EP0189472A1 - Pyrimidinone derivatives - Google Patents

Abstract

Bisulfite adducts of compounds having formula (I) in which R represents a group of formula (II), in which R1 represents a halogen atom or a trifluoromethyl group; R2 represents a hydrogen atom or a C1-4 alkyl, C6-10 aryl or benzoyl group; R3 represents a hydrogen atom or, with R2, represents a chain -CH2- or -CH2-CH2-; and formula (III) represents an aromatic carbocyclic C6-10 group or a carbon-linked heterocyclic group containing a 5- or 6-membered unsaturated heterocyclic ring. This ring contains one or more heteroatoms selected from O, N and S and optionally carries a fused carbocyclic ring. Said carbocyclic or heterocyclic group may carry one or more substituents selected from halogen atoms, C1-4 alkyl, C1-4 alkanoyl, C1-4 alkoxy, C1-4 alkoxycarbonyl, C1-4 alkylthio, hydroxyl, nitro groups, cyano and formyl, -NR4R5 groups (where R4 is a hydrogen atom or a C1-4 alkyl group, and R5 is a hydrogen atom or a C1-4 alkyl, C1-4 alkanoyl or aroyl group) and C1-4 alkyl groups substituted by one or more hydroxy groups or -NR4R5 and halogen atoms. The salts of these adducts have good metaphase blocking properties and good water solubility, and can be useful in combating abnormal cell proliferation.

Description

Pyrimidinone derivatives.

This invention relates to pyrimidinone derivatives, to processes for their preparation, and to pharmaceutical compositions containing them.

European Patent Applications Publication Nos. 44704 and 44705 disclose 5-halo-pyrimidin¬

2-ones which possess a metaphase arresting ability. This ability is useful for combating abnormal cell proliferation, which can be found in auto-immune diseases, and diseases such as cancers, leukaemias or cutaneous cellular proliferation, e.g. contact dermatitis or psoriasis.

We have found a new group of pyrimidin-2one derivatives which have very good metaphase arresting ability and which are useful in combating abnormal cell proliferation.

In general, these compounds possess good water-solubility and by virtue of this are particularly easy to administer.

In particular, we have found that 5-halopyrimidin-2-ones according to the European Patent

Applications referred to above are capable of forming bisulphite adducts having metaphase arresting abilities and enhanced water solubilities.

According to one preferred aspect of the present invention we provide bisulphite adducts of compounds of general formula (I) (I)

wherein R represents a group

R¹ represents a halogen atom or a trifluoromethyl group; R² represents a hydrogen atom or a C_{1 -4} alkyl,

C_6-10 aryl or benzoyl group;

R³ represents a hydrogen atom or, together with R², represents a -CH₂- or -CH₂-CH₂- chain; and represents a C_6-10 carbocyclic aromatic group or a carbon-attached heterocyclic group containing a 5- or 6- membered unsaturated heterocyclic ring which ring contains one or more heteroatoms selected from O, N and S and optionally carries a fused carbocyclic ring, which carbocyclic or heterocyclic group may carry one or more substituents selected from halogen atoms, C_{1 -4} alkyl, C_{1 -4} alkanoyl,

C_1-4 alkoxy, C_1-4 alkoxycarbonyl, C_1-4 alkylthio, hydroxyl, nitro, cyano and formyl groups, -NR⁴R⁵ groups (where R⁴ is a hydrogen atom or a C_{1 -4} alkyl group, and R⁵ is a hydrogen atom or a C_{1- 4} alkyl,

C_1-4 alkanoyl or aroyl group) and C_{1 -4} alkyl groups substituted by one or more hydroxy or -NR⁴R⁵ groups and halogen atoms; and salts thereof. The adducts according to the invention are salts of sulphonic acids and are thus ionic materials. Such salts are conveniently physiologically acceptable, water soluble salts and may advantageously be sodium, potassium, calcium, magnesium, ammonium, mono-, di- or trialkylammonium salts, or salts derived from polyamines.

The adducts of the invention are conveniently formed directly through an addition reaction, however the term "adduct" is used herein to refer to the final product irrespective of its manner of production and thus includes within its scope compounds produced other than by direct bisulphite addition to compounds of formula (I). Thus in a further aspect of the invention we provide compounds of formula (II)

(II)

(wherein X represents the group

M represents a cation; and R and R¹ are as defined above. Thus, the sulphonic acid grouping can be in either the 4- or 6-position as in the compounds of formula (Ila) and (lIb) below:

(IIa) (lIb)

(wherein M represents a cation, preferably selected from sodium, potassium, calcium, magnesium, ammonium, mono-, di-and trialkylammonium, or a cation derived from a polyamine e.g. ethylenediamine; and R and

R¹ are as defined above) and salts thereof, separately or in admixture.

It will be appreciated from the above definition of M that even though the precise structures depicted in formulae (Ila) and (lIb) relate only to those salts containing a 1:1 ratio of acid and cation, the invention extends to salts containing other acid: cation ratios. In the above definitions of the compounds according to the invention, the term "halogen" is used to mean fluorine, chlorine, bromine or iodine. The group R² may be for example a methyl, ethyl, phenyl or benzoyl group, but conveniently represents a hydrogen atom.

Examples of the C_6-10 carbocyclic aromatic groups within the definition of the ring A are phenyl or naphthyl groups which may be substituted by the groups indicated above. Examples of the optional substituents which may be present on a phenyl or naphthyl group include one, two or more chlorine or fluorine atoms, or methyl, acetyl, methoxy, methoxycarbonyl, ethoxycarbonyl, methylthio, hydroxyl, nitro, cyano, formyl, -NH₂, dimethylamino, acetylammino or hydroxymethyl groups. Substituents on the phenyl group may be present, for example, in the 2-, 3- and/or 4- positions. The ring A may conveniently be a five or six-membered unsaturated heterocyclic ring containing one, two or three hetero atoms. Such heterocyclic rings include thienyl, thiazolyl and pyrrolyl.

By referring to the heterocyclic group as being carbon-attached it is meant that it is linked by carbon-carbon bonds to the remainder of group R.

The five- or six-membered unsaturated heterocyclic ring may have another ring, fused to it, which may be a carbocyclic ring such as phenyl. Examples of the substituents which optionally may be present on the heterocyclic ring, or on any fused ring, are halogen atoms such as chlorine atoms or C_1-4 alkyl groups e.g. methyl groups. When R³ and R² together represents a -CH₂- or -CH₂CH₂- chain, the group R represents

(where n is an integer having the value 1 or 2) and may be for example

Further examples of the group R include J in which R² represents a hydrogen atom or a methyl or phenyl group.

When the cation M in formulae (Ila) or (lIb) is a mono-, di- or trialkylammonium ion, each alkyl group conveniently contains up to 4 carbon atoms.

Such cations include for example dimethylammonium and triethylammonium.

When the cation M is derived from a polyamine, it may be derived, for example, from ethylenediamine, The cation M in formula (IIa) or (lIb) is preferably a sodium ion.

Particularly interesting compounds include those water-soluble compounds of formulae (Ila) and (lIb) in which: M is a sodium, potassium, calcium, magnesium, ammonium, mono-, di- or trialkylammonium ion, or an ion derived from a polyamine, preferably a sodium, potassium, ammonium, dimethylammonium, triethylammonium or ethylenediamine ion, especially a sodium ion;

R¹ is a chlorine atom: and R is a group

(where R² represents a hydrogen atom or a methyl or phenyl group) or the group

Particularly interesting compounds according to the invention include the following: 5-chloro-1,2,3,4-tetrahydro-2-oxo-1-[2-oxo-2-(2thienyl)ethyl]-4-pyrimidinesulphonic acid, sodium salt;

5-chloro-1,2,3,4-tetrahydro-1-[2-(4-methylphenyl)¬

2-oxoethyl]-2-oxo-4-pyrimidinesulphonic acid, sodium salt;

5-chloro-1-(1,3-dihydro-1-oxo-2H-inden-2-yl)-1,2,3,4tetrahydro-2-oxo-4-pyrimidinesulphonic acid, sodium salt; and

5-chloro-3-(1,3-dihydro-1-oxo-2H-inden-2-yl)-1,2,3,4tetrahydro-2-oxo-4-pyrimidinesulphonic acid, sodium salt. It will be appreciated that the compounds according to the invention may exist as stereoisomers and/or tautomers and the invention is to be understood to include all such isomers as well as mixtures thereof, including racemates. As indicated above, our tests have shown that the bisulphite adducts of the invention have a metaphase arresting ability. The test we have used to determine this ability is that using a growing culture of L1210 cells as described in European Patent Application Publication No. 87326. The compounds according to the invention are thus of interest in combatting abnormal cell proliferation. Their use is based on the concept of using a drug to arrest the cell-division cycle reversibly in metaphase, so that subsequent treatment with a cytotoxic drug is less indiscriminate in its effects, as discussed in European Patent Application Publication No. 87326. As described therein, it will normally be necessary to have a knowledge of the cell cycle kinetics of both the normal and abnormal cells to be treated, and to employ this to achieve the optimum result in the use of the compounds of the invention. The compounds according to the invention may be formulated for use in the conventional manner, and in a further aspect of the invention we provide pharmaceutical compositions comprising at least one adduct according to the invention together with one or more pharmaceutical carriers or excipients.

The adducts according to the invention may be incorporated into pharmaceutical compositions of either solid or liquid forms. The compositions may, for example, be presented in forms suitable for administration by the rectal, parenteral or topical routes. Preferred forms include, for example suspensions, suppositories, creams, ointments, lotions and solutions, e.g. for injection or infusion. The active ingredient may be incorporated in excipients customarily employed in pharmaceutical compositions such as, for example, talc, gum arabic, lactose, starch, magnesium stearate, cocoa butter, aqueous or non-aqueous vehicles, fatty substances of animal or vegetable origin, paraffin derivatives, glycols, various wetting, dispersing or emulsifying agents and/or preservatives.

Advantageously, the compositions may be formulated as dosage units, each unit being adapted to supply a fixed dose of active ingredient. Suitable dosage units for adult humans contain from 50 mg to 1.0 g of active ingredient. The dosage, which may be varied according to the compound used, the subject treated and the complaint concerned, may, for example, be from 0.25 to 7.0 g in a day in adult humans.

In one aspect of the invention the compositions of the invention may take the form of compositions comprising a compound of formula (I) formulated with an aqueous solution of a physiologically acceptable bisulphite whereby the adduct is formed in situ in the composition. In such cases, it is convenient to use an excess of the physiologically acceptable bisulphite and the formulation of the compound of formula (I) with the bisulphite solution is preferably carried out immediately or shortly before administration of the composition.

In another aspect, the invention provides the use of adducts or compounds of formula II according to the invention (wherein the or any countercation is physiologically acceptable) for the manufacture of a therapeutic agent for use in the treatment of the human or non-human animal body to effect metaphase arrest of cell growth.

In a further aspect , the invention prov ides the use of adducts or compounds of formula II according to the invention (wherein the or any countercation is physiologically acceptable) for the treatment of the human or non-human animal body to effect metaphase arrest of cell growth.

In a st ill further aspect , the invent ion provides a method of treatment of the human or non-human animal body to effect metaphase arrest of cell growth which method comprises administering to said body an effective amount of an adduct or compound of formula II according to the invention (wherein the or any countercation is physiologically acceptable). In another aspect the invention provides a process for the preparation of a pharmaceutical composition comprising admixing an adduct or compound of formula II according to the invention (wherein the or any countercation is physiologically acceptable) with one or more pharmaceutical carriers or diluents. The adducts of the invention may be prepared by bisulphite addition to compounds of formula (I).

In one process, a bisulphite adduct of the invention may be prepared by addition of bisulphite to a pyrimidinone of formula (I), where R and R¹ are as previously defined. The reaction may be effected using a substance providing bisulphite ions, e.g. an appropriate metabisulphite, or sulphite in an aqueous medium such as water or water with a miscible or immiscible co-solvent such as chloroform, dimethylformamide or dioxan optionally in the presence of a phase transfer catalyst such as benzyltrimethylammonium chloride. The reaction may be performed at for example 20° - 100°C, conveniently at 20° - 60°C. In a modifification of this process, where a salt derived from an amine is desired, it may be convenient to react the amine, e.g. dimethylamine, and the appropriate pyrimidinone of formula (I) in the presence of sulphur dioxide in an aqueous medium, as just described. The reaction may be performed at for example ambient temperature.

The preparation of certain of the pyrimidinone starting materials for this process is described in European Patent Applications Publication Nos. 44704 and 44705. Other compounds of formula (I) whose preparation is not specifically disclosed in those publications may be prepared using analogous methods. Certain of these novel compounds, which possess useful metaphase arrest activity and which fall within the scope of the general disclosure of European Patent Applications Publication Nos.44704 and 44705 although not being specifically disclosed therein are valuable as intermediates in the preparation of the adducts of the invention and so form another aspect of the present invention. Thus in a further aspect the present invention provides compounds of formula (III)

(III)

(wherein R' represents a group selected from the following:

(a) 2- (4-methylphenyl)-2-oxoethyl;

(b) 2-oxo-2-(2-thienyl)ethyl; (c) 2-[4-(dimethylamino)phenyl]-2-oxoethyl;

(d) 2-[4-(acetylamino)phenyl]-2-oxoethyl;

(e) 1-methyl-2-oxo-2-phenylethyl;

(f) 1,2-diphenyl-2-oxoethyl; and

(g) 1-methyl-2-oxo-2-(2-thienyl)ethyl, and salts thereof.

Certain further novel compounds falling within the scope of formula (I) posses particularly useful metaphase arrest activity and are particularly valuable as intermediates in the preparation of the adducts of the invention and so form another aspect of the invention. Thus according to this further aspect, the present invention provides compounds of formula (IV)

(IV)

wherein n is an integer having the value 1 or 2;

A represents a C_6-10 carbocylic aromatic group or a carbon-attached heterocyclic group containing a 5- or 6-membered unsaturated heterocyclic ring which ring contains one or more, preferably from 1, 2 or 3, heteroatoms selected from O, N and S and optionally carries a fused carbocyclic ring, which carbocyclic or heterocyclic group may carry one or more substituents selected from halogen atoms, C_1-4 alkyl, C_1-4 alkanoyl, C_1-4 alkoxy,

C_1-4 alkoxycarbonyl, C_1-4 alkylthio, hydroxyl, nitro, cyano and formyl groups, -NR⁴R⁵ groups (where

R⁴ is a hydrogen atom or a C_1-4 alkyl group, and R⁵ is a hydrogen atom or a C_1-4 alkyl, C_1-4 alkanoyl or aroyl group) and C_{1 -4} alkyl groups substituted by one or more hydroxy or -NR⁴R⁵ groups and halogen atoms; and salts thereof.

The metaphase arresting ability of the compounds of formulae (III) and (IV) may be determined using the test described above and the compounds of formulae (III) and (IV) may be formulated for use as previously described for the bisulphite adducts of the invention and in another aspect, the invention accordingly provides pharmaceutical compositions containing at least one compound of formula (III) or (IV) together with one or more pharmaceutical carriers or excipients.

According to another aspect of the invention, we provide a process for the preparation of a compound of formula (IV) as defined above wherein: a compound of the formula (V)

(V)

(wherein R¹ is as hereinbefore defined) or a salt thereof is reacted with an agent or agents serving to introduce the group

This agent may, for example, be a compound of formula (VI)

(VI) (wherein n and A are as hereinbefore defined and

Y represents a leaving atom or group e.g. a halogen atom, a hydroxy group or a reactive ether or ester derivative). A compound of formula (VI) is advantageously used in which Y represents an iodine, bromine or chlor ine atom or a hydrocarbonsulphonyloxy der ivative such as a mesylate, brosylate or tosylate.

The reaction between the compounds of formulae (V) and (VI) is conveniently effected in the presence of a polar solvent such as an alkanol e.g. ethanol or dimethylformamide or a halogenated hydrocarbon such as dichloromethane. The reaction may also conveniently be effected in the presence of a base, e.g. a tertiary organic base such as triethylamine or an inorganic base e.g. an alkali metal hydroxide, such as potassium hydroxide, or an alkali metal carbonate, such as sodium carbonate, in the presence of a phase transfer catalyst such as benzyltrimethylammonium chloride. Where a salt of the compound of formula (V) is used, an added base will not normally be required. Such a salt may, for example, be an alkali metal, e.g. sodium or potassium, salt. The group of formula

may also be introduced by a two stage reaction in which the compound of formula (V) is reacted with an O-silylating agent to form an O-silyl derivative, e.g. a trialkylsilyl ether, followed by reaction with a compound of formula (VI), preferably in the presence of a Lewis acid. The reagent serving to introduce the group

may, as indicated above, also be an alcohol of the formula

In this case the reaction is carried out in the presence of a condensing agent such as an acetal of a C_{1 -5} dialkylformamide e.g. dimethylformamide. The alkyl groups of the acetal are preferably neopentyl groups, thus dimethylformamide dineopentylacetal is a preferred condensing agent.

Alternatively, the compound of formula (VI) may be in the form of an acetal of a C_1-5 dialkylformamide carrying at least one acetal group derived from the alcohol

The intermediate compounds of formula (VI) are either known compounds or may be prepared by methods amalogous to those used for the preparation of the known compounds.

The following non-limiting Examples are provided to illustrate the invention. Example 1

5-Chloro-1,2,3,4-tetrahydro-1-[2-(4-methylphenyl)2-oxoethyl]-2-oxo-4-pyrimidinesulphonic acid, compound with 1,2-ethanediamine (2:1)

5-Chloro-1-[2-(4-methylphenyl)-2-oxoethyl]2(1H)-pyrimidinone (263 mg) was added to a stirred solution of 1,2-ethylenediamine sulphite (210 mg) in water (22 ml) and the resulting suspension was sealed under nitrogen and stirred at ambient temperature, After 2.75 hours the suspension was cooled in an ice-bath. The solid was then collected, washed with water and dried in vacuo at ambient temperature to give white crystals, the title amine bisulphite salt (338 mg) m.p. 218-225°C (decomp.), λ_max (EtOH) 254 nm (ε 38,760), 332.5 nm (ε 5,200).

Example 2 5-Chloro-1,2,3,4-tetrahydro-2-oxo-1-[2-oxo-2-(2thienyl)ethyl]-4-pyrimidinesulphonic acid, compound with 1,2-ethanediamine (2:1)

5-Chloro-1-[2-oxo-2-(2-thienyl)ethyl]-2(1H)pyrimidinone (178 mg) was added to a solution of 1,2-ethylenediamine sulphite (147 mg) in water (4.2 ml) and the resultant suspension was sealed under nitrogen and stirred at ambient temperature. After 1.5 hours the reaction mixture was cooled in an ice-bath and then after 2 hours the solid was collected, washed with water and dried in vacuo at ambient temperature to give the title amine bisulphite (200 mg), m.p. 164-174°C (decomp.), λ_max (EtOH) 261 nm (ε 29,690). Example 3

5-Chloro-1,2,3,4-tetrahydro-2-oxo-1-(2-oxo-2-phenylethyl)-

4-pyrimidinesulphonic acid, sodium salt

A suspension of 5-chlofo-1-(2-oxo-2-phenylethyl)2(1H)-pyrimidinone (1.110 g) in water (50 ml) was treated with a 0.375 M solution of sodium metabisulphite in water (9 ml), then stirred and heated at ca 50°C. After 19 hours the suspension was cooled, diluted with water (200 ml), then filtered. Concentration of the filtrate caused crystallisation of the product, which was collected by filtration, washed with water and dried in vacuo to give the hydrated title pyrimidine salt (763 mg); m.p. 199-200°C (dec); λ_max (EtOH) 243.5 nm (ε 15,520), λ_inf 264 nm (ε 7,440).

Example 4

5-Chloro-1,2,3,4-tetrahydro-1-[2-(4-methylphenyl)2-oxoethyl]-2-oxo-4-pyrimidinesulphonic acid, sodium salt

A suspension of 5-chloro-1-[2-(4-methylphenyl)2-oxoethyl]-2(1H)-pyrimidinone (657 mg) in 0.375M aqueous sodium metabisulphite solution (5 ml) was stirred at ca 50°C, then gradually diluted with water (50 ml), under a nitrogen atmosphere. After 1.25 hours the resulting suspension was filtered. The filtrate was chilled in ice causing crystallisation of the product. This was collected by filtration, washed with water and dried in vacuo to give the hydrated title pyrimidine salt (353 mg); m.p. 205-208°C (dec); λ_max (EtOH) 254.5 nm (ε 20,530), 332.5 nm (ε 1,270). Example 5

5-Chloro-[2-[4-(dimethylamino)phenyl]-2-oxoethyl]1,2,3,4-tetrahydro-2-oxo-4-pyrimidinesulphonic acid, sodium salt

a) 5-Chloro-1- 2-[4-(dimethylamino)phenyl]-2-oxoethyl]2(1H)-pyrimidinone

A stirred suspension of 5-chloro-2(1H)-pyrimidinone (404 mg)and 2-bromo-1-[4-(dimethylamino)phenyl]ethanone (730 mg) in triethylamine (1 ml) and ethanol (20 ml) was stirred at ambient temperature for 2 hours, when solvents were removed by evaporation. The residue was treated with water (50 ml). The collected solid was crystallised from ethanol, and the resulting solid was washed with hot ethyl acetate then dried in vacuo to give the title pyrimidinone (492 mg); m.p. 240-245°C; λ_max (EtOH) 228 nm (ε 14,030), 341 nm (ε 32,040).

b) 5-Chloro-1-[2-[4-(dimethylamino)phenyl]-2-oxoethyl]1,2,3,4-tetrahydro-2-oxo-4-pyrimidinesulphonic acid, sodium salt

A stirred solution of 5-chloro-1-[2-[4-(dimethylamino) phenyl]-2-oxoethyl]-2(1H)-pyrimidinone (271 mg) in dimethylformamide (6 ml) was treated with 0.25M aqueous sodium metabisulphite (3 ml), then warmed to ca 50°C. After 2 hours solvents were removed by evaporation and the residue was triturated with water. The resulting solid was collected by filtration, washed with water and dried in vacuo to give the hydrated title pyrimidine salt (207 mg); m.p. 231¬

240°C; λ_max (EtOH) 243 nm (ε 8,410), 335 nm (ε 29,470). Example 6

1-[2-[4-(Acetylamino)phenyl]-2-oxoethyl]-5-chloro1,2,3,4-tetrahydro-2-oxo-4-pyrimidinesulphonic acid, sodium salt

a) 1-[2-[4-(Acetylamino)phenyl]-2-oxoethyl]-5-chloro2(1H)-pyrimidinone

A suspension of 5-chloro-2(1H)-pyrimidinone (410 mg) and 1-[4-(acetylamino)phenyl]-2-bromoethanone (776 mg) in triethylamine (1 ml) and ethanol (20 ml) was stirred at ambient temperature for 1.5 hours, then diluted with dimethylformamide (10 ml). After 4.5 hours the resulting suspension was heated to reflux for 2.5 hours then left to cool overnight. Water (100 ml) was added, giving a precipitate. This was collected by filtration, washed with hot glacial acetic acid, then dried in vacuo to give the title pyrimidinone (673 mg); m.p. 313-315°C; λ_max (EtOH) 222-5 nm (ε 17,560), 292.5 nm (ε 22,900).

b) 1-[2-[4-(Acetylamino)phenyl]-2-oxoethyl]-5chloro-1,2,3,4-tetrahydro-2-oxo-4-pyrimidinesulphonic acid, sodium salt

A suspension of 1-[2-[4-(acetylamino)phenyl]2-oxoethyl]-5-chloro-2(1H)-pyrimidinone (301 mg) in water (10 ml) was stirred at ca 50°C and treated with 0.25M aqueous sodium metabisulphite solution (3 ml). The mixture was diluted with water (100 ml). After 2 hours the suspension was filtered. The filtrate was evaporated to give the title pyrimidine salt (155 mg); m.p. 285-295°C (dec); λ_max (pH 6 buffer) 291.5 nm 677). Example 7

5-Chloro-1,2,3,4-tetrahydro-1-(1-methyl-2-oxo-2phenylethyl)-2-oxo-4-pyrimidinesulphonic acid, sodium salt

A solution of 5-chloro-1-(1-methyl-2-oxo2-phenylethyl)-2(1H)-pyrimidinone (109 mg) in purified dioxan (5 ml) was stirred at ambient temperature and treated with 0.501M aqueous sodium metabisulphite solution (0.8 ml). After 5 minutes water (5 ml) was added, and the resulting mixture was filtered. The filtrate was freeze-dried to give the title pyrimidine salt (193 mg); m.p. 132-134°C; λ_max (EtOH) 248.5 nm ( 299), 264 nm 180).

Example 8

5-Chloro-1-(1,2-diphenyl-2-oxoethyl)-1,2,3,4-tetrahydro¬

2-oxo-4-pyrimidinesulphonic acid, sodium salt

A solution of 5-chloro-1-(1,2-diphenyl-2oxoethyl)-2(1H)-pyrimidinone (191 mg) in purified dioxan (5 ml) was stirred at ambient temperature and treated with 0.501M aqueous sodium metabisulphite solution (1.2 ml). After 30 minutes water (5 ml) was added, and the resulting mixture was filtered. The filtrate was freeze-dried to give the title pyrimidine salt (307 mg); m.p. 140-144°C; λ_{ma x} (EtOH) 250.5 nm (E£ 334), λ_inf 255 nm 316), 262 nm ( J 245), 269 nm ( ^ 165).

Example 9

5-Chloro-1-(1,3-dihydro-1-oxo-2H-inden-2-yl)-2(1H)pyrimidinone

A solution of 5-chloro-2(1H)-pyrimidinone (410 mg) and 2-bromo-1-indanone (635 mg) in triethylamine (1 ml) and ethanol (20 ml) was stirred at ambient temperature for 1 hour, then heated at reflux for 2 hours. The resulting suspension was cooled, concentrated, then partitioned between water (50 ml) and ethyl acetate (150 ml). The organic solution was dried over magnesium sulphate then evaporated to a solid. This was crystallised from ethyl acetate to give the title pyrimidinone (231 mg); m.p. 228231°C; λ_max (EtOH) 246 nm (ε 17,430), 294 nm (ε 3,170),

335 nm (ε 2,010).

Example 10

5-Chloro-1-(1,3-dihydro-1-oxo-2H-inden-2-yl)-1,2,3,4tetrahydro-2-oxo-4-pyrimidinesulphonic acid, sodium salt and 5-chloro-3-(1,3-dihydro-1-oxo-2H-inden2-yl)-1,2,3,4-tetrahydro-2-oxo-4-pyrimidinesulphonic acid, sodium salt

A solution of 5-chloro-1-(1,3-dihydro-1-oxo2H-inden-2-yl)-2(1H)-pyrimidinone (63 mg) in purified dioxan (6.3 ml) was stirred at ambient temperature and treated with 0.501M aqueous sodium metabisulphite solution (0.48 ml). After 30 minutes, water (8 ml) was added, and the resulting mixture was filtered. The filtrate was freeze-dried to give a solid (117 mg), a mixture of mainly the former title pyrimidine salt and a small amount of the latter title pyrimidine salt; m.p. ca 160°C; λ_{ma x} (EtOH) 247.5 nm ( X 315), λ_inf 270 nm 131)_' 292.5 nm 69).

Example 11 5-Chloro-1,2,3,4-tetrahydro-2-oxo-1-[2-oxo-2-(2thienyl)ethyl]-4-pyrimidinesulphonic acid, sodium salt

A stirred suspension of 5-chloro-1-[2-oxo2-(2-thienyl)ethyl]-2(1H)-pyrimidinone (891 mg) in water (35 ml) was treated with 0.375M aqueous sodium metabisulphite solution (7 ml) then heated at ca 50°C under a nitrogen atmosphere. After 10 minutes, more water (15 ml) was added. After 1.25 hours the resulting mixture was filtered. The filtrate was concentrated, then chilled in ice, causing crystallisation of the product. This was collected by filtration, washed with water and dried in vacuo to give the hydrated title pyrimidine salt (264 mg); m.p. 195-198°C (dec); λ_max (EtOH)

227 nm (ε 6,550), 260.5 nm (ε 13,360).

Example 12

5-Chloro-1,2,3,4-tetrahydro-1-[1-methyl-2-oxo-2(2-thienyl)ethyl]-2-oxo-4-pyrimidinesulphonic acid, sodium salt

A solution of 5-chloro-1-[1-methyl-2-oxo2-(2-thienyl)ethyl]-2(1H)-pyrimidinone (144 mg) in purified dioxan (5 ml) was stirred at ambient temperature and treated with 0.501M aqueous sodium metabisulphite solution (1.1 ml). After 30 minutes, water (8 ml) was added, and the resulting mixture was filtered. The filtrate was freeze-dried to give the title pyrimidine salt (258 mg); m.p. 141144°C; λ_max (EtOH) 264 nm * 308), λ _inf 282.5 nm * 212).

Example 13

5-Chloro-1-(4,5,6,7-tetrahydro-4-oxo-5-benzo[b]thiophenyl)

2(1H)-pyrimidinone

A mixture of 5-chloro-2(1H)-pyrimidinone (1.565 g) and 5-bromo-4,5,6,7-tetrahydro-4-oxobenzo[b]thiophene (2.91 g) in triethylamine (2.52 ml) and ethanol (50 ml) was stirred at ambient temperature for 4 days, then at 60°C for 1 day. The resulting mixture was concentrated, then diluted with ethyl acetate and filtered. The filtrate was evaporated to an oil. This was purified by column chromatography on silica, then crystallised twice from ethyl acetate to give the title pyrimidinone (220 mg); m.p. 161165°C (dec); λ_{ma x} (EtOH) 224 nm (ε 24,400), 254 nm

(ε 13,200), 334.5 nm (ε 4,700).

Example 14

5-Chloro-1,2,3,4-tetrahydro-2-oxo-1-(4,5,6,7-tetrahydro4-oxo-5-benzo[b]thiophenyl)-4-pyrimidinesulphonic acid, sodium salt and 5-chloro-1,2,3,4-tetrahydro2-oxo-3-(4,5,6,7-tetrahydro-4-oxo-5-benzo[b]thiophenyl)4-pyrimidinesulphonic acid, sodium salt

A solution of 5-chloro-1-(4,5,6,7-tetrahydro4-oxo-5-benzo[b]thiophenyl)-2(1H)-pyrimidinone (83 mg) in purified dioxan (5 ml) was stirred at ambient temperature and treated with 0.501M aqueous sodium metabisulphite solution (0.6 ml). After 30 minutes water (8 ml) was added, and the resulting mixture was filtered. The filtrate was freezedried to give a solid (152 mg), a mixture of mainly the former title pyrimidine salt and a trace of the latter t itle pyr imidine salt ; m. p . 158-160°C; λ_max (EtOH) 254 nm ( 320)_' λ_inf 270 nm ( 183).

Example 15 5-Chloro-1,2,3,4-tetrahydro-1-[2-(4-methyl-5-thiazolyl)2-oxoethyl]-2-oxo-4-pyrimidinesulphonic acid, sodium salt and 5-chloro-1,2,3,4-tetrahydro-3-[2-(4-methyl5-thiazolyl)-2-oxoethyl]-2-oxo-4-pyrimidinesulphonic acid, sodium salt

a) A suspension of 5-chloro-1-[2-(4-methyl-5thiazolyl)-2-oxoethyl]-2(1H)-pyrimidinone (270 mg) in 0.375M sodium metabisulphite solution (2 ml) was stirred at ca 50°C under a nitrogen atmosphere. After 5 minutes the resulting solution was filtered. The filtrate was concentrated, then chilled in ice, giving a precipitate. This was collected by centrifugation then twice crystallised from water to give a solid (174 mg), a mixture (10:1, by p.m.r.) of the two title pyrimidine salts; m.p. 174-180°C (dec); λ_max (EtOH) 267.5 nm ( 341). b) A suspension of 5-chloro-1-[2-(4-methyl-5thiazolyl)-2-oxoethyl]-2(1H)-pyrimidinone (234 mg) in 0.25M sodium metabisulphite solution (1.74ml) was stirred at ca 50°C. After 3 minutes the resulting mixture was filtered. The filtrate was freezedried to give a solid (325 mg), a mixture (2:1 by p.m.r.) of the two hydrated title pyrimidine salts; m.p. 160-190°C (dec); λ_max (EtOH) 267 nm 369). Example 16

5-Chloro-1,2,3,4-tetrahydro-1-[2-(4-methylphenyl)2-oxoethyl]-2-oxo-4-pyrimidinesulphonic acid, compound with N-methylmethanamine

5-Chloro-1-[2-(4-methylphenyl)-2-oxoethyl]2(1H)-pyrimidinone (131 mg) was added to a solution of 25-30% dimethylamine in water (0.45 ml) in water (14 ml) and the resulting suspension was then rapidly stirred while sulphur dioxide was passed through. After 10 minutes most of the solid had dissolved and the flow of sulphur dioxide was stopped. After 20 minutes the reaction mixture was filtered and evaporated to dryness. The residue was triturated with ethanol, the solid collected, washed with ethanol and dried in vacuo at ambient temperature to give the title amine bisulphite (116 mg); m.p. 214-216°C; λ_max (EtOH) 255 nm (ε 20,580), 330 nm (ε 700).

Claims

CLAIMS :

1. Compounds being bisulphite adducts of compounds of formula I

(I)

wherein R represents a group

R¹ represents a halogen atom or a trifluoromethyl group; R² represents a hydrogen atom or a C_1-4 alkyl,

C_6-10 aryl or benzoyl group;

R³ represents a hydrogen atom or, together with R², represents a -CH₂- or -CH₂-CH₂- chain; and represents a C_6-10 carbocyclic aromatic group or a carbon-attached heterocyclic group containing a 5- or 6- membered unsaturated heterocyclic ring which ring contains one or more heteroatoms selected from O, N and S and optionally carries a fused carbocyclic ring, which carbocyclic or heterocyclic group may carry one or more substituents selected from halogen atoms, C_1-4 alkyl, C_1-4 alkanoyl, C_{1 -4} alkoxy, C_1-4 alkoxycarbonyl, C_1-4 alkylthio, hydroxyl, nitro, cyano and formyl groups, -NR⁴R⁵ groups (where R⁴ is a hydrogen atom or a C_{1 -4} alkyl group, and R⁵ is a hydrogen atom or a C_{1 -4} alkyl,

C_1-4 alkanoyl or aroyl group) and C_{1 -4} alkyl groups substituted by one or more hydroxy or -NR⁴R⁵ groups and halogen atoms; and salts of such adducts.

2 . Compounds of formula II

(II)

(wherein X represents the group

M represents a cation; and R and R¹ are as defined in claim 1).

3. Compounds as claimed in claim 2 of formula (Ila)

(Ila)

(wherein M, R and R¹ are as defined in claim 2).

4. Compounds as claimed in either of claims 2 and 3 wherein M represents a sodium, potassium, calcium, magnesium, ammonium, ethylenediammonium or tri (C_1-4alkyl)ammonium ion.

5. Compounds as claimed in any one of claims 1 to 4 wherein R² represents a hydrogen atom or a methyl, ethyl, phenyl or benzoyl group and the C_6-10 carboxylic aromatic group within the definition of ring A is an optionally substituted phenyl or naphthyl group or an optionally substituted 5 or 6 membered heterocyclic ring having one, two or three heteroatoms.

6. Compounds as claimed in any one of the preceding claims wherein R represents a group of formula

in which R² represents a hydrogen atom or a methyl or phenyl group.

7. A pharmaceutical composition comprising an effective amount of a compound as claimed in any one of the preceding claims (wherein the or any countercation is a physiologically acceptable cation) together with one or more pharmaceutical carriers or excipients.

8. A pharmaceutical composition comprising an effective amount of a compound of formula I (as defined in claim 1), or a physiologically acceptable addition salt thereof, formulated with an aqueous solution of a physiologically acceptable bisulphite ion providing substance.

9. A process for the preparation of compounds as claimed in any one of claims 1 to 6 comprising bisulphite addition to a compound of formula I (as defined in claim 1).

10. A process as claimed in claim 9 comprising reacting said compound of formula I with a bisulphite ion providing substance in an aqueous medium, optionally in the presence of a phase transfer catalyst.

11. The use of compounds as claimed in any of claims 1 to 6 (wherein the or any counter cation is physiologically acceptable) for the manufacture of a therapeutic agent for use in the treatment of the human or non-human animal body to effect metaphase arrest of cell growth.

12. The use of compounds as claimed in any of claims 1 to 6 (wherein the or any counter cation is physiologically acceptable) for the treatment of the human or non-human animal body to effect metaphase arrest of cell growth.

13. A method of treatment of the human or nonhuman animal body to effect metaphase arrest of cell growth which method comprises administering to said body an effective amount of a compound as claimed in any of claims 1 to 6 (wherein the or any counter cation is physiologically acceptable).

14. Compounds of formula (IV)

(IV)

wherein n is an integer having the value 1 or 2;

A represents a C₆_₁₀ carbocylic aromatic group or a carbon-attached heterocyclic group containing a 5- or 6-membered unsaturated heterocyclic ring which ring contains one or more, preferably 1, 2 or 3, heteroatoms selected from O, N and S and optionally carries a fused carbocyclic ring, which carbocyclic or heterocyclic group may carry one or more substituents selected from halogen atoms, C₁_₄ alkyl, C_{1 -4} alkanoyl, C₁_₄ alkoxy,

C_1-4 alkoxycarbonyl, C_{1 -4} alkylthio, hydroxyl, nitro, cyano and formyl groups, -NR⁴R⁵ groups (where R⁴ is a hydrogen atom or a C_1-4 alkyl group, and

R⁴ is a hydrogen atom or a C₁_₄ alkyl, C_{1 -4} alkanoyl or aroyl group) and C_{1 -4} alkyl groups substituted by one or more hydroxy or -NR⁴R⁵ groups and halogen atoms; and salts thereof.

15. A process for the preparation of a compound of formula (IV) as claimed in claim 14 wherein a compound of the formula (V)

(V)

(wherein R¹ is as hereinbefore defined) or a salt thereof is reacted with an agent or agents serving to introduce the group

L