APHIDICOLANE DERIVATIVES, THEIR PREPARATION AND PHARMACEUTICAL COMPOSITIONS COMPRISING THEM

Abstract: Aphidicolane derivatives of the formula: wherein R¹ stands for hydrogen or a hydroxy radical, R² stands for a hydroxy or methyl radical, or the group CR¹R² stands for a keto group; R³ stands for a formyl or hydroxymethyl radical, or for the group -CH₂O.CO.OR⁶, wherein R⁶ stands for a defined radical or R² and R³ are joined together to form the group -O.CO.OCH₂-; R⁴ stands for a hydroxy radical; R⁵ stands for a formyl radical, a hydroxyalkyl radical -(CH₂)₁₋₃OH, a radical -CHR⁷OH, wherein R⁷ stands for a defined radical, or R⁵ stands for an azidomethyl or pyrrolidinylcarbonyloxymethyl radical, or for the group -CH₂O.CO.OR⁸, wherein R⁸ stands for defined radical, or R⁵ stands for the group -CH₂O.CO.(CH₂) m .CR¹¹R¹².(CH₂) n .NR⁹R¹⁰. wherein m, n, R⁹, R¹⁰, R¹¹ and R¹² have defined values, or R⁵ stands for the group -CH₂O.SO₂.R¹³, wherein R¹³ stands for a defined radical; or R⁴ and R⁵ are joined together to form the group -O.CH₂- or -O.CO.OCH₂-; and, where appropriate, pharmaceutically acceptable salts thereof. Processes for the preparation of said aphidicolane derivatives. Pharmaceutical compositions comprising one of the compounds and a pharma­ ceutical diluent or carrier. The compounds exhibit inhibitory activity against DNA-containing viruses and they inhibit the growth of some tumours.

Description: This invention relates to homocyclic derivatives, and more particularly it relates to aphidicolin derivatives which possess inhibitory activity against DNA-containing viruses and which inhibit the growth of certain tumours. Aphidicolin is a known compound which has the following structure:- It is produced by the fermentation of Cephalosporium aphidicoloa , Nigrospora sphaerica and Harziella entomophilla , and it is known from United Kingdom patent specification No. 1,331,520 to be a mitotic suppressant and to possess inhibitory activity against DNA-containing viruses, for example Herpes simplex and Vaccinia viruses. Also, aphidicolin has been tested against certain tumours in experimental animals, and encouraging results have been obtained. Certain analogues of aphidicolin have been prepared by microbial transformation and are the described by Ipsen J. et al in J. Org. Chem. 1982, 47, 3278-3282, but none of the metabolites prepared were active in an in vivo antitumour test system at the dosage employed. According to the invention there are provided compounds of the formula:- (wherein R⁵ stands for a piperidin-4-yloxycarbonyloxymethyl, m-carboxybenzenesulphonyloxymethyl, or 5-dimethylaminonaphthalenesulphonyloxymethyl radical or a group of the formula:- wherein m stands for 0 to 4, R⁹ stands for hydrogen, an alkyl radical of not more than 6 carbon atoms, an aryl radical of not more than 10 carbon atoms, a phenylalkyl radical of not more than 9 carbon atoms, an alkoxycarbonyl radical of not more than 6 carbon atoms, or a R⁶O.CO radical wherein R⁶ stands for a phenyl radical which may optionally be substituted by an amino radical, an alkylamino radical of not more than 6 carbon atoms, or dialkylamino radical of not more than 12 carbon atoms, or a carboxy or hydroxysulphonyl radical, or R⁶ stands for a phenylalkyl radical of not more than 9 carbon atoms which may optionally bear an amino radical, an alkylamino radical of not more than 6 carbon atoms, a dialkylamino radical of not more than 12 carbon atoms, or a carboxy or hydroxysulphonyl radical, on the phenyl moiety; and R¹⁰ stands for hydrogen or an alkyl radical of not more than 6 carbon atoms, or R⁹ and R¹⁰ are joined to form, together with the adjacent nitrogen atom, a saturated nitrogen-containing heterocyclic radical) or, where appropriate, a pharmaceutically-acceptable salt thereof. It will be appreciated by those skilled in the art that, since the basic nucleus of the compounds of the invention contains several asymmetric centres, some of the compounds of the invention exist in diastereoisomeric forms. This is the case, for example, when R⁵ contains at least one asymmetric centre, for example when R⁵ stands for a 1-hydroxyethyl or α-hydroxybenzyl radical. Such diastereoisomeric forms can be separated from one another by conventional methods, for example by fractional crystallisation or chromatography. R⁵ may for example represent a group of formula V wherein m has the meaning stated above, R⁹ stands for hydrogen or a methyl, phenyl, benzyl, t-butoxycarbonyl or benzyloxycarbonyl radical, and R¹⁰ stands for hydrogen or a methyl radical, or R⁹ and R¹⁰ are joined to form, together with the adjacent nitrogen atom, a saturated N -linked heterocyclic radical of 5 or 6 ring atoms containing a nitrogen atom as a hetero-atom, for example such a radical containing a nitrogen atom as the sole hetero-atom, or containing two hetero-atoms consisting of two nitrogen atoms, or a nitrogen atom and an oxygen atom, or a nitrogen atom and a sulphur atom, for example a pyrrolidino, piperidino, piperazino or morpholino radical. One preferred embodiment of the invention consists of compounds of the formula II wherein R⁵ stands for a group of the formula: wherein m stands for 0 or 1, R⁹ stands for hydrogen, an alkyl radical of not more than 3 carbon atoms, an alkoxycarbonyl radical of not more than 6 carbon atoms, or a phenylalkoxycarbonyl radical of not more than 10 carbon atoms, and R¹⁰ stands for hydrogen or an alkyl radical of not more than 3 carbon atoms, or wherein R⁹ and R¹⁰ are joined to form, together with the adjacent nitrogen atom, a saturated N -linked heterocyclic radical of 5 or 6 ring atoms containing a nitrogen atom as the sole hetero-atom, or containing two hetero-atoms consisting of two nitrogen atoms, or a nitrogen atom and an oxygen atom, or a nitrogen atom and a sulphur atom, and pharmaceutically-acceptable acid-addition salts thereof. In the case where the compounds of the formula II are sufficiently basic, a suitable salt is an acid-addition salt derived from an inorganic or organic acid which affords a pharmaceutically-acceptable anion, for example hydrochloric or citric acid. In the case where the compounds of the formula II are sufficiently acidic, a suitable salt is a base-addition salt derived from a pharmaceutically-acceptable inorganic base, for example an alkali metal or alkaline earth metal salt, or an aluminium salt, or a salt derived from a pharmaceutically-acceptable organic base, for example trimethylamine, triethylamine, ethanolamine, ethylenediamine, morpholine or guanidine. Aphidicolin and many of its derivatives have the disadvantage that they have any extremely low solubility in water. In the case of aphidicolin, for example, the aqueous solubility is 112±9µg.per ml. Such a low solubility causes problems as regards the preparation of aqueous pharmaceutical formulations, for example aqueous formulations suitable for administration by injection, and therefore there is a need for water-soluble derivatives of aphidicolin. According to a further feature of the invention there are provided water-soluble derivatives of aphidicolin, which are pharmaceutically-acceptable salts of compounds of the formula II wherein R⁵ stands for a glycyloxymethyl, piperidin-4-yloxycarbonyloxymethyl, γ-( N -morpholino)-n-butyryloxy-methyl, m -carboxybenzenesulphonyloxymethyl or 5-dimethylaminonaphthalenesulphonyloxymethyl radical. A preferred water-soluble compound is a pharmaceutically-acceptable salt, for example the hydrochloride, of a compound of the formula II wherein R⁵ stands for a glycyloxymethyl radical. According to further features of the invention there are provided the following processes:- (a) hydrolysing the corresponding compound of the formula II wherein R³ represents a t-butyldimethylsilyloxy radical; (b) a process for the prepartion of compounds of the formula II wherein R⁵ stands for a radical of the formula -CH₂O.SO₂.R¹³, wherein R¹³ represents a m-carboxyphenyl or 5-dimethylaminonaphthalene moiety and, where appropriate, pharmaceutically-acceptable salts thereof, which comprises reacting the corresponding compound wherein R⁵ stands for a hydroxymethyl radical with a compound of the formula R¹³.SO₂.X wherein R¹³ has the meaning stated above and Z stands for a halogen atom; (c) a process for the preparation of compounds of the formula II wherein R⁵ stands for a piperidin-4-yloxycarbonyloxymethyl radical, and pharmacetically-acceptable acid-addition salts thereof, which comprises hydrogenolysing the corresponding compound wherein R⁵ stands for a radical of the formula:- (wherein R⁶ represents a phenylalkyl radical of not more than 9 carbon atoms); (d) a process for the preparation of compounds of the formula II wherein R⁵ stands for a group of the formula:- (wherein m, R⁹ and R¹⁰ have the meanings stated above) and pharmaceutically-acceptable acid-addition salts thereof, which comprises reacting the corresponding compound wherein R⁵ stands for a hydroxymethyl radical with an acid of the formula R⁹R¹⁰N(CH₂) m+1 CO₂H, or an acid halide or anhydride thereof, and wherein m, R⁹ and R¹⁰, have the meanings stated above; (e) a process for the preparation of compounds of the formula II wherein R⁵ stands for a group of the formula -CH₂O.CO.(CH₂) m+1 NHR¹⁴, and pharmaceutically-acceptable acid-addition salts thereof, which comprises hydrogenolysing a corresponding compound, wherein R⁵ stands for a group of the formula -CH₂O.CO.(CH₂) m+1 .N(R¹⁴)CO₂R¹⁵, wherein m, has the meaning stated above, R¹⁴ stands for hydrogen, an alkyl radical of not more than 6 carbon atoms, or an aryl radical of not more than 10 carbon atoms, and R¹⁵ stands for an α-phenylalkyl radical of not more than 9 carbon atoms; (f) a process for the preparation of compounds of the formula -CH₂O.CO.(CH₂) m+1 .NHR¹⁴, and pharmaceutically-acceptable acid-addition salts thereof, which comprises selectively hydrolysing, under acidic conditions, the corresponding compound wherein R⁵ stands for a group of the formula -CH₂O.CO.(CH₂) m+1 .N(R¹⁴).CO₂C₄H₉ t , and wherein m, and R¹⁴ have the meanings stated above. In process (a) the hydrolytic agent may be a suitable inorganic or organic acid, for example hydrochloric acid or trifluoroacetic acid. The hydrolysis is preferably carried out in the presence of an organic solvent, for example ethanol, and at or below ambient temperature. In process (b) Z may, for example, stand for a chlorine or bromine atom, and each of these processes is conveniently carried out in pyridine. Processes (c) and (e) are carried out by reacting the starting material with hydrogen gas in the presence of a hydrogenation catalyst, for example a palladium-on-charcoal catalyst. The processes are carried out in an organic solvent, for example an alkanol of not more than 3 carbon atoms, for example ethanol, or an alkyl alkanoate of not more than 8 carbon atoms, for example ethyl acetate, at ambient temperature and at atmospheric pressure or a slightly elevated pressure. The starting material for use in process (c) in which R⁵ represents a radical of formula VIII as hereinbefore defined may be prepared by reacting a corresponding compound in which R⁵ stands for a hydroxymethyl radical with a compound of the formula:- in which R⁶ represents a phenylalkyl radical of not more than 9 carbon atoms and Z stands for a halogen atom. Z may for example stand for a chlorine or bromine atom and the process is conveniently carried out in pyridine. In process (d) the acid halide may, for example, be an acid chloride or bromide, and the acid anhydride may either be derived wholly from the parent acid (i.e. of the type R-CO-O-CO-R) or it may be a mixed anhydride obtained in conventional manner. The process may be carried out in an organic solvent, for example pyridine. Process (f) may be carried out by, for example, the use of hydrogen chloride or trifluoracetic acid as the hydrolytic agent. It may be carried out in a mixture of water and an organic solvent containing a relatively substantial amount of water, or in an organic solvent, for example diethyl ether, containing a very small amount of water. The acid-addition salts of the invention are obtainable by conventional procedures. Aphidicolin, which is used as a starting material in some of the processes of the invention, is obtainable as described in United Kingdom patent specification No.1,331,520. Other starting materials are obtained as described below. The antiviral activity of compounds of the invention has been demonstrated against Herpes simplex in vitro . The anti-tumour activity of compounds of the invention has been demonstrated against the mouse C₂₆ colonic tumour. The potency of any particular compound depends upon its chemical structure, but generally speaking the compounds of the invention exhibit antiviral activity in vitro at a concentration in the range 0.01 to 50 µg./ml. and they exhibit activity in vivo against the mouse C₂₆ colonic tumour at a dose in the range 25 to 200mg./kg. No toxic effects have been observed with the compounds of the invention at doses at which they exhibit activity in the above mentioned tests. For example, this is the case with the compound of Example 5 at an effective dose (75 mg./kg. intraperitoneally) against the mouse C₂₆ colonic tumour. According to a further feature of the invention there are provided pharmaceutical compositions comprising a compound of the formula II, wherein R⁵ has the meaning stated above, or, where appropriate, a pharmaceutically-acceptable salt thereof, and a pharmaceutically-acceptable diluent or carrier. The compositions of the invention may, for example, be in a suitable form for oral, parenteral or rectal administration. Thus, for example, they may be in an orally-administrable unit dosage form, for example a tablet or capsule, which may optionally be adapted for sustained or controlled release, or they may be in an injectable form, for example a sterile injectable solution or suspension, or in the form of a suppository. The pharmaceutical compositions of the invention are obtainable by conventional methods using conventional diluents and carriers. The invention is illustrated but not limited by the following Examples in which the temperatures are expressed in degrees Celsius and the nomenclature is based on the parent hydrocarbon (aphidicolane) having the following structure and numbered as shown (see J.C.S. Chem. Comm., 1972, 1027):- Unless otherwise stated, the expression " in vacuo " means that the pressure used was approximately 12mm. (water pump pressure). Example 1 17-[1-(Benzyloxycarbonyl)piperidin-4-yloxycarbonyloxy]-3α, 16β, 18-trihydroxyaphidicolane, (3.0028g., 0.00501 mole) was dissolved in ethanol (25ml) and the solution added to a suspension of 30% w/w palladium-on-charcoal catalyst (0.2997g) in ethanol (100ml) containing N-hydrochloric acid (10ml). The mixture was hydrogenated at ambient temperature and atmospheric pressure for 2 hours. The catalyst was removed by filtration (Celite; Trade Mark), the solvent in the filtrate was evaporated in vacuo (1mm pressure, solid CO₂ cold finger condenser), ethanol (20ml) was added to the residue, and the solvent evaporated in vacuo . The residue was then freeze-dried from water (200ml) to give 3α, 16β, 18-trihydroxy-17-piperidin-4-yloxycarbonyloxy-aphidicolanehydrochloride, NMR (d₅ pyridine solution, 90 MHz): 2.2-3.8τ (ca. 8H, very broad s, exchanged with D₂O), 4.94τ (1H, broad s), 5.63τ (2H, s), 6.1τ (1H, broad s), 6.1-6.5τ (2H, AB quartet), 6.4-6.9τ (4H, broad m), 9.0τ (3H, s) and 9.23τ (3H, s). Example 2 γ-(1-Morpholino)butyric acid hydrochloride (2.2895g., 0.109 mole) was dissolved in pyridine (50ml), N -methylmorpholine (4.46ml, 4.04g, 0.04 mole) was added, and the solution was cooled in an ice-salt mixture (internal temperature -10°). The mixture was stirred rapidly and benzenesulphonyl chloride (1.28ml, 1.77g, 0.01 mole) was added dropwise over 15 min. The mixture was added to a solution of aphidicolin (1.689g., 0.005 mole) in pyridine (50ml.), itself cooled in an ice-salt mixture. The mixture was stirred with cooling for 2 hr. and then allowed to warm to ambient temperature. Water (5ml.) was added and the solvents evaporated in vacuo (1mm. pressure, solid CO₂ cold finger condenser). The residue was shaken together with ethyl acetate (100ml.) and water (100ml.), and the mixture was separated, both phases being retained. The aqueous phase was extracted with ethyl acetate (2 x 100ml.), and the combined organic phases were extracted with 0.4N-hydrochloric acid (3 x 50ml.). The combined aqueous extracts were washed with ethyl acetate (2 x 50ml.), neutralised first with solid sodium bicarbonate and finally to pH 9 with saturated aqueous sodium carbonate solution. The aqueous solution was extracted with ethyl acetate (3 x 100ml.), the combined extracts dried (Na₂SO₄) and the solvent evaporated in vacuo to give 3α,16β,18-trihydroxy-17-(γ-morpholino-n-butyroxy)aphidicolane as a gum which crystallised on the addition of ether and then had m.p. 157-8°. A small sample was crystallised from ethyl acetate and had m.p. 159°. The hydrochloride was prepared by dissolving the free base in methanol:water (1g. of the base to 25ml. of methanol and 50ml. of water) and titrating the solution to pH 6 with 0.1N-hydrochloric acid. The solvent in the resulting solution was evaporated in vacuo (0.1mm. pressure, solid CO₂ cold finger condenser) to a volume of approx. 50ml and the residue was freeze-dried. The hydrochloride was obtained as a voluminous white solid, NMR (d₅ pyridine solution, 90 MHz): 2.68τ (ca. 6H, broad s, exchanged with D₂O), 5.67τ (2H, s) 5.77-6.02τ (4H, m), 6.06τ (1H, broad s), 6.08-6.50τ (2H, AB quartet, J = 10.8 Hz), 6.80-7.10τ (4H, m), 9.0τ (3H, s) and 9.21τ (3H, s). Example 3 N -Benzyloxycarbonylglycine (3.135g, 0.015 mole) was dissolved in dry pyridine (30ml) and the solution was protected from atmospheric moisture (drying tube) and stirred at -20° (acetone-solid CO₂ bath). Benzenesulphonyl chloride (1.94 g, 1.41ml, 0.011 mole) was added over 5 minutes. Stirring at -20° was continued for 10 minutes. A solution of aphidicolin (3.38g, 0.01 mole) in pyridine (30ml) at -20° was added. The mixture was stirred for 70 minutes and then poured into water (500ml). The mixture was extracted with ethyl acetate (3 x 100ml) and the combined organic extracts were washed successively with N-hydrochloric acid (4 x 100ml) saturated sodium bicarbonate solution (100ml) and water (2 x 100ml). The organic phase was dried (Na₂SO₄) and the solvent evaporated in vacuo . The residual yellow oil was triturated with ethyl acetate (25ml) and the solid which crystallised was separated by filtration. The solid was crystallised twice from ethyl acetate to give 17-[ N -benzyloxycarbonylglycyloxy)-3α, 16β, 18-trihydroxyaphidicolane, m.p. 179-181°. Example 4 N -t-Butoxycarbonylglycine (0.75g, 0.00429 mole) was dissolved in dry pyridine (5ml) and the solution was protected from atmospheric moisture (drying tube) and stirred at -10° (ice-salt bath). Benzenesulphonyl chloride (0.554g, 0.4ml, 0.00314 mole) was added over 5 minutes. Stirring at -10° was continued for 10 minutes and a solution of aphidicolin (1.0g, 0.00301 mole) in dry pyridine (6ml) at -20° was then added. Stirring at -10° was continued for 1 hour and the mixture was then poured into water (150ml) and extracted with ethyl acetate (3 x 75 ml). The combined extracts were washed successively with 1.5N-hydrochloric acid (3 x 50 ml), saturated sodium bicarbonate solution (3 x 25ml) and water (25ml). The organic solution was dried (Na₂SO₄) and the solvent evaporated in vacuo . The residue was crystallised from ethyl acetate to give 17-( N -t-butoxycarbonylglycyloxy)-3α, 16β, 18-trihydroxyaphidicolane, m.p. 193-4°. A small sample was recrystallised from ethyl acetate:methanol 9:1 v/v; the crystals softened at 193-4° and melted at 194-6°. Example 5 17-( N -Benzyloxycarbonylglycyloxy)-3α, 16β, 18-trihydroxyaphidicolane (2.5g, 0.00479 mole) was dissolved in dry ethanol (150 ml) and the solution was added to a pre-hydrogenated suspension of 30% w/w palladium-on-charcoal catalyst (0.25g) in dry ethanol (150ml). The mixture was hydrogenated at ambient temperature and atmospheric pressure until no further hydrogen was consumed (approximately 100ml. total; approximately 2.5 hours). The catalyst was removed by filtration (Celite; Trade Mark) and the solvent evaporated in vacuo from the filtrate. The residue was dissolved in ethanol (50ml), water (100ml) was added, and the solution was adjusted to pH 6 with 0.1N-hydrochloric acid. The ethanol was evaporated in vacuo (1mm pressure; solid CO₂ cold finger condenser) and the resulting aqueous solution was washed with ethyl acetate (4 x 50 ml). The aqueous phase was evaporated in vacuo (1mm pressure; solid CO₂ cold finger condenser) to a volume of approximately 50ml and then freeze-dried. There was thus obtained 17-glycyloxy-3α, 16β, 18-trihydroxyaphidicolane hydrochloride as a white solid, NMR (d₅ pyridine solution, 90 MHz): 2.71τ (ca. 10H, broad s, exchanged with D₂O), 5.43τ (2H, s), 5.60τ (2H, s), 6.05τ (1H, broad s), 6.11-6.50τ (2H, AB quartet, J = 11.7 Hz), 9.01τ (3H, s) and 9.21τ (3H, s). Example 6 Aphidicolin (6.76g, 0.02 mole) was dissolved in dry pyridine (100ml) and the solution was stirred at ambient temperature and protected from atmospheric moisture (drying tube). m-Chlorosulphonylbenzoic acid (8.82g, 0.04 mole) was added to the stirred solution over 1 hour. The mixture was stirred for a further 3 hours and the solvent then evaporated in vacuo (1mm, pressure; solid CO₂ cold finger condenser). The residue was shaken together with ethyl acetate (300ml) and water (300ml), and the mixture was separated, both phases being retained. The aqueous phase was extracted with ethyl acetate (2 x 300ml). The combined organic phases were dried (Na₂SO₄) and the solvent evaporated in vacuo . The residue was chrmatographed on silica gel (Merck Art. 9385, 200g), eluting with ethyl acetate: methanol 9:1 v/v and collecting 29ml. fractions, to remove less polar impurities, and then with ethyl acetate: methanol: acetic acid 90:10:1 v/v. Fractions containing the desired product (detected by tlc) were combined and the solvent evaporated in vacuo . The residue was twice dissolved in a small volume of toluene and the solvent evaporated in vacuo . The residues from the reactions carried out as described above were combined and chromatographed on silica gel (Merck Art. 9385, 100g), eluting with ethyl acetate: methanol: acetic acid 90:10:1 v/v and collecting 20ml. fractions. Fractions 11 to 16 were combined, the solvents were evaporated in vacuo , and the residue was dissolved three times in a small volume of toluene and the solvent evaporated in vacuo . There was thus obtained 17- m -carboxybenzenesulphonyloxy-3α, 16β, 18-trihydroxyaphidicolane as a white solid, NMR (CDCl₃-dimethyl sulphoxide solution, 90 MHz): 1.54τ (1H, broad s), 1.76τ (1H, d, J = 7.2 Hz), 6.18τ (1H, s), 6.47τ (1H, broad s), 6.50-6.87τ (2H, AB quartet, J = 11.7 Hz), 9.10τ (3H, s) and 9.37τ (3H, s). The sodium salt was prepared by dissolving the free acid (0.20g) in a mixture of methanol (25ml) and water (35ml) and adjusting the solution at 0° to pH 7.5 with 0.1N-sodium hydroxide. The resulting solution was evaporated in vacuo (0.1mm, solid CO₂ cold finger condenser) to a volume of approximately 25 ml. and then freeze-dried to give the sodium salt as a white voluminous solid. Example 7 Aphidicolin (3.38g, 0.01 mole) was dissolved in dry pyridine (50ml) and the solution was stirred at ambient temperature and protected from atmospheric moisture (drying tube). 1-Dimethylaminonaphthalene-8-sulphonyl chloride (4.04g, 0.015 mole) was added to the stirred solution over 2 hours. Stirring was continued for a further hour and the solvent was then evaporated in vacuo (1mm pressure; solid CO₂ cold finger condenser). The residue was shaken together with ethyl acetate (60ml) and water (70ml) and the mixture was separated, both phases being retained. The aqueous phase was extracted with ethyl acetate (20ml.) and the combined organic phases were dried (Na₂SO₄ ) and the solvent evaporated in vacuo . The residual pale yellow solid was chromatographed on silica gel (Merck Art. 9385, 350g.), eluting with ethyl acetate and collecting 32ml. fractions. Fractions 10 to 24 were combined and the solvent evaporated in vacuo to give 17-(1-dimethylaminonaphthalene-8-sulphonyloxy)-3α,16β,18-trihydroxyaphidicolane as a pale yellow solid which showed no clear melting point and which decomposed above 255°. The product had NMR (d₆ dimethyl sulphoxide solution plus d₄ acetic acid, 90 MHz): 1.38τ (1H, d, J = 7.5Hz), 1.77τ (2H, m), 2.33τ (2H, t, J = 7.5Hz), 1.72τ (1H, d, J = 7.5Hz), 6.28τ (2H, s), 6.55τ (1H, broad s), 6.57-7.0τ (2H, AB quartet, J = 12Hz), 7.1τ (6H, s), 9.13τ (3H, s) and 9.37τ (3H, s).

Claims: Claims for the following Contracting State : AT 1. A process for the preparation of a compound of the formula:- (wherein R⁵ stands for a piperidin-4-yloxycarbonyloxymethyl, m-carboxybenzenesulphonyloxymethyl, or 5-dimethylaminonaphthalenesulphonyloxymethyl radical or a group of the formula:- wherein m stands for 0 to 4, R⁹ stands for hydrogen, an alkyl radical of not more than 6 carbon atoms, an aryl radical of not more than 10 carbon atoms, a phenylalkyl radical of not more than 9 carbon atoms, an alkoxycarbonyl radical of not more than 6 carbon atoms, or a R⁶O.CO radical wherein R⁶ stands for a phenyl radical which may optionally be substituted by an amino radical, an alkylamino radical of not more than 6 carbon atoms, or a dialkylamino radical of not more than 12 carbon atoms, or a carboxy or hydroxysulphonyl radical, or R⁶ stands for a phenylalkyl radical of not more than 9 carbon atoms which may optionally bear an amino radical, an alkylamino radical of not more than 6 carbon atoms, a dialkylamino radical of not more than 12 carbon atoms, or a carboxy or hydroxysulphonyl radical, on the phenyl moiety; and R¹⁰ stands for hydrogen or an alkyl radical of not more than 6 carbon atoms, or R⁹ and R¹⁰ are joined to form, together with the adjacent nitrogen atom, a saturated nitrogen-containing heterocyclic radical) or, where appropriate, a pharmaceutically-acceptable salt thereof; which comprises:- (a) hydrolysing the corresponding compound of the formula II wherein R³ represents a t-butyldimethylsilyloxymethyl radical; (b) in the case where R⁵ stands for a radical of the formula -CH₂O.SO₂R¹³, wherein R¹³ represents a m-carboxyphenyl or 5-dimethylaminonaphthalene moiety, reacting the corresponding compound wherein R⁵ stands for a hydroxymethyl radical with a compound of the formula R¹³.SO₂.Z wherein R¹³ has the meaning stated above and Z stands for a halogen atom; (c) in the case where R⁵ stands for a piperidin-4-yloxycarbonyloxymethyl radical hydrogenolysing the corresponding compound wherein R⁵ stands for a radical of the formula:- (wherein R⁶ represents a phenylalkyl radical of not more than 9 carbon atoms); (d) in the case where R⁵ stands for a group of the formula:- reacting the corresponding compound wherein R⁵ stands for a hydroxymethyl radical with an acid of the formula R⁹R¹⁰N (CH₂) m+1 CO₂H, or an acid halide or anhydride thereof, and wherein m, R⁹ and R¹⁰ have the meanings stated herein; (e) in the case where R⁵ stands for a group of the formula -CH₂O.CO(CH₂) m+1 .NHR¹⁴, hydrogenolysing a corresponding compound wherein R⁵ stands for a group of the formula -CH₂O.CO(CH₂) m+1 .N(R¹⁴)CO₂R¹⁵, wherein m has the meaning stated above, R¹⁴ stands for hydrogen, an alkyl radical of not more than 6 carbon atoms, or an aryl radical of not more than 10 carbon atoms, and R¹⁵ stands for an α-phenylalkyl radical of not more than 9 carbon atoms; or (f) in the case where R⁵ stands for a group of the formula -CH2O.CO.(CH₂) m+1 . NHR¹⁴, selectively hydrolysing under acidic conditions the corresponding compound wherein R⁵ stands for a group of the formula -CH₂O.CO(CH₂) m+1 .N(R¹⁴).CO₂C₄H₉ t , and wherein m, and R¹⁴ have the meanings stated above. 2. A process as claimed in claim 1 for the preparation of a pharmaceutically-acceptable salt of a compound of the formula II where R⁵ stands for a glycyloxymethyl, piperidin-4-yloxycarbonyloxymethyl, γ-(N-morpholino)-n-butyryloxymethyl, m-carboxybenzenesulphonyloxymethyl or 5-dimethylaminonapthalenesulphonyloxymethyl radical. 3. A process as claimed in claim 2 in which R⁵ stands for a glycyloxymethyl radical. 4. A process as claimed in claim 1(a) in which the hydrolytic agent is hydrochloric acid or trifluoroacetic acid. 5. A process as claimed in claim 1(b) in which Z stands for a chlorine or bromine atom. 6. A process as claimed in claim 1(c) or (e) which is carried out by reacting the starting material with hydrogen gas in the presence of a hydrogenation catalyst. 7. A process as claimed in claim 1(d) in which the acid halide is an acid chloride or bromide, or the acid anhydride is derived wholly from the parent acid or it is a mixed anhydride. 8. A process as claimed in claim 1(f) in which the hydrolytic agent is hydrogen chloride or trifluoroacetic acid. Claims for the following Contracting States : BE, CH, DE, FR, GB, IT, LI, LU, NL, SE 1. A compound of the formula:- (wherein R⁵ stands for a piperidin-4-yloxycarbonyloxymethyl, m-carboxybenzenesulphonyloxymethyl, or 5-dimethylaminonaphthalenesulphonyloxymethyl radical or a group of the formula:- wherein m stands for 0 to 4, R⁹ stands for hydrogen, an alkyl radical of not more than 6 carbon atoms, an aryl radical of not more than 10 carbon atoms, a phenylalkyl radical of not more than 9 carbon atoms, an alkoxycarbonyl radical of not more than 6 carbon atoms, or a R⁶O.CO radical wherein R⁶ stands for a phenyl radical which may optionally be substituted by an amino radical, an alkylamino radical of not more than 12 carbon atoms, or a carboxy or hydroxysulphonyl radical, or R⁶ stands for a phenylalkyl radical of not more than 9 carbon atoms which may optionally bear an amino radical, an alkylamino radical of not more than 6 carbon atoms, a dialkylamino radical of not more than 12 carbon atoms, or a carboxy or hydroxysulphonyl radical, on the phenyl moiety; and R¹⁰ stands for hydrogen or an alkyl radical of not more than 6 carbon atoms, or R⁹ and R¹⁰ are joined to form, together with the adjacent nitrogen atom, a saturated nitrogen-containing heterocyclic radical) or; where appropriate, a pharmaceutically-acceptable salt thereof. 2. A compound as claimed in claim 1 wherein R⁵ stands for a group of formula V in which m stands for 0 or 1, R⁹ stands for hydrogen, an alkyl radical of not more than 3 carbon atoms, an alkoxycarbonyl radical of not more than 6 carbon atoms, or a phenylalkoxycarbonyl radical of not more than 10 carbon atoms, and R¹⁰ stands for hydrogen or an alkyl radical of not more than 3 carbon atoms, or wherein R⁹ and R¹⁰ are joined to form, together with the adjacent nitrogen atom, a saturated N -linked heterocyclic radical of 5 or 6 ring atoms containing a nitrogen atom as the sole hetero-atom, or containing two hetero-atoms consisting of two nitrogen atoms, or a nitrogen atom and oxygen atom, or a nitrogen atom and a sulphur atom, or a pharmaceutically-acceptable acid-addition salt thereof. 3. A compound as claimed in claim 1 which is a pharmaceutically-acceptable salt of a compound of the formula II wherein R⁵ stands for a glycyloxymethyl, piperidin-4-yloxycarbonyloxymethyl, γ-( N -morpholino)-n-butyryloxymethyl, m -carboxybenzene-sulphonyloxymethyl or 5-dimethylaminonaphthalenesulphonyloxymethyl radical. 4. A salt as claimed in claim 3 wherein R⁵ stands for a glycyloxymethyl radical. 5. A salt as claimed in claim 1 where the compound of the formula II is sufficiently basic, which is an acid-addition salt derived from an inorganic or organic acid which affords a pharmaceutically-acceptable anion. 6. A salt as claimed in claim 1 where the compound of the formula II is sufficiently acidic, which is a base-addition salt derived from a pharmceutically-acceptable inorganic or organic base, or an aluminium salt. 7. A salt as claimed in claim 4 which is the hydrochloride. 8. A process for the preparation of a compound of the formula II, wherein unless otherwise stated R⁵ has the meaning stated in claim 1, or, where appropriate, a pharmaceutically-acceptable salt thereof, which comprises: (a) hydrolysing the corresponding compound of the formula II wherein R³ represents a t-butyldimethylsilyloxymethyl radical; (b) in the case where R⁵ stands for a radical of the formula -CH₂O.SO₂R¹³, wherein R¹³ represents a m-carboxyphenyl or 5-dimethylaminonaphthalene moiety reacting the corresponding compound where R⁵ stands for a hydroxymethyl radical with a compound of the formula R¹³.SO₂.Z wherein R¹³ is as herein defined and Z stands for a halogen atom; (c) in the case where R⁵ stands for a piperidin-4-yloxycarbonyloxymethyl hydrogenolysing the corresponding compound wherein R⁵ stands for a radical of the formula:- (wherein R⁶ represents a phenylalkyl radical of not more than 9 carbon atoms); (d) in the case where R⁵ stands for a group of the formula:- reacting the corresponding compound wherein R⁵ stands for a hydroxymethyl radical with an acid of the formula R⁹R¹⁰N (CH₂) m+1 CO₂H, or an acid halide or anhydride thereof, and wherein m, R⁹ and R¹⁰ have the meanings stated in claim 1; (e) in the case where R⁵ stands for a group of the formula -CH₂O.CO(CH₂) m+1 .NHR¹⁴, hydrogenolysing a corresponding compound wherein R⁵ stands for a group of the formula -CH₂O.CO(CH₂) m+1 .N(R¹⁴)CO₂R¹⁵, wherein m has the meaning stated above, R¹⁴ stands for hydrogen, an alkyl radical of not more than 6 carbon atoms, or an aryl radical of not more than 10 carbon atoms, and R¹⁵ stands for an α-phenylalkyl radical of not more than 9 carbon atoms; or (f) in the case where R⁵ stands for a group of the formula -CH2O.CO.(CH₂) m+1 . NHR¹⁴, selectively hydrolysing under acidic conditions the corresponding compound wherein R⁵ stands for a group of the formula -CH₂O.CO(CH₂) m+1 .N(R¹⁴).CO₂C₄H₉ t , and wherein m, and R¹⁴ have the meanings stated in claim 1. 9. A pharmaceutical composition comprising a compound of the formula II, wherein R¹, R², R³, R⁴ and R⁵ have the meanings stated in Claim 1 or where appropriate, a pharmaceutically-acceptable salt thereof, and a pharmaceutically-acceptable diluent or carrier.

Inventors: RATCLIFFE, ARNOLD HARRY
Applicants: IMPERIAL CHEMICAL INDUSTRIES PLC
Application year: 1983
Main classification: C07C35
IPC codes: C07C49, C07C309, A61P31, C07D493, C07C68, C07C41, C07C271, C07D319, C07C215, A61K31, C07C301, C07C241, C07C223, C07C303, C07C47, C07C227, C07D295, A61P35, C07C229, C07D303, C07C65, C07D211, C07C35, C07D317, C07C225, C07C213, C07C69, C07C27, C07C45, C07C247, C07C219, C07F7, C07C43, C07C51, C07C67