxes and its oxygen content, following the principles described by J.B. de V. Weir, J. Physiol . (London) 109, 1-9 (1949). The results are expressed as a percentage of the rate of energy expenditure of the rats dosed with water. d) Hypoglycaemic activity Female CFLP mice, weighing approximately 25 g, were fasted for 24 hours prior to the study. The compounds under study were administered orally as an aqueous solution to each of 6 mice. 30 minutes later a blood sample (20 µl) was obtained from the tail for the analysis of blood glucose. Immediately after taking this blood sample, glucose (1 g/kg body weight) was administered subcutaneously to each mouse. 6 mice were given water as a control. Blood samples were then obtained from each mouse at 30 minute intervals for 120 minutes. Compounds that produced a significant (p<0.05) reduction of blood glucose, compared with control mice given water, at any time interval, were considered active. The area under the blood glucose curve over the 2 hour period after the administration of the glucose was calculated for each compound and compared with the value for control animals. e) Effect of Compounds on Isolated Rat Atria Sprague-Dawley male rats (300-400 g) are killed and the right and left atria dissected out independently and mounted on a combined tissue holder/electrode. The tissues are then immersed in a glass bath containing Krebs solution maintained at 32°C. The rate of the spontaneously beating right atrium (via an isometric tranducer and a ratemeter) and the tension of the electrically paced left atrium (via an isometric transducer) are recorded on an M19 chart recorder. After an initial stabilization period, the tissues are exposed to a maximal concentration of isoprenaline (10⁻⁶M). The tissues are then washed several times until rate and tension return to baseline level. A dose-response curve to the test compound is then carried out. Compounds of Example Nos. 1, 4, 8, 13 and 14 had no effect on rate or tension up to 3x10⁻⁵M.

Claims: A compound of the general formula (I): or a pharmaceutically acceptable salt thereof, in which R¹ represents a 2-hydroxy-2-(benzofuran-2-yl)ethyl group or a radical of the general formula (a) or (b): R² represents a hydrogen atom or a methyl group, D represents either a benzofuran-2-yl moiety or a radical of general formula (c): R³ represents a hydrogen atom or a CH₂CONH₂ group, and where there are two R³s in the compound these are the same or different, provided that there is a maximum of one CH₂CONH₂ group in the compound, R⁴ represents a radical -(CH₂) a COOH, -O(CH₂) b COOH, or -C(R⁸)=C(R⁹)COOH or an ester or an amide, lower alkylamide, di-lower alkylamide or saturated 5- or 6-membered ring amide derivative of one of these groups, or -SO₂NR¹⁰R¹¹, -(CH₂) a CH₂X, or -O(CH₂) b CH₂X in which a represents zero or an integer from 1 to 6, b represents an integer from 1 to 6, R⁸ and R⁹, which may be the same or different, each represents a hydrogen atom or a methyl group, R¹⁰ and R¹¹, which may be the same or different, each represents a hydrogen atom or a lower alkyl radical or, together with the nitrogen atom to which they are attached, form a saturated 5- or 6- membered ring, and X represents a hydrogen atom or a lower alkyl radical, a hydroxy group or an ester thereof,a lower alkoxy radical, an unsubstituted or substituted benzyloxy radical or a (lower alkyl)carbonyl radical, or a radical NR¹⁰R¹¹ in which R¹⁰ and R¹¹ have the meanings given above, R⁴, represents a hydrogen or a halogen atom or a lower alkyl or lower alkoxy radical, a CF₃ group or a hydroxy group or an ester thereof, R⁵ represents a hydrogen or halogen atom, a hydroxy or hydroxymethyl group or an ester of either of these groups, or a group CF₃, NH₂, NHR¹², NHCOOR¹², or CH₂SO₂R¹² in which R¹² represents a lower alkyl radical, R⁶ represents a hydrogen or halogen atom, or a hydroxy group or ester thereof, R⁷ represents a hydrogen or halogen atom, n represents 1 or 2, m represents 0 or 1, provided that n + m = 1 or 2, and Q¹ represents a hydrogen atom and Q² represents a hydroxy group or a pharmaceutically acceptable in - vivo hydrolysable ester thereof or Q¹ and Q² together represent an oxo group,the two Q¹Q² pairs in the compound being the same or different, provided there is a maximum of one Q¹Q² oxo group in the compound; with the proviso that when R¹ represents a radical of the abovementioned formula (a), wherein R³ and Q¹ each represent a hydrogen atom and Q² represents a hydroxy group or a pharmaceutically acceptable in-vivo hydrolysable ester thereof, or R¹ represents a radical of the abovementioned formula (b) wherein R⁵ represents a hydrogen or halogen atom or a trifluoromethyl group and R⁶, R⁷ and Q¹ each represent a hydrogen atom and Q² represents a hydroxy group or an in-vivo hydrolysable ester thereof; and R² represents a hydrogen atom or a methyl group; and D represents a radical of the abovementioned formula (c) wherein R³ represents a hydrogen atom; Q¹ represents a hydrogen atom and Q² represents a hydroxy group or an in-vivo hydrolysable ester thereof; R⁴ represents a para substituent on the phenyl ring, relative to the -(O) m - moiety, and represents either a radical -(CH₂) a CO₂H, -C(R⁸)=C(R⁹)CO₂H, or an ester or amide, lower alkylamide or di- lower alkylamide of one of these groups; or -SO₂NR¹⁰R¹¹; -(CH₂) a CH₂X, wherein X represents hydroxy or a (lower alkyl)carbonyl radical; -O(CH₂) b CH₂X wherein X represents hydroxy, lower alkoxy or an unsubstituted benzyloxy group; and a represents zero or an integer from 1 to 6; and b represents an integer from 1 to 6; and R⁸ represents a hydrogen atom or a methyl group; and R⁹, R¹⁰ and R¹¹ each represents a hydrogen atom; and n represents 1 or 2 and m represents zero; then R⁴, does not represent a hydrogen atom. A compound as claimed in claim 1, wherein in each of the radicals (a) and(b) represented by R¹, Q¹ represents a hydrogen atom and Q² represents a hydroxy group or a pharmaceutically acceptable in - vivo hydrolysable ester thereof. A compound as claimed in claim 1 or claim 2, of formula (I'): or a pharmaceutically acceptable salt thereof, in which R¹ represents a 2-hydroxy-2-(benzofuran-2-yl) ethyl group or a radical of the general formula (a') or (b'): and R², R³, R⁴, R⁴',R⁵, R⁶, R⁷, m and n are as defined in respect of formula (I) in claim 1; and D represents a benzofuran-2-yl moiety or a radical of formula (c) as defined in claim 1. A compound as claimed in any one of claims 1 to 3, wherein R¹ represents a 2-hydroxy-2-(benzofuran-2-yl)ethyl group or a moiety of formula (a') or (b'): R³, R⁶ and R⁷ are as defined in relation to formula (I) in claim 1, and R⁵ represents a hydrogen or halogen atom, a hydroxy or hydroxymethyl group or an ester of either of these groups, or a group NH₂ or NHR¹² in which R¹² represents a lower alkyl radical. A compound as claimed in any one of claims 1 to 4, wherein the moiety of formula (b) is one of the following groups: A compound as claimed in any one of claims 1 to 5, wherein R⁴ is in the para position. A compound as claimed in any one of claims 1 to 6, wherein R⁴ represents a radical of formula -O(CH₂) b COOH or an ester or amide derivative thereof. A compound as claimed in any one of claims 1 to 7, wherein b represents 1. A compound as claimed in claim 1, selected from the group consisting of: methyl 4-[(R)-2-[bis-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]benzoate; methyl 4-[(R)-2-[bis-[(R)-2-hydroxy-3-phenoxypropyl]amino]propyl]benzoate; N-methyl 4-[(R)-2-[bis-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]benzamide; methyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]benzoate; methyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[(R)-2-hydroxy-3-phenoxypropyl]amino]propyl]benzoate; N-methyl 4-[(R)-2-[N'-[(R)-2-hydroxy-2-phenethyl]-N'-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl] benzamide; N-methyl 4-[(R)-2-[N'-[(R)-2-hydroxy-2-phenethyl]-N'-[(R)-2-hydroxy-3-phenoxypropyl]amino]propyl] benzamide; 4-[2-[N-[2-(3-chlorophenyl)-2-hydroxyethyl]-N-[2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyacetamide; methyl 4-[2-[N-[2-hydroxy-2-[4-hydroxy-3-hydroxymethylphenyl]ethyl]-N-[2-hydroxy-3-phenoxypropyl] amino]propyl]benzoate; methyl 4-[(R)-2-[N-[2-[4-amino-3,5-dichlorophenyl]-2-hydroxyethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]benzoate; methyl 4-[2-[N-[2-(3-chlorophenyl)-2-hydroxyethyl]-N-[2-hydroxy-3-(4-carboxamidomethyl)phenoxypropyl]amino]propyl]phenoxyacetate; 4-[(R)-3-[N-(R)-2-hydroxy-2-phenethyl-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]butyl]benzamide; 4-[(R)-2-[bis-(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyacetamide; ethyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl] phenoxyacetate; 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl] phenoxyacetamide; ethyl 4-[(R)-2-bis-[(S)-2-hydroxy-3-phenoxypropyl] amino]propyl]phenoxyacetate; ethyl 4-[(R)-2-[N-[(R)-2(3-chlorophenyl) -2-hydroxyethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl] phenoxyacetate; 4-[(R)-2-[N-[(R)-2-(3-chlorophenyl)-2-hydroxyethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl] phenoxyacetamide; 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyethylamine; ethyl 4-[(R)-3-[N-[(R)-2-hydroxy-2-phenethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]butyl]phenoxyacetate; 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyethanol; ethyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[(R)-2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyacetate; methyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[(S) -2-hydroxy-3-phenoxypropyl]amino]propyl]phenoxyacetate; 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propoxy]phenoxyacetamide; ethyl 4-[(R)-2[N-[2-(2-benzofuranyl)-2-hydroxyethyl] -N-[(S)-2-hydroxy-3-phenoxypropyl]amino]propyl] phenoxyacetate; ethyl 4-[(R)-2-[N-[(R)-2-hydroxy-2-phenethyl]-N-[2-(2-benzofuranyl)-2-hydroxyethyl]amino]propyl] phenoxyacetate; 4-[(R)-2-[N-[(R)-2-hydroxy-2-(4-hydroxyphenylethyl]-N-[(R)-2-hydroxy-3-phenoxypropyl]amino]propyl] phenoxyacetamide; methyl 4-[2-[N-[2-(4-amino-3,5-dichlorophenyl)-2-hydroxyethyl]-N-[2-hydroxy-3-phenoxypropyl]amino] propyl]phenoxyacetate; and 4-[2-[N-[2-(4-amino-3,5-dichlorophenyl)-2-hydroxyethyl] -N-[2-hydroxy-3-phenoxypropyl]amino]propyl] phenoxyacetamide; or a pharmaceutically acceptable salt thereof. A process for the preparation of a compound of the general formula (I) as defined in claim 1, or a pharmaceutically acceptable salt thereof, characterized in that the process comprises: A) reacting a compound of the general formula (II): in which R², D, R⁴, R⁴', n , m , Q¹ and Q² are as defined in relation to formula (I) in claim 1 with (i) a compound of the general formula in which R represents a benzofuran-2-yl moiety or a group of the general formula in which R³, R⁵, R⁶ and R⁷ are as defined in relation to formula (I) in claim 1, or (ii) a compound of the general formula (IV): in which R is as defined in relation to formula (III) and Z represents a leaving group, or an ester thereof; or B) for the preparation of a compound of the general formula (I) in which there is one oxo group represented by Q¹ + Q², or a pharmaceutically acceptable salt thereof, reacting a compound of the general formula (II), as defined above, provided that Q¹ and Q² do not represent an oxo group, with a compound of the general formula (V): RCOCH₂Z (V) in which R and Z are as defined in relation to formula (III) and, if desired, converting the resulting compound of the general formula (VI): in which R, R², D, R⁴, R⁴,, n , m , Q¹ and Q² are as defined in relation to formula (I) in claim 1, and provided that Q¹ and Q² do not represent an oxo group, into another compound of the general formula (VI) (or I); or C) reacting a compound of the general formula (IX): in which R², R⁴, R⁴', n , m , Q¹ and Q² are as defined in relation to formula (I) in claim 1 and R is as defined in relation to formula (III), with the hereinbefore defined compound of the general formula (VII)a or (VII)b, providing that if Q¹ and Q² together represent a carbonyl group then compound (IX) is reacted with compound (VII)a; or D) reacting a compound of the abovementioned general formula (II): (i) with a compound of the general formula (X): R-CO.CHO (X) in which R, is as defined in relation to formula (III) and subsequently treating with a reducing agent, or (ii) with a compound of the general formula (XI): in which R is as defined in relation to formula (III) and subsequently reducing the resulting hydroxyamide; or E) reacting a compound of the general formula (XII): in which D, Q¹ and Q² are as defined in relation to formula (I) in claim 1 and R is as defined in relation to formula (III), (i) with a compound of the general formula (XIII): in which R², R⁴, R⁴,, n and m are as defined in relation to formula (I) in claim 1 and Z¹ represents a leaving group and Z² represents a hydrogen atom, or (ii) with a compound of the general formula (XIII) in which R², R⁴, R⁴,, n and m are as defined in relation to formula (I) in claim 1 and Z¹ and Z² together represent an oxo group; and if necessary treating with a reducing agent; or F) reducing a compound of the abovementioned general formula (VI) in which R, R², D, R⁴, R⁴', n , m , Q¹ and Q² are as defined in relation to formula (I) in claim 1, or a salt thereof; and thereafter, if necessary, converting a compound of formula (I) to another compound of formula (I) and/or forming a pharmaceutically acceptable salt of the compound so formed. A compound of formula (I) as defined in claim 1, or a pharmaceutically acceptable salt thereof, for use as an active therapeutic substance. A compound of formula (I) as defined in claim 1, or a pharmaceutically acceptable salt thereof, for use in the treatment of obesity and/or hyperglycaemia in humans or non-human animals. A pharmaceutical composition comprising a compound of formula (I) as defined in claim 1, or a pharmaceutically acceptable salt thereof, with a pharmaceutically acceptable carrier therefore. A method for improving the weight gain and/or improving the feed utilisation efficiency and/or increasing lean body mass of livestock, which method comprises the administration to livestock of an effective non-toxic amount of a compound of formula (I) as defined in claim 1, or a veterinarily acceptable salt thereof.

Inventors: AINSWORTH, ANTHONY TREVOR, CAWTHORNE, MICHAEL ANTHONY
Applicants: BEECHAM GROUP PLC
Application year: 1985
Main classification: C07C217
IPC codes: C07C217, C07C237, C07C67, C07D307, C07C227, C07C317, C07C311, C07C231, A61K31, C07C301, C07C239, C07C315, C07C235, C07C303, C07C229, C07C313, C07C225, C07C213, A61P3