IE910287A1 - Therapeutic agents - Google Patents

Abstract

Compounds of formula (I), in which R1 represents hydrogen, cyano, C2-6 alkanoyl, C2-6 alkoxycarbonyl, CONH2, or R1 represents C1-6 alkyl or C2-6 alkenyl both of which may be substituted by cyano, halo, trifluoromethyl, hydroxy, benzoyl, C2-6 alkanoyloxy, C3-8 cycloalkoxycarbonyl, a 5-7 membered non-aromatic heterocyclic group containing 2 oxygen heteroatoms, CONR9R9', phenoxy or C1-6 alkoxy, in which C1-6 alkoxy may be further substituted by halo, hydroxy, C1-6 alkoxy or C2-6 alkanoyloxy; R2 represents hydrogen or chloro; R3 represents chloro or trifluoromethyl; or R2 and R3 are joined to form a fused benz ring; R4 represents hydrogen, C1-6 alkyl, C1-6 alkoxy or halo; R9 and R9', which may be the same or different represent hydrogen, C1-6 alkyl or benzyl, for use as immunomodulatory agents.

Description

THERAPEUTIC AGENTS The present invention relates to novel therapeutic agents, and in particular to [1]benzopyrano[4,3-c]pyrazoles, to processes for their preparation, to pharmaceutical compositions containing them and to their therapeutic activity as immunomodulatory agents.

The present invention relates to novel compounds of formula I in which R. represents hydrogen, cyano, C alkanoyl·, C? 6 alkoxycarbonyl, CONH^, or R^ represents C-|_g alkyl or C_ . alkenyl both of which may be substituted by 2 —o cyano, halo, trifluoromethyl, hydroxy, benzoyl, C2-6 alkanoyloxy, C_ _ cycloalkoxycarbonyl, a 5-7 membered non-aromatic heterocyclic group containing 2 oxygen heteroatoms, CONR^R^,, phenoxy or alkoxy, in which C- c alkoxy may be further substituted by halo, 1 “6 hydroxy, alkoxy or C2-6 alkanoyloxy; R2 represents hydrogen or chloro; Rg represents chloro or trifluoromethyl; or R2 and Rg are joined to form a fused benz ring; R. represents hydrogen, C., c alkyl, C. _ alkoxy or l—o I — b halo; Rg and Rg, , which may be the same or different, represent hydrogen, C^_g alkyl or benzyl, or pharmaceutically acceptable salts thereof.

It will be understood that a group containing a 5 chain of 3 or more carbon atoms may be straight or branched, for example propyl includes n-propyl and isopropyl, and butyl includes n-butyl, sec-butyl, isobutyl and tert-butyl♦ The term halo” includes fluoro, chloro or bromo.

Preferably R1 represents hydrogen, cyano, carbamoyl, c2_4 alkanoyl (for example acetyl), c2_4 alkoxycarbonyl (for example methoxycarbonyl or ethoxycarbonyl), or -CH2R-|q in which R^o represents hydrogen, cyano, trifluoro15 methyl, halo, hydroxy, C3_g cycloalkoxycarbonyl (preferably cyclobutoxycarbonyl), benzoyl, CONHRg (for example carbamoyl, methylcarbamoyl, ethylcarbamoyl or propyIcarbamoyl) or a 5-7 membered non-aromatic heterocyclic group containing two oxygen heteroatoms (for example 1,3-dioxolan-2-yl or 1,3-dioxan-2-yl; or R represents 4 alkyl, (for example methyl, ethyl or propyl, more preferably methyl or ethyl) or C2-4 alkenyl (for example vinyl) both optionally substituted with hydroxy, cyano, trifluoromethyl, halo (preferably chloro or bromo), C1-g alkoxy ^(preferably methoxy or ethoxy), C-j _galkoxy (C^ _g) alkoxy (preferably 2-methoxyethoxy), C2_galkanoyloxy(C^_g)alkoxy (preferably acetoxyethoxy), hydroxy(C^_g alkoxy) (preferably 2-hydroxyethoxy), C2-6 alkanoyloxy (preferably acetoxy or propionyloxy), phenoxy, benzoyl, CONHRg (for example carbamoyl, methylcarbamoyl, IE 91287 ethylcarbamoyl or propylcarbamoyl) or a 5-7 membered non-aromatic heterocyclic group containing two oxygen heteroatoms (for example 1,3-dioxolan-2-yl or 1,3-dioxan-2-yl).

In preferred compounds, represents (CH2)pJ in which J represents hydrogen, Ci_6 alkoxy, cyano, halo or carbamoyl, and p is 0, 1 or 2, particularly hydrogen, methyl, cyanomethyl, (CH2)2halo, carbamoylmethyl or C1__4 alkoxyethyl.

Preferred substituents are hydrogen, methyl, ethyl, propyl, butyl, allyl, 2-methoxyethyl, 2-ethoxyethyl, 2-ethoxypropyl, 2-(2-methoxyethoxy)ethyl 2-(2-acetoxyethoxy)ethyl, 2-(2-hydroxyethoxy)ethyl cyclobutyloxycarbonylmethyl, carbamoyl, methylcarbamoylmethyl, 2-carbamoylethyl,3-carbamoylpropyl ethylcarbamoylmethyl, propylcarbamoylmethyl, isopropylcarbamoylmethyl, benzyl(methyl)carbamoylmethy1, carbamoylmethyl, 2-hydroxyethyl, 3-hydroxypropyl 2-acetoxyethyl, cyano, cyanomethyl, 2-cyanoethyl, 2-phenoxyethyl, 2-chloroethyl, 2-bromoethyl, 2,2,2-trifluoroethyl 2-propionyloxyethyl, 1,3-dioxolan-2-ylmethyl, 2-(1,3-dioxan-2-yl)ethyl, z 2-(1,3-dioxolan-2-yl)ethyl, acetyl, benzoylmethyl, ethoxycarbonyl.

In especially preferred compounds represents methyl or 2-ethoxyethyl.

In preferred compounds of formula I, R2 represents hydrogen.

IE 91287 In preferred compounds of formula I, Rg represents chloro or trifluoromethyl, more preferably trifluoromethyl.

In preferred compounds of formula I, R4 represents 5 hydrogen, C^_4 alkyl, Cq_4 alkoxy, fluoro, chloro, or bromo. More preferably R4 represents hydrogen, methyl, methoxy or ethoxy most preferably hydrogen or methoxy.

Preferably Rg represents hydrogen, methyl or ethyl or benzyl, especially hydrogen or methyl.

Preferably Rg, represents hydrogen or benzyl.

Particular compounds of formula I are the compounds listed in Table A provided in the specific Examples of the invention, or pharmaceutically acceptable salts thereof.

Compounds of formula I may contain one or more chiral centres and exist in different optically active forms. When compounds of formula I contain one chiral centre the compounds exist in two enantiomeric forms and the present invention includes both enantiomers and mixtures of enantiomers. The enantiomers may be resolved by methods known to those skilled in the art, for example by formation of diastereoisomeric salts or complexes which may be separated, for example, by crystallisation; formation zof diastereoisomeric derivatives which may be separated, for example, by crystallisation, gas-liquid or liquid chromatography; selective derivatisation of one enantiomer by reaction with an enantiomer-specific reagent, for example enzymatic oxidation or reduction; or gas-liquid or liquid chromatography in a chiral environment, for IE 91287 - 5 example on a chiral support, for example silica with a bound chiral ligand or in the presence of a chiral solvent. Alternatively, specific enantiomers may be synthesised by asymmetric synthesis using optically active reagents, substrates, catalysts or solvents, or by converting one enantiomer into the other by asymmetric transformation.

For example, the following compound may also exist in the R- or S- enantiomeric form: 4-(4-chlorophenyl)-2-(2-ethoxypropyl) [1J benzopyrano[4,3-c]pyrazol-3(2H)-one.

When compounds of formula I contain more than one chiral centre, the compounds may exist in diastereoisomeric forms. The present invention includes each diastereoisomer and mixtures of the diastereoisomers. The diastereoisomers may be separated by methods known to those skilled in the art, for example by crystallisation or liquid chromatography.

Certain compounds of formula I may exist in different tautomeric forms or as different geometric isomers.

Certain compounds of formula I may exist in more than one crystal form and Jthe present invention includes each crystal form and mixtures thereof.

IE 91287 Certain compounds of formula I may also exist in the form of solvates, for example hydrates, and the present invention includes each solvate and mixtures thereof.

The present invention also includes pharmaceutical compositions containing a therapeutically effective amount of a compound of formula I together with a pharmaceutically acceptable diluent or carrier.

As used hereinafter, the term active compound 10 denotes a [1]benzopyrano[4,3-c]pyrazole of formula I. In therapeutic use, the active compound may be administered orally, rectally, parenterally or topically, preferably orally or topically. Thus the therapeutic compositions of the present invention take the form of any of the known pharmaceutical compositions for oral, rectal, parenteral or topical administration. Pharmaceutically acceptable carriers suitable for use in such compositions are well known in the art of pharmacy. The compositions of the invention may contain 0.1-90% by weight of active compound. The compositions of the invention are generally prepared in unit dosage form. The excipients used in the preparation of these compositions are the excipients known in the pharmacist's art.

Compositions for oral administration are preferred compositions of the invention, and these are known pharmaceutical forms for such administration, for example tablets, capsules, syrups and aqueous or oily suspensions. Tablets may be prepared by mixing the active compound with an inert diluent such as lactose IE 91287 - 7 or calcium phosphate in the presence of disintegrating agents, for example maize starch, and lubricating agents, for example magnesium stearate, and tableting the mixture by known methods. The tablets may be formulated in a manner known to those skilled in the art so as to give a sustained release of the compounds of the present invention. Such tablets may, if desired, be provided with enteric coatings by known methods, for example by the use of cellulose acetate phthalate. Similarly, capsules, for example hard or soft gelatin capsules, containing the active compound with or without added excipients, may be prepared by conventional means and, if desired, provided with enteric coatings in a known manner. The tablets and capsules may conveniently each contain 0.1 to 500 mg of the active compound. Other compositions for oral administration include, for example, aqueous suspensions containing the active compound in an aqueous medium in the presence of a non-toxic suspending agent such as sodium carboxymethylcellulose, and oily suspensions containing a compound of the present invention in a suitable vegetable oil, for example arachis oil.

Compositions for topical administration are also preferred compositions of the invention. The pharmaceutically active compound may be dispersed in a pharmaceutically acceptable cream, ointment or gel. A suitable cream may be prepare^ by incorporating the active compound in a topical vehicle such as petrolatum and/or light liquid paraffin, dispersed in an aqueous medium using surfactants. An ointment may be prepared by mixing the active compound with a topical vehicle such as a mineral oil, petrolatum and/or a wax e.g. paraffin wax or beeswax. A gel may be prepared by mixing the active compound with a topical vehicle, comprising a gelling agent e.g. basified Carbomer BP, in the presence of water. Topically administrable compositions may also comprise a matrix in which the pharmaceutically active compounds of the present invention are dispersed so that the compounds are held in contact with the skin in order to administer the compounds transdermally. A suitable transdermal composition may be prepared by mixing the pharmaceutically active compound with a topical vehicle, such as described above, together with a potential transdermal accelerant such as dimethyl sulphoxide or propylene glycol.

Compositions of the invention suitable for rectal administration are known pharmaceutical forms for such administration, for example suppositories with semi-synthetic glycerides or polyethylene glycol bases.

Compositions of the invention suitable for parenteral administration are known pharmaceutical forms for such administration, for example sterile suspensions in aqueous and oily media or sterile solutions in a suitable solvent.

In some formulations it may be beneficial to use the compounds of the present invention in the form of particles of very small size, for example as obtained by fluid energy milling.

In the compositions of thq present invention the active compound may, if desired, be associated with other compatible pharmacologically active ingredients.

The compounds of formula I are indicated for use as immunomodulatory agents, and are generally immunosuppressants, but some compounds, in certain disease states, may exhibit immunostimulant activity.

The compounds according to the invention are useful in IE 91287 - 9 the treatment of diseases resulting from an aberrant immune reaction. Thus the pharmaceutical compositions containing a therapeutically effective amount of a compound of formula I may be used to treat diseases with an immunological association for example tissue rejection, such as kidney rejection; autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus; cutaneous disorders, such as contact sensitivity, eczema and psoriasis; and neoplasia, such as melanoma.

In such treatment the amount of the compound of formula I administered per day will be such as to give a therapeutic effect and is generally in the range 0.1 to 2000 mg, preferably 1 to 500 mg.

Accordingly, in another aspect, the present invention also includes a method of treating diseases with an immunological association, comprising the administration of a therapeutically effective amount of a compound of formula I.

The therapeutic activity of compounds of formula I has been demonstrated by means of tests on standard laboratory animals. Such tests include, for example, the oral and parenteral administration of the compounds to BALB/c mice. Thus, compounds of formula I are useful as immunomodulatory agents. Whilst the precise amount of active compound administered will depend on a number of factors, for example the age of the patient, the severity of the condition and the past medical history and always lies within the sound discretion of the administering physician, a suitable dose for oral administration to mammals, including humans, is generally within the range 0.01-40 mg/kg/day, more usually 0.2-25 mg/kg/day given in single or divided doses. For parenteral administration, a suitable dose is generally within the range 0.001-4.0 mg/kg/day, more usually 0.005-1 mg/kg/day given in single or divided doses or by continuous infusion. A suitable preparation for topical administration generally contains the active ingredient within the range 0.01-20% by weight, more usually 0.05-5% by weight. Oral administration is preferred.

Processes for the preparation of compounds of formula I will now be described. These processes form a further aspect of the present invention.

Compounds of formula I may be prepared by reacting a compound of formula II, or a tautomer thereof with a compound of formula III in which 4 represents (OQ)2 or (SQ)2and R]5 represents OQ or SQ or NQ* 2? R-j 4 represents = NH and represents OQ or SQ? or R^ 4 represents = 0 and represents hydrogen, halo or 1-imidazolyl; and Q and represent a C^_4 alkyl group or a benzyl group.

Compounds of formula I may be prepared by reacting compounds of formula IV in which R^ g represents hydrogen, or a tautomer thereof, or in which R^ g represents a group COR·] θ wherein R^ θ represents hydrogen, a C^_4 alkyl group, a benzyl group or a group Rg and R^ ? represents CORg in which Rg represents Ilia R 2' «3 Ilia with a base e.g. piperidine in a suitable solvent e.g ethanol. , Compounds of formula I may be prepared by reacting compounds of formula IV in which R^ and R^ g represent COR. o and R, -. represents hydrogen with a carboxylic acid chloride for example a substituted benzoyl chloride in the presence of a base for example triethylamine followed by heating in the presence of a base for example piperidine.

Compounds of formula I in which represents an alkyl group or alkenyl group substituted as herein described may be prepared by alkylating corresponding compounds of formula I in which R^ represents hydrogen, for example by reaction with a compound of formula R^X in which X represents halo in the presence of a base e.g. sodium hydride.

Compounds of formula I in which R^ represents C2_g alkanoyl may be prepared by acylation of corresponding compounds of formula I in which R^ represents hydrogen, for example by reaction with an acyl halide.

Compounds of formula I in which represents cyano may be prepared by cyanation of corresponding compounds of formula I in which R^ represents hydrogen, for example by reaction with cyanogen bromide in the presence of a base, for example sodium hydride.

Compounds of formula I in which R^ represents c2_g alkoxycarbonyl may be prepared by the substitution of corresponding compounds of formula I in which R^ represents hydrogen with a C2_g alkoxycarbonyl group, for example by reaction with compounds of formula alkoxycarbonyl)A where A is a leaving group, for example cyano or halo.

Compounds of formula I in which R^ represents carbamoylalkyl, e.g. carbamoyImethyl, may be prepared by the hydrolysis of corresponding compounds of formula I in which R-| represents cyanoalkyl, e.g. cyanomethyl.

Compounds of formula I in which R^ represents CONHR30 in which R3Q represents a readily hydrolysable group for example chlorosulphonyl, may be prepared by reacting corresponding compounds of formula I in which represents hydrogen with an isocyanate of - 13 IE 91287 formula RggN=C=O. Compounds of formula I in which R^ represents carbamoyl may be prepared by hydrolysis, for example acid hydrolysis, of corresponding compounds of formula I in which R^ represents CONHRgg.

Compounds of formula I in which R^ is substituted by a carboxylic amide group (CONRgRg,) may be prepared by reacting corresponding compounds of formula I substituted by a group -COA where A represents a leaving group for example, hydroxyl, halo, alkoxy, aryloxy, arylmethoxy or C^_g acyloxy with a C^_g alcohol or amine (HNRgRg,) respectively, for example at 0-250°C, optionally in the presence of an organic liquid which is preferably a solvent for the reactants and optionally in the presence of a catalyst for the reaction.

Compounds of formula I in which R^ represents a group substituted by a hydroxyl group may be prepared by the hydrolysis of corresponding compounds of formula substituted by a C2_g alkanoyloxy group, for example acetoxy.

Compounds of formula I in which R^ is substituted by a C. , alkanoyloxy group may be prepared by acylation of corresponding compounds of formula I substituted by a hydroxy group. z Compounds of formula II may be prepared by reacting compounds of formula V r4 oh V with a hydrazine of formula H2NNHR^.

Compounds of formula III wherein R-j 4 represents (OQ)2 and R^ represents OQ may be prepared for example a) by reacting compounds of formula R^CX^ in which X is halo with a sodium alkoxide of formula NaOQ in which Q is a C.j_4 alkyl group or a benzyl group, or b) by reacting compounds of formula R^CN with an alcohol of formula QOH in the presence of an anhydrous acid, for example hydrogen chloride, to give compounds of formula R^C^NHJOQ as their acid salts, e.g. hydrochloride salts, which are then reacted with further alcohol of formula QOH.

Compounds of formula IV in which R^ g represents COR- o and R represents COR may be prepared by acylation of compounds of formula IV in which g represents COR^θ and R^? represents hydrogen, for example by reaction with an acid anhydride of formula (R^CO) 2O in the presence of a salt (e.g. the sodium salt) of the corresponding acid or an acid halide e.g. of formula RgCOCl in the presence of a base e.g. triethylamine.

Compounds of formula IV in which R^ g represents COR] 8 and R^ 7 represents hydrogen may be prepared by the acylation of compounds of formula II for example by reaction with an acid anhydride of formula (R^gCO^O in the presence of a salt (e.g. the sodium salt) of the corresponding acid.

Compounds of formula IV in which R17 represents CORc and R.c represents hydrogen, or tautomers thereof, 5 1 0 may be prepared by reacting a compound of formula IV in which R-c represents COR and R-_ represents COR_ with lb 10 1 / 0 a base e.g. piperidine in a suitable solvent e.g. ethanol.

Compounds of formula IV in which and R^ g represents COR^ θ in which R^ θ is as hereinbefore defined, and R^ represents hydrogen may be prepared by reacting compounds of formula II in which R^ represents hydrogen with an acid anhydride of formula (R^CO^O in the presence of a salt (e.g. the sodium salt) of the corresponding acid.

Compounds of formula V may be reacting compounds of formula VI prepared by VI in which R22 represents hydrogen with malonic acid in the presence of an acid chloride e.g. phosphoryl chloride and a Lewis acid e.g. zinc chloride.

Compounds of formula V may be prepared by reacting compounds of formula VI in which R22 represents an acetyl group with a base, for example sodium hydride, and a dialkyl carbonate of formula (QO)2CO in which Q represents a C.|_4 alkyl group or a benzyl group, e.g. dime thy I, carbonate.

Compounds of formula V in which R^ represents C-|_g alkoxy may be prepared from compounds of formula VI in which R^ represents represents an acetyl example sodium hydride, halo e.g. fluoro, and group with a base and a dialkyl carbonate of for formula (QO)2C0 in which Q represents a C^_4 alkyl group or a benzyl group, e.g. dimethyl carbonate.

Certain intermediate compounds of formulae II, III, IV, V, and VI are believed to be novel compounds.

All novel compounds herein are claimed as a further aspect of the invention.

This invention is illustrated by the following non-limitative Examples. In the Examples parts and percentages are by weight and compositions of mixed solvents are given by volume. Characterisation was by elemental analysis and one or more of the following spectroscopic techniques: nuclear magnetic resonance, infra-red and mass spectroscopy.

Example 1 a) 2’-Fluoro-6'-hydroxyacetophenone (30 g) was added dropwise over 30 minutes to a stirred suspension of sodium hydride (17.1 g, 60% dispersion in mineral oil) in dry toluene (400 ml) which was boiling under reflux under nitrogen. After boiling for a further 20 minutes .20 heating was continued while diethyl carbonate (50.8 g) was added dropwise over 10 minutes. The resulting mixture was stirred and heated under reflux for 20 hours. The reaction mixture was cooled to ambient temperature and water (150 ml) added dropwise. After separation, the aqueous phase wa,s washed with ether and then acidified with concentrated hydrochloric acid. The precipitate was collected by filtration and washed with water to give, after drying and recrystallisation from ethyl acetate, 5-ethoxy-4-hydroxycoumarin, m.p. no-m°c.

Example 2 A stirred mixture of 4-hydroxycoumarin (10.0 g), ethylhydrazine oxalate (14.25 g) and triethylamine (24.0 ml) in dry toluene (50 ml) was heated under reflux for 3 hours with removal of water formed in the reaction. The solid collected after filtration was partitioned between water and dichloromethane. The organic layer was dried and evaporated to give a solid which was recrystallised from butanol to give 1-ethyl-3-(2-hydroxyphenyl)-2-pyrazolin-5-one, m.p. 147-150°C.

Example 3 Hydrazine (32.3 g) was added dropwise during 0.25 hours to a stirred solution of 4-hydroxycoumarin (50.0 g) in absolute alcohol (1.2 1) and the reaction mixture was heated under reflux with stirring for 20 hours. The solution was cooled and acidified with glacial acetic acid (154 ml) and the ethanol was evaporated off under reduced pressure to leave an oil which was then poured into water (1.5 1). The resulting solid was filtered off, washed with water, dried and recrystallised from isopropanol to give 3-(2-hydroxyphenyl)-2-pyrazolin-5-one, m.p. 205-207°C.

Examples 4 to 6 z In a similar manner to that described in Example 3, a compound of formula II was prepared by reacting a compound of formula V, with a hydrazine of formula H2NNHR^, as summarized in Table A below in which substituents R4 and R1 are given.

Table Notes f— OJ CO X r— 0 u in ι- 0 r— ΟΝ • ~ | | Ch E 00 • l-l a o g l-l r“ Cp 04 X! tn 3 P rd Φ 3 X g 0 in ω •Ρ X O • Oi E-i — OJ r- ι—1 0 3 3 tn JS i—l O x X _g O 3 W Ό in (0 X o T— φ Oi K X vo vo 2 CO ο* o m z • • • 0 CN tP 1— OJ Ol X ’-r CN X 3 OJ 3 O co vo 0 • • • ff CP in cn CN > CN f— Oi X z 2 n m m CN t— X X X K Oi u u u n X m 0 3* u X >1 oi X o u φ r-l Ch g (0 X w X in io 33 φ Φ tr p 33 tr Φ 3 3 X Φ 3 P 3 33 Ή X x 3 3 cn Φ X 0 X ρ tn X g 0 Φ Φ OOO 33 3 cn 3 P 3 0 3 3 3 Ch 33 Ρ 3 3 X 3 X 3 X Φ O X X 33 3 X X g tn Φ Φ •Ρ φ Φ Eh P 3 g 3 3 o 3 o S 0 33 3 •p cn Φ X P -P 33 33 P 3 · g 0 Φ 0 tn Φ Φ 3 s x 3 P 3 ιΡ φ X P g 3 X Ο 33 X P 3 3 Φ X 0 r—l ·Ρ o ιΡ P 0 P P > JS m •Ρ φ •Ρ Φ 0 3 Φ ϋ Φ 3X33 SpX X S P Eh c X X 3 0 o 0 3 3 0 X g X X X 0 P g 3 X 3 · •P 33 33 Φ 0 •ρ Eh •ρ 33 X Φ Sp tn χ x Φ 3 X X 3 X Φ Φ X ip 3 1 0 3 33 P * P 3 0 P φ χ φ · 3 33 3 P tn o 13 0X3 X φ X 0 Ch x tr tn 3 o X -P X Ch tn 3 Sp 3 3 Ρ -P •P 3 P 3 •P > X XXX g P g > X Φ X Φ 3 3 o Φ X Φ X Φ Φ P CO Ch cn tn g X g O X 3 3 · 3 33 33 3 1 0 3 X O > — 0 3 3 3 in g to ο p Φ Φ l- Φ 3 3 0 ox 3 3 Φ X Ρ Φ CT33 ·- tT33 Ρ X 0 X > 33 Sp 3 3 — 3 Φ 0 3 0 3 X 3 •H 1 P Φ X g 3 Φ Φ Φ P CN X Ρ Ο Φ 33 33 3 X 13 1 Ή 3 3 P 33 Φ X Φ 3 X 3 -P X 33 Φ X •P X K 3 X X 0 0 X 0 g Ρ Φ g p Ch .p p +J Ρ Φ O 33 X Ο Φ Ο Φ g Ch 33 X P O P X P X 33 X X - Ip X 3 ChEn 3 Φ Φ - 0 P ο 3 X P P 0 33 Φ Sp 33 X . tn Eh Φ Φ Φ X Ο Φ X 0 33 3 x x tn X 3 X X Φ έ X 3 3 O 5 Φ 0 -H Φ P • -P S S 3 3 3 3 g Φ X 3 X P X Φ P 3 X 3 -Ρ X 33 X X 3 X 33 r—l X •ρ p 33 X Φ X -Ρ ι—1 X Φ 0 -P P 3 3 -Ρ X Φ £ 0 Φ X > X φ g 3 5 3 X cn X 3 P tn ό 3 3 X 3 3 0 Φ 33 3 3 φ ε 3 3 X Φ g O 3 ID a S X o 3 3 X Sp 3 X Φ tn ρ Φ g x tr X x tn tn +1 3 P X P tn 3 0X3 O 5 0 Φ P •Ρ Ρ Φ 5 X 3 33 3 3 3 Φ · X 33 g O 3 Φ Φ 33 X g P Sp Ο Φ -P Ο P in 0 tn 3X3 3 X Ρ Ρ X Ρ Φ -P P X •ρ Φ tr X 1 0 Φ 5 Ch S i-l Ch O tn χ x 5 »—1 3 33 X 3 1 X 33 Φ cn 3 φ P Φ 0 φ X Ο Μ *P XXX X X > Φ x >.p χ x Eh o cn Eh X X Φ > Eh X 33 O 0 3 Sp Φ 0 g -P x 3 tn P P tn 3 tr Φ O P ~ x o X- φ tn x ~ g X X Φ >- X Φ CN X •POO cn 1 3 X X — Φ P — X 33 > X — r-~ -ρ φ x in o CN in The compounds of formula II prepared in Examples 4-6 were as follows: Example 4 3-(2-hydroxyphenyl)-1-methyl-2-pyrazolin-5-one Example 5 3-(2-hydroxy-6-methoxyphenyl)-1-methyl-2-pyrazolin-5one Example 6 3-(2-hydroxy-6-methylphenyl)-1-methyl-2-pyrazolin-5-one Example 7 A solution of 4-trifluoromethylbenzonitrile (25 g) in dry ether (120 ml) and dry methanol (6 ml) was cooled at 0-5°C and saturated with hydrogen chloride gas. The reaction mixture was allowed to stand overnight in a melting ice bath and the imidate salt which precipitated was collected by filtration, washed with ether and dried in a desiccator. This solid was added to AR methanol (78.3 ml) with stirring and the mixture stirred at ambient temperature for 5 days. The reaction mixture was filtered and the filtrate was evaporated under reduced pressure to give trimethyl ortho(4-trifluoromethylbenzoate) as an oil which was used without further purification.

Example 8 a) A mixture of 4-hydroxy-5-methoxycoumarin (4.0 g) and hydrazine hydrate (3.0 ml) in industrial methylated spirit (84 ml) was boiled under reflux for 4.75 hours. On cooling, glacial acetic acid (13.3 ml) was added and the alcohol .removed under reduced pressure. The residue was added to water and a gum separated which solidified on the addition of a small amount of dichloromethane. The solid was collected by filtration to give 3-(2-hydroxy-6-methoxyphenyl)-2pyrazolin-5-one, m.p. 208-210°C. b) A mixture of 3-(2-hydroxy-6-methoxyphenyl)and 1 -(4-trifluoromethy1in dry xylene (50 ml) was reflux under nitrogen for ambient temperature. The by filtration and then industrial methylated Dichloromethane was 2-pyrazolin-5-one (2.06 g) benzoyl)imidazole (5.04 g) stirred and heated under 0.5 hours then cooled to solid formed was collected 10 dissolved in boiling spirit/dichloromethane (1 :2) . boiled off until a solid separated. The mixture was cooled to ambient temperature and filtered to give 9-methoxy-4-(4-trifluoromethylphenyl)[1]benzopyrano15 [4,3-c]pyrazol-3(2H)-one, m.p. >280°C (with decomposition). c) Sodium hydride (0.114 g, 60% dispersion in mineral oil) was added to a suspension of 9-methoxy-4{4-trifluoromethylphenyl) [1]benzopyrano [4,3-c]pyrazol20 3(2H)-one (0.94 g) in dry Ν,Ν-dimethylformamide (55 ml) . The mixture was stirred at ambient temperature for 10 minutes, then 2-bromoethyl ethyl ether (0.36 ml, 90%) was added dropwise followed by stirring at ambient temperature for 16h. The mixture was added to water containing a small amount of petroleum ether (b.p. 62-68°C). The mixture was acidified with 2M hydrochloric acid and filtered to z give 2-(2-ethoxyethyl)-9-methoxy-4-(4-trifluoromethylphenyl)[1]benzopyrano[4,3-c]pyrazol-3(2H)-one, m.p. 164-168°C.

Example 9 a) A mixture. . of 5-ethoxy-4-hydroxycoumarin (5.0 g) (Example 1) and methylhydrazine (2.2 g) in industrial methylated spirit (60 ml) was heated under reflux for 20 hours. On cooling, the solvent was evaporated off under reduced pressure to give the crude product.

Methanol (50 ml) and concentrated hydrochloric acid (20 ml) were added to this crude product and the solution obtained was heated under reflux for 2 hours. After evaporating off the solvents under reduced pressure, the residue was triturated with water and the solid obtained collected by filtration and dried to give 3-(2-hydroxy-6-ethoxyphenyl)-1-methyl-2-pyrazolin5-one. b) The solid obtained in (a) above (3.2 g) and trimethyl ortho (4-chlorobenzoate) (9.0 g) were heated together at 130-140°C for 45 minutes. The mixture was cooled to ambient temperature and hexane (50 ml) was added. The supernatant liguid was decanted off and ether (80 ml) added to the residual oil to precipitate a solid. The solid was collected by filtration, washed with ether, dried and then recrystallised from propan20 2-ol to give 4-(4-chlorophenyl)-9-ethoxy-2-methyl[1]benzopyrano[4,3-c]pyrazol-3(2H)-one, m.p. 197-199°C.

Example 10 a) A mixture of 4-hydroxycoumarin (3.6 g) and a 70% aqueous solution of 2,2,2-trifluoroethylhydrazine (5.0 g) in toluene (27 ml) was heated under reflux for hours with removal of water. The solid collected after cooling and filtration was extracted with hot dichloromethane, filtered and the filtrate was evaporated. The solid product was recrystallised from toluene and then from dichloromethane to give 3-(2hydroxyphenyl)-1 -(2,2,2-trifluoroethyl)-2-pyrazolin-5one, m.p. 163-165°C. b) The solid obtained in (a) above (1.2 g) and trimethyl ortho(4-chlorobenzoate) (3.0 g) were heated together at 125°C for 10 minutes. The mixture was cooled, diluted with ether (10 ml) and the solid obtained was recrystallised from a mixture of Ν,Νdimethylformamide and methanol to give 4-(4-chlorophenyl) -2-(2,2,2-trifluoroethyl) [ 1]benzpyrano[4,3-c]pyrazol-3(2H)-one, m.p. 214-215°C (decomposed).

Example 11 a) A mixture of 3-(2-hydroxyphenyl)-1-methyl-2pyrazolin-5-one (3.8 g) , prepared as in Example 4, anhydrous sodium acetate (1.64 g) and acetic anhydride (30 ml) was stirred at ambient temperature for l. 5 hours. The reaction mixture was added to water (10 volumes) and extracted with ethyl acetate. The combined organic extracts were washed with water, dried and evaporated. The semi-crystalline residue was triturated with petroleum ether (b.p. 60-80°C) and the solid collected by filtration and dried to give 3-(2-hydroxyphenyl)-1-methyl-5-pyrazolyl acetate, m. p. 113-116°C. b) A solution of 3,4-dichlorobenzoyl chloride (4.4 g) in tetrahydrofuran (80 ml) was added over 10 minutes to a stirred solution of 3-(2-hydroxyphenyl)-1-methyl-525 pyrazolyl acetate (4.5 g) in tetrahydrofuran (100 ml) and triethylamine (3 ml) at 0-5°C. The mixture was z stirred for 18 hours at ambient temperature and then more 3,4-dichlorobenzoyl chloride (4.4 g) in tetrahydrofuran (80 ml) and triethylamine (3 ml) was added. After stirring for a further 24 hours, the reaction mixture was poured into water (1 1) and extracted with ethyl acetate. The combined organic extracts were dried and then concentrated until precipitation occurred. After filtration to remove 3.4- dichlorobenzoic acid, the filtrate was evaporated under reduced pressure and the residue crystallised from ethyl acetate to give 2-(5-acetoxy-1-methyl-3pyrazolyl)phenyl 3,4-dichlorobenzoate, m.p. 123°C. c) 2-(5-Acetoxy-l-methyl-3-pyrazolyl)phenyl 3,4dichlorobenzoate (1.0 g) and piperidine (0.27 ml) were heated in ethanol (10 ml) under reflux for 2 hours. The reaction mixture was cooled to 0°C. The product was collected by filtration and recrystallised from ethanol to give 4-(3,4-dichlorophenyl)-2-methyl[1] benzopyrano[4,3-c]pyrazol-3(2H)-one, m.p. 193-194°C.

Example 12 a) A solution of 3-(2-hydroxyphenyl)-1-methyl-5pyrazolyl acetate (2.32 g), prepared as in Example 11a, in dry tetrahydrofuran (50 ml) was treated successively with triethylamine (1.5 ml) and 2-naphthoyl chloride (2.1 g) in dry tetrahydrofuran (10 ml) at 0-5°C. The mixture was stirred at ambient temperature for 20 hours and then more triethylamine (0.75 ml, and 2-naphthoyl chloride (1.05 g) were added and the mixture was stirred for another 20 hours. The reaction mixture was poured into water (10 volumes) and extracted with ethyl acetate. The combined organic extracts were washed with saturated sodium carbonate solution, then water and then dried. After evaporation under reduced pressure the residue was triturated with ether and the solid formed collected by filtration. b) Part of the crude solid of stage (a) (2.43 g) and piperidine (0.63 ml) were boiled under reflux in absolute ethanol (19 ml) for 30 minutes. On cooling, the mixture was filtered to give 2-(1-methyl-5-oxo4.5- dihydro-3-pyrazolyl)phenyl 2-naphthoate, m.p. 207-210°C. c) The filtrate was boiled under reflux for a further hour. The mixture was concentrated and then cooled. The solid formed was collected by filtration to give 2-methyl-4-(2-naphthyl)[1]benzopyrano[4,3-c]pyrazol5 3(2H)-one, m.p. 159-161°C.

Example 13 A stirred mixture of 3-(2-hydroxyphenyl)-2pyrazolin-5-one (2.32 g) and triethyl ortho(4-chlorobenzoate) (10.2 g) was heated at 130-135°C for 1 hour.

The mixture was cooled to ambient temperature, diluted with ether and the resulting solid filtered off, washed and dried. The solid was recrystallised from industrial methylated spirit (charcoal used) to give 4-(4-chlorophenyl)[1]benzopyrano[4,3-c]pyrazol-3(2H)15 one, m.p. 255-257°C.

Examples 14 to 18 In a similar manner to that described in Example 13, a compound of formula I was prepared by reacting a compound of formula II with a compound of formula III as summarized in Table B below in which substituents and R^ in compound II are given. The compounds of formula III used were of the type R^C(OQ)3 in which R2 represents hydrogen and R3 and Q are as given in Table B.

Table ω ω ο Ζ O — u o cx — ε Η +> tP a •Η -Ρ ω Φ β β (0 ε ή cO Φ •η ε +J a O cd © a m Η Η 0 Η +j c 3 0 ε . Ι—Ι CP Η rt » CN rt cn -τ m ιη cn ο ιη CN 1— CN CN CM 1— I I I I I CN 31 i— CN i- ο in CM CN rt— CM CM r- o in o o o KO rt— ko KO in σι CM cn CM cn in • « • « • O 00 m CM KO t— o o r* in CN o KO in « • • • • CM CN o CM i—l i—l i—l pH rt a CJ CJ CJ CJ CJ LD ID K S rt rt rt CJ CJ CJ CJ CJ (ύ Φ i—l cx ε (0 X ω in SB η a CJ o η a cj a in rt X rt a cn x CJ o CJ C*f rt X X CJ CJ in io > oo cn Φ +> z Recrystallisation from propan-2-ol.

The reaction mixture was heated at 125°C.

The reaction mixture was heated at 130-140°C The reaction mixture was heated at 135-140°C CN rt in Example 19 A mixture of 3-(2-hydroxyphenyl)-2-pyrazolin-5-one (16 g) and 1 -(4-chlorobenzoyl)imidazole (37.5 g) in xylene (200 ml) was stirred and heated under reflux for 3 hours. The mixture was allowed to cool to 70°C and then filtered to give 4-(4-chlorophenyl)[1]benzopyrano[4,3-c]pyrazol-3(2H,-one, m.p. 255-257°C.

Example 20 A mixture of trimethyl ortho (4-trifluoromethyl10 benzoate) (5.5 g), prepared as in Example 7, and 3-(2hydroxyphenyl)-2-pyrazolin-5-one (1.94 g) was heated at 135-1 40°C for 4 hours. The mixture was cooled to 0°C and the solid formed filtered off and washed with ether. This solid was triturated with hot water and filtered to give 4-(4-trifluoromethylphenyl)[1]benzopyrano [4 , 3-c] pyrazol-3 (2H) -one, m.p. 271-273°C.

Example 21 A mixture of 3-(2-hydroxyphenyl)-2-pyrazolin-5-one . (30.2 g), 1-(4-trifluoromethyIbenzoyl)imidazole (86.5 g) and xylene (800 ml) was stirred and boiled under reflux for 4 hours under nitrogen. The reaction mixture was allowed to cool to 40°C and filtered to give 4-(4-trifluoromethylphenyl)[1Jbenzopyrano[4,3-c]pyrazol-3 (2H)-one , m.p. 270-272oj3.

Example 22 a) A mixture of 3-(2-hydroxyphenyl)-2-pyrazolin-5-one (3.52 g) and sodium acetate (1.64 g) in acetic anhydride (30 ml) was stirred at ambient temperature for 3 hours. The mixture was poured, into water and petroleum ether (b.p. 62-68°C, 10:1) and the solid collected by filtration to give crude 1-acetyl-3-(2hydroxyphenyl)-5-pyrazolyl acetate, m.p. 62-64°C. b) A mixture of crude 1-acetyl-3-(2-hydroxyphenyl)-5-pyrazolyl acetate (1.53 g) , triethylamine (2.1 ml) and dry tetrahydrofuran (25 ml) was stirred at 0-5°C while 4-trifluoromethylbenzoyl chloride (3.21 g) was added dropwise. The resultant mixture was stirred at ambient temperature for 64 hours and then poured into water. The product was extracted into ethyl acetate and the combined extracts were washed with water, saturated sodium bicarbonate solution and finally water. After drying, the solvent was evaporated off under reduced pressure. The residue was digested with hot propan-2-ol then cooled and filtered.

The filtrate was evaporated to give crude 2-(5-acetoxy1-acetyl-3-pyrazolyl)phenyl 4-trifluoromethylbenzoate as an oil. c) were The oil from stage boiled under reflux (b) in and piperidine absolute ethanol (0.7 ml) (22 ml) 20 for 1 hour. The mixture was cooled to 0-5°C and then filtered to give the crude product which was purified . . . by preparative layer chromatography on silica, using dichloromethane/methanol (9:1) as the mobile phase, to give 4-(4-trifluoromethylpheny1)[1] benzopyrano25 [4,3-c]pyrazol-3(2H)-one , m.p. 268-272°C.

Example 23 , A mixture of 3-(2-hydroxyphenyl)-2-pyrazolin-5-one (2.9 g) and potassium carbonate (3.2 g) in dry xylene (30 ml) was stirred and heated under reflux while 4-trifluoromethylbenzoyl chloride (6.9 g) was added dropwise over 15 minutes. The mixture was boiled and stirred for 2 hours then hot filtered. The solid collected was washed with toluene, water and finally ether to give 4-(4-trifluoromethylphenyl)[1]benzopyrano[4,3-c]pyrazol-3(2H)-one, m.p. 259-263°C.

Example 24 3-(2-Hydroxyphenyl)-1-methyl-2-pyrazolin-5-one 5 (Example 4) (1.90 g) was dissolved in warm toluene (100 ml) then cooled to ambient temperature and added over 5.25 hours to a stirred, boiling solution of 4-chlorobenzaldehyde (1.4 g) in dry toluene (50 ml) containing piperidine (1 ml) , with removal of water formed in the reaction. The reaction mixture was evaporated under reduced pressure and the residue triturated with ether and recrystallised from propan2-ol to give 4-(4-chlorophenyl)-2-methyl[1]benzopyrano[4,3-c]pyrazol-3(2H)-one , m.p. 204-205°C.

Example 25 A mixture of 2-(2-chloroethoxy)ethyl acetate (16.7 g), sodium bromide (103 g) , Ν,Ν-dimethylformamide (200 ml) and dibromomethane (100 ml) was stirred and heated at 100°C for 48 hours. The mixture was poured into ether (300 ml) and water (200 ml). The organic layer was separated, washed with water, dried and evaporated to give an oil. Distillation under reduced pressure gave 2—(2—bromoethoxy)ethyl acetate, b.p. 100-103°C (7mm Hg) . s Example 26 Sodium hydride (0.60 g, 50% dispersion in mineral oil) was added to a stirred solution of 4-(4-chlorophenyl)[1]benzopyrano[4,3-c]pyrazol-3(2H)-one (3.70 g) , prepared as in Example 13, in dry Ν,Ν-dimethylformamide (1 45 ml) under nitrogen. The mixture was stirred at ambient temperature for 5 minutes and then 2-bromoethyl acetate (1.38 ml) was added dropwise. The reaction mixture was stirred at ambient temperature for 16 hours and then poured into water and petrol (b.p. 60-80°: approx. 10:1 by volume). The mixture was cooled in an ice bath and the deposited solid filtered off and washed to give 2-[4-(4-chlorophenyl)-3-oxo-2,3-dihydro[1]benzopyrano[4,3-c]pyrazol-2-yl]ethyl acetate, m.p. 126-129°C.

Examples 27 to 41 In a similar manner to Example 26, compounds of formula I were prepared by reacting 4-(4-chlorophenyl) [1]benzopyrano[4,3-c]pyrazol-3(2H)-one (A) (Example 13) with compounds of formula R^X, in which X is halo as summarized in Table C below. z Table ω Ρ C (0 Ρ ο (0 φ a ω φ 4-» ο Ζ a +J ο ο • Ό ϋ Ο • Ρ s a η tn C —•ρ ω ρ ρ Ρ Φ 3 •η ε ο +J ·Ρ Λ ω Ε-ι a α χ τ— ι—1 a ε φ ε ό 3 ·ρ •Ρ Ρ Π3 Ό — ο >ι tn W £ ~ CP χ ar φ ι—Ι a ε (0 X W in CM cn sr in KO π— O r- CP ι— Γ- Γ- 00 m KO T3* r- ΟΟ ΓΟ Γ- r— CM r— | CM I | CM I 1 1 00 1 in 1 r- 1 1 ^r 1 KO m in *3* KO 00 m Γ— π- CM T“ 1— CM 1— CM ιη oo CM CM 00 00 00 KO r— CM Γ- i— r- r— 00 in 00 τ— o O 00 P' 00 KO co o in 00 KO r— >- CM tP CP tP sr 00 KO ^4· o CP cr» in KO o CM 00 Γ- o r— r— r— CN o o o in 00 IO O 'φ -tf io CN sr o cn KO TJ· CM cn cn o - o o - o o o CM KO CM o CM CM CM o in CM o CN CN rt 1- CN CN η X JB CN u a a z o o u a cj CN CN II CN CN X z X a O a cj cj u cj cj u CN CN CN CN CN CN t X X a a a a a z cj u u u u u rt CJ P rp P P P pH CJ P a cj a a a cj h a η- co σι ο ΓΜ CM CM rt CN rt Μ* rt rt rt in φ Ό •Η ε (C ε Ρ ο a Fp Λ -Ρ Φ ε •Η Ό I ZJ ζΊ II m Φ x o co cm co cm X X 00 CO σ oo Γ- r-· 0 o cn 1— r— 00 ι— ιο 3 r— σ r— Τ- 1— »— « 33 1 1 1 Ι 1 I 1 cu 0 σ Γ- Γ- Γ* in m X cn 00 Γ-- ΟΟ 1— ιο ι— g’ Cb H 1— t— — *— r— r— Table C continued tn X C X O Φ X X o X c o c Ή (Ω Μ 3-1 3-1 Φ 3 Η g 0 X •Η X ω Η 2 S rH Q g X ,— r—1 OS g φ g 33 •rd •Η S-i 33 33 — 0 >ί σ ω χ σ < in r* cn οο ι— νο «ςρ γ- 00 γμ σ CM CM ιη ττ ο ιη ο ΓΜ νο ΓΜ ιη ΓΜ ιη ο ιη Ο Ο CM 0·' Cn Cn cn ο 00 Γ* νο νο • cn CM Γ— • • ΓΜ • • « • ο ο γ— ο σ CM η X OS Φ r—l Cb g X w in ιη Ο ΓΜ ο Γ* cn σ σ ο Ό ΓΜ Γ- ο Γ- • ο ο ο ο ο ιη ο ιη • • • • • • • ΓΜ ιη ιη Γ” Γ— 00 σ cn X m υ I X ο C ο U 3 ο ο γΗ ΓΜ CM ο X cn ιη ΓΜ CM ο X X X X •Η υ ΓΜ υ υ 33 — ο ο *— 1 rH U ο ο X ο Π >. ο ΓΜ ΓΜ X CM X cn ο Γ— X S. ΓΜ σι CM Ο ΓΜ φ CM X X X CM X '\ X υ υ X U CM Γ—1 υ υ *—* υ *-«* >1 3η 3η 3η 3η 3η X 1 X X X X X X X ΓΜ X in ό r- oo σ n m cn ro n o HT in Notes for Table C (1) The reaction mixture was added to water (2 1) , acidified with concentrated hydrochloric acid and extracted with ethyl acetate. The combined extracts were washed with water, dried and concentrated until crystallisation occurred. On cooling, the product was obtained by filtration. (2) The solid obtained was dissolved in a mixture of dichloromethane/ethanol and concentrated until crystallisation occurred. The product was collected by filtration. (3) The quenched mixture was extracted with ethyl acetate. The combined extracts were washed with water, dried and concentrated until crystallisation occurred.

The product was collected by filtration. (4) The reaction mixture was added to water (10 volumes) and acidified with 2M hydrochloric acid. The solid formed was collected by filtration, dried and then dissolved in boiling industrial methylated spirit/dichloromethane, 1:2. The dichloromethane was removed and the solution cooled in an ice bath. The solid formed was collected by filtration. (5) The reaction mixture was added to water (500 ml) and extracted with ethyl acetate. The combined extracts were washed with water, dried and evaporated. The solid obtained was recrystallised from propan-1-ol. (6) The reaction mixture was added to water and the solid formed collected by filtration and dried. This solid was triturated with acetone and filtered. The residue was triturated with boiling industrial methylated spirit then filtered and the residue dissolved in warm dichloromethane, treated with charcoal and filtered. The filtrate was evaporated and the residue triturated with petrol and filtered to give the product. (7) The reaction mixture was quenched into water (300 ml) containing 2M hydrochloric acid (5 ml) and extracted with dichloromethane. The combined extracts were dried and evaporated. The residue was partitioned between ether and water, then separated. The aqueous layer was extracted with ether and the combined ether extracts dried and concentrated (to 10 ml). The solid formed was collected by filtration, washed with petroleum ether (b.p. 40-60°C) and dried. After recrystallisation from ethanol the product was purified by flash chromatography on silica using dichloromethane/methanol, 98:2 as the mobile phase.

The eluted material was recrystallised from ethanol to give the product. (8) The reaction mixture was partitioned between 5M hydrochloric acid (600 ml) and ether (300 ml) . The aqueous layer was separated off and washed with ether. The combined ether extracts were washed well with water, dried and evaporated. The residue was purified by flash chromatography on silica using dichloromethane/methanol, 97:3 as the mobile phase. The solid obtained was recrystallised twice from a mixture of ether and ethyl acetate to give the product. (10) The reaction mixture was added to water and acidified with 5M hydrochloric acid. The solid was collected by filtration and recrystallised from N,N-dimethyIformamide. (11) The reaction mixture was added to water. The solid obtained was collected by filtration and recrystallised from propan-2-ol. (12) 60% dispersion of sodium hydride in mineral oil 5 used. (13) The reaction mixture was added to water (500 ml) and extracted with ether. The combined extracts were washed with water, dried and evaporated. The solid obtained was recrystallised from ethanol. (14) The reaction mixture was added to water (2 1) , acidified with 5M- hydrochloric acid and extracted with ethyl acetate. The combined extracts were washed with water, dried and evaporated. The oil obtained was crystallised from ether.

Example 42 In a similar manner to Example 26, a mixture of sodium hydride (0.74 g, 60% dispersion in mineral oil), dry Ν,Ν-dimethylformamide (180 ml), 4-(4-chlorophenyl)[1]benzopyrano[4,3-c]pyrazol-3(2H)-one (Example 13) (5.0 g) and 2-bromomethyl-1,3-dioxolane (1.97 ml) was stirred at ambient temperature for 16 hours. More sodium hydride (0.74 g) was added in portions followed by more 2-bromomethyl-1,3-dioxolane (1.97 ml). The mixture was stirred at ambient temperature for 24 hours and then warmed at 70-80°C for 1 hour. The mixture was cooled to ambient temperature and then added to water. The solid formed was collected by filtration, dried and recrystallised from ethanol/dichloromethane to give 4-(4-chlorophenyl)30 2-(1,3-dioxolan-2-ylmethyl)[1]benzopyrano[4,3-c]pyrazol-3(2H)-one, m.p. 230-231 °C.

Example 43 In a similar manner to Example 26, a mixture of sodium hydride (0.44 g, 60% dispersion in mineral oil), dry Ν,Ν-dimethylformamide (100 ml), 4-(4-chloro5 phenyl)[1]benzopyrano[4,3-c]pyrazol-3(2H)-one (3.0 g) (Example 13 ) and 1-bromo-2-ethoxypropane (2.9 g) was stirred at ambient temperature for 16 hours. The mixture was warmed at about 60°C for 1.5 hours then cooled to ambient temperature. The mixture was added to water and the product extracted into ether. The combined ether extracts were dried and evaporated. The residue was separated by flash chromatography on silica, using ethyl acetate/petroleum ether (b.p. 80-100°) (1:3) as the mobile phase, to give a red solid which was recrystallised from ethanol to give 4-(4-chlorophenyl)-2-(2-ethoxypropyl) [1Jbenzopyrano[4,3-c]pyrazol-3(2H)-one, m.p. 118-119°C.

Example 44 In a similar manner to Example 26, a mixture of sodium hydride (1.82 g, 60% dispersion in mineral oil), dry Ν,Ν-dimethylformamide (450 ml), 4-(4trifluoromethylphenyl)[1]benzopyrano[4,3-c]pyrazol3(2H)-one (15.0 g) (Example 20) and 2-bromoethyl acetate (7.62 g) was stirred at ambient temperature for 48 hours. The mixture was added to water. The solid formed was filtered off and dissolved in ethyl acetate which was washed with water. The residue obtained, after removal of the ethyl acetate under reduced pressure, was recrystallised from propan-2-ol to give 2-[3-oxo-4-(4-trifluoromethylphenyl)-2,3-dihydro[1]benzopyrano[4,3-c]pyrazol-2-yl]ethyl acetate, m.p. 134-136°C.

Example 45 In a similar manner to Example 26, a mixture of sodium hydride (0.74 g, 60% dispersion in mineral oil), dry Ν,Ν-dimethylformamide (150 ml), 4-(4-chloro5 phenyl)[1]benzopyrano(4,3-c]pyrazol-3(2H)-one (5.0 g) and 2-(2-bromoethyl)-1,3-dioxane (2.52 ml) was stirred at ambient temperature for 42 hours. The reaction mixture was added to water. The product was extracted into ether and the extracts washed with water.

Evaporation of the ether left a solid residue which was recrystallised from ethanol to give 4-(4-chlorophenyl)2-(2-(1,3-dioxan-2-yl)ethyl][1]benzopyrano(4,3-c]pyrazol-3(2H)-one, m.p. 1 57-1 63°C.

Example 46 A mixture of 2-[3-oxo-4-(4-trifluoromethylphenyl)2,3-dihydro[1]benzopyrano[4,3-c]pyrazol-2-yl]ethyl acetate (17.93 g) (Example 44), 2M hydrochloric acid (22 ml) and industrial methylated spirit (750 ml) was stirred and boiled under reflux for 18 hours. The mixture was cooled to 0°C and the solid formed collected, by filtration to give 2-(2-hydroxyethyl)4-(4-trifluoromethylphenyl)[1]benzopyrano[4,3-c]pyrazol-3(2H)-one, m.p. 1 99-201 °C.

Example 47 s Dilute hydrochloric acid (2 ml) was added to a stirred suspension of 2-[4-(4-chlorophenyl)-3-oxo-2,3dihydro[1]benzopyrano[4,3-c]pyrazol-2-yl]ethyl acetate (1.53 g) , prepared as in Example 26, in industrial methylated spirit (80 ml) at ambient temperature. The mixture was heated under reflux for 6.5 hours. The - solution was allowed to cool and was kept at ambient temperature for 16 hours. The resulting crystals were filtered off and washed with industrial methylated spirit to give 4-(4-chlorophenyl)-2-(2-hydroxye'thyl)[1]benzopyrano[4,3-c]pyrazol-3(2H)-one, m.p. 179-183°C.

Example 48 A mixture of 3-[4-(4-chlorophenyl)-3-oxo-2,3dihydro[1]benzopyrano[4,3-c]pyrazol-2-yl]propyl acetate (1.5 g) (Example 41), 2M hydrochloric acid (1.9 ml) and industrial methylated spirit (75 ml) was boiled under reflux for 5 hours. The mixture was cooled to room temperature and the solid formed collected by filtration to give 4-(4-chlorophenyl)-2-(3-hydroxypropyl) [1]benzopyrano[4,3-c]pyrazol-3(2H)-one, m.p. 166-168°C.

Example 49 A mixture of 2-f2-[4-(4-chlorophenyl)-3-oxo-2,3dihydro[1]benzopyrano[4,3-c]pyrazol-2-yl]ethoxy)ethyl acetate (11 g) (Example 39), 5M hydrochloric acid (100 ml) and water (100 ml) was stirred and boiled under reflux for 24 hours. The mixture was evaporated and the solid obtained was recrystallised from propan2-01 (100 ml) to give 4-(4-chlorophenyl)-2-[2-(2hydroxyethoxy)ethyl][1]benzopyrano[4,3-c]pyrazol-3(2H)one, m.p. 110-112°C.

Example 50 , A mixture of 4-(4-chlorophenyl)-3-oxo-2,3-dihydro[1]benzopyrano[4,3-c]pyrazole-2-acetonitrile (0.68 g), prepared as in Example 28, and concentrated sulphuric acid (6 ml) was heated at 120°C for 0.5 hour. The reaction mixture was poured on to ice (10 volumes) and the solid product was collected, washed and dried to give 4- (4-chlorophenyl)-3-oxo-2,3-dihydro[1]benzopyrano [4, 3-c] pyrazole-2-acetamide, m.p. 279-283°C.

Example 51 In a similar manner to Example 50, a mixture of 5 4-(4-chlorophenyl)-3-oxo-2,3-dihydro[1]benzopyrano[4,3-c]pyrazole-2-propionitrile (1.0 g), prepared in Example 32, and concentrated sulphuric acid (10 ml) was heated at 120-125°C for 15 minutes to give, after recrystallisation from industrial methylated spirit, 4-(4-chlorophenyl)-3-oxo-2,3-dihydro[1]benzopyrano[4,3-c]pyrazole-2-propionamide, m.p. 264-266°C.

Example 52 a) A stirred suspension of 4-(4-chlorophenyl)-3oxo-2,3-dihydro[1]benzopyrano[4,3-c]pyrazole-2-acetic acid (2.16 g), prepared as in Example 31, in dichloromethane (50 ml) was treated with dry Ν,Ν-dimethylformamide (0.24 ml) and then thionyl chloride (1.51 ml). The mixture was stirred at ambient temperature for 16 hours and then evaporated under reduced pressure. The residue was triturated with dry ether and the solid collected by filtration to give 4- (4-chlorophenyl)-3-oxo-2,3-dihydro[1]benzopyrano [4, 3-c] pyrazole-2-acetyl chloride. b) A portion of this acid chloride (1.08 g) in dry tetrahydrofuran (100 ml) was treated dropwise with an aqueous solution of ethylamine (0.43 ml, 70% w/w). The mixture was stirred at 0-5°C for 1.5 hours and then filtered. The filtrate was diluted with ether (100 ml), cooled in an ice-bath for 3 hours and the solid filtered off. On standing for several days a ' second crop of solid was obtained. The two combined crops were washed with water and then petroleum ether (b.p. 60-80°C) to give 4-(4-chlorophenyl)-N-ethyl-3oxo-2,3-dihydro[1]benzopyrano[4,3-c ]pyrazole-2acetamide, m.p. 238-239°C.

Example 53 In a similar manner to Example 52(a) 4-(4-chlorophenyl)-3-oxo-2,3-dihydro[1]benzopyrano [4,3-c]pyrazole-2-acetic acid (1.87 g) was converted into the acid chloride (1.89 g) and then suspended in dry tetrahydrofuran (172 ml) at 0-5°C. Aqueous methylamine (0.69 ml, 25/30% w/v) was added dropwise and the mixture stirred in a melting ice bath for 2.5 hours. The solid was filtered off, washed with water and then ether to give 4-(4-chlorophenyl) -Nmethyl-3-oxo-2,3-dihydro[1]benzopyrano[4,3-c]pyrazole15 2-acetamide, m.p. 244-250°C.

Example 54 A solution of propylamine (0.2 ml) in dry tetrahydrofuran (10 ml) was added dropwise to a mixture of 4-(4-chlorophenyl)-3-oxo-2,3-dihydro(1]20 benzopyrano[4,3-c]pyrazole-2-acetyl chloride (1.07 g) (Example 52a) in dry tetrahydrofuran (95 ml) with stirring at 0-5°C. The mixture was stirred at 0-5°C for 50 minutes and then more propylamine (0.1 ml) in dry tetrahydrofuran (5 ml) was added. This mixture was stirred at 0-5°C for 2.3 hours and then diluted with A dry ether (95 ml) and stirred at 0-5°C for 1 hour. The mixture was filtered and the filtrate washed with water, dried and evaporated under reduced pressure. The residue was separated on a Florisil® column using dichloromethane and then dichloromethane/methanol (95:5) as the mobile phase. The solid obtained was triturated with ether to. give 4.-(4-chlorophenyl)-340 oxo-N-propyl-2,3-dihydro[1]benzopyrano[4,3-c]pyrazole2-acetamide, m.p. 218-223°C.

Example 55 A stirred mixture of 4-(4-chlorophenyl) [1]benzo5 pyrano[4,3-c]pyrazol-3(2H)-one (Example 13) (1.0 g) in toluene (20 ml) was treated with chlorosulphonyl isocyanate (0.53 g) at ambient temperature. The mixture was heated to 70 °C and stirred at this temperature for 15 minutes. On cooling to 0°C, the mixture was filtered and the residue washed with ether then suspended in glacial acetic acid (6 ml) and water (3 ml). This mixture was heated at 60°C for 15 minutes and then filtered. The residue was washed with water, dried and recrystallised from dichloromethane/methanol, 4:1, to give 4-(4-chlorophenyl)-3-oxo-2,3-dihydro[1]benzopyrano[4,3-c]pyrazole-2-carboxamide, m.p. 215-216°C.

Example 56 Acetyl chloride (0.86 ml) was added dropwise to a stirred mixture of 4-(4-chlorophenyl)[1]benzopyrano[4,3-c]pyrazol-3(2H)-one (Example 13) (3.0 g) and potassium carbonate (2.79 g) in AR acetone (20 ml) at ambient temperature. The mixture was stirred at ambient temperature for 42 hours. More potassium carbonate (6.98 g) was added fpllowed by more acetyl chloride (3.6 ml) in AR acetone (15 ml). The mixture was stirred at ambient temperature for 18 hours. More potassium carbonate (2.79 g) and acetyl chloride (1.44 ml) were added and the mixture stirred at ambient temperature for 2.25 hours. The mixture was then boiled under reflux for 1 hour, cooled to ambient -temperature and then added to water. The solid formed was collected by filtration, dried and then I recrystallised from acetonitrile to give 2-acetyl-4(4-chlorophenyl)[1]benzopyrano[4,3-c]pyrazol-3(2H)-one, m.p. 224-226°C.

Example 57 A stirred mixture of 4-(4-chlorophenyl)[1]benzopyrano[4,3-c]pyrazol-3(2H)-one (Example 13) (20 g) and ethyl chloroformate (200 ml) was boiled under reflux for 5 hours. More ethyl··.:chloroformate (50 ml) was added and the mixture was stirred and boiled under reflux for 4 hours. The reaction mixture was cooled to ambient temperature and the solid was collected by filtration and recrystallised from acetonitrile. The crude product obtained was purified by flash column chromatography on silica using dichloromethane/methanol (9:1) as the mobile phase. Evaporation of the eluent gave a solid which was recrystallised from ethyl acetate to give ethyl 4-(4-chlorophenyl)-3-oxo-2,3dihydro[1]benzopyrano[4,3-c]pyrazole-2-carboxylate, m.p. 187-188°C.

Example 58 A stirred mixture of 4-(4-chlorophenyl)[1]benzopyrano[4,3-£]pyrazol-3(2H)-one (Example 13) (5 g) and ethyl cyanoformate (50 ml) was boiled under reflux for 3.5 hours. The reaction mixture was cooled to ambient z temperature, diluted with petroleum ether (30 ml), filtered and dried to give ethyl 4-(4-chlorophenyl)-3oxo-2,3-dihydro[1]benzopyrano[4,3-c]pyrazole-2-carboxylate, m.p. 187-189°C.

Example 59 A stirred suspension of 4-(4-chlorophenyl)-3-oxo2,3-dihydro[1]benzopyrano[4,3-c]pyrazole-2-acetyl chloride (0.97 g) , prepared as in Example 52(a), in dry tetrahydrofuran (76 ml) was treated with a solution of cyclobutanol (0.7 g) in dry tetrahydrofuran (10 ml) followed by triethylamine (0.35 ml). The resulting mixture was stirred at ambient temperature for 2.67 hours and then filtered. The filtrate was diluted with ether, washed with water, dried and then evaporated under reduced pressure. The residue was purified by preparative layer chromatography on silica using dichloromethane/methanol (9:1) as the mobile phase. The fast running band was extracted with ethyl acetate. Evaporation under reduced pressure gave a gum which was triturated with ether/petroleum ether (b.p. 62-68°C, 1:1) and filtered to give cyclobutyl 4-(4-chlorophenyl)-3-oxo-2,3-dihydro[1]benzopyrano[4,3-c]pyrazole-2-acetate, m.p. 135-138°C.

Example 60 Sodium hydride (0.48 g, 60% dispersion in mineral oil) was added to a stirred solution of 4-(4-trifluoromethylphenyl) [1]benzopyrano[4,3-c]pyrazol-3(2H)-one (3.3 g), prepared as in Example 20, in dry N,N25 dimethylformamide (60 ml) underznitrogen. The mixture was stirred at ambient temperature for 0.5 hours and then bromoacetonitrile (1.46 g) added in one portion. The mixture was stirred at ambient temperature for 18 hours and then added to iced water. The mixture was extracted with ethyl acetate and the combined extracts washed with water, dried and evaporated to give a solid which was recrystallised from propanol to give 3-oxo43 4-(4-trifluoromethylphenyl)-2,3-dihydro[1]benzopyrano[4,3-c]pyrazole-2-acetonitrile, m.p. 215-217°C.

Example 61 In a similar manner to Example 60, 4-(45 trifluoromethylphenyl) [1 ]benzopyrano[4,3-c]pyrazol3(2H)-one (1.35 g) , sodium hydride (0.21 g, 50% dispersion in mineral oil), 2-bromoethyl ethyl ether (0.77 g) and dry Ν,Ν-dimethylformamide (50 ml) were mixed and stirred at ambient temperature for 42 hours.

The crude product obtained was purified by flash column chromatography on silica using ethyl acetate as the mobile phase to give, after recrystallisation from propan-2-ol, 2-(2-ethoxyethyl)-4-(4-trifluoromethylphenyl)[1]benzopyrano[4,3-c]pyrazol-3(2H)-one, m.p. 126-128°C.

Example 62 2-(2-Hydroxyethyl)-4-(4-trifluoromethylphenyl) [1]benzopyrano[4,3-c]pyrazol-3(2H)-one (8.22 g) prepared as in Example 46 and 48% aqueous hydrobromic acid (500 ml) were stirred and heated under reflux for 28 hours. The reaction mixture was cooled to 0°C and the solid collected by filtration washed with water and then dried and recrystallised from acetonitrile to give 2-(2-bromoethyl)-4-(4-trifluoromethylphenyl)[1]benzo25 pyrano[4,3-c]pyrazol-3(2H)-one , m.p. 1 45-1 47°C.

Example 63 a) In a similar manner to Example 60, 4-(4-trifluoromethylphenyl)[1]benzopyrano[4,3-c]pyrazol-3(2H)-one (5 g), sodium hydride (0.7 g, 60% dispersion in mineral oil), ethyl 4-bromobutyrate (2.4 ml) and dry N,N44 dimethylformamide (230 ml) were mixed and stirred at ambient temperature for 24 hours. The reaction mixture was added to water (2.3 1) and petrol (b.p. 60-80°C), acidified with 5M hydrochloric acid and the product formed was collected by filtration and dried to give ethyl 3-OXO-4-(4-trifluoromethylphenyl)-2,3-dihydro tl] — benzopyrano[4,3-c]pyrazole-2-butyrate, m.p. 112—115°C. b) A mixture of ethyl 3-oxo-4-(4-trifluoromethylphenyl) -2,3-dihydro[1]benzopyrano[4,3-c]pyrazole-210 butyrate (3.0 g) and 5M hydrochloric acid (30 ml) was stirred and heated at 96-105°C for 5 hours. The reaction mixture was allowed to cool and was kept at ambient temperature for 24 hours. The solid obtained was collected by filtration, washed with water and then ether, and dried to give 3-oxo-4-(4-trifluoromethylphenyl) -2,3-dihydro[1]benzopyrano[4,3-c]pyrazole-2-butyric acid, m.p. 197-200°C with shrinking from 189 °C. c) A stirred suspension of 3-oxo-4-(4-trifluoro20 methylphenyl)-2,3-dihydro[1]benzopyrano[4,3-c]pyrazol2-butyric acid (1.8 g) in dichloromethane (37 ml) was treated with N,N,-dimethylformamide (0.2 ml) and then thionyl chloride (1.2 ml). The mixture was stirred at ambient temperature for 24 hours and then evaporated under reduced pressure to give 3-oxo-4-(4-trifluoromethylphenyl) -2,3-dihydro[1]benzopyrano[4,3-c]pyrazole2-butyryl chloride. , d) A solution of the acid chloride from stage (c) in dry tetrahydrofuran (88 ml) was stirred at 0.5°C and treated with concentrated aqueous ammonia solution (0.6 ml). The reaction mixture was stirred at 0-5°C for 1 hour. More concentrated ammonia solution (0.2 ml) was added and the mixture was stirred at 0-5°C for 0.75 hour. The solid formed was collected by IE 91287 - 45 filtration, washed with tetrahydrofuran and water, and dried to give 3-oxo-4-(4-trifluoromethylphenyl)-2,3dihydro[1]-benzopyrano[4,3-c]pyrazole-2-butyramide, m.p. 218-221°C.

Example 64 4-(4-Chlorophenyl)-2-(2-hydroxyethyl)[1]benzopyrano[4,3-c]pyrazol-3(2H)-one (28 g) , prepared as in Example 47, and thionyl chloride (300 ml) were stirred and boiled under reflux for 3.5 hours. Excess thionyl chloride was distilled off under reduced pressure and the residue stirred with acetonitrile. The mixture was filtered and the solid collected was recrystallised from dichloromethane to give 2-(2-chloroethyl)-4-(4chlorophenyl) [1]benzopyrano[4,3-c]pyrazol-3(2H)-one, m.p. 169-170°C.

Example 65 In the preparation of capsules, 10 parts by weight of active compound and 240 parts by weight of lactose are de-aggregated and blended. The mixture is filled into hard gelatin capsules, each capsule containing 10 mg active compound.

Example 66 In the preparation of capsules, 50 parts by weight of active compound, 300 parts by weight of lactose and 3 parts by weight of magnesium stearate are de-aggregated and blended. The mixture is filled into hard gelatin capsules, each capsule containing 50 mg of active ingredient.

Example 67 Tablets are prepared from the following ingredients.

Parts by weight Active compound Lactose Maize starch Polyvinylpyrrolidone Magnesium stearate 1 90 The active compound, the lactose and some of the starch are de-aggregated, blended and the resulting mixture is granulated with a solution of the polyvinylpyrrolidone in ethanol. The dry granulate is blended with magnesium stearate and the rest of the starch. The mixture is then compressed in a tableting machine to give tablets containing a) 10 mg, b) 100 mg and c) 500 mg of active compound.

Example 68 Tablets are prepared by the method of Example 67.

The tablets are enteric coated in a conventional manner using a solution of 20% cellulose acetate phthalate and 3% diethyl phthalate in ethanol:dichloromethane (1:1).

Example 69 z In the preparation of suppositories, 100 parts by 25 weight of active compound is incorporated in 1300 parts by weight of semi-synthetic glycerides as the suppository base and the mixture formed into suppositories each confining 100 mg of active ingredient.

Example 70 In the preparation of ointments the active compound is incorporated into the base by thorough homogenization until the drug is evenly distributed.

The ointment is packed into 10 g amber jars with screwcapped lined lids.

Active compound 0.1 g White soft paraffin to 10 g The compounds of the invention are immuno10 modulatory agents, especially immunosuppressants and may show therapeutic activity at a dose of 200 mg/kg or lower. Preferred compounds of the invention show activity at 50 mg/kg or lower. The therapeutic activity of the preferred compounds of the present invention has been demonstrated by a cutaneous hypersensitivity test {CH test) in which the compounds are administered parenterally to BALB/c mice. This test was carried out in the following way.

Female BALB/c mice, weight range 16-24 g, were used in groups of eight. The abdomen of each mouse was shaved and 20 μΐ of a solution of a sensitising agent, 5% w/v 4-ethoxymethylene-2-phenyl-2-oxazolin-5-one (oxazolone) in acetone: ethanol (1:1 by volume), was applied to the shaved area. Immediately after sensitisation, the test compound in one of the dosages listed below was injected intraperitoneally as a suspension in 1.5% v/v sorbitan esters, under the trade name Tween 80, in sterile water (100 μΐ) . 100 μΐ of the same suspension was injected likewise every 24 hours for a. further . 7 days. The dosages used were selected from the following values: 50, 30, TO, 3, 1, 0.3, 0.1, 0.03 or 0.01 mg/kg.

Two groups of at least eight BALB/c mice were used as a control simultaneously with each test in a similar manner to that described above except that no test compound was included in the daily injections.

On the seventh day after sensitisation, 10 μ.1 of a solution of 1% w/v oxazolone in acetone: olive oil (3:1 by volume) was applied to one ear (the challenged ear) of each of the test mice and the control mice. (A more potent challenge dose of 1.5% w/v oxazolone in acetone:olive oil was employed in a few cases). After 24 hours the thickness of the challenged ear and the thickness of the non-challenged ear of the same animal were measured with an engineer's screw gauge micrometer. The difference in thickness between the challenged ear and the non-challenged ear in each animal is a measure of the response of that animal to oxazolone. A comparison between the response of mice treated with the test compound and mice treated with the control indicates the effectiveness of the test compound as an immunomodulatory agent. The compounds were considered to be active at a particular dose if a 20% or greater reduction in ear swelling, which was statistically significant (p <0.05) according to Dunnett's test, between treated and control groups was obtained in at least two out of three CH tests, (or, where more than three tests have been carried out, a majority of the tests) at that dose (see for example Int. Arch. Allergy, 38, p246-259 (1970)).

Each of the compounds of formula I illustrated in Table A below was active at 50 mg/kg in at least two - out of three tests at 50 mg/kg unless indicated otherwise (see Notes following the Table). The minimum effective dose for each compound is given in Table A.

The Example (Ex) number or numbers listed adjacent to each compound indicates the process or processes illustrating the preparation of that compound in the Examples.

X Minimum Effective Dose (mg/kg) «3 Ex Compound Name Table A 9-methoxy-4-(4-trifluoromethylphenyl)8b [1 ]benzopyrano[4,3-c]pyrazol-3(2H)-one 2-(2-ethoxyethyl)-9-methoxy-4-(48c trifluoromethylphenyl)[1]benzopyrano10 [4,3-c]pyrazol-3(2H)-one 4-(4-chlorophenyl)-9-ethoxy-2-methyl9 [1]benzopyrano[4,3-c]pyrazol-3(2H)one 4-(4-chlorophenyl)-2-(2,2,2-trifluoro15 10 ethyl) [1]benzopyrano[4,3-c]pyrazol-3(2H)-one 4-(3,4-dichlorophenyl)-2-methyl[1]11 benzopyrano[4,3-c]pyrazol-3(2H)-one 2-methyl-4-(2-naphthyl)[1]benzo20 12 pyrano[4,3-c]pyrazol-3(2H)-one 4-(4-chlorophenyl)[1]benzopyrano13,19 [ 4,3-c]pyrazol-3(2H,-one 4-(4-chlorophenyl)-2-methyl[1]benzo14,24 pyrano[4,3-c]pyrazol-3(2H)-one 4-(4-chlorophenyl)-2-ethyl[1]benzo15 pyrano[4,3-c]pyrazol-3(2H)-one ^50 Minimum Effective Dose Ex Compound Name 18 23,20 21,22 26 4-(4-chlorophenyl)-9-methoxy-2-methyl[1]benzopyrano[4,3-c]pyrazol-3(2H)-one 4-(4-chlorophenyl)-2,9-dimethyl[1]benzopyrano[4,3-c]pyrazol-3(2H)-one 2-methyl-4-(4-trifluoromethylphenyl)[1]benzopyrano[4,3-c]pyrazol-3 (2H)one 4-(4-trifluoromethylphenyl)[1]benzopyrano [4,3-c]pyrazol-3(2H)-one 2-[4-(4-chlorophenyl)-3-oxo-2,3dihydro[1]benzopyrano[4,3-c]pyrazol2-yl]ethyl acetate 4-(4-chlorophenyl)-2-(2-methoxyethyl)[1]benzopyrano[4,3-c]pyrazol-3(2H)one 4-(4-chlorophenyl)-3-oxo-2,3-dihydro [1]benzopyrano[4,3-c]pyrazole-2acetonitrile 4-(4-chlorophenyl)-2-(2-phenoxyethyl)[ 1]benzopyrano[4,3-c]pyrazole-3(2H)one 2-allyl-4-(4-chlorophenyl)[1]benzopyrano[4,3-c]pyrazol-3(2H)-one (mg/kg) <50 Minimum Effective Dose (mg/kg) Ex Comound Name 32 4-(4-chlorophenyl)-3-oxo-2,3-dihydro[1]benzopyrano[4,3-c]pyrazole-2propionitrile 4-(4-chlorophenyl)-2-propyl[1]benzopyrano [ 4,3-c]pyrazol-3(2H)-one 34 4-(4-chlorophenyl)-3-ΟΧΟ-2,3-dihydro[ 1]benzopyrano[4,3-c]pyrazole-2carbonitrile 4-(4-chlorophenyl)-2-(2-ethoxyethyl)[1]benzopyrano[4,3-c]pyrazol-3(2H)15 one 2-butyl-4-(4-chlorophenyl)[1]benzopyrano[4,3-cJpyrazol-3(2H)-one 4-(4-chlorophenyl)-2-[2-(2-methoxyethoxy) ethyl][1]benzopyrano[4,3-c]20 pyrazol-3(2H)-one 4-(4-chlorophenyl)-3-oxo-2,3-dihydro[ 1 ] benzopyrano [4,3-c] pyrazoljs-2acetophenone 2-(2- [4-(4-chlorophenyl)-3-oxo-2,325 dihydro[1]benzopyrano[4,3-c]pyrazol2-yl]ethoxy)ethyl acetate ^30(a) Minimum Effective Dose (mg/kg) Ex Compound Name 4-(4-chlorophenyl)-2-[2-(1, 3-dioxolan40 2-yl)ethyl] [1]benzopyrano[4,3-c]pyrazol3(2H)-one 4-(4-chlorophenyl)-2-(1,3-dioxolan-242 ylmethyl) [1]benzopyrano[4,3-c]pyrazol10 3(2H)-one 4-(4-chlorophenyl)-2-(2-ethoxypropyl)43 [ 1 ]benzopyrano[4,3-c]pyrazol-3(2H)-one 2-[3-oxo-4-(4-trifluoromethylphenyl)44 2,3-dihydro[1]benzopyrano[4 ,3-c]pyrazol15 2-yl]ethyl acetate 4-(4-chlorophenyl)-2-[2-(1,3-dioxan-245 yl)ethyl][1]benzopyrano[4,3-c]pyrazol3(2H)-one 2-(2-hydroxyethyl)-4-(4-trifluoro20 46 methylphenyl)[1]benzopyrano[4,3-c]pyrazol-3(2H)-one 4-(4-chlorophenyl)-2-(2-hydroxyethyl)47 [1]benzopyrano[4,3-c]pyrazol-3(2H)-one 4-(4-chlorophenyl)-2-(3-hydroxypropyl)25 48 [1]benzopyrano[4,3-c]pyrazol-3(2H)-one 4-(4-chlorophenyl)-2-[2-(2-hydroxy49 ethoxy)ethyl] [1]benzopyrano[4,3-c]pyrazol-3(2H)-one IE 91287 Minimum Effective Dose (mg/kg) - 54 Ex Compound Name 4-(4-chlorophenyl)-3-oxo-2,3-dihydro50 [1]benzopyrano[4,3-c]pyrazole2-acetamide 4-(4-chlorophenyl)-3-oxo-2,3-dihydro51 [1]benzopyrano[4,3-c]pyrazole-210 propionamide 4-(4-chlorophenyl)-N-ethyl-3-oxo-2,352 dihydro[1]benzopyrano[4,3-c]pyrazole2-acetamide 4- (4-chlorophenyl)-N-methyl-3-oxo-2,315 53 dihydro[1]benzopyrano[4,3-c]pyrazole2-acetamide 4-(4-chlorophenyl)-3-oxo-N-propyl-2,354 dihydro[1]benzopyrano[4,3-c]pyrazole2-acetamide 4-(4-chlorophenyl)-3-oxo-2,3-dihydro55 [1]benzopyrano[4,3-c]pyrazole-2-carboxamide X 2-acetyl-4-(4-chlorophenyl)[1]benzo56 pyrano[4,3-c]pyrazol-3(2H)-one Ethyl 4-(4-chlorophenyl)-3-oxo-2,357,58 dihydro[1]benzopyrano[4,3-c]pyrazole-2carboxylate ,$50 Ex Compound Name cyclobutyl 4-(4-chlorophenyl)-3-oxo59 2,3-dihydro[1]benzopyrano[4,3-c]pyrazole-2-acetate 3-OXO-4-(4-trifluoromethylphenyl)-2,360 dihydro[1]benzopyrano[4,3-c]pyrazole10 2-acetonitrile 2-(2-ethoxyethyl)-4-(4-trifluoromethyl61 phenyl)[1]benzopyrano[4,3-c]pyrazol3(2H)-one 2- (2-bromoethyl)-4-(4-trifluoromethyl15 62 phenyl)[1]benzopyrano[4,3-c]pyrazol3 (2H)-one 3- OXO-4-(4-trifluoromethylphenyl)-2,363 dihydro[1]benzopyrano[4,3-c]pyrazole2-butyramide 2-(2-chloroethyl)-4-(4-chlorophenyl)64 [1]benzopyrano[4,3-c]pyrazol-3(2H)-one The following compounds were, prepared in analogous manner and also found to be active above described CH test at 50 mg/kg. 2-[4-(4-chlorophenyl)-3-oxo-2,3-dihydro[1]benzopyrano[4,3-c]pyrazol-2-yl]ethyl propionate, m.p. 112-114°C.

Minimum Effective Dose (mg/kg) ^50 ^50 an in the Ex Compound Name 4-(4-chlorophenyl)-N-isopropyl-3-oxo2,3-dihydro[1]benzopyrano[4,3-c]pyrazole2-acetamide, m.p. 238-241 (decomposition) N-benzyl-4-(4-chlorophenyl)-N-methyl-3oxo-2,3-dihydro[1]benzopyrano[4,3-c]10 pyrazole-2-acetamide m.p. 182-183°C Notes (a) Active in each of two tests at 30 mg/kg.

The compounds of the present invention also show activity in a variety of other in-vivo screens, which show the utility of the compounds as immunomodulants, particularly in suppressing the immune response. Administration of the compounds has been carried out orally, or parenterally. Some compounds have been found to be active in a test which determines their effects on humoral immunity by assaying the sera collected at the end of the oxazolone induced cutaneous hypersensitivity test described above (CH test) for changes in the amount of anti-039azolone antibody produced, and a Graft versus Host test similar to that used by Smith S R, Terminelli C, Kipilman C T and Smith Y., J. Immunopharmacology 1981;3(2),133-170.

For example, the compounds prepared in the following Examples were also found to be active in the above-described antibody test after parenteral administration at 50 mg/kg. A compound was deemed to be active, if at a dose of 50 mg/kg it caused a decrease in the relative serum anti-oxazolone antibody concentration determined by an enzyme linked immunosorbent assay (ELISA) by a factor of 0.5 or greater calculated by the following formula:O.D. (C] ) - O.D. (Tp O.D.(C]) - O.D.(C2) where O.D.(C^) is the optical density of the control serum at a dilution of 1/128 O.D.(C2) is the optical density of the control serum at a dilution of 1/256 O.D.(T^) is the optical density of the test serum at a dilution of 1/128 The control and test sera were diluted with phosphate buffered saline (pH 7.3) containing 0.05% v/v Tween 20 (trade name).

Compounds active in above test: Examples: 8b, 8c, 10-15, 18, 20, 26, 27, 30, 33, , 37, 38, 40, 42, 44-47, 49, 52, 55-64.

Claims (18)

1 . A compound of formula I in which represents hydrogen, cyano, C 2 _g alkanoyl, C 2 alkoxycarbonyl, CONH^, or R^ represents c -,_g 5 alkyl or C 2 g alkenyl both of which may be substituted by cyano, halo, trifluoromethyl, hydroxy, benzoyl, C 2 _g alkanoyloxy, C 3 g cycloalkoxycarbonyl, a 5-7 membered non-aromatic heterocyclic group containing 2 oxygen heteroatoms, CONRgRg,, phenoxy or C 1-6 alkoxy, in which 10 C, , alkoxy may be further substituted by halo, hydroxy, C^g alkoxy or C 2 _ g alkanoyloxy; R 2 represents hydrogen or chloro; R 3 represents chloro or trifluoromethyl; or R 2 and R 3 are joined to form a fused benz ring; 15 R 4 represents hydrogen, C^g alkyl, C-|_g alkoxy or halo; Rg and Rg, , which may be the same or different, represent hydrogen, C^_g alkyl or benzyl. IE 91287

2. A compound according to claim 1 in which R 2 represents hydrogen; R g represents chloro or trifluoromethyl; R^ represents (CH 2 ) p J, J represents hydrogen, <-η_θ alkoxy, carbamoyl, cyano or halo; R 4 represents hydrogen or C-|_g alkoxy and p is 0, 1 or 2.

3. A compound according to claim 2 in which R^ represents hydrogen, methyl, cyanomethyl, (CH 2 ) 2 halo, carbamoylmethyl or C^_ 4 alkoxyethyl.

4. A compound according to claim 3 in which Rg represents methyl or 2-ethoxyethyl.

5. A compound selected from: 2- (2-ethoxyethyl)-9-methoxy-4-(4-trifluoromethylphenyl) [1]benzopyrano[4,3-c]pyrazol-3(2H)-one 2-methyl-4-(4-trifluoromethylphenyl) (1 ]benzopyrano (4,3—£Ϊpyrazol-3(2H)-one 2-(2-ethoxyethyl)-4-(4-trifluoromethylphenyl)[1)benzopyrano [4,3-c] pyrazol-3 (2H) -one

6. A pharmaceutical composition comprising a compound of formula I as claimed in any one of claims 1-5 together with a pharmaceutical carrier.

7. A pharmaceutical compositign according to claim 6 in unit dosage form.

8. Use of a compound of formula I as claimed in any one of claims 1-5 for treating diseases with an immunological association. c. IE 91287 -/ -60

9. A compound of formula I as claimed in any one of claims 1-5 for use as an immunomodulatory agent.

10. A compound of formula I as claimed in any one of claims 1-5 in the manufacture of a medicament for use in 5 the treatment of diseases with an immunomological association.

11. A process to prepare a compound of formula I as claimed in claim 1:a) comprising the reaction of a compound of formula 10 II or a tautomer thereof, with a compound of formula III R 2 R 3 ' CR 14 R 15 III in which R^ 4 represents (OQ) 2 or (SQ) 2 and R-j 5 represents OQ or SQ or NQ* 2 ; R^ 4 represents =NH; and R 15 represents OQ or SQ; or R^ 4 represents =0 and R 15 15 represents hydrogen, halo or 1-imidazolyl; and Q and Q’ represent a C-,_ 4 alkyl group or a benzyl group; b) comprising the reaction of compounds of formula IV IE 91287 IV in which R-. represents hydrogen, or a tautomer Ί o thereof, or in which R 1 g represents a group COR-j θ wherein in R^θ represents hydrogen, a alkyl group, a benzyl group or a group R g and R^ ? represent COR,. 5 with a base;

12. A compound of formula II II OH in which R ] and R 4 are as defined in claim 1. IE 91287 •Τ

13. A compound of formula I given and defined in claim 1, substantially as hereinbefore described and exemplified.

14. A process to prepare a compound of formula I given and defined in claim 1, substantially as hereinbefore described and exemplified.

15. A compound of formula I given and defined in claim 1, whenever prepared by a process claimed in claim 11 or 14.

16. A pharmaceutical composition according to claim 6, substantially as hereinbefore described and exemplified.

17. A compound of formula II according to claim 12, substantially as hereinbefore described and exemplified.

18. Use according to claim 8, substantially as hereinbefore described.