Prevention, inhibition or treatment of conditions or disorders mediated by urocanate reductase

Abstract

The invention provides compounds of formula (I), stereoisomers, tautomers, or pharmaceutically acceptable salts thereof for use in preventing, inhibiting or treating a condition or disorder which is mediated by urocanate reductase: (I) wherein A is a 5-membered heteroaromatic ring containing 1 to 4 heteroatoms selected from nitrogen, oxygen and sulphur, and in which at least one of said heteroatoms is nitrogen; R1 and R2 are independently selected from: -H; C1-6 alkyl; C1-6 haloalkyl; C1-6 alkoxy; halogen; and -CN; when present, each R3 is independently selected from: C1-6 alkyl; C1-6 haloalkyl; C1-6 alkoxy; halogen; -OH; -CN; -NO2; -NR5R6 wherein R5 and R6 are independently selected from H and C1-3 alkyl; and -C(=NR7)(NR8R9) wherein each of R7, R8 and R9 is independently selected from H and C1-3 alkyl; R4 is selected from: -OH; -SH; C1-6 alkoxy; and -NR10R11 wherein R10 and R11 are independently selected from H and C1-3 alkyl; and n is an integer from 0 to 2. Such compounds are particularly suitable for use in preventing, inhibiting or treating gastrointestinal disorders or conditions, cardiovascular diseases or disorders, and metabolic disorders, such as but not limited to primary sclerosing cholangitis (PSC), myocardial fibrosis, heart failure, type 2 diabetes and pre-diabetes. The invention further provides certain novel compounds, methods for their preparation and pharmaceutical compositions containing such compounds.

Description

[0001] PREVENTION, INHIBITION OR TREATMENT OF CONDITIONS OR DISORDERS MEDIATED BY UROCANATE REDUCTASE

[0002] TECHNICAL FIELD

[0003] The present invention relates to the use of compounds in preventing, inhibiting or treating conditions which are mediated by urocanate reductase, more specifically conditions which are mediated by urocanate reductase present in the gut microbiota of a subject. In particular, it relates to the use of such compounds in preventing, inhibiting or treating conditions which arise from and / or are associated with the production of imidazole propionate, such as metabolic disorders, cardiovascular disorders, and disorders of the gastrointestinal system. The invention further relates to certain novel compounds, to pharmaceutical compositions containing them, and to their use in such treatment.

[0004] BACKGROUND

[0005] Urocanate reductase is a bacterial enzyme which catalyses the conversion of urocanate to imidazole propionate (ImP) in the microbial histidine degradation pathway.

[0006] Elevated ImP levels have been linked to a wide range of conditions, diseases and disorders. These include metabolic disorders, such as type 2 diabetes (T2D), a range of cardiovascular disorders such as cardiovascular disease (CVD), heart failure (HF) and myocardial fibrosis, and various gastrointestinal conditions such as inflammatory bowel disease (IBD).

[0007] Metabolic disorders may be associated with altered gut microbiota structure and function. The microbial metabolite ImP is present at higher concentrations in individuals with T2D and impaired glucose tolerance (IGT) as compared to healthy individuals with normal glucose tolerance (NGT) (Koh et al., Cell 175, 947-961, e17, 2018; and Molinaro et al., Nat. Commun. 11 , 5881 , 2020). Microbially produced ImP reduces insulin receptor substrate (IRS) protein levels and impairs insulin signaling through the alternative p38y mitogen-activated protein kinase (MAPK) activation pathway of mechanistic target of the rapacymin complex 1 (mTORCI). ImP thus contributes to the pathogenesis of T2D and IGT. Furthermore, elevated ImP levels are also associated with the inability of metformin to lower blood glucose levels by interfering with AMPK phosphorylation through a p38y / Akt dependent pathway (Koh et al., Cell Metabolism 32(4): 643-653, 2020). It has been shown that plasma ImP concentrations are positively correlated with diastolic blood pressure (Son et al., Nutrients 13, 2021). Pharmacological inhibition of p38y, the molecular target of ImP, has also been found to reduce myocardial fibrosis in patients with HFpEF (Lewis et al., Nature Medicine 27, 1477-1482, 2021), and the activation of p38y / 5 has been shown to induce cardiac hypertrophy and thus potentially contribute to diabetic cardiomyopathy (DCM) (Gonzalez-Teran et al., Nat. Commun. 7:10477, 2016). More recently, it has been demonstrated that ImP levels are associated with CVD and HF in human subjects, independently of T2D and other established cardiovascular risk factors, and that ImP levels are an independent risk factor for overall mortality (Molinaro et al., JACC Heart Fail. 2023 Apr 1 ; S2213-1779(23) 00138-5, doi: 10.1016 / j.jchf.2023.03.008). Specifically, elevated ImP levels were found to be associated with reduced left ventricular systolic ejection fraction and a predictor of 5 years mortality. Increased levels of the gut microbial metabolite ImP thus contribute to CVD and HF, and are a predictor of overall survival.

[0008] An earlier study reported that ImP is excreted from patients with intestinal disorders but is almost absent in faeces and urine from healthy subjects (Van Der Heiden et al., Clinica Chimica Acta 39, 201 - 214, 1972). ImP is associated with inflammatory bowel disease and rectal ImP administration has also been shown to induce intestinal inflammation, impair the intestinal barrier, and affect the proliferation of goblet cells (Vich Vila et al., Gut 0:1-14, 2023; and Wu et al., Mol. Nutr. Food Res. 66, e2101175, 2022). ImP is also associated with colorectal cancer (Gao et al., Gastroenterology 163(4): P1024- 1037, 2022). Previous studies have also shown that the mTORC pathway, which includes p38y, the molecular target of ImP, is activated in patients with primary sclerosing cholangitis (PSC) which is a long-term progressive disease of the liver and gallbladder (Panzitt et al., J. Hepatol. 72, 1122-1131 , 2020). PSC increases the risk of various cancers, including liver cancer, gallbladder carcinoma, colorectal cancer and cholangiocarcinoma. For example, it has been shown that ImP is increased in patients with colon carcinoma (Gao et al., Gastroenterology 163: 1024-1037, e1029, 2022). Increased ImP levels have also been shown to be associated with a NASH Gottingen Minipig model (Liitzhoft et al., BMC Microbiol. 22, 287, 2020). These studies suggest that decreasing ImP levels is a therapeutic target in the treatment of various gastrointestinal disorders and associated conditions.

[0009] SUMMARY

[0010] ImP is a known microbial histidine degradation product. Fig. 1 shows the histidine degradation pathway in which urocanate reductase is involved in the conversion of urocanate into ImP. By way of the present invention, the inventors have identified compounds which are urocanate reductase inhibitors. Such compounds are thus capable of inhibiting the conversion of urocanate into ImP by urocanate reductase and are proposed herein for use in preventing, inhibiting or treating disorders and conditions mediated by microbial urocanate reductase.

[0011] It is a general objective therefore to provide compounds which are capable of inhibiting urocanate reductase, in particular bacterially derived urocanate reductase, and in that way reduce the levels of ImP in the intestine, in the circulation or in body tissues.

[0012] It is another general objective to provide compounds useful in the prevention, inhibition or treatment of disorders and conditions mediated by urocanate reductase, more specifically disorders and conditions which arise from and / or are associated with urocanate reductase mediated production of ImP. Such disorders and conditions include, but are not limited to, metabolic disorders, cardiovascular disorders, and disorders of the gastrointestinal system. The use of such compounds in the treatment of patients suffering from such disorders and conditions is also an objective.

[0013] These and other objectives are met by embodiments disclosed herein.

[0014] In one aspect the invention provides compounds of formula (I), stereoisomers, tautomers, or pharmaceutically acceptable salts thereof for use in preventing, inhibiting or treating a condition or disorder which is mediated by urocanate reductase: wherein:

[0015] A is a 5-membered heteroaromatic ring containing 1 to 4 heteroatoms selected from nitrogen, oxygen and sulphur, and in which at least one of said heteroatoms is nitrogen;

[0016] R1and R2are independently selected from:

[0017] -H;

[0018] C1-6 alkyl, preferably C1-3 alkyl, e.g. -CH3;

[0019] C1-6 haloalkyl, preferably C1-3 haloalkyl, e.g. -CF3; Ci-6 alkoxy, preferably C1-3 alkoxy, e.g. -OCH3; halogen, preferably F, Cl, Br or I; and

[0020] -CN; when present, each R3is independently selected from:

[0021] C1-6 alkyl, preferably C1-3 alkyl, e.g. -CH3;

[0022] C1-6 haloalkyl, preferably C1-3 haloalkyl, e.g. -CF3;

[0023] C1-6 alkoxy, preferably C1-3 alkoxy, e.g. -OCH3; halogen, preferably F, Cl, Br or I;

[0024] -OH;

[0025] -CN;

[0026] -NO2;

[0027] -NR5R6wherein R5and R6are independently selected from H and C1-3 alkyl, preferably selected from H and -CH3; and

[0028] -C(=NR7)(NR8R9) wherein each of R7, R8and R9is independently selected from H and C1-3 alkyl, preferably selected from H and -CH3;

[0029] R4is selected from:

[0030] -OH;

[0031] -SH;

[0032] C1-6 alkoxy, preferably C1-3 alkoxy; and

[0033] -NR10R11wherein R10and R11are independently selected from H and C1-3 alkyl, preferably selected from H and -CH3; and n is an integer from O to 2.

[0034] In another aspect the invention provides compounds of formula (I), stereoisomers, tautomers, and pharmaceutically acceptable salts thereof for use as a medicament.

[0035] In a further aspect the invention provides a pharmaceutical composition comprising a compound of formula (I), or a tautomer, stereoisomer, or pharmaceutically acceptable salt thereof, together with one or more pharmaceutically acceptable carriers, excipients or diluents.

[0036] In another aspect the invention relates to novel compounds of formulae (II), (III), (IV) and (V) as herein described, their stereoisomers, tautomers, and pharmaceutically acceptable salts. In a further aspect the invention relates to a compound of formula (II), (III), (IV) or (V), or a stereoisomer, tautomer, or pharmaceutically acceptable salt thereof for use as a medicament.

[0037] In a further aspect the invention relates to a compound of formula (II), (III), (IV) or (V), or a stereoisomer, tautomer, or pharmaceutically acceptable salt thereof for use in preventing, inhibiting or treating a condition or disorder which is mediated by urocanate reductase.

[0038] In a further aspect the invention relates to a process for the preparation of a compound of formula (II), (III), (IV) or (V), or a stereoisomer, tautomer, or pharmaceutically acceptable salt thereof.

[0039] In a further aspect the present invention provides a pharmaceutical composition comprising a compound of formula (II), (III), (IV) or (V), or a stereoisomer, tautomer, or pharmaceutically acceptable salt thereof, together with one or more pharmaceutically acceptable carriers, excipients or diluents.

[0040] Use of any of the compounds herein described, or a stereoisomer, tautomer, or pharmaceutically acceptable salt thereof, in the manufacture of a medicament for use in preventing, inhibiting or treating a condition or disorder mediated by urocanate reductase forms a further aspect of the invention.

[0041] A method of preventing, inhibiting or treating a condition or disorder mediated by urocanate reductase, said method comprising the step of administering to a patient in need thereof (e.g. a human subject) a pharmaceutically effective amount of any compound as herein described, or a stereoisomer, tautomer, or pharmaceutically acceptable salt thereof, forms a yet further aspect of the invention.

[0042] DETAILED DESCRIPTION

[0043] Definitions

[0044] The term “alkyl” as used herein refers to a monovalent saturated, linear or branched, carbon chain. An alkyl group preferably contains from 1-3 carbon atoms. Examples of alkyl groups include methyl, ethyl, n-propyl and iso-propyl. The term “alkoxy” as used herein refers to an -O-alkyl group, wherein alkyl is as defined herein. An alkoxy group preferably contains from 1-3 carbon atoms. Examples of alkoxy groups include methoxy, ethoxy, n-propoxy and isopropoxy.

[0045] The term “halogen” as used herein refers to F, Cl, Br or I.

[0046] The term “haloalkyl” refers to an alkyl group as defined herein in which at least one of the hydrogen atoms of the alkyl group is replaced by a halogen atom, preferably F, Cl or Br. Examples of such groups include -CH2F, -CHF2, -CF3, -CCI3, -CHCI2, -CH2CF3, etc.

[0047] The term “heteroaromatic ring” refers to a heterocyclic aromatic group. A heterocyclic aromatic group comprises at least one unsaturated heteroaromatic ring system. It contains at least one heteroatom selected from nitrogen, oxygen and sulfur and contains sufficient conjugated bonds to form an aromatic system. In the compounds herein described, the heteroaromatic ring is a 5-membered ring containing 1 to 4 heteroatoms in which at least one of the heteroatoms is nitrogen. Examples of such heteroaromatic rings include, but are not limited to, thiazolyl, pyrrolyl, triazolyl, imidazolyl, oxadiazolyl, pyrazolyl, tetrazolyl and thiadiazolyl. Unless otherwise stated, any heteroaromatic ring mentioned herein may optionally be substituted by one or more groups. Where more than one substituent group is present, these may be the same or different.

[0048] Unless otherwise stated, all substituents are independent of one another.

[0049] In the case where a subscript is the integer 0 (i.e. zero), it is intended that the group to which the subscript refers is absent.

[0050] Unless specifically indicated, throughout the application and appended claims, a given chemical formula or name shall encompass all tautomers and all stereoisomers, and racemates thereof as well as mixtures in different proportions of any of these forms.

[0051] The compounds of the invention may exist in different stereoisomeric forms. The term “stereoisomer” refers to compounds which have identical chemical constitution but which differ in respect of the spatial arrangement of the atoms or groups. For example, the compounds may contain one or more stereocenters and therefore exist as different enantiomers or diastereomers. The term “enantiomers” refers to two stereoisomers of a compound which are non-superimposable mirror images of one another. The term “diastereoisomers” refers to stereoisomers with two or more stereocenters which are not mirror images of one another. The invention is considered to extend to diastereomers and enantiomers, as well as racemic mixtures and enantioenriched mixtures in which the ratio of enantiomers is other than 1 :1.

[0052] The compounds herein described may be resolved into their enantiomers and / or diastereomers. For example, where these contain only one chiral center, these may be provided in the form of a racemate or racemic mixture (a 50:50 mixture of enantiomers) or may be provided as pure enantiomers, i.e. in the R- or S-form. Any of the compounds which occur as racemates may be separated into their enantiomers by methods known in the art, such as column separation on chiral phases or by recrystallization from an optically active solvent. Those compounds with at least two asymmetric carbon atoms may be resolved into their diastereomers on the basis of their physical-chemical differences using methods known perse, e.g. by chromatography and / or fractional crystallization, and where these compounds are obtained in racemic form, they may subsequently be resolved into their enantiomers.

[0053] Due to the presence of the carbon-carbon double bond in the compounds herein described, their isomers also encompass cis / trans or E / Z isomers. These may also be referred to as geometric isomers. In a preferred embodiment, the compounds herein described are provided as the specific geometric isomer in which ring A and the group -C(O)R4are located trans to one another.

[0054] The term “tautomer” as used herein refers to structural isomers which readily interconvert. This may, for example, be by way of a chemical reaction which involves the migration of a proton accompanied by a switch of a single bond and adjacent double bond. It includes, in particular, keto-enol tautomers and amide-imidic acid tautomers, as well as tautomeric forms of 5-membered heterocyclic compounds which contain two or more ring nitrogen atoms (e.g. imidazoles, pyrazoles, triazoles, tetrazoles, etc.). Dependent on the conditions, the compounds may predominantly exist in one of the tautomeric forms. Neutral and zwitterionic forms of a compound are also encompassed by the term “tautomer” as used herein. These may arise, for example, by migration of a proton from a carboxylic acid to an amine group within the molecule. The predominance of the zwitterionic form of a compound will be dependent on pH. The invention is considered to extend to the use of tautomers of any of the compounds herein described and mixtures of tautomers. The term “pharmaceutically acceptable salt” as used herein refers to any pharmaceutically acceptable organic or inorganic salt of any of the compounds herein described. A pharmaceutically acceptable salt may include one or more additional molecules such as counter-ions. The counter-ions may be any organic or inorganic group which stabilizes the charge on the parent compound. If the compound of the invention is a base, a suitable pharmaceutically acceptable salt may be prepared by reaction of the free base with an organic or inorganic acid. If the compound of the invention is an acid, a suitable pharmaceutically acceptable salt may be prepared by reaction of the free acid with an organic or inorganic base. Non-limiting examples of suitable salts are described herein.

[0055] The term “pharmaceutically acceptable” means that the compound or composition is chemically and / or toxicologically compatible with other components of the formulation or with the patient (e.g. human) to be treated.

[0056] By “a pharmaceutical composition” is meant a composition in any form suitable to be used for a medical purpose.

[0057] As used herein, “treatment” includes any therapeutic application that can benefit a human or nonhuman animal (e.g. a non-human mammal). Both human and veterinary treatments are within the scope of the present invention, although primarily the invention is aimed at the treatment of humans. Treatment may be in respect of an existing disease or condition or it may be prophylactic.

[0058] As used herein, “prevention” refers to any preventative treatment of the defined disorder in a subject. Specifically, it includes prevention of the disorder from occurring, or reduction of the risk that the disorder may occur, in particular when the subject may be predisposed to the disorder but has not yet been diagnosed as having it.

[0059] As used herein, “inhibiting” of a defined disorder in a subject includes (i) arresting further development (progression) of the disorder or delaying its onset; and (ii) relieving the disorder, in particular causing the regression of the disorder until a desired outcome is reached.

[0060] As used herein, a “pharmaceutically effective amount” relates to an amount that will lead to the desired pharmacological and / or therapeutic effect, i.e. an amount of the agent which is effective to achieve its intended purpose. While individual patient needs may vary, determination of optimal ranges for effective amounts of the active agent is within the capability of one skilled in the art. Generally, the dosage regimen for treating a disease or condition with any of the compounds described herein is selected in accordance with a variety of factors including the nature of the medical condition and its severity.

[0061] As used herein, “urocanate reductase" refers to an enzyme which catalyses the conversion of urocanate to ImP in the microbial histidine degradation pathway. In particular, it refers to an enzyme having the classification EC 1.3.99.33. Urocanate reductase is an enzyme enriched in the gut microbiota of subjects suffering from, for example, T2D or pre-diabetes. In these bacteria, the urocanate reductase, encoded by the gene urdA, is involved in the conversion of urocanate into ImP, see Fig. 4. The enzyme urocanate reductase is not, as far as the inventors are aware, present in humans since no urdA homologs with more than 30% sequence identity have been identified in the human genome. ImP producing bacteria include, but are not limited to, Aerococcus urinae, Anaerococcus prevotii, Brevibacillus laterosporus, Eggerthella lenta and Shewanella oneidensis.

[0062] Any reference herein to "urocanate reductase activity" relates to the conversion of urocanate to ImP, or to any other enzymatic activity of urocanate reductase, or a fragment thereof. Reference to a "urocanate reductase inhibitor" or “inhibition of urocanate reductase” should be construed accordingly. A "urocanate reductase inhibitor” is thus a compound that reduces the conversion of urocanate to ImP, or that otherwise reduces urocanate reductase enzymatic activity. Such a reduction need not be complete but will typically be a reduction of at least about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or may be as high as at least 90% or at least 95%.

[0063] “Pre-diabetes” as referred to herein is either impaired fasting glycemia (IFG) or impaired glucose tolerance (IGT).

[0064] “Impaired fasting glycemia” or “IFG” as referred to herein is a type of pre-diabetes in which a subject’s blood sugar levels during fasting are consistently above the normal range, but below the diagnostic cut-off for a formal diagnosis of type 2 diabetes. According to the criteria of the World Health Organization (WHO), IFG is defined as a fasting plasma glucose level from 110 to 125 mg per dl, i.e., 6.1 to 6.8 mmol / l. “Impaired glucose tolerance” or “IGT” as referred to herein is a pre-diabetic state of hyperglycemia that is associated with insulin resistance and increased risk of cardiovascular pathology. IGT, as well as IFG, may precede type 2 diabetes (T2D) by many years. According to the criteria of the World Health Organization (WHO) and the American Diabetes Association (AAD), IGT is defined as two-hour glucose levels of 140 to 199 mg per dl, i.e., 7.8 to 11 .0 mmol / l, on the 75-g oral glucose tolerance test. A patient is said to be under the condition of IGT when he / she has an intermediately raised glucose level after 2 hours, but less than the level that would qualify for T2D. The fasting glucose may be either normal or mildly elevated, typically less than 6.1 mmol / l.

[0065] “Type 2 diabetes” or “T2D” as referred to herein, which may also be referred to as type 2 diabetes mellitus, is a long-term metabolic disorder that is characterized by high blood sugar, insulin resistance, and relative lack of insulin. Long-term complications from high blood sugar include heart disease; stroke; diabetic retinopathy, which can result in blindness; kidney failure; and poor blood flow in the limbs which may lead to amputations. The WHO definition of T2D is for a single raised glucose reading with symptoms, otherwise raised values on two occasions, of either fasting plasma glucose > 7.0 mmol / l (126 mg / dl) or with a glucose tolerance test, two hours after the oral dose a plasma glucose > 11.1 mmol / l (200 mg / dl). The WHO definition of T2D in relation to HbAic is > 48 mmol / mol. The table below summaries the WHO diabetes diagnostic criteria:

[0066] WHO diabetes diagnostic criteria

[0067] IFG - impaired fasting glycemia

[0068] HbAic - levels of glycated hemoglobin

[0069] DOOT - Diabetes Control and Complications Trial

[0070] The inventors have found that the compounds herein described can act as inhibitors of urocanate reductase (e.g. urocanate reductase according to the enzyme classification EC 1.3.99.33). This discovery leads to the use of the compounds to treat or prevent conditions or diseases in subjects, e.g. in humans, which are mediated by the activity of urocanate reductase. As inhibitors of the bacterial enzyme urocanate reductase, the compounds herein described are particularly suitable for inhibiting the production of the deleterious ImP, making the compounds useful for preventing or treating disorders or conditions which are associated with elevated levels of ImP in the intestine, in the circulatory system or in body tissues, for example elevated levels of ImP in the blood (e.g. plasma or serum), urine or faeces. These include metabolic disorders (e.g. T2D, IGT and pre-diabetes), cardiovascular disorders, and disorders of the gastrointestinal system.

[0071] In one aspect the invention relates to compounds of formula (I), stereoisomers, tautomers, or pharmaceutically acceptable salts thereof for use in preventing, inhibiting or treating a condition or disorder which is mediated by urocanate reductase: wherein:

[0072] A is a 5-membered heteroaromatic ring containing 1 to 4 heteroatoms selected from nitrogen, oxygen and sulphur, and in which at least one of said heteroatoms is nitrogen;

[0073] R1and R2are independently selected from:

[0074] -H;

[0075] C1-6 alkyl, preferably C1-3 alkyl, e.g. -CH3;

[0076] C1-6 haloalkyl, preferably C1-3 haloalkyl, e.g. -CF3;

[0077] C1-6 alkoxy, preferably C1-3 alkoxy, e.g. -OCH3; halogen, preferably F, Cl, Br or I; and

[0078] -CN; when present, each R3is independently selected from:

[0079] C1-6 alkyl, preferably C1-3 alkyl, e.g. -CH3;

[0080] C1-6 haloalkyl, preferably C1-3 haloalkyl, e.g. -CF3;

[0081] C1-6 alkoxy, preferably C1-3 alkoxy, e.g. -OCH3; halogen, preferably F, Cl, Br or I;

[0082] -OH;

[0083] -CN;

[0084] -NO2; -NR5R6wherein R5and R6are independently selected from H and C1-3 alkyl, preferably selected from H and -CH3; and

[0085] -C(=NR7)(NR8R9) wherein each of R7, R8and R9is independently selected from H and C1-3 alkyl, preferably selected from H and -CH3;

[0086] R4is selected from:

[0087] -OH;

[0088] -SH;

[0089] C1-6 alkoxy, preferably C1-3 alkoxy; and

[0090] -NR10R11wherein R10and R11are independently selected from H and C1-3 alkyl, preferably selected from H and -CH3; and n is an integer from O to 2.

[0091] In formula (I), heteroaromatic ring A may be linked to the group any suitable point on the ring. As will be understood, linkage may either be via a ring nitrogen atom or via a carbon atom in the ring. In one embodiment, the heteroaromatic ring A is bound to the group R1via a carbon atom in the ring.

[0092] Where present, any R3groups may be linked to the heteroaromatic ring A at any suitable point on the ring. As will be understood, linkage may either be via a ring nitrogen atom or via a carbon atom in the ring. In one embodiment, a single group R3is present (n is 1) and is joined to the heteroaromatic ring via a ring nitrogen atom. In another embodiment, a single group R3is present (n is 1) and is joined to the heteroaromatic ring via a ring carbon atom. In yet another embodiment, two groups R3are present (n is 2) and these are joined to two carbon atoms present in the heteroaromatic ring, e.g. to two adjacent carbon atoms.

[0093] In one embodiment, the compounds for use in the invention are those of formula (I), stereoisomers, tautomers, and pharmaceutically acceptable salts thereof, wherein A is a 5-membered heteroaromatic ring containing 1 to 3 heteroatoms selected from nitrogen and sulphur. In one embodiment, A is a 5- membered heteroaromatic ring containing 1 or 2 heteroatoms selected from nitrogen and sulphur. In one embodiment, the compounds for use in the invention are those of formula (I), stereoisomers, tautomers, and pharmaceutically acceptable salts thereof, wherein A is a 5-membered heteroaromatic ring containing 1 to 3 nitrogen atoms. In one embodiment, A is a 5-membered heteroaromatic ring containing 1 or 2 nitrogen atoms.

[0094] In one embodiment, the compounds for use in the invention are those of formula (I), stereoisomers, tautomers, and pharmaceutically acceptable salts thereof, wherein A is an optionally substituted imidazolyl, pyrazolyl, pyrrolyl, or thiazolyl group. In one embodiment, A is optionally substituted imidazolyl, pyrazolyl, or pyrrolyl. In another embodiment, A is optionally substituted 4-imidazolyl, 3- pyrazolyl, 4-pyrazolyl, 3-pyrrolyl, or 4-thiazolyl.

[0095] As will be understood, the optional substituents present in ring A are groups R3as herein defined. In one embodiment, each R3is independently selected from C1-3 alkyl, C1-3 haloalkyl, C1-3 alkoxy, F, Cl, Br, I, -OH, -NH2, and -C(=NH)(NH2). In one embodiment, each R3is independently selected from -CH3, -CF3, -OCH3, -OH, -NH2, and -C(=NH)(NH2). In one embodiment, each R3is independently selected from -CH3 and -NH2.

[0096] Where the substituent group R3is C1-6 alkyl, this may be linked either to a ring nitrogen atom or to a ring carbon in group A. In one embodiment, any substituent groups R3that are present are linked to a carbon atom which forms part of the ring.

[0097] The number of substituent groups R3present in ring A may vary. In one embodiment, there are no substituent groups present on ring A (i.e. n is 0). In one embodiment, there is a single substituent group, i.e. n is 1.

[0098] In one embodiment, the compounds for use in the invention are those of formula (I), stereoisomers, tautomers, and pharmaceutically acceptable salts thereof, wherein n is other than 0, and R3is selected from C1-3 alkyl (e.g. -CH3 or -CH2CH3), C1-3 haloalkyl (e.g. -CF3), C1-3 alkoxy (e.g. -OCH3), F, Cl, -NH2 and -OH.

[0099] In one embodiment, the compounds for use in the invention are those of formula (I), stereoisomers, tautomers, and pharmaceutically acceptable salts thereof, wherein n is 1 , and R3is selected from C1-3 alkyl (e.g. -CH3or -CH2CH3), C1-3 haloalkyl (e.g. -CF3), C1-3 alkoxy (e.g. -OCH3), F, Cl, -NH2 and -OH, preferably wherein R3is either -CH3 or -NH2.

[0100] In one embodiment, the compounds for use in the invention are those of formula (I), stereoisomers, tautomers, and pharmaceutically acceptable salts thereof, wherein R1and R2are independently selected from -H, C1-3 alkyl (e.g. -CH3 or -CH2CH3), C1-3 haloalkyl (e.g. -CF3), F and Cl.

[0101] In one embodiment, R1is H, -CH3, -CH2CH3 or F.

[0102] In one embodiment, R1is H.

[0103] In one embodiment, R2is H, -CH3, -CH2CH3 or F.

[0104] In one embodiment, R2is H, -CH3 or -CH2CH3.

[0105] In one embodiment, R2is -CH3 or -CH2CH3, preferably -CH3.

[0106] In one embodiment, R2is other than H.

[0107] In one embodiment, the compounds for use in the invention are those of formula (I), stereoisomers, tautomers, and pharmaceutically acceptable salts thereof, wherein in formula (I), R4is -OH or C1-3 alkoxy. In one embodiment, R4is OH.

[0108] In one embodiment, the compounds for use in the invention are any of the compounds of formula (I) as herein described in which the heteroaromatic ring A and the group -C(O)R4are trans to one another.

[0109] In one embodiment, the compounds for use in the invention are those of formula (II), stereoisomers, tautomers, or pharmaceutically acceptable salts thereof: wherein R1, R2, R3and R4are as herein defined; and m is an integer from 0 to 2, preferably 0 or 1 .

[0110] In one embodiment, the compounds for use in the invention are those of formula (II) as herein described in which the imidazolyl ring and the group -C(O)R4are trans to one another.

[0111] In one embodiment, the compounds for use in the invention are those of formula (III), stereoisomers, tautomers, or pharmaceutically acceptable salts thereof: wherein R1, R2, R3and R4are as herein defined; and p is an integer from 0 to 2, preferably 0 or 1 .

[0112] In one embodiment, the compounds for use in the invention are those of formula (III) as herein described in which the pyrazolyl ring and the group -C(O)R4are trans to one another.

[0113] In one embodiment, the compounds for use in the invention are those of formula (IV), stereoisomers, tautomers, or pharmaceutically acceptable salts thereof: wherein R1, R2, R3and R4are as herein defined; and q is an integer from 0 to 2, preferably 0 or 1 .

[0114] In one embodiment, the compounds for use in the invention are those of formula (IV) as herein described in which the pyrrolyl ring and the group -C(O)R4are trans to one another. In one embodiment, the compounds for use in the invention are those of formula (V), stereoisomers, tautomers, or pharmaceutically acceptable salts thereof: wherein R1, R2, R3and R4are as herein defined; and s is an integer from 0 to 2, preferably 0 or 1 .

[0115] In one embodiment, the compounds for use in the invention are those of formula (V) as herein described in which the thiazolyl ring and the group -C(O)R4are trans to one another.

[0116] Examples of compounds for use in accordance with the invention include, but are not limited to, the following, their stereoisomers, their tautomers and their pharmaceutically acceptable salts:

[0117]

[0118]

[0119]

[0120] Preferred for use in the invention are the specific geometric isomers of Compound Nos. 1-28 shown in the table above in which the 5-membered heteroaromatic ring is positioned trans to the -C(O)OH group, their tautomers and their pharmaceutically acceptable salts.

[0121] Preferred for use in the invention are Compound Nos. 1-12, their stereoisomers, tautomers, and pharmaceutically acceptable salts. Particularly preferred for use in the invention are the specific geometric isomers of Compound Nos. 1-12 shown in the table above in which the 5-membered heteroaromatic ring is positioned trans to the -C(O)OH group, and pharmaceutically acceptable salts thereof.

[0122] Certain compounds described herein are novel and these form a further aspect of the invention. Thus, in a further aspect, the present invention provides certain novel compounds of formula (II), (Ila), (III), (Illa), (IV), (IVa), (V) and (Va), stereoisomers, tautomers, and pharmaceutically acceptable salts thereof.

[0123] The novel compounds of formula (II) are those having the following structural formula: wherein:

[0124] R1and R2are independently selected from:

[0125] -H;

[0126] C1-6 alkyl, preferably C1-3 alkyl, e.g. -CH3;

[0127] C1-6 haloalkyl, preferably C1-3 haloalkyl, e.g. -CF3;

[0128] C1-6 alkoxy, preferably C1-3 alkoxy, e.g. -OCH3; halogen, preferably F, Cl, Br or I; and

[0129] -CN; when present, each R3is independently selected from:

[0130] C1-6 alkyl, preferably C1-3 alkyl, e.g. -CH3;

[0131] C1-6 haloalkyl, preferably C1-3 haloalkyl, e.g. -CF3;

[0132] C1-6 alkoxy, preferably C1-3 alkoxy, e.g. -OCH3; halogen, preferably F, Cl, Br or I;

[0133] -OH;

[0134] -CN;

[0135] -NO2;

[0136] -NR5R6wherein R5and R6are independently selected from H and C1-3 alkyl, preferably selected from H and -CH3; and

[0137] -C(=NR7)(NR8R9) wherein each of R7, R8and R9is independently selected from H and C1-3 alkyl, preferably selected from H and -CH3;

[0138] R4is selected from:

[0139] -OH;

[0140] -SH;

[0141] C1-6 alkoxy, preferably C1-3 alkoxy; and

[0142] -NR10R11wherein R10and R11are independently selected from H and C1-3 alkyl, preferably selected from H and -CH3; and m is an integer from 0 to 2, preferably 0 or 1 ; with the proviso that the compound is other than:

[0143]

[0144] In one embodiment, the novel compounds of formula (II) are those in which m is 0 (i.e. the heteroaromatic ring is unsubstituted) or in which m is 1 and R3is a group -NR5R6, preferably -NH2.

[0145] In one embodiment, the novel compounds of formula (II) are those in which R1and R2are independently selected from -H and C1-6 alkyl, preferably from -H and C1-3 alkyl, e.g. from -H and -CH3

[0146] In one embodiment, the novel compounds of formula (II) are those in which R4is OH.

[0147] In one embodiment, the novel compounds of formula (II) are those in which the imidazolyl ring and the group -C(O)R4are trans to one another.

[0148] The novel compounds of formula (Ila) are those having the following structural formula, their stereoisomers, tautomers, or pharmaceutically acceptable salts: wherein: when present, each R3is independently selected from:

[0149] C1-6 alkyl, preferably C1-3 alkyl, e.g. -CH3;

[0150] C1-6 haloalkyl, preferably C1-3 haloalkyl, e.g. -CF3;

[0151] C1-6 alkoxy, preferably C1-3 alkoxy, e.g. -OCH3; halogen, preferably F, Cl, Br or I;

[0152] -OH;

[0153] -CN;

[0154] -NO2;

[0155] -NR5R6wherein R5and R6are independently selected from H and C1-3 alkyl, preferably selected from H and -CH3; and

[0156] -C(=NR7)(NR8R9) wherein each of R7, R8and R9is independently selected from H and C1-3 alkyl, preferably selected from H and -CH3; and m is an integer from 0 to 2, preferably 0 or 1 .

[0157] In one embodiment, the novel compounds of formula (Ila) are those in which m is 0 or m is 1 and R3is either a group -NR5R6, preferably -NH2, or R3is C1-3 alkyl, preferably -CH3.

[0158] In one embodiment, the novel compounds of formula (Ila) are those in which the imidazolyl ring and the group -C(O)OH are trans to one another.

[0159] The compounds of formula (III) are those having the following structural formula: wherein:

[0160] R1and R2are independently selected from:

[0161] -H;

[0162] C1-6 alkyl, preferably C1-3 alkyl, e.g. -CH3;

[0163] C1-6 haloalkyl, preferably C1-3 haloalkyl, e.g. -CF3;

[0164] C1-6 alkoxy, preferably C1-3 alkoxy, e.g. -OCH3; halogen, preferably F, Cl, Br or I; and

[0165] -CN; when present, each R3is independently selected from:

[0166] C1-6 alkyl, preferably C1-3 alkyl, e.g. -CH3;

[0167] C1-6 haloalkyl, preferably C1-3 haloalkyl, e.g. -CF3;

[0168] C1-6 alkoxy, preferably C1-3 alkoxy, e.g. -OCH3; halogen, preferably F, Cl, Br or I;

[0169] -OH;

[0170] -CN;

[0171] -NO2;

[0172] -NR5R6wherein R5and R6are independently selected from H and C1-3 alkyl, preferably selected from H and -CH3; and

[0173] -C(=NR7)(NR8R9) wherein each of R7, R8and R9is independently selected from H and C1-3 alkyl, preferably selected from H and -CH3;

[0174] R4is selected from:

[0175] -OH;

[0176] -SH;

[0177] C1-6 alkoxy, preferably C1-3 alkoxy; and

[0178] -NR10R11wherein R10and R11are independently selected from H and C1-3 alkyl, preferably selected from H and -CH3; and p is an integer from 0 to 2, preferably 0 or 1 ; with the proviso that the compound of formula (III) is other than:

[0179] In one embodiment, the novel compounds of formula (III) are those in which p is 0 (i.e. the heteroaromatic ring is unsubstituted) or in which p is 1 and R3is C1-6 alkyl, preferably C1-3 alkyl, e.g. -CH3.

[0180] In one embodiment, the novel compounds of formula (III) are those in which R1and R2are independently selected from -H and C1-6 alkyl, preferably from -H and C1-3 alkyl, e.g. from -H, -CH3 and -CH2CH3.

[0181] In one embodiment, the novel compounds of formula (III) are those in which R4is OH.

[0182] In one embodiment, the novel compounds of formula (III) are those in which the pyrazolyl ring and the group -C(O)R4are trans to one another.

[0183] The novel compounds of formula (Illa) are those having the following structural formula, their stereoisomers, tautomers, or pharmaceutically acceptable salts: wherein: when present, each R3is independently selected from:

[0184] C1-6 alkyl, preferably C1-3 alkyl, e.g. -CH3;

[0185] C1-6 haloalkyl, preferably C1-3 haloalkyl, e.g. -CF3;

[0186] C1-6 alkoxy, preferably C1-3 alkoxy, e.g. -OCH3; halogen, preferably F, Cl, Br or I;

[0187] -OH;

[0188] -CN; -N02;

[0189] -NR5R6wherein R5and R6are independently selected from H and C1-3 alkyl, preferably selected from H and -CH3; and

[0190] -C(=NR7)(NR8R9) wherein each of R7, R8and R9is independently selected from H and C1-3 alkyl, preferably selected from H and -CH3; and p is an integer from 0 to 2, preferably 0 or 1 ;

[0191] In one embodiment, the novel compounds of formula (Illa) are those in which p is 0 or p is 1 and R3is C1-3 alkyl, preferably -CH3.

[0192] In one embodiment, the novel compounds of formula (Illa) are those in which the pyrazolyl ring and the group -C(O)OH are trans to one another.

[0193] The compounds of formula (IV) are those having the following structural formula: wherein:

[0194] R1and R2are independently selected from:

[0195] -H;

[0196] C1-6 alkyl, preferably C1-3 alkyl, e.g. -CH3;

[0197] C1-6 haloalkyl, preferably C1-3 haloalkyl, e.g. -CF3;

[0198] C1-6 alkoxy, preferably C1-3 alkoxy, e.g. -OCH3; halogen, preferably F, Cl, Br or I; and -CN; when present, each R3is independently selected from:

[0199] C1-6 alkyl, preferably C1-3 alkyl, e.g. -CH3;

[0200] C1-6 haloalkyl, preferably C1-3 haloalkyl, e.g. -CF3;

[0201] C1-6 alkoxy, preferably C1-3 alkoxy, e.g. -OCH3; halogen, preferably F, Cl, Br or I;

[0202] -OH; -CN;

[0203] -NO2;

[0204] -NR5R6wherein R5and R6are independently selected from H and C1-3 alkyl, preferably selected from H and -CH3; and

[0205] -C(=NR7)(NR8R9) wherein each of R7, R8and R9is independently selected from H and C1-3 alkyl, preferably selected from H and -CH3;

[0206] R4is selected from:

[0207] -OH;

[0208] -SH;

[0209] C1-6 alkoxy, preferably C1-3 alkoxy; and

[0210] -NR10R11wherein R10and R11are independently selected from H and C1-3 alkyl, preferably selected from H and -CH3; and q is an integer from 0 to 2, preferably 0 or 1 ; with the proviso that the compound of formula (IV) is other than:

[0211] In one embodiment, the novel compounds of formula (IV) are those in which q is 0 (i.e. the heteroaromatic ring is unsubstituted).

[0212] In one embodiment, the novel compounds of formula (IV) are those in which R1and R2are independently selected from -H and C1-6 alkyl, preferably from -H and C1-3 alkyl, e.g. from -H and -CH3.

[0213] In one embodiment, the novel compounds of formula (IV) are those in which R4is OH.

[0214] In one embodiment, the novel compounds of formula (IV) are those in which the pyrrolyl ring and the group -C(O)R4are trans to one another. The novel compounds of formula (IVa) are those having the following structural formula, their stereoisomers, tautomers, or pharmaceutically acceptable salts: wherein: each R3is independently selected from:

[0215] C1-6 alkyl, preferably C1-3 alkyl, e.g. -CH3;

[0216] C1-6 haloalkyl, preferably C1-3 haloalkyl, e.g. -CF3;

[0217] C1-6 alkoxy, preferably C1-3 alkoxy, e.g. -OCH3; halogen, preferably F, Cl, Br or I;

[0218] -OH;

[0219] -CN;

[0220] -NO2;

[0221] -NR5R6wherein R5and R6are independently selected from H and C1-3 alkyl, preferably selected from H and -CH3; and

[0222] -C(=NR7)(NR8R9) wherein each of R7, R8and R9is independently selected from H and C1-3 alkyl, preferably selected from H and -CH3; and q is 1 or 2; with the proviso that the compound of formula (IVa) is other than:

[0223] In one embodiment, the novel compounds of formula (IVa) are those in which the pyrrolyl ring and the group -C(O)OH are trans to one another.

[0224] The compounds of formula (V) are those having the following structural formula: wherein:

[0225] R1and R2are independently selected from:

[0226] -H;

[0227] C1-6 alkyl, preferably C1-3 alkyl, e.g. -CH3;

[0228] C1-6 haloalkyl, preferably C1-3 haloalkyl, e.g. -CF3;

[0229] C1-6 alkoxy, preferably C1-3 alkoxy, e.g. -OCH3; halogen, preferably F, Cl, Br or I; and

[0230] -CN; when present, each R3is independently selected from:

[0231] C1-6 alkyl, preferably C1-3 alkyl, e.g. -CH3;

[0232] C1-6 haloalkyl, preferably C1-3 haloalkyl, e.g. -CF3;

[0233] C1-6 alkoxy, preferably C1-3 alkoxy, e.g. -OCH3; halogen, preferably F, Cl, Br or I;

[0234] -OH;

[0235] -CN;

[0236] -NO2;

[0237] -NR5R6wherein R5and R6are independently selected from H and C1-3 alkyl, preferably selected from H and -CH3; and

[0238] -C(=NR7)(NR8R9) wherein each of R7, R8and R9is independently selected from H and C1-3 alkyl, preferably selected from H and -CH3;

[0239] R4is selected from:

[0240] -OH;

[0241] -SH;

[0242] C1-6 alkoxy, preferably C1-3 alkoxy; and

[0243] -NR10R11wherein R10and R11are independently selected from H and C1-3 alkyl, preferably selected from H and -CH3; and s is an integer from 0 to 2, preferably 0 or 1 ; with the proviso that the compound is other than:

[0244] In one embodiment, the novel compounds of formula (V) are those in which s is 1 and R3is a group -NR5R6, preferably -NH2.

[0245] In one embodiment, the novel compounds of formula (V) are those in which R1and R2are both -H.

[0246] In one embodiment, the novel compounds of formula (V) are those in which R4is OH.

[0247] In one embodiment, the novel compounds of formula (V) are those in which the thiazolyl ring and the group -C(O)R4are trans to one another.

[0248] The novel compounds of formula (Va) are those having the following structural formula, their stereoisomers, tautomers, or pharmaceutically acceptable salts: wherein: when present, each R3is independently selected from:

[0249] C1-6 alkyl, preferably C1-3 alkyl, e.g. -CH3;

[0250] C1-6 haloalkyl, preferably C1-3 haloalkyl, e.g. -CF3;

[0251] C1-6 alkoxy, preferably C1-3 alkoxy, e.g. -OCH3; halogen, preferably F, Cl, Br or I;

[0252] -OH;

[0253] -CN; -N02;

[0254] -NR5R6wherein R5and R6are independently selected from H and C1-3 alkyl, preferably selected from H and -CH3; and

[0255] -C(=NR7)(NR8R9) wherein each of R7, R8and R9is independently selected from H and C1-3 alkyl, preferably selected from H and -CH3; and s is an integer from 0 to 2, preferably 0 or 1 ; with the proviso that the compound of formula (Va) is other than:

[0256] In one embodiment, the novel compounds of formula (Va) are those in which the thiazolyl ring and the group -C(O)OH are trans to one another.

[0257] In one embodiment, the compounds of formula (II) according to the invention include the following compounds, their stereoisomers, tautomers and pharmaceutically acceptable salts thereof:

[0258] In one embodiment, the compound of formula (II) according to the invention is a compound selected from Compound Nos. 5, 8, 15-21 , 25 and 28 in which the imidazolyl ring and the -C(O)OH group are trans to one another, their tautomers and their pharmaceutically acceptable salts.

[0259] In one embodiment, the compounds of formula (III) according to the invention include the following compounds, their stereoisomers, tautomers and pharmaceutically acceptable salts thereof:

[0260] In one embodiment, the compound of formula (III) according to the invention is a compound selected from Compound Nos. 1 , 4, 6, 26 and 27 in which the pyrazolyl ring and the -C(O)OH group are trans to one another, their tautomers and their pharmaceutically acceptable salts.

[0261] In one embodiment, the compounds of formula (IV) according to the invention include the following compounds, their stereoisomers, tautomers and pharmaceutically acceptable salts thereof:

[0262] In one embodiment, the compound of formula (IV) according to the invention is a compound selected from Compound Nos. 22 and 23 in which the pyrrolyl ring and the -C(O)OH group are trans to one another, their tautomers and their pharmaceutically acceptable salts.

[0263] In one embodiment, the compounds of formula (V) according to the invention include the following compound, its stereoisomers, tautomers and pharmaceutically acceptable salts thereof:

[0264] In one embodiment, the compound of formula (V) according to the invention is Compound No. 2 in which the thiazolyl ring and the -C(O)OH group are trans to one another, and its pharmaceutically acceptable salts.

[0265] The novel compounds of formulae (II), (Ila), (III), (Illa), (IV), (IVa), (V) and (Va), their stereoisomers and their tautomers according to the invention may further be provided in the form of a pharmaceutically acceptable salt.

[0266] In a further aspect the present invention provides a novel compound of formula (II), (Ila), (III), (Illa), (IV), (IVa), (V), or (Va), or a stereoisomer, tautomer, or pharmaceutically acceptable salt thereof as herein defined, for use as a medicament.

[0267] In a further aspect the present invention provides a novel compound of formula (II), (Ila), (III), (Illa), (IV), (IVa), (V) or (Va), or a stereoisomer, tautomer, or pharmaceutically acceptable salt thereof as herein defined, for use in preventing, inhibiting or treating a condition or disorder which is mediated by urocanate reductase. In a further aspect the present invention provides a pharmaceutical composition comprising a novel compound of formula (II), (Ila), (III), (Illa), (IV), (IVa), (V) or (Va), or a stereoisomer, tautomer, or pharmaceutically acceptable salt thereof as herein defined, together with one or more pharmaceutically acceptable carriers, excipients or diluents.

[0268] Use of a novel compound of formula (II), (Ila), (III), (Illa), (IV), (IVa), (V) or (Va), or a stereoisomer, tautomer, or pharmaceutically acceptable salt thereof as herein defined, in the manufacture of a medicament for use in preventing, inhibiting or treating a condition or disorder which is mediated by urocanate reductase forms a further aspect of the invention.

[0269] A method of preventing, inhibiting or treating a condition or disorder which is mediated by urocanate reductase, said method comprising the step of administering to a patient in need thereof (e.g. a human subject) a pharmaceutically effective amount of a novel compound of formula (II), (Ila), (III), (Illa), (IV), (IVa), (V) or (Va), or a stereoisomer, tautomer, or pharmaceutically acceptable salt thereof as herein defined, forms a yet further aspect of the invention.

[0270] Any of the compounds herein described may be converted into a salt thereof, particularly into a pharmaceutically acceptable salt thereof with an inorganic or organic acid or base.

[0271] A suitable pharmaceutically acceptable salt of a compound herein described is, for example, an acid addition salt of a compound which is sufficiently basic, for example, an acid addition salt with, for example, an inorganic or organic acid. Acids which may be used for this purpose include hydrochloric acid, hydrobromic acid, nitric acid, sulphuric acid, sulphonic acid, methanesulphonic acid, phosphoric acid, fumaric acid, succinic acid, lactic acid, citric acid, tartaric acid, malic acid, malonic acid, maleic acid, acetic acid, trifluoroacetic acid and ascorbic acid, para-toluene sulphonic acid, 2-mesitylene sulphonic acid, 1,2-ethanedisulphonic, adipic, aspartic, benzenesulphonic, benzoic, ethanesulphonic or nicotinic acid.

[0272] In addition a suitable pharmaceutically acceptable salt of a compound herein described, is, for example, a base addition salt of a compound which is sufficiently acidic, for example, a metal salt, for example, a sodium, potassium, calcium, magnesium, zinc or aluminium salt, an ammonium salt, or a salt with an organic base which affords a physiologically acceptable cation, which includes quarternary ammonium hydroxides, for example methylamine, ethylamine, diethylamine, trimethylamine, tert-butylamine, triethylamine, dibenzylamine, N,N-dibenzylethylamine, cyclohexylethylamine, tris-(2-hydroxyethyl) amine, hydroxyethyl diethylamine, (IR, 2S)-2-hydroxyi nden-l -amine, morpholine, N-methylpiperidine, N-ethylpiperidine, piperazine, methylpiperazine, adamantylamine, choline hydroxide, tetrabutylammonium hydroxide, tris-(hydroxymethyl)methylamine hydroxide, L-arginine, N-methyl D- glucamine, lysine or arginine, and organic amines such as diethylamine, triethylamine, ethanolamine, diethanolamine, cyclohexylamine and dicyclohexylamine.

[0273] Procedures for salt formation are conventional in the art.

[0274] As will be understood, the compounds described herein may exist in various stereoisomeric forms, including enantiomers, diastereomers, and mixtures thereof. The invention encompasses all optical isomers of the compounds described herein and mixtures of optical isomers. Hence, compounds that exist as diastereomers, racemates and / or enantiomers are within the scope of the invention. In a preferred embodiment, the compounds described herein are provided as a particular geometric isomer in which the heteroaromatic ring A and group -C(O)R4are trans to one another.

[0275] The compounds of formula (I) are either known in the art, or can be prepared by methods known to those skilled in the art. Many of the compounds are commercially available from sources including Merck Sigma-Aldrich (St. Louis, USA), Enamine LLC (Cincinnati, USA), Chemspace - FCH Group (Riga, Latvia), Aurora Fine Chemicals LLC (San Diego, USA), and Rare Chemicals GmbH (Kiel, Germany).

[0276] Any of the compounds herein described which are not known in the art, including the compounds of formula (II), (Ila), (III), (Illa), (IV), (IVa), (V) and (Va) may be prepared from readily available starting materials using synthetic methods known in the art such as those described in known textbooks, for example, in Advanced Organic Chemistry (March, Wiley Interscience, 8thEd. 2019) or Advanced Organic Chemistry (Carey and Sundberg, KA / PP, Part B, 5thEd. 2007).

[0277] The following schemes show general methods for preparing the compounds herein described. Such methods for the preparation of the compounds of formula (II), (Ila), (III), (Illa), (IV), (IVa), (V) and (Va) form a further aspect of the invention. The compounds used as starting materials are either known from the literature or may be commercially available. Alternatively, these may readily be obtained by methods known from the literature. As will be understood, other synthetic routes may be used to prepare the compounds using different starting materials, different reagents and / or different reaction conditions. A more detailed description of how to prepare the compounds in accordance with the invention is found in the Examples.

[0278] Scheme 1 :

[0279] In Scheme 1, R3and m are as herein defined.

[0280] Scheme 2: powder

[0281] In Scheme 2, R3and m are as herein defined.

[0282] Scheme 3:

[0283] In Scheme 3, R3and p are as herein defined. Scheme 4:

[0284] In Scheme 4, R3and p are as herein defined.

[0285] Scheme 5:

[0286] In Scheme 5, R3and q are as herein defined. Any method for the preparation of a novel compound of formula (II), (Ila), (III), (Illa), (IV), (IVa), (V) or (Va) which comprises the step of deprotecting a protected derivative thereof also forms part of the invention.

[0287] The compounds herein described have valuable pharmacological properties, particularly an inhibitory effect on microbial urocanate reductase. In view of their ability to inhibit microbial urocanate reductase, the compounds herein described are suitable for the prevention, inhibition or treatment of any condition or disease which is mediated by the activity of microbial urocanate reductase. As described herein, microbial urocanate reductase plays a central role in the microbial histidine degradation pathway, specifically in the production of ImP. The compounds herein described are thus particularly suitable for preventing, inhibiting or treating conditions in which microbial urocanate reductase is involved and, in particular, conditions which arise from and / or are associated with the production of ImP. Such conditions include, but are not limited to, metabolic disorders, cardiovascular disorders, and disorders of the gastrointestinal system.

[0288] Metabolic disorders may be associated with altered gut microbiota structure and function. The microbial metabolite ImP is present at higher concentrations in individuals with T2D and impaired glucose tolerance (IGT) as compared to healthy individuals with normal glucose tolerance (NGT). ImP thus contributes to the pathogenesis of T2D and IGT.

[0289] The compounds herein described find use in the prevention, inhibition or treatment of the following metabolic disorders: type 2 diabetes (T2D), pre-diabetes, impaired glucose tolerance (IGT) and impaired fasting glucose (IFG).

[0290] Due to their activity in the inhibition of urocanate reductase and the subsequent reduction in ImP, the compounds can also be expected to be effective in the treatment of complications associated with T2D, such as diabetic nephropathy, non-alcoholic fatty liver disease and steatohepatitis, diabetic retinopathy and diabetic neuropathy. Furthermore, ImP is associated with poor glycemic control following metformin treatment in patients with T2D, and ImP inhibits the glucose lowering effect of metformin in mice (Koh et al., Cell Metabolism 32(4): 643-653, 2020). Blocking of ImP production may thus improve the therapeutic effect of metformin. The compounds herein described may thus find use in a combination therapy with metformin for the treatment of T2D. The compounds herein described also find use in the prevention, inhibition or treatment of gastrointestinal disorders associated with elevated levels of ImP. Gastrointestinal disorders which may be treated include disorders of the digestive system which consists of the gastrointestinal tract (esophagus, stomach, small intestine and large intestine) and accessory organs of digestion which include the pancreas, gallbladder and liver. Gastrointestinal inflammatory conditions which may be treated in accordance with the invention include inflammatory bowel disease (IBD). As used herein, IBD refers to a group of inflammatory conditions of the colon and small intestine and includes Crohn’s disease and ulcerative colitis. Hepatic or biliary conditions which may be treated include primary sclerosing cholangitis (PSC). PSC is a long-term progressive disease of the liver and gallbladder characterised by inflammation and scarring of the bile ducts (which normally allow bile to drain from the gallbladder). The bile duct scarring narrows the ducts and reduces the flow of bile to the intestines. This disruption of bile duct function can lead to cirrhosis of the liver and liver failure. PSC also increases the risk of various cancers including liver cancer, gallbladder carcinoma, colorectal cancer and cholangiocarcinoma. Many patients with PSC also have IBD, typically ulcerative colitis.

[0291] Cardiovascular diseases and disorders that may be treated in accordance with the invention are those that affect the heart itself or the blood vessel system, specifically the veins and arteries leading to and from the heart. Examples of such diseases and disorders include, but are not limited to, cardiovascular disease, myocardial fibrosis, heart failure and diabetic cardiomyopathy. Myocardial fibrosis refers to the excess deposition of extracellular matrix in the cardiac muscle or abnormal thickening of the heart valves. This results in stiffening of the cardiac muscle which becomes less compliant and which can lead to heart failure.

[0292] Treatment, prevention or inhibition of cardiovascular disease, in particular prevention of heart failure, forms a preferred aspect of the invention.

[0293] Viewed from a further aspect the invention thus provides a compound as herein described for use in therapy. Unless otherwise specified, the term "therapy" as used herein is intended to include treatment, prevention and inhibition.

[0294] In a further aspect the invention provides a compound as herein described for use in the prevention, inhibition or treatment of any of the conditions herein described. In another aspect the invention provides the use of a compound as herein described in the manufacture of a medicament for use in a method of treatment, prevention or inhibition of any of the conditions herein described.

[0295] Also provided is a method of treatment of a human or non-human animal body to combat, prevent or inhibit any of the conditions herein described, said method comprising the step of administering to said body an effective amount of a compound as herein described. The patient may be a human.

[0296] The compounds herein described may be administered to a subject (e.g. a patient) suffering from a gastrointestinal disorder, a cardiovascular disease or a metabolic disorder, or may be administered to a subject (e.g. a patient) who is at risk from developing such a disorder.

[0297] In one embodiment, any of the uses or methods herein described may further comprise the step of determining whether a subject is suffering from, or at risk of suffering from any of the disorders herein described, based on the determined amount or concentration of ImP in a body sample from the subject, for example in a body fluid sample. Examples of body fluid samples include a blood sample, a plasma sample, a serum sample, a urine sample and a fecal sample. In one embodiment, ImP may be used as a biomarker in order to identify individuals that may suffer from T2D or IGT or are likely to suffer from, i.e. are at risk of suffering from, these metabolic disorders. The amount of ImP in the body sample can be determined to identify such individuals as described in WO 2018 / 097793, the entire content of which is incorporated herein by reference. The determined amount or concentration of ImP is compared with a threshold concentration and the subject is determined to suffer from, or be at risk of suffering from, T2D or IGT if the concentration of ImP is equal to or larger than the threshold value. ImP measurements may also be performed to monitor and / or control treatment of any subject in accordance with any of the aspects of the invention herein described.

[0298] The subject for treatment in accordance with the embodiments of the invention is a mammalian subject, preferably a human subject. However, the embodiments may also be applied to other mammalian subjects that may suffer from any of the conditions herein described, for example metabolic disorders such as T2D or IGT. Thus, the embodiments can also be used for veterinary purposes in order to treat animal subjects that are suffering from, or at risk of suffering from any of the conditions or disorders herein described, such as T2D or IGT. For use in a therapeutic or prophylactic treatment, the compounds herein described may be administered alone or in combination with pharmaceutically acceptable carriers, excipients or diluents. Typically, these will be formulated as a pharmaceutical formulation.

[0299] In a further aspect, the invention thus provides a pharmaceutical composition comprising a compound as herein described, or a stereoisomer, tautomer, or pharmaceutically acceptable salt thereof, together with one or more pharmaceutically acceptable carriers, excipients or diluents.

[0300] Acceptable carriers, excipients and diluents for therapeutic use are well known in the art and can be selected with regard to the intended route of administration and standard pharmaceutical practice. Examples include binders, lubricants, suspending agents, coating agents, solubilizing agents, preserving agents, wetting agents, emulsifiers, surfactants, sweeteners, colorants, flavoring agents, antioxidants, odorants, buffers, stabilizing agents and / or salts.

[0301] The compounds for use in the invention may be formulated with one or more conventional carriers and / or excipients according to techniques well known in the art. Typically, the compositions will be adapted for enteral administration, for example oral or rectal administration.

[0302] For example, these may be formulated in conventional oral administration forms, e.g. tablets, coated tablets, pills, hard or soft capsules, powders (e.g. reconstitutable powders), granulates, liquid preparations, aqueous or oily solutions, dispersions, aqueous or oily suspensions, syrups, elixirs, lozenges, emulsions, etc. using conventional excipients, e.g. solvents, diluents, binders, sweeteners, aromas, pH modifiers, viscosity modifiers, antioxidants, etc. Suitable excipients may include, for example, corn starch, lactose, glucose, microcrystalline cellulose, magnesium stearate, polyvinylpyrrolidone, citric acid, tartaric acid, water, ethanol, glycerol, sorbitol, polyethylene glycol, propylene glycol, cetylstearyl alcohol, carboxymethylcellulose or fatty substances such as saturated fats or suitable mixtures thereof, etc. Depending on the administration form, the product may be provided in the form of a sachet or vial containing the pharmaceutical composition. The formulations may be prepared using conventional techniques, such as dissolution and / or mixing procedures, tableting, etc. Alternatively, the compounds may be formulated in conventional rectal administration forms, e.g. as suppositories. When provided in the form of a suppository, the compounds are formulated in a suppository base. Any known suppository base may be used including both water soluble or water- miscible bases and fatty bases.

[0303] The use of orally administrable compositions, e.g. tablets, coated tablets, capsules, syrups, etc. is especially preferred. In one embodiment, such administration forms may be formulated for delayed release, for example for release of the active compound in the colon. Enteric coatings that prevent dissolution or disintegration of tablets or capsules in the gastric fluid in the stomach are well known in the art and any such coatings may be used.

[0304] The dosage required to achieve the desired activity of the compounds herein described will depend on various factors, such as the compound selected, its mode and frequency of administration, whether the treatment is therapeutic or prophylactic, and the nature and severity of the disease or condition, etc. Typically, a physician will determine the actual dosage which will be most suitable for an individual subject. The specific dose level and frequency of dosage for any particular patient may be varied and will depend upon factors such as the activity of the specific compound employed, the metabolic stability and length of action of that compound, the relation of potency to absorbability of the compound, the age of the patient, the mode and timing of administration, and the severity of the particular condition and any associated comorbidity such as chronic kidney disease (CKD). The compound and / or the pharmaceutical composition may be administered in accordance with a regimen from 1 to 10 times per day, such as once or twice per day. For oral and parenteral administration to human patients, the daily dosage level of the agent may be in single or divided doses.

[0305] Typically, doses may be administered once, twice or three or more times daily. The compounds may be administered to humans in doses ranging from 0.001 mg to 100 mg per kg of body weight per day, e.g. 0.01 mg to 100 mg per kg of body weight per day, although variations will necessarily occur depending upon the weight, sex and condition of the subject being treated, the disease state being treated and the particular route of administration chosen. However, a dosage level that is in the range of from 0.1 mg to 10 mg per kg of body weight per day, in a single or divided dosage, is most desirably employed in humans. For example, such a dose may be appropriate for the treatment of metabolic disorders, cardiometabolic disorders and fibrotic diseases. The pharmacological properties of the compounds of the invention can be analysed using standard assays for functional activity. Detailed protocols for testing of the compounds of the invention are provided in the Examples.

[0306] Examples

[0307] The invention will now be described in more detail by way of the following non-limiting Examples and with reference to the accompanying figures, in which:

[0308] Fig. 1. Imidazole propionate as a histidine degradation product. The figure shows the histidine degradation pathway.

[0309] The chemical reactions described in the Examples may readily be adapted to prepare other compounds for use in accordance with the invention, for example by using other reagents known in the art, by modifying the reaction conditions, and / or by choosing any suitable protecting groups, etc.

[0310] 1H NMR spectra were obtained using a Bruker-AVANACE-ll (300 MHz) or -III (400 MHz) spectrometer with TopSpin software, Bruker BioSpin Corp, Germany. HPLC: chromatograms were obtained using an Agilent, 1200 Series HPLC system, Agilent Technologies, United states. LCMS: chromatograms were recorded on Agilent, 1200 Series with LC / MSD Trap XCT plus, United States.

[0311] Abbreviations:

[0312] ACN: Acetonitrile

[0313] BOC: Butyloxycarbonyl

[0314] DCM: Dichloromethane

[0315] DIPEA: N,N-Diisopropylethylamine

[0316] DMAP: 4-Dimethylaminopyridine

[0317] DMF: Dimethylformamide

[0318] DMSO: Dimethylsulfoxide

[0319] EDC.HCI: 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride

[0320] HEPES / Tris: 2-[4-(2-hydroxyethyl)piperazin-1 -yl]ethanesulfonic acid / 2-Amino-2-hydroxymethyl- propane-1 ,3-diol

[0321] HOBt: Hydroxybenzotriazole HPLC: High Pressure Liquid Chromatography

[0322] KHMDS: Potassium bis(trimethylsilyl)amide

[0323] LCMS: Liquid Chromatography Mass Spectroscopy

[0324] MTBE: Methyl tertiary butyl ether

[0325] MR-1 : Strain name of the Shewanella oneidensis used

[0326] NMR: Nuclear Magnetic ResonanceMQ

[0327] Pd(DPPF)Cl2-CH2-Cl2: [1 ,1 '-Bis(diphenylphosphino)ferrocene]dichloropalladium(ll), complex with dichloromethane

[0328] SEM-CI: 2-(Trimethylsilyl)ethoxymethyl chloride

[0329] TEA: Triethylamine

[0330] TFA: Trifluoroacetic Acid

[0331] THF: Tetrahydrofuran

[0332] TPGS-750 M: DL-a-Tocopherol methoxypolyethylene glycol succinate solution

[0333] TLC: Thin Layer Chromatography

[0334] Example 1 - Synthesis of (E)-3-(4-pyrazolyl)-2-butenoic acid (E) (Compound 1)

[0335] Step 1: Synthesis of 1-(1-{[2-(trimethylsilyl)ethoxy]methyl}-4-pyrazolyl)-1 -ethanone (B):

[0336] A B

[0337] To a stirred solution of (1 H-pyrazol-4-yl)-ethanone (A) (250 mg, 2.27 mmol, 1 eq) in THF (5 mL), sodium hydride (60% in mineral oil) (100 mg, 2.5 mmol, 1.1 eq) was added in 3 equal lots at 0°C and the mixture was stirred at 25°C over a period of 1 h. To the resulting mixture, SEM-CI (382.3 mg, 2.29 mmol, 1.01 eq) was added dropwise at 0°C. The resulting reaction mixture was stirred at 25°C for 16 h under argon atmosphere. The progress of the reaction was monitored by TLC. The reaction mixture (yellow suspension) was quenched by addition of ice-cold water (15 mL) and extracted with ethyl acetate (3 x 20 mL). The combined organic layer was dried over anhydrous sodium sulphate and concentrated under reduced pressure to afford crude product (350 mg). This was purified by flash column chromatography using 20-25 % ethyl acetate in hexanes as an eluent to afford the product B as a pale, yellow oil. Yield: 250 mg, 46 %

[0338] 1H-NMR (DMSO-cfe, 300 MHz) 5: 8.57 (1 H, d, J= 4.5 Hz), 7.97 (1 H, s), 5.43 (2H, s), 3.56 -3.52 (2H, m), 2.37 (3H, s), 0.85 (2H, t, J= 3.3 Hz), - 0.01 (9H, s)

[0339] LCMS: 241.1 [M+H]+

[0340] Step 2: Synthesis of tert-butyl (E)-3-(1-{[2-(trimethylsilyl)ethoxy]methyl}-4-pyrazolyl)-2-butenoate (D):

[0341] To a stirred suspension of sodium hydride (60 % in mineral oil) (140 mg, 3.33 mmol, 2 eq) in THF (6 mL), compound C (0.839 g, 3.33 mmol, 2 eq) was added in dropwise manner at 0°C and the mixture was stirred for 30 min in an ice bath. To the resulting suspension, compound B (400 mg, 1.66 mmol, 1 eq) was added in a dropwise manner. The resulting reaction mixture was gradually warmed to ambient temperature and stirred over a period of 16 h under argon atmosphere. The progress of the reaction was monitored by TLC.

[0342] The reaction mixture (yellow suspension) was quenched by addition of ice-cold water (10 mL) and extracted with ethyl acetate (3 x 15 mL). The combined organic layer was dried over anhydrous sodium sulphate and was then concentrated under reduced pressure to afford crude product (350 mg). The crude product was purified by flash column chromatography using 5-10 % ethyl acetate in hexanes as an eluent to afford the product D.

[0343] Yield: 280 mg, 49.7 % as a yellow viscous liquid.

[0344] 1H-NMR (DMSO-cfe, 300 MHz) 5: 8.38 - 8.28 (1 H, m), 7.92 - 7.88 (1 H, m), 6.08 (1 H, s), 5.40 - 5.35 (2H, m), 3.52 (2H, t, J = 7.8 Hz), 2.37 - 2.41 (3H, m), 1 .43 - 1 .40 (9H, s), 0.82 (2H, t, J = 8.1 Hz), - 0.02 (9H, s)

[0345] LCMS: 339.0 [M+H]+

[0346] Step 3: Synthesis of (E)-3-(4-pyrazolyl)-2-butenoic acid (E):

[0347] A solution of compound C (280 mg, 0.82 mmol, 1 eq) in 4M HCI in 1 ,4 dioxane (6 mL) was stirred at RT for 48h. The reaction mixture (white colour suspension) was evaporated to remove excess HCI at 45°C and dried. The semi-solid residue obtained was triturated with diethyl ether (5 mL x 2) to afford the HCI salt of product E as a white solid.

[0348] Yield: 110 mg, 87.4 %

[0349] 1H-NMR (DMSO-cfe, 400 MHz) 5: 8.00 (2H, s), 6.13 (1 H, s), 2.39 (3H, s);

[0350] LCMS: 152.9 [M+H]+, HPLC: 94.21 % purity

[0351] Example 2 - Synthesis of (E)-3-(2-amino-1 ,3-thiazol-4-yl)acrylic acid (D) (Compound 2)

[0352] Step 1: Synthesis of (E)-3-[2-(ted-butoxycarbonylamino)-1 ,3-thiazol-4-yl]acrylic acid (C):

[0353] To a stirred solution of (4-formyl-thiazol-2-yl)-carbamic acid tert-butyl ester (A) (200 mg, 0.877 mmol, 1 eq) in pyridine (4 mL), malonic acid (B) (104 mg, 1.01 mmol, 1.15 eq) and piperidine (11.2 mg, 0.131 mmol, 0.15 eq) were added at ambient temperature under argon atmosphere. The resulting reaction mixture was stirred at 90°C for 16 h in a sealed vessel. The progress of the reaction was monitored by TLC. The reaction mixture was evaporated under reduced pressure to afford crude material (300 mg). The crude material was then purified by trituration with MTBE to give the product C.

[0354] Yield: 200 mg, 84.5 %

[0355] 1H-NMR (DMSO-de, 300 MHz) 5: 7.35 (1 H, s), 7.18 (1 H, d, J= 14.7 Hz,), 6.36 (1 H, d , J= 15.6 Hz, d),1.47 (9H, s)

[0356] LCMS: 269.0 [M-H]

[0357] Step 2: Synthesis of (E)-3-(2-amino-1 ,3-thiazol-4-yl)acrylic acid (D):

[0358] To a stirred solution of compound C (100 mg, 0.370 mmol, 1 eq) in DCM (1 mL) was added TFA (1 mL) at 0°C in dropwise manner. The resulting reaction mixture was stirred at 25-30°C over a period of 16 h under argon atmosphere. The reaction progress was monitored by TLC. After completion of the reaction, the white suspension was evaporated under reduced pressure, and the residue was triturated with diethyl ether (2 mL) to give the crude product (80 mg). The crude material was purified by RP- HPLC to afford the product D.

[0359] Yield: 55 mg, 87.3 %) (CFB-34) as an off white solid.

[0360] 1H-NMR (DMSO-cfe, 300 MHz) 5: 7.90 (2H, bs), 7.27 (1 H, d, J= 15.6 Hz), 7.14 (1 H, s), 6.26 (1 H, d, J = 15.6 Hz)

[0361] LCMS: 171.0 [M+H]+, HPLC: 99.96 % purity

[0362] Example 3 - Synthesis of (E)-3-(2-amino-4-imidazolyl)acrylic acid (F) (Compound 3)

[0363] Step 1: Synthesis of {2-[(4-bromo-2-nitro-1-imidazolyl)methoxy]ethyl}tris(methyl)silane (B) and its isomer (i.e. {2-[(5-bromo-2-nitro-1-imidazolyl)methoxy]ethyl}tris(methyl) silane): somer

[0364] To a stirred solution of compound A (1.5 g, 7.89 mmol, 1 eq) in THF (40 mL) was added sodium hydride (60 % in mineral oil) (0.350 g, 8.68 mmol, 1.1 eq) portion wise at 0°C. The resulting reaction mixture was stirred at 22°C over a period of 1 h. After 1 h, SEM-CI (1.46 mL, 8.28 mmol, 1.05 eq) was added in a drop wise manner over a period of 10 mins at 0°C. The reaction mixture was then stirred at ambient temperature for 16 h under argon atmosphere. The progress of the reaction was monitored by TLC. The reaction mixture (brown colour solution) was quenched by the addition of an ice-cold solution of saturated NH4CI (100 mL) and the product was extracted into ethyl acetate (3 x 50 mL). The combined organic layer was dried over anhydrous sodium sulphate and was concentrated under reduced pressure to afford crude product (2.3 g). The crude material was purified by flash column chromatography using 10-15 % ethyl acetate in hexanes as an eluent to afford compound B and its isomer as a colourless viscous liquid.

[0365] Yield: 1.6 g, 63.6 % : (Mixture of isomers)

[0366] 1H-NMR (CDCh, 400 MHz) 5: (Mixture of isomers): 7.30 - 7.21 (1 H, m), 5.88 - 5.77 (2H, m), 3.70 - 3.72 (2H, m), 0.99 - 0.90 (2H, m), 0.07- 0.02 (9H, m)

[0367] LCMS: No Ionization.

[0368] Step 2: Synthesis of 4-bromo-1-{[2-(trimethylsilyl)ethoxy]methyl}-2-imidazolylamine (C) and its isomer:

[0369] To a stirred solution of compound B and its isomer (3 g, 9.3 mmol, 1 eq) in THF (30 mL) and (2 % TPGS-750 M) in water (12 mL), was added NH4CI (1.50 g, 27.9 mmol, 3 eq) followed by addition of iron carbonyl powder (2.5 g, 46.5 mmol, 5 eq). The resulting reaction mixture was stirred vigorously at 40°C for 24 h under argon atmosphere. The progress of the reaction was monitored by TLC. The reaction mixture (yellow colour solution with black suspension) was filtered through a celite bed. The filtrate was diluted with water (50 mL) and extracted with ethyl acetate (3 x 50 mL). The combined organic layer was dried over anhydrous sodium sulphate and then concentrated under reduced pressure to afford a mixture of compound C and its isomer as a pale, yellow viscous oil.

[0370] Yield: 2 g crude material : (Mixture of isomers)1H-NMR (DMSO, 400 MHz) 5: (Mixture of isomers) 6.71 (1 H, s), 5.75 - 5.73 (2H, m), 5.06 - 5.01 (2H, m), 3.47-3.742 (2H, m), 0.83 - 0.77 (2H, m), -0.04 - -0.06 (9H, m) LCMS: 294.1 [M+H]+

[0371] Step 3: Synthesis of (4-bromo-1-{[2-(trimethylsilyl)ethoxy]methyl}-2-imidazolyl)-N-ted- butoxycarbonylamino-ted-butylformylate (D):

[0372] To a stirred solution of compound C and its isomer (1 g, 3.42 mmol, 1 eq) in THF (10 mL), DIPEA (1.10 g, 8.56 mmol, 2.5 eq), DMAP (83 mg, 0.68 mmol, 0.2 eq) and BOC anhydride (1.85 g, 8.55 mmol, 2.5 eq) were added successively at 0°C. The resulting reaction mixture was stirred at ambient temperature over a period of 16 h under argon atmosphere. The reaction mixture (yellowish coloured solution) was added to 100 mL of purified water and extracted with ethyl acetate (2 x 100 mL). The combined organic layer was dried over anhydrous sodium sulphate and was then concentrated under reduced pressure to afford crude product (1.3 g). The crude material was purified by flash column chromatography using 30 % ethyl acetate in hexanes as an eluent to afford compound D as a yellow coloured solid.

[0373] Yield: 700 mg, 42 %1H-NMR (DMSO-cfe, 400 MHz) 5: 7.49 (1 H, s), 5.12 (2H, s), 3.46 - 3.42 (2H, m), 1.38 - 1.36 (18H, m), 0.87 - 0.83 (2H, m), -0.033 (9H, s) LCMS: 492 [M+H]+.

[0374] Step 4: Synthesis of tert-butyl (E)-3-(2-amino-1-{[2-(trimethylsilyl)ethoxy]methyl}-4-imidazolyl)acrylate

[0375] A stirred solution of compound D (500 mg, 1.02 mmol), TEA (283 mL, 2.03 mmol, 2 eq) and t-butyl acrylate (652 mg, 5.1 mmol, 5 eq) in DMF (5 mL) was degassed with argon for 15 min. Pd(PPh3)2Cl2 (63.72 mg, 0.051 mmol, 0.05 eq) was added to the reaction mixture and further degassed with argon for 5 minutes. The resulting reaction mixture was stirred at 120°C for 48 h under argon atmosphere in sealed condition. The progress of the reaction was monitored by TLC. The reaction mixture (a brown coloured solution) was concentrated under reduced pressure. The residue obtained was suspended in 50 mL of purified water and extracted with ethyl acetate (2 x 100 mL). The combined organic layer was dried over anhydrous sodium sulphate and concentrated under reduced pressure to afford the crude product (600 mg). The crude material was purified by flash column chromatography using 5-8 % MeOH in DCM followed by RP HPLC to afford compound E as a pale brown solid.

[0376] Yield: 4 mg, 0.9 %

[0377] 1H-NMR (CD3OD, 400 MHz) 5: 7.25 (1 H, d, J= 15.6 Hz), 7.02 (1 H, s), 6.15 (1 H, d, J= 15.2Hz), 5.13 (2H, s), 3.56 (2H, t, J= 8.2Hz), 1.48 (9H, bs), 0.91 - 0.87 (2H, m), -0.023 (9H, s) LCMS: 340.3 [M+H]+

[0378] Step 5: Synthesis of (E)-3-(2-amino-4-imidazolyl)acrylic acid (F):

[0379] A solution of compound E (7 mg, 0.020 mmol, 1 eq) in 4 N HCI in dioxane (2 mL) was stirred at ambient temperature over a period of 4 days in sealed condition. The progress of the reaction was monitored by TLC. The reaction mixture (a white coloured suspension) was concentrated under reduced pressure to obtain crude product (6 mg). The crude material obtained was diluted with purified water (5 mL) and the aqueous layer was washed with diethyl ether (3 mL x 2). The aqueous layer was concentrated to 2 mL under reduced pressure and lyophilized to get the product F as an off-white semi-solid.

[0380] Yield 3 mg

[0381] LCMS: 154.06 [M+H]+

[0382] Example 4 - Synthesis of (E)-3-(4-pyrazolyl)-2-pentenoic acid (G) (Compound 4)

[0383] Step 1: Synthesis of 1-{[2-(trimethylsilyl)ethoxy]methyl}-4-pyrazolecarboxylic acid (B):

[0384] To a stirred solution of compound A (2.5 g, 0.022 mol, 1 eq) in THF (25 mL), sodium hydride (60 % in mineral oil) (2.81 g, 0.0669 mol, 3 eq) was added in 4 equal lots at 0-5°C and stirred over a period of 1 h at the same temperature. After 1 h, SEM-CI (4.14 mL, 0.023 mol, 1.05 eq) was added in dropwise manner at 0-5°C. The resulting reaction mixture was stirred at 25-30°C for 16 h under argon atmosphere. The progress of the reaction was monitored by TLC. The reaction mixture (a grey suspension) was quenched by addition of ice-cold water (25 mL), acidified to pH - 4 using 1 .5 N HCI and was then extracted with ethyl acetate (3 x 30 mL). The combined organic layer was dried over anhydrous sodium sulphate and concentrated under reduced pressure to afford crude product (3.8 g). The crude material was purified by flash column chromatography using 20-23 % ethyl acetate in hexanes as an eluent to afford the product B as a white solid.

[0385] Yield: 3.5 g, 63.0 %1H-NMR (CDCh, 400 MHz) 5: 8.14 (1 H, s), 8.01 (1 H, s), 5.47 (2H, s), 3.63 - 3.59 (2H, m), 0.96 - 0.92 (2H, m), -0.04 (9H, s).

[0386] LCMS: 245.1 [M+H]+

[0387] Step 2: Synthesis of N-meVnoxy-N-methy\-1-{[2-(trimethylsilyl)ethoxy]methyl}-4-pyrazolecarboxamide (C):

[0388] To a stirred solution of compound B (3 g, 0.0124 mol, 1 eq) in DCM (60 mL) at 0-5 °C, TEA (3.7 g, 0.0186 mol, 3 eq), EDC.HCI (3.5 g, 0.0186 mol, 1.5 eq) and HOBt (0.95 g, 0.0062 mol, 0.5 eq) were added successively and stirred at same temperature for 5 min. N-dimethyl hydroxylamine (1.45 g, 0.014 mol, 1 .2 eq) was added to the reaction mixture in 1 lot. The resulting reaction mixture was stirred at 25-30°C for 16 h under argon atmosphere. The progress of the reaction was monitored by TLC.

[0389] The reaction mixture (yellow solution) was quenched by addition of ice-cold water (50 mL) and extracted into DCM (3 x 50 mL). The combined organic layer was dried over anhydrous sodium sulphate and was then concentrated under reduced pressure to afford the crude product (3.5 g). The crude material was purified by flash column chromatography using 15-20 % ethyl acetate in hexanes as an eluent to afford the product C as a pale, yellow viscous liquid.

[0390] Yield: 2.7 g, 76.2 %

[0391] 1H-NMR (CDCh, 400 MHz) 5: 8.12 (1 H, s), 8.02 (1 H, s), 5.45 (2H, s), 3.73 (3H, s), 3.61 - 3.57 (2H, m), 3.34 (3H, s), 0.92 (2H, t, J= 8.4 Hz), - 0.02 (9H, s) LCMS: 286.2 [M+H]+

[0392] Step 3: Synthesis of 1-(1-{[2-(trimethylsilyl)ethoxy]methyl}-4-pyrazolyl)-1 -propanone (D):

[0393] To a solution of compound C (2.5 g, 0.0087 mol, 1eq) in dry THF (50 mL), ethyl magnesium bromide (5.8 g, 0.0437 mol, 5 eq) was added in dropwise manner at 0°C. The resulting reaction mixture was stirred at ambient temperature for 5h under argon atmosphere. The progress of the reaction was monitored by TLC. The reaction mixture (a yellow solution) was quenched by addition of saturated NH4CI solution (50 mL) and extracted into ethyl acetate (3 x 50 mL). The combined organic layer was dried over anhydrous sodium sulphate and was concentrated under reduced pressure to afford the crude product (2.8 g). The crude material was purified by flash column chromatography using 15-20 % ethyl acetate in hexanes as an eluent to afford product as a pale yellow viscous liquid.

[0394] Yield: 1.8 g, 81.1 %

[0395] 1H-NMR (CDCh, 400 MHz) 5: 8.06 (1 H, s), 7.96 (1 H, s), 5.45 (2H, s), 3.61 - 3.57 (2H, m), 2.84 (2H, q, J = 7.2 Hz), 1 .21 (3H, t, J = 7.6 Hz), 0.95 - 0.91 (2H, M), - 0.01 (9H, s).

[0396] LCMS: 255.1 [M+H]+ Step 4: Synthesis of tert-butyl (E)-3-(1-{[2-(methylsilyl)ethoxy]methyl}-4-pyrazolyl)-2-pentenoate (F):

[0397] To a solution of NaH (60 % in mineral oil) (1 .24 g, 0.031 mol, 5 eq) in THF (13 mL) at 0°C, tert-butyl diethylphosphonoacetate (E) (7.9 g, 0.031 mol, 5 eq) was added and stirred for 20 minutes at 0-5°C. Compound D (1 .6 g, 0.0062 mol, 1 eq) in THF (5 mL) was added to this mixture at 0-5°C and the resulting reaction mixture was stirred at 25-30°C for 16 h under argon atmosphere. The progress of the reaction was monitored by TLC. The reaction mixture (yellow coloured) was quenched by addition of ice-cold water (25 mL) and extracted with ethyl acetate (3 x 30 mL). The combined organic layer was dried over anhydrous sodium sulphate and concentrated under reduced pressure to afford the crude product (1 .8 g). The crude material was purified by flash column chromatography using 20-23 % ethyl acetate in hexanes as an eluent to afford compound F as a pale, yellow viscous liquid.

[0398] Yield: 1.1 g, 45 %

[0399] 1H-NMR (CDCh, 400 MHz) 5: 8.06 (1 H, s), 7.96 (1 H, s), 5.45 (2H, s), 3.61 - 3.57 (2H, m), 2.84 (2H, q, J = 7.2 Hz), 1 .21 (3H, t, J = 7.6 Hz), 0.95 - 0.91 (2H, M), - 0.01 (9H, s);

[0400] LCMS: 353.3 [M+H]+

[0401] Step 5: Synthesis of (E)-3-(4-pyrazolyl)-2-pentenoic acid (G):

[0402] To a solution of compound F (700 mg, 0.0019 mol, 1 eq) in 1 ,4 dioxane (3.5 mL), 4M HCI in 1 ,4 dioxane (3.5 mL) was added and the resulting reaction mixture was stirred at 25-30°C for 16 h under argon atmosphere. The progress of the reaction was monitored by TLC. The reaction mixture (a white coloured suspension) was evaporated to remove excess HCI at 45°C and dried. The semi-solid residue that was obtained was triturated with diethyl ether (5 mL x 2) to afford product G as a white solid.

[0403] Yield: 55 mg, 16.7 %

[0404] 1H-NMR (DMSO-cfe, 400 MHz) 5: 7.99 (2H, s), 6.05 (1 H, s), 2.93 (2H, q, J= 7.6 Hz), 1.07 (3H, t, J= 7.2 Hz)

[0405] LCMS: 167.0 [M-HH] -, HPLC: 95.6 % purity

[0406] Example 5 - Synthesis of (E)-3-(4-imidazolyl)-2-butenoic acid (F) (Compound 5)

[0407] Step 1: Synthesis of 1-(1-{[2-(trimethylsilyl)ethoxy]methyl}-4-imidazolyl)-1 -ethanone (B) and its isomer:

[0408] To a stirred solution of compound A (2 g, 0.0181 mol, 1 eq) in THF (20 mL), sodium hydride (60 % in mineral oil) (0.79 g, 0.0199 mol, 1.1 eq) was added in 4 equal lots at 0°C and stirred over a period of 1 h at 25°C. After 1 h, SEM-CI (3.17 g, 0.019 mol, 1.05 eq) was added in dropwise manner at 0°C. The resulting reaction mixture was then stirred at 25-30°C for 16 h under argon atmosphere. The progress of the reaction was monitored by TLC. The reaction mixture (a grey suspension) was quenched by addition of ice-cold water (20 mL) and extracted with ethyl acetate (3 x 30 mL). The combined organic layer was dried over anhydrous sodium sulphate and concentrated under reduced pressure to afford crude product (2.8 g). The crude material was purified by flash column chromatography using 20-23 % ethyl acetate in hexanes as an eluent to afford the product B and its isomer as a white solid.

[0409] Yield: 2.3 g, 52.7 % (Mixture of isomers)

[0410] 1H-NMR (CDCh, 400 MHz) 5: : (Mixture of isomers) 7.69 (1 H, d, J= 1.2 Hz), 7.61 (1 H, d, J= 1.2 Hz), 5.31 (2H, s), 3.50 (2H, t, J = 8.2 Hz), 0.95 - 0.90 (2H, m), 0.02 - -0.01 (9H, m).

[0411] LCMS: 240.90 [M+H]+

[0412] Step 2: Synthesis ethyl (E)-3-(1-{[2-(trimethylsilyl)ethoxy]methyl}-4-imidazolyl)-2-butenoate (D):

[0413] To a stirred solution of compound C (691 .93 mg, 2.0833 mmol) in THF at -75°C was added dropwise KHMDS (1 M in THF) (2.18 mL, 2.1874 mmol) while maintaining internal temperature at <-65°C and then the mixture was stirred for 30 min. To the above reaction mixture compound B and its isomer (250 mg, 1.04166 mmol) in THF (2 mL) was added dropwise while still maintaining the internal temperature at <-65°C. The resulting reaction mixture was gradually warmed to ambient temperature within 1 .5 h and stirred over a period of 18 h at ambient temperature. The progress of the reaction was monitored using TLC. The resulting reaction mixture was quenched by adding saturated aqueous NH4CI (5 mL) at 0°C and extracted with ethyl acetate (3x 15 mL). The combined organic layer was dried over sodium sulphate and concentrated at 40°C to afford the crude product, which was purified by flash column to afford compound D and its isomers as a thick oily yellow liquid.

[0414] Yield: 90 mg, (27.8 %) (Mixtures of isomers)1H-NMR (CDCh, 300 MHz) 5: (Mixture of isomers) 8.30 (1 H, s), 7.76 (1 H, s), 7.60 (1 H, s), 6.69 (1 H, s), 5.88 (1 H, s), 5.33 (2H, s), 5.27 (2H, s), 4.23 - 4.14 (2H, m), 3.57 - 3.48 (2H, m), 2.51 (3H, s), 2.38 (3H, s), 1.28 (6H, t, J = 7.2 Hz), 0.93 (4H, t, J = 8.1 Hz), 0.01 (18H, s) LCMS: 311.2 [M+H]+

[0415] Step 3: Synthesis of (E)-3-(1-{[2-(trimethylsilyl)ethoxy]methyl}-4-imidazolyl)-2-butenoic acid (E):

[0416] To a stirred solution of compound D and its isomers (90 mg, 0.2898 mmol) in THF: ethanol: water (1 mL, 1 :1 :1 eq) was added lithium hydroxide monohydrate (30.42 mg, 0.7245 mmol). The resulting reaction mixture was stirred over a period of 18 h at 25-30°C. The progress of the reaction was monitored by TLC. After 18 h the reaction mixture was concentrated, the residue was dissolved in water, and the aqueous layer was acidified to pH ~ 5-6 using 1.5 N HCI. The solution was extracted with ethyl acetate (3 x 10 mL) and the combined organic layer was dried over sodium sulphate and concentrated at 40°C to afford crude material. The crude material was washed with hexane (5 mL) to afford crude compound E and isomers as a thick oily yellow liquid.

[0417] Yield: 55 mg (Mixture of isomers)

[0418] 1H-NMR (CDCh, 300 MHz) 5: (Mixture of isomers) 7.92 (1 H, s), 7.79 (1 H, s), 6.78 (1 H, s), 5.99 (1 H, s), 5.35 (4 H, s), 3.57 - 3.52 (4H, m), 2.52 (3H, s), 2.20 (3H, s), 1 .79 - 1 .70 (4H, m), 0.01 (18H, s) LCMS: 283.2 [M+H]+

[0419] Step 4: Synthesis of (E)-3-(4-imidazolyl)-2-butenoic acid (F):

[0420] To a stirred solution of pooled compound E and its isomers (1.7 g, 0.0060 mmol) in 1 ,4-dioxane (15 mL), 4M HCI in 1 ,4-dioxane was added (34 mL). The resulting reaction mixture was stirred over a period of 18 h at 25-30°C. The progress of the reaction was monitored by TLC. The reaction mixture was evaporated under reduced pressure followed by toluene chasing to get a crude product (1 .2 g). This was purified by RP-HPLC and dried by lyophilization to afford compound F (fraction 1) and its Z isomer (fraction 2). Fraction 1 was further purified by sonification with water (10 mL) and filtered. This gave the expected product F.

[0421] Yield: 150 mg

[0422] 1H-NMR (CD3OD, 400 MHz) 5: 7.71 (1 H, d, J= 0.8 Hz), 7.4 1 (1 H, d, J= 0.8 Hz), 6.4 1 (1 H, d, J= 1.2 Hz), 2.28 (3H, s)

[0423] LCMS: 153.0 [M+H]+, HPLC purity 99.96 %

[0424] Example 6 - Synthesis of (E)-3-(5-methyl-4-pyrazolyl)-2-butenoic acid (E) (Compound 6)

[0425] Step 1: Synthesis of 1-(5-ethyl-1-{[2-(trimethylsilyl)ethoxy]methyl}-4-pyrazolyl)-1 -ethanone (B) and its isomer:

[0426] To a stirred solution of compound A (230 mg, 2.416 mmol, 1 eq) in THF (5 mL), sodium hydride (57 % in mineral oil) (122.1 mg, 2.899 mmol, 1.2 eq) was added in 2 equal lots at 0°C and stirred over a period of 1 h at 25°C. After 1 h, SEM-CI (443.13 mg, 2.658 mmol, 1.1 eq) was added in dropwise manner at 0°C. The resulting reaction mixture was stirred at 25-30°C for 16 h under argon atmosphere. The progress of reaction was monitored by TLC.

[0427] The reaction mixture (a grey suspension) was quenched by addition of ice-cold water (10 mL) and extracted with ethyl acetate (3 x 15 mL). The combined organic layer was dried over anhydrous sodium sulphate and concentrated under reduced pressure to afford a crude product (520 mg). The crude material was purified by flash column chromatography using 30-40 % ethyl acetate in hexanes as an eluent to afford product B and its isomer as a white solid.

[0428] Yield: 320 mg, 52.2 % (Mixture of isomers)1H-NMR (CDCh, 400 MHz) 5: (Mixture of isomers) 7.96 (1 H, s), 7.82 (1 H, s), 5.44 (2H, s ), 5.36 (2H, s ), 3.62 - 3.54 (4H, m), 2.63 (3H, s,), 2.48 (3H, s), 2.44 (3H, s), 2.43 (3H, s), 2.42 (3H, s), 0.94 - 0.87 (4H, m), -0.01 (9H, s,), -0.03 (9H, s) LCMS: 255.03 [M+H]+

[0429] Step 2: Synthesis of tert-butyl (E)-3-(5-methyl-1-{[2-(trimethylsilyl)ethoxy]methyl}-4-pyrazolyl)-2- butenoate (D):

[0430] To a stirred suspension of NaH (57 % in mineral oil) (253.1 mg, 6.014 mmol, 5.1 eq) in THF (5 mL) at 0°C compound C (1 .49 g, 5.895 mmol, 5 eq) was added and stirred for 30 min at 0°C. To this the mixture of compound B and its isomers (300 mg, 1.179 mmol, 1 eq) was added at 0°C and the resulting reaction mixture was stirred at 25-30°C for 16 h under argon atmosphere. The progress of the reaction was monitored by TLC. The reaction solution (pale yellow) was quenched by addition of ice-cold water (10 mL) and extracted with ethyl acetate (3 x 20 mL). The combined organic layer was dried over anhydrous sodium sulphate and concentrated under reduced pressure to afford crude product (480 mg). The crude material was purified by flash column chromatography using 10-15 % ethyl acetate in hexanes as an eluent to afford product D and isomers as a pale yellow, viscous liquid.

[0431] Yield: 315 mg, 75.8 % (Mixture of isomers)

[0432] 1H-NMR (CDCh, 400 MHz) 5: (Mixture of isomers) 7.59 (1 H, s), 7.53 (1 H, s), 5.91 (1 H, d, J= 1.2Hz), 5.91 (1 H, d, J = 1 ,2Hz), 5.77 (1 H, d, J = 1 .6 Hz), 5.42 (2H, s), 5.40 (2H, s), 3.58 - 3.52 (4H, m), 2.47 - 2.39 (12 H, m), 2.57 - 2.38 (18 H, m), 0.93 - 0.86 (4H, m), - 0.01 - 0.04 (18H, m) LCMS: 353.4 [M+H]+

[0433] Step 3: Synthesis of (E)-3-(5-methyl-4-pyrazolyl)-2-butenoic acid (E):

[0434] To a stirred solution of compound D and its isomers (300 mg, 1.477 mmol, 1 eq) in 1 ,4 dioxane (3 mL), 4M HCI in 1 ,4 dioxane (6 mL) was added and the resulting reaction mixture was stirred at 25-30°C for 16 h under argon atmosphere. The progress of the reaction was monitored by TLC. The reaction mixture (a white coloured suspension) was evaporated under reduced pressure to remove volatiles at 45°C to get the crude product which was further purified by RP-HPLC to afford two fractions with same mass. The collected fractions of isomers were evaporated at 45°C, the residues obtained were dissolved in ACN: water (1 :2) (2 mL) and dried by lyophilization to get the desired product E as fraction 2 (58 mg) (an off-white solid).

[0435] Yield of compound E: 58 mg, 23.7 %1H-NMR (CD3OD, 400 MHz) 5: 7.72 (1 H, s), 5.93 (1 H, d, J= 1.2 Hz), 2.47 (3H, d, J= 1.2 Hz), 2.38 (3H, s)

[0436] LCMS: 167.0 [M+H]+, HPLC: 99.56 % purity Example 7 - Synthesis of (E)-3-(3-pyrrolyl)-2-butenoic acid (F) (Compound 7)

[0437] Step 1: Synthesis of 1-(1-tosyl-3-pyrrolyl)-1 -ethanone (B):

[0438] To a stirred solution of compound A (0.5 g, 0.0046 mol, 1 eq) in DCM (5 mL), TEA (1.16 g, 0.0115 mol, 2.5 eq), and DMAP (28 mg, 0.0002 mol, 0.05 eq) were added at ambient temperature. To this reaction mixture, p-toluene sulfonyl chloride (1.13 g, 0.0059 mol, 1.3 eq) was added. The resulting reaction mixture was stirred at ambient temperature for 16 h under argon atmosphere. The progress of the reaction was monitored by TLC. The reaction mixture (a white suspension) was quenched by the addition of ice-cold water (10 mL) and extracted with ethyl acetate (3 x 25 mL). The combined organic layer was dried over anhydrous sodium sulphate and concentrated under reduced pressure to afford crude product (0.6 g). The crude material was purified by flash column chromatography using 20-30 % ethyl acetate in hexanes as an eluent to afford compound B as a white solid.

[0439] Yield: 0.59 g, 48.7 %

[0440] 1H-NMR (CDCh, 400 MHz) 5: 7.79 (2H, q, J = 1.24 Hz), 7.71 (1 H, q, J = 1.33 Hz), 7.34 (2H, t, J = 2.8 Hz), 7.13 (1 H, q, J = 1.8 Hz), 6.67 (1 H, q, J = 1.6 Hz), 2.43 (3H, s), 2.40 (3H, s) LCMS: 264.0 [M+H]+

[0441] Step 2: Synthesis of tert-butyl (E)-3-(1-tosyl-3-pyrrolyl)-2-butenoate (D):

[0442] To a stirred solution of compound B (0.58 g, 0.0022 mol, 1 eq) in ACN (2.32 mL), compound C (0.99 g, 0.0026 mol, 1 .2 eq) was added in one lot. The resulting reaction mixture was stirred at 85°C for 48 h under argon atmosphere. The progress of the reaction was monitored by TLC. The reaction mixture (a brown solution) was quenched by addition of ice-cold water (10 mL) and extracted with ethyl acetate (3 x 20 mL). The combined organic layer was dried over anhydrous sodium sulphate and concentrated under reduced pressure to afford crude product (0.62 g). The crude material was purified by flash column chromatography using 5-10 % ethyl acetate in hexanes as an eluent to afford compound D as a pale yellow viscous liquid.

[0443] Yield: 0.33 g, 41.5 %

[0444] 1H-NMR (CDCh, 400 MHz) 5: 7.78 - 7.74 (2H, m), 7.33 - 7.29 (3H, m), 7.12 (1 H, t, J = 1 .6 Hz), 6.59 - 6.47(1 H, m), 5.98 (1 H, d, J= 1.2 Hz), 2.39 (6H, q, J= 3.2 Hz), 1.48 (9H, s) LCMS: 384.2 [M+Na]+

[0445] Step 3: Synthesis of (E)-3-(1-tosyl-3-pyrrolyl)-2-butenoic acid (E):

[0446] To a stirred solution of compound D (320 mg, 0.885 mmol, 1 eq) in 1 ,4 dioxane (1 .6 mL), 4 M HCI in 1 ,4 dioxane (12.8 mL) was added and the resulting reaction mixture was stirred at 25-30°C for 16 h under argon atmosphere. The progress of the reaction was monitored by TLC. The reaction mixture (a white coloured suspension) was evaporated and dried at 45°C under reduced pressure to afford compound E as a white solid.

[0447] Yield: 230 mg, 85.1 %

[0448] 1H-NMR (DMSO, 400 MHz) 5: 7.88 (2H, d, J= 8.4 Hz), 7.67 (1 H, d, J= 2.0 Hz), 7.43 (2H, d, J= 8 Hz), 7.33 (1 H, t, J = Hz), 6.69 (1 H, t, J = Hz), 6.07 (1 H, s), 2.35 - 2.30 (6H, m) LCMS: 304.1 [M+H]

[0449] Step 4: Synthesis of (E)-3-(3-pyrrolyl)-2-butenoic acid (F): To a stirred solution of compound E (220 mg, 0.721 mmol, 1 eq) in THF (4.4 mL) and methanol (2.2 mL), CS2CO3 (704.2 mg, 2.164 mmol, 3eq) was added, and the resulting reaction mixture was stirred at 50°C for 18 h under argon atmosphere. The progress of the reaction was monitored by TLC. The reaction mixture (a yellow suspension) was concentrated under reduced pressure at 25-30°C to afford crude product (350 mg). The crude material was purified by RP-HPLC and dried by lyophilisation (without the use of a rotavapor due to the sensitivity of the product). This afforded the product F as an off-white solid.

[0450] Yield: 66 mg, 26.9 %1H-NMR (CD3OD, 400 MHz) 5: 7.06 (1 H, t, J= 1.6 Hz), 6.71 (1 H, q, J= 1.6 Hz), 6.35 (1 H, q, J= 1.6 Hz), 6.05 (1 H, d, J= 1.2 Hz), 2.42 (3H, d, J= 0.8 Hz) LCMS: 149.7 [M+H] -, HPLC: 94.1 % purity

[0451] Example 8 - Synthesis of (E)-3-(2-amino-4-imidazolyl)-2-butenoic acid (H) (Compound 8)

[0452] Step 1: Synthesis of ethyl (Z)-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2-butenoate (B):

[0453] A stirred suspension of but-2-ynoic acid ethyl ester (A) (2 g, 17.86 mmol) in water (200 mL) was degassed with nitrogen for 10 min. To this solution CuSCU (142 mg, 0.89 mmol) and 4-methylpyridine (415 mg, 4.47 mmol) and bis(pinacolato)diboron (B2pin2) (3.40 g, 13.40 mmol) were successively added and the resulting reaction mixture was then stirred at 50°C for 10 min. To the resulting solution a second batch of B2pin2 (3.40 g, 13.40 mmol) was added and the reaction progress was monitored by TLC. After 16 h the reaction mixture was diluted by addition of hexane. The organic phase was separated, and the aqueous phase was extracted with hexane (150 mL x 3). The combined organic phases were washed with water and dried over Na2SO4. The solvent was evaporated at reduced pressure at 45°C and the crude residue was purified by Combiflash® chromatography using 8-10 % of ethyl acetate in hexane. The collected fractions were concentrated under reduced pressure to get compound B as a colourless, thick oil.

[0454] Yield 1.1 g, 52 %1H-NMR (CDCh, 400 MHz) 5: 6.45 (1 H, d, J= 1.6 Hz), 4.17 (2H, q, J= 7.2 Hz), 2.17 (3H, s,), 1.29 -

[0455] 1.26 (15 H, m)

[0456] Step 2: Synthesis of {2-[(4-bromo-2-nitro-1-imidazolyl)methoxy]ethyl}tris(methyl)silane (D) or its isomer

[0457] (i.e. {2-[(5-bromo-2-nitro-1-imidazolyl)methoxy]ethyl}tris(methyl)silane)

[0458] To a stirred solution of 4-bromo-2-nitro-1 H-imidazole (C) (300 mg, 1.57 mmol) in THF (15 mL) was added sodium hydride (60 % in mineral oil) (70 mg, 1.74 mmol) portion wise at 0°C. The resulting reaction mixture was stirred at 22°C over a period of 1 h. SEM-CI (2-(trimethylsilyl) ethoxymethyl chloride) (325 mg, 1.65 mmol) was then added in a drop wise manner over a period of 10 mins at 0°C. The reaction mixture was stirred at ambient temperature for 16 h under argon atmosphere. The progress of the reaction was monitored by TLC. The reaction mixture (a brown solution) was quenched by the addition of an ice-cold solution of saturated NH4CI (75 mL) and the product was extracted into ethyl acetate (3 x 50 mL). The combined organic phases were dried over anhydrous sodium sulphate and then concentrated under reduced pressure to afford crude material (530 mg). This was purified by flash column chromatography using 10-15 % ethyl acetate in hexanes as an eluent to afford compound D or its isomer as a colourless, viscous liquid.

[0459] Yield 260 mg (50 %) of D or its isomer1H-NMR (CDCh, 400 MHz) 5 (D or its isomer): 7.29 (1 H, s), 5.76 (2H, s), 3.67 (2H, t, J= 8.4 Hz), 0.98 (2H, t, J = 8.4 Hz), 0.02 (9H, s).

[0460] Step 3: Synthesis of ethyl (E)-3-(2-nitro-1-{[2-(trimethylsilyl)ethoxy]methyl}-4-imidazolyl)-2-butenoate (E) or its isomer: A stirred solution of compound D or its isomer (600 mg, 1.86 mmol) and compound B (895 mg, 3.72 mmol) in 1 ,4-dioxane (10 mL) was degassed with argon for 5 min. To this solution Pd(dppf)Cl2 CH2CI2 complex (151 mg, 0.186 mmol) and K2CO3 (1.02 g, 7.44 mmol) were added with continued degassing during 5 min. The resulting reaction mixture was then stirred at 90°C under argon atmosphere for 12 h. The progress of the reaction was monitored by TLC. The reaction mixture was diluted with water and extracted with EtOAc (3 x 20 mL). The combined organic phases were dried over Na2SO4 and concentrated under reduced pressure. The resulting crude material was purified by flash chromatography (30 % EtOAc in hexanes) to obtain compound E or its isomer as a yellow solid. Yield: 328 mg (50 %) of E or its isomer

[0461] 1H-NMR (CDCh, 400 MHz) 5 (E or its isomer): 7.45 (1 H, s), 6.72 (1 H, d, J = 1.6 Hz), 5.76 (2H, s), 4.23 - 4.16 (2 H, m), 3.68 - 3.64 (2 H, m), 2.51 (3H, d, J = 1 .6 Hz), 1 .32 - 1 .23 (3 H, m), 0.99 - 0.98 (2 H, m), 0.01 (9H, s).

[0462] LCMS: 378.3 [M+Na]+

[0463] Step 4: Synthesis of ethyl (E)-3-(2-amino-1-{[2-(trimethylsilyl)ethoxy]methyl}-4-imidazolyl)-2-butenoate (F) or its isomer:

[0464] To a solution of compound E or its isomer (280 mg, 0.789 mmol) in THF (10 mL), Zn (280 mg, w / w) and NH4CI (280 mg) in water (3 mL) were added successively and the mixture was stirred at ambient temperature for 24 h. The reaction progress was monitored by TLC. After complete consumption of the starting material, the reaction mixture was diluted with ethyl acetate (50 mL) and filtered through a celite bed. The organic layer was separated and concentrated to afford compound F or its isomer as an off-white solid.

[0465] Yield: 163 mg (63 %) of F or its isomer.

[0466] 1H-NMR (CDCh, 400 MHz) 5 (F or its isomer): 6.80 (1 H, s), 6.49 (1 H, d, J = 1.2 Hz), 5.09 (2H, s), 4.48 (2H, bs), 4.19 - 4.14 (2 H, m), 3.56 - 3.51 (2 H, m), 2.40 (3H, d, J = 1 .2 Hz), 1 .29 - 1 .24 (3 H, m), 0.94 - 0.90 (2 H, m), 0.0 (9H, s) LCMS: 326.4 [M+H]+ Step 5: Synthesis of (E)-3-(2-amino-1-{[2-(trimethylsilyl)ethoxy]methyl}-4-imidazolyl)-2-butenoic acid (G) or its isomer:

[0467] To a stirred solution of compound F or its isomer (150 mg, 0.462 mol) in THF (10 mL) was added a solution of LiOH (55 mg, 2.31 mmol) in water (3 mL) at room temperature. The resulting reaction mixture was stirred at room temperature for 16 h. The progress of the reaction was monitored by TLC. The reaction mixture was concentrated under reduced pressure, the resulting residue was suspended in water (13 mL) and was acidified using 1 .5 N HCI to pH - 4. The obtained precipitate was collected by filtration and dried in high vacuum to give compound G or its isomer as an off white solid.

[0468] Yield: 106 mg (77 %) of G or its isomer

[0469] 1H-NMR (DMSO, 400 MHz) 5 (G or its isomer): 11.93 (1 H, bs), 6.80 (1 H, s), 6.49 (1 H, d, J = 1.2 Hz), 5.15 (2H, s), 3.53 - 4.48 (2 H, m), 2.25 (3H, d, J = 1 .2 Hz), 0.86 - 0.84 (2 H, m), - 0.03 (9H, s) LCMS: 298.3 [M+H]+

[0470] To a stirred solution of compound G or its isomer (100 mg, 0.337 mmol) in 1,4 dioxane (1 mL), 4M HCI in 1 ,4 dioxane (1 mL) was added. The resulting reaction mixture was stirred at 25-30°C for 16 h under argon atmosphere in a sealed condition. The progress of the reaction was monitored by TLC. The reaction mixture was evaporated under reduced pressure to remove the volatiles at 45°C. The remaining crude product was further purified by RP-HPLC. The combined fractions were evaporated at 45°C and the residue obtained was dissolved in acetonitrile:water (2:1) (3 mL) and this solution was dried by lyophilisation to give the final product H (as an off-white solid).

[0471] Yield: 22 mg, 39 %

[0472] 1H-NMR (DMSO, 400 MHz) 5: 11.93 (1 H, bs), 7.13 (1 H, s), 6.54 (2H, bs), 6.06 (1 H, s), 2.25 (3H, d, J = 1.2 Hz)

[0473] LCMS: 168.0 [M+H]+; HPLC purity 94.4 %

[0474] Example 9 - Urocanate reductase enzyme assays in cell lysates

[0475] Urocanate reductase (UrdA) enzyme activity of the compounds was determined in cell lysates of the following bacteria that endogenously express the enzyme: Shewanella oneidensis MR-1 (ATCC 700550), Eggerthella lenta (CCUG 17323 AT), Anaerococcus prevotii (CCUG 41932) and Brevibacillus laterosporus (CCUG 52899). All chemicals were purchased from Sigma-Aldrich if not otherwise stated.

[0476] Bacterial cell cultures were diluted to 2 % in their respective growth medium - S. oneidensis: Trypticase Soy Yeast Extract Medium (TSB, Becton Dickinson AB, supplemented with 0.25 % yeast, Oxoid), E. lenta: LYBHI - brain-heart infusion medium (BHI, Oxoid) supplemented with 0.5 % yeast, A prevotii and B. laterosporus: BHI medium. The cultures were maintained under aerobic conditions at 30°C for S. oneidensis and at 37°C for A. prevotii and B. laterosporus or strict anaerobic conditions in a Coy chamber (5 % hydrogen, 10 % carbon dioxide and 8 5% nitrogen) at 37°C for E. lenta until the stationary growth phase was reached. For lysate preparations, the cells were harvested by centrifugation (4700 g, 4°C, 20 min) and washed once with buffer (50 mM HEPES, 100 mM NaCI, Tris pH 7.0) before re-suspending E. lenta cells in the same buffer to a final 50-fold concentration, or A. prevotii and B. laterosporus cells in the same buffer to a final 10-fold concentration. Aliquots were snap-frozen on dry ice and stored at -80°C until further lysis preparation by glass bead treatment (6 x 1 min at 4°C with 3 min pause on ice for E. lenta and A. prevotii and 4 x 30 sec at 4°C with 3 min pause on ice for B. laterosporus). S. oneidensis cells were re-suspended to a final 10 x concentration in buffer containing 0.025 % n-dodecyl-p-d-maltoside and further lysed by sonication (5 x 1 min in a sonication water bath with 30 sec pause on ice). Aliquots were snap-frozen and stored at -80°C until further use.

[0477] Apparent kinetic parameters were evaluated by non-linear regression and under the assumption of Michaelis-Menten kinetics for S. oneidensis, E. lenta, A. prevotii and B. laterosporus to determine the appropriate substrate concentration (corresponding to the Michaelis-Menten constant KM) for each homologue used in the subsequent enzyme activity assays. Reactions were performed under anaerobic conditions and at room temperature (for S. oneidensis) or 37°C (E. lenta, A. prevotii and B. laterosporus) in a total volume of 210 pL buffer (50 mM HEPES, 100 mM NaCI, Tris pH 7.0) containing the respective urocanate concentrations (S. oneidensis 25 pM urocanate, E. lenta 5 pM urocanate, A. prevotii 10 pM urocanate and B. laterosporus 0.5 pM urocanate). 100 mM methyl viologen was reduced with 505 mM sodium dithionite in 100 mM Tris-HCI pH 8 and added to the reaction mixture to a final concentration of 680 pM as electron donor. Compounds (UrdA inhibitors) were added in different concentrations. The incubation time was adjusted to the linear range of product formation in each lysate preparation. The reactions were stopped by removing the samples from the anaerobic environment and adding 210 pL acetonitrile (UHPLC-grade purity, Thermo Fisher) for sample extractions.

[0478] The substrate conversion rate was determined by measuring urocanate and imidazole propionate (ImP) concentrations using reversed-phase liquid chromatography tandem mass spectrometry. The extracted samples were mixed with 100 nM of internal standards (lmP-13C3 and urocanate-13C3, Astra Zeneca) before drying the samples under a flow of nitrogen. The samples were then reconstituted with 5 % HCI (37 %) in 1 -butanol, subjected to n-butyl ester derivatization at 70°C for 40 min and finally reconstituted in water : acetonitrile (9:1). The samples were analysed using a Waters Acquity UPLC system coupled to a Xevo TQ XS tandem mass spectrometer (Waters) operated in positive electrospray ionization mode. The samples were loaded onto a BEH C18 analytical column (2.1 x 50 mm with 1.7 mm particles; Waters) and separated using a gradient consisting of water with 0.1 % formic acid (A-phase) and acetonitrile with 0.1 % formic acid (B-phase). ImP and urocanate levels were determined according to the method described in Koh et al. (Cell 175(4): 947-961 e17, 2018) using multiple reaction monitoring (MRM) of the transitions 197.2 > 81.2 and 195.2 > 93.0. For the internal standards, the transitions 200.2 > 82.0 (lmP-13C3) and 198.2 > 95.0 (urocanate-13C3) were used. Enzyme activities were normalized to vehicle control samples and substrate conversion rates kept in the linear velocity range. ICso values were determined by fitting the normalized data to a non-linear regression equation with a variable slope and are shown in Table 1 . Table 1 : IC50 values for compounds inhibiting UrdA in lysates from Shewanella oneidensis,

[0479] Eggerthella lenta, Anaerococcus prevotii and Brevibacillus laterosporus

[0480] Example 10 - Urocanate reductase enzyme assay with purified protein from Shewanella oneidensis

[0481] Inhibition of urocanate reductase (UrdA) enzyme activity was determined using purified UrdA (so_4620) from Shewanella oneidensis MR-1 . The plasmid for expressing UrdA was introduced into E. coll BL21 (DE3) cells via electroporation. At an OD600 of 0.8, gene expression was induced with 1 .0 mmol / L IPTG at 16°C for 16 h. Cells were harvested by centrifugation, resuspended in a buffer (20 mM Tris, pH 7.9, 10% glycerol, 500 mM KCI, 10 mM imidazole, 3 mM DTT), lysed using a 1 :1 volume of ESPER Bacterial Protein Extraction Reagent (Thermo Scientific). The lysate was centrifuged, and the supernatant was purified using a Ni Sepharose™ 6 Fast Flow agarose column, with impurities removed using a 10 mM, 20 Mm and 50 mM imidazole wash, and the target enzyme eluted with 250 mM imidazole. The eluted proteins were desalted using a PD-10 Desalting column with an elution buffer (20 mM Tris-HCI, 500 mM KCI, 10% glycerol, 3 mM DTT), transferred to an air-tight bottle, sealed, and stored in 50% glycerol at -20°C.

[0482] Apparent kinetic parameters were evaluated by non-linear regression and under the assumption of Michaelis-Menten kinetics to determine the appropriate substrate concentration (corresponding to the Michaelis-Menten constant KM) used in the subsequent enzyme activity assays.

[0483] Reactions were performed under anaerobic conditions in a total volume of 210 pL buffer (50 mM HEPES, 100 mM NaCI, Tris pH 7.0) containing 1.5 pM urocanate and 100 pM FAD. 100 mM methyl viologen was reduced with 505 mM sodium dithionite in 100 mM Tris-HCI pH 8 and added to the reaction mixture to a final concentration of 680 M as electron donor. Compounds (UrdA inhibitors) were added in different concentrations as well as 1 ng UrdA / reaction and incubated at 37°C for 15 min. The reactions were stopped by removing the samples from the anaerobic environment and adding 210 pL acetonitrile (UHPLC-grade purity, Thermo Fisher) for sample extractions.

[0484] The substrate conversion rate was determined by measuring urocanate and imidazole propionate (ImP) concentrations using reversed-phase liquid chromatography tandem mass spectrometry. The extracted samples were mixed with 100 nM of internal standards (lmP-13C3 and urocanate-13C3, Astra Zeneca) before drying the samples under a flow of nitrogen. The samples were then reconstituted with 5 % HCI (37 %) in 1 -butanol, subjected to n-butyl ester derivatization at 70°C for 40 min and finally reconstituted in water : acetonitrile (9:1). The samples were analysed using a Waters Acquity UPLC system coupled to a Xevo TQ XS tandem mass spectrometer (Waters) operated in positive electrospray ionization mode. The samples were loaded onto a BEH C18 analytical column (2.1 x 50 mm with 1.7 mm particles; Waters) and separated using a gradient consisting of water with 0.1 % formic acid (A-phase) and acetonitrile with 0.1 % formic acid (B-phase). ImP and urocanate levels were determined according to the method described in Koh et al. (Cell 175(4): 947-961 e17, 2018) using multiple reaction monitoring (MRM) of the transitions 197.2 > 81.2 and 195.2 > 93.0. For the internal standards, the transitions 200.2 > 82.0 (lmP-13C3) and 198.2 > 95.0 (urocanate-13C3) were used. Enzyme activities were normalized to vehicle control samples and substrate conversion rates kept in the linear velocity range. ICso values were determined by fitting the normalized data to a non-linear regression equation with a variable slope and are shown in Table 2.

[0485] Table 2: ICso values for compounds inhibiting purified UrdA from Shewanella oneidensis

[0486] Example 11 - Urocanate reductase enzyme assay in intact cells

[0487] Bacterial cell cultures from S. oneidensis were maintained under aerobic conditions at 30°C until the log growth phase (OD600 of 0.25) was reached. The cells were then harvested by centrifugation (4700 g, 4°C, 10 min), and washed once with buffer (50 mM HEPES, 100 mM NaCI, Tris pH 7.0) before transferring the cells to anaerobic conditions and re-suspending in growth media (TSBYE) to a final 0.5- fold concentration.

[0488] The reactions were performed under anaerobic conditions in a total volume of 200 pL containing S. oneidensis cells, 25 pM urocanate and UrdA inhibitors in different concentrations. The samples were incubated for 5 min at room temperature before removing from the anaerobic environment and adding 210 pL acetonitrile.

[0489] The substrate conversion rate and ICso values were determined using the same method as in Example 10.

[0490] Compound 8 inhibited UrdA activity in intact S. oneidensis cells with an ICso value of 0.4 pM and compound 9 with 37 pM, confirming the results from the S. oneidensis UrdA lysate assay in Example 10.

[0491] Example 12 - Inhibition of urocanate reductase enzyme activity in a polymicrobial human fecal culture

[0492] Material and Methods

[0493] In order to determine the efficacy of UrdA inhibitors in a complex environment, UrdA enzyme activities were investigated in polymicrobial human fecal cultures. A simulated human intestinal redox model (SHIRM) was used (Koh et al., Cell, 175(4), 947-961. e17, 2018) with some modifications. The SHIRM model consisted of a two-chamber fermenter with an anaerobic luminal chamber continuously purged with nitrogen and maintained at 37°C, as well as an oxygen chamber containing 100 mM potassium phosphate buffer. Both compartments were separated by a CMI-7000S membrane (Membrane International, NJ). The luminal chamber feed contained (g / L) arabinogalactan (1), pectin (2), xylan (1), starch (3), glucose (0.4), yeast extract (3), peptone (3), mucin type II (1), NaCI (0.9), KH2PO4 (0.45), K2HPO4 (0.45), CaCb (0.12), MgSO4.7H2O (0.09), hemin (0.02) and a vitamin mix [consisting of ( g / L) biotin (10), cobalamin (10), p-aminobenzoic acid (30), folic acid (50), pyridoxamine (150), riboflavin (50) and thiamine-HCI (50)]. The digestion process was simulated by acidifying the feed with 6 M HCI to a pH of approximately 2 and adding 10 mg / L of pepsin before incubating the feed at 37°C for 30-45 min. The feed was then neutralized to a pH of 6.9 with simulated pancreatic juice [(g / L) NaHCOs (12.5), Ox gall bile salts (6) and pancreatin (0.9)] and 0.5 g / L cysteine added. The luminal chamber was continuously supplied with this feed at a rate giving a retention time of around 24 h and the pH maintained at 6.6-6.9 using a pH controller and dosing pump (Black Stone BL7916-2, Hanna Instruments, UK).

[0494] To start up the SHIRM system, it was inoculated with an aliquot of a feces sample from a subject with type 2 diabetes. A pre-culture was prepared under anaerobic conditions in a Coy chamber (5% hydrogen, 10% carbon dioxide and 85% nitrogen) by adding 2% fecal material to 5 mL of LYBHI medium containing (g / L) yeast extract (5), cellobiose (1), maltose (1), cysteine (0.5) and hemin (0.01). The pre-culture was incubated at 37°C for 5h and then seeded into the luminal compartment of the SHIRM system. The luminal community was incubated for 24 h before UrdA enzyme activity tests were performed.

[0495] The enzymatic reactions were performed under anaerobic conditions in a Coy chamber at 37°C in a total volume of 1 mL. The luminal community was transferred from the SHIRM system to the Coy chamber, and aliquots of 1 mL were prepared for the different experimental conditions containing either 50 pM or 250 pM urocanate and UrdA inhibitors at different concentrations (two concentrations of uroconate substrate were used to account for the polymicrobial environment and the potential of slightly different kinetic parameters for the UrdA activity of different bacterial species). The vehicle control consisted of 2.5% DMSO. The reactions were incubated for 24 h and samples were taken at 1 h, 2 h, 4 h, 8 h, and 24 h in order to capture the incubation time within the linear range of product formation. The reactions were stopped by removing the samples from the anaerobic environment and storing at -20°C until further analysis. The substrate conversion rate and IC50 values were determined using the same method as in Example 10.

[0496] Results

[0497] The results for tested compound Nos. 5, 1 and 9 are set out in Table 3:

[0498] Table 3: ICso values for compounds inhibiting UrdA in a polymicrobial human fecal culture

[0499] The tested compounds showed their potential to inhibit the enzymatic activity of UrdA in a polymicrobial human fecal culture from a type 2 diabetes donor. This confirmed the results found in the single-strain lysate UrdA assays with S. oneidensis, E. lenta, A. prevotii and B. laterosporus in Example 9.

[0500] Example 13 - In vitro ADME properties

[0501] The extent to which a compound will permeate through a membrane will influence the absorption from the gastrointestinal tract, the distribution of the compound throughout the body, the metabolism, and the excretion pattern. By studying the apparent permeability (Papp) in a human cell monolayer (Hubatsch et al. Nature Protocols, 2007), information regarding these properties can be obtained.

[0502] Caco-2 cell monolayers were grown on permeable filter support. On day 21 after seeding, the Caco-2 filters were washed with pre-warmed HBSS (pH 7.4) and compounds (UrdA inhibitors) (1 pM in HBSS) added on either the apical or basolateral side. The cells were then incubated at 37°C on an orbital shaker (500 rpm). After 30 min, a sample was withdrawn from both compartments. The samples (100 pL) were transferred to a 96-well plate containing 100 pL methanol and Warfarin as IS and analyzed by LC-MS / MS. 5 uM enalaprilat was used as membrane integrity control in each filter. The Papp of enalaprilat for a tight monolayer has been determined as < 1 x 10A-6 cm / s.

[0503] Compound Nos. 8, 5, 1 and 6 showed permeability through the Caco2 cells monolayer, with no elevated efflux ratio (Table 4). The results indicate that the compounds can be absorbed from the gastrointestinal tract and enter systemic circulation.

[0504] Table 4: Caco2 cell permeability

[0505] Plasma protein binding, fraction of unbound compound and plasma stability were assessed in the presence of human and mouse plasma. The fraction of unbound compound (fu) in plasma from human (UU0938013) and mouse (CD1 / K2 EDTA, Lot: 34617, 2021-05-06, Innovative Research) was determined by equilibrium dialysis at 37°C for 4 hours using the Rapid Equilibrium Dialysis (RED) device (ThermoFisher Scientific). Compounds (UrdA inhibitors) were added at a concentration of 0.1 , 1 , or 10 pM to the plasma samples and dialyzed against an isotonic phosphate buffer (67mM, pH 7.4). After dialysis, the compound concentration in the buffer and plasma was quantified by LC-MS / MS analysis. In parallel, the stability of the UrdA inhibitors in plasma was determined by incubating compound-spiked plasma (0.1 , 1, and 10 pM, respectively) at 37°C for 4 hours. Compound concentrations were quantified by LC-MS / MS analysis.

[0506] The results for tested Compound Nos. 8, 5, 1 and 9 are set out in Tables 5 and 6. Compound Nos. 8, 5, 1 and 6 showed low plasma protein binding in the presence of human and mouse plasma and were stable in both human and mouse plasma.

[0507] Table 5: Human plasma protein binding and stability of Compounds (UrdA inhibitors)

[0508] Table 6: Mouse plasma protein binding and stability of Compounds (UrdA inhibitors)

[0509] Metabolic stability of Compounds (UrdA inhibitors) was tested in human (pool of 50, mixed gender) and mouse (CD-1 , male) liver microsomes by measuring the in vitro half-time (t1 / 2). To this end, 0.5 mg / mL of human or mouse liver microsomes were incubated with 1 pM of Compounds (UrdA inhibitors) in 100 mM KPO4 buffer (pH 7.4) in a total incubation volume of 500 pL. The reaction was initiated by the addition of 1 mM NADPH and samples withdrawn at different incubation time points up to 300 min. The reaction was terminated by the addition of cold acetonitrile and the amount of parent compound remaining analyzed by LC-MS / MS.

[0510] The results for tested Compound Nos. 8, 5, 1 and 6 are set out in Tables 7 and 8. Compound Nos. 8, 5, 1 and 6 showed very high microsomal stability in human liver microsomes, as well as in mouse liver microsomes (except Compound No. 5 for which t1 / 2was 120 min).

[0511] Table 7: Human liver microsomal stability of Compounds (UrdA inhibitors)

[0512] Table 8: Mouse liver microsomal stability of Compounds (UrdA inhibitors)

Claims

Claims:1 . A compound of formula (I), a stereoisomer, tautomer, or pharmaceutically acceptable salt thereof for use in preventing, inhibiting or treating a condition or disorder which is mediated by urocanate reductase:wherein:A is a 5-membered heteroaromatic ring containing 1 to 4 heteroatoms selected from nitrogen, oxygen and sulphur, and in which at least one of said heteroatoms is nitrogen;R1and R2are independently selected from:-H;C1-6 alkyl, preferably C1-3 alkyl, e.g. -CH3;C1-6 haloalkyl, preferably C1-3 haloalkyl, e.g. -CF3;C1-6 alkoxy, preferably C1-3 alkoxy, e.g. -OCH3; halogen, preferably F, Cl, Br or I; and-CN; when present, each R3is independently selected from:C1-6 alkyl, preferably C1-3 alkyl, e.g. -CH3;C1-6 haloalkyl, preferably C1-3 haloalkyl, e.g. -CF3;C1-6 alkoxy, preferably C1-3 alkoxy, e.g. -OCH3; halogen, preferably F, Cl, Br or I;-OH;-CN;-NO2;-NR5R6wherein R5and R6are independently selected from H and C1-3 alkyl, preferably selected from H and -CH3; and-C(=NR7)(NR8R9) wherein each of R7, R8and R9is independently selected from H and C1-3 alkyl, preferably selected from H and -CH3;R4is selected from:-OH-SHC1-6 alkoxy, preferably C1-3 alkoxy; and-NR10R11wherein R10and R11are independently selected from H and C1-3 alkyl, preferably selected from H and -CH3; and n is an integer from O to 2.

2. A compound for use as claimed in claim 1 , wherein said condition or disorder is a gastrointestinal disorder or condition, a cardiovascular disease or disorder, or a metabolic disorder.

3. A compound for use as claimed in claim 1 , wherein said condition or disorder is primary sclerosing cholangitis (PSC), myocardial fibrosis, heart failure, type 2 diabetes or pre-diabetes.

4. A compound for use as claimed in any one of claims 1 to 3, wherein in formula (I), A is a 5- membered heteroaromatic ring containing 1 to 3 heteroatoms selected from nitrogen and sulphur, preferably 1 or 2 heteroatoms selected from nitrogen and sulphur.

5. A compound for use as claimed in any one of claims 1 to 3, wherein in formula (I), A is a 5- membered heteroaromatic ring containing 1 to 3 nitrogen atoms, preferably 1 or 2 nitrogen atoms.

6. A compound for use as claimed in any one of claims 1 to 3, wherein in formula (I), A is imidazolyl, pyrazolyl, pyrrolyl, or thiazolyl, preferably 4-imidazolyl, 5-imidazolyl, 3-pyrazolyl, 4-pyrazolyl, 3-pyrrolyl, or 4-thiazolyl.

7. A compound for use as claimed in any one of the preceding claims, wherein in formula (I), n is 0 or 1.

8. A compound for use as claimed in any one of claims 1 to 6, wherein in formula (I), n is other than 0, and R3is selected from C1-3 alkyl (e.g. -CH3 or -CH2CH3), C1-3 haloalkyl (e.g. CF3), C1-3 alkoxy (e.g.-OCH3), F, Cl, -NH2 and -OH.

9. A compound for use as claimed in any one of the preceding claims, wherein in formula (I), R1and R2are independently selected from -H, C1-3 alkyl (e.g. -CH3 or -CH2CH3), C1-3 haloalkyl (e.g. -CF3), F and Cl.

10. A compound for use as claimed in any one of claims 1 to 9, wherein in formula (I), R1is H, -CH3, -CH2CH3 or F.

11. A compound for use as claimed in any one of claims 1 to 9, wherein R1is H.

12. A compound for use as claimed in any one of claims 1 to 11 , wherein in formula (I), R2is H,-CH3, -CH2CH3 or F, preferably H, -CH3 or -CH2CH3.

13. A compound for use as claimed in claim 12, wherein R2is H, -CH3 or -CH2CH3.

14. A compound for use as claimed in claim 13, wherein R2is -CH3 or -CH2CH3, preferably -CH3.

15. A compound for use as claimed in any one of claims 1 to 11 , wherein R2is other than H.

16. A compound for use as claimed in any one of the preceding claims, wherein in formula (I), R4is -OH or C1-3 alkoxy, preferably -OH.

17. A compound for use as claimed in any one of the preceding claims, wherein in formula (I), the heteroaromatic ring A and the group -C(O)R4are trans to one another.

18. A compound for use as claimed in any one of claims 1 to 3, wherein said compound is a compound of formula (II), a stereoisomer, tautomer, or pharmaceutically acceptable salt thereof:wherein:R1is as defined in any one of claims 1 and 9 to 11 ;R2is as defined in any one of claims 1 , 9 and 12-15;R3is as defined in claim 1 or claim 8;R4is as defined in claim 1 or claim 16; and m is an integer from 0 to 2, preferably 0 or 1 .

19. A compound for use as claimed in claim 18, wherein said compound is a compound of formula (II) in which the imidazolyl ring and the group -C(O)R4are trans to one another, a tautomer or pharmaceutically acceptable salt thereof.

20. A compound for use as claimed in any one of claims 1 to 3, wherein said compound is a compound of formula (III), a stereoisomer, tautomer, or pharmaceutically acceptable salt thereof:wherein:R1is as defined in any one of claims 1 and 9 to 11 ;R2is as defined in any one of claims 1 , 9 and 12-15;R3is as defined in claim 1 or claim 8;R4is as defined in claim 1 or claim 16; and p is an integer from 0 to 2, preferably 0 or 1 .21 . A compound for use as claimed in claim 20, wherein said compound is a compound of formula (III) in which the pyrazolyl ring and the group -C(O)R4are trans to one another, a tautomer or pharmaceutically acceptable salt thereof.

22. A compound for use as claimed in any one of claims 1 to 3, wherein said compound is a compound of formula (IV), a stereoisomer, tautomer, or pharmaceutically acceptable salt thereof:wherein:R1is as defined in any one of claims 1 and 9 to 11 ;R2is as defined in any one of claims 1 , 9 and 12-15;R3is as defined in claim 1 or claim 8;R4is as defined in claim 1 or claim 16; and q is an integer from 0 to 2, preferably 0 or 1 .

23. A compound for use as claimed in claim 22, wherein said compound is a compound of formula (IV) in which the pyrrolyl ring and the group -C(O)R4are trans to one another, a tautomer or a pharmaceutically acceptable salt thereof.

24. A compound for use as claimed in any one of claims 1 to 3, wherein said compound is a compound of formula (V), a stereoisomer, tautomer, or pharmaceutically acceptable salt thereof:wherein:R1is as defined in any one of claims 1 and 9 to 11 ;R2is as defined in any one of claims 1 , 9 and 12-15;R3is as defined in claim 1 or claim 8;R4is as defined in claim 1 or claim 16; and s is an integer from 0 to 2, preferably 0 or 1 .

25. A compound for use as claimed in claim 24, wherein said compound is a compound of formula (V) in which the thiazolyl ring and the group -C(O)R4are trans to one another, a tautomer or pharmaceutically acceptable salt thereof.

26. A compound for use as claimed in any one of claims 1 to 3, wherein said compound of formula (I) is selected from the following, their stereoisomers, their tautomers and their pharmaceutically acceptable salts:

27. A compound for use as claimed in claim 26, wherein said compound is selected from Compound Nos. 1-28 in which the 5-membered heteroaromatic ring is positioned trans to the -C(O)OH group, their tautomers and their pharmaceutically acceptable salts.

28. A compound of formula (II), a stereoisomer, tautomer, or pharmaceutically acceptable salt thereof:wherein:R1is as defined in any one of claims 1 and 9 to 11 ;R2is as defined in any one of claims 1 , 9 and 12-15;R3is as defined in claim 1 or claim 8;R4is as defined in claim 1 or claim 16; and m is an integer from 0 to 2, preferably 0 or 1 ; with the proviso that the compound is other than:

29. A compound as claimed in claim 28, wherein in formula (II), m is 0 or m is 1 and R3is a group - NR5R6, preferably -NH2.

30. A compound as claimed in claim 28 or 29, wherein in formula (II), R1and R2are independently selected from -H and C1-6 alkyl, preferably from -H and C1-3 alkyl, e.g. from -H and -CH331 . A compound as claimed in any one of claims 28 to 30, wherein in formula (II), R4is OH.

32. A compound as claimed in claim 28 which is a compound of formula (Ila), a stereoisomer, tautomer, or pharmaceutically acceptable salt thereof:wherein R3and m are as defined in claim 28.

33. A compound as claimed in claim 32, wherein in formula (Ila), m is 0 or m is 1 and R3is either a group -NR5R6, preferably -NH2, or R3is C1-3 alkyl, preferably -CH3.

34. A compound as claimed in any one of claims 28 to 33 which is a compound of formula (II) in which the imidazolyl ring and the group -C(O)R4are trans to one another, or a compound of formula (Ila) in which the imidazolyl ring and the group -C(O)OH are trans to one another, or a tautomer, or pharmaceutically acceptable salt thereof.

35. A compound of formula (III), a stereoisomer, tautomer, or pharmaceutically acceptable salt thereof:wherein:R1is as defined in any one of claims 1 and 9 to 11 ;R2is as defined in any one of claims 1 , 9 and 12-15;R3is as defined in claim 1 or claim 8;R4is as defined in claim 1 or claim 16; and p is an integer from 0 to 2, preferably 0 or 1 ; with the proviso that the compound is other than:

36. A compound as claimed in claim 35, wherein in formula (III), p is 0 or p is 1 and R3is C1-6 alkyl, preferably C1-3 alkyl, e.g. -CH3.

37. A compound as claimed in claim 35 or 36, wherein in formula (III), R1and R2are independently selected from -H and C1-6 alkyl, preferably from -H and C1-3 alkyl, e.g. from -H, -CH3 and -CH2CH3.

38. A compound as claimed in any one of claims 35 to 37, wherein in formula (III), R4is OH.

39. A compound as claimed in claim 35 which is a compound of formula (Illa), a stereoisomer, tautomer, or pharmaceutically acceptable salt thereof:wherein R3and p are as defined in claim 35.

40. A compound as claimed in claim 39, wherein in formula (Illa), p is 0 or p is 1 and R3is C1-3 alkyl, preferably -CH3.

41. A compound as claimed in any one of claims 35 to 40 which is a compound of formula (III) in which the pyrazolyl ring and the group -C(O)R4are trans to one another, or a compound of formula (Illa) in which the pyrazolyl ring and the group -C(O)OH are trans to one another, or a tautomer, or pharmaceutically acceptable salt thereof.

42. A compound of formula (IV), a stereoisomer, tautomer, or pharmaceutically acceptable salt thereof:wherein:R1is as defined in any one of claims 1 and 9 to 11 ;R2is as defined in any one of claims 1 , 9 and 12-15;R3is as defined in claim 1 or claim 8;R4is as defined in claim 1 or claim 16; and q is an integer from 0 to 2, preferably 0 or 1 ; with the proviso that the compound is other than:

43. A compound as claimed in claim 42, wherein in formula (IV), q is 0.

44. A compound as claimed in claim 42 or 43, wherein in formula (IV), R1and R2are independently selected from -H and C1-6 alkyl, preferably from -H and C1-3 alkyl, e.g. from -H and -CH3.

45. A compound as claimed in any one of claims 42 to 44, wherein in formula (IV), R4is OH.

46. A compound as claimed in claim 42 which is a compound of formula (IVa), a stereoisomer, tautomer, or pharmaceutically acceptable salt thereof:wherein R3and q are as defined in claim 42.

47. A compound as claimed in any one of claims 42 to 46 which is a compound of formula (IV) in which the pyrrolyl ring and the group -C(O)R4are trans to one another, or a compound of formula (IVa) in which the pyrrolyl ring and the group -C(O)OH are trans to one another, or a tautomer, or pharmaceutically acceptable salt thereof.

48. A compound of formula (V), a stereoisomer, tautomer, or pharmaceutically acceptable salt thereof:wherein:R1is as defined in any one of claims 1 and 9 to 11 ;R2is as defined in any one of claims 1 , 9 and 12-15;R3is as defined in claim 1 or claim 8;R4is as defined in claim 1 or claim 16; and s is an integer from 0 to 2, preferably 0 or 1 ; with the proviso that the compound is other than:

49. A compound as claimed in claim 48, wherein in formula (V), s is 1 and R3is a group -NR5R6, preferably -NH2.

50. A compound as claimed in claim 48 or 49, wherein in formula (V), R1and R2are both -H.51 . A compound as claimed in any one of claims 48 to 50, wherein in formula (V), wherein R4is OH.

52. A compound as claimed in claim 48 which is a compound of formula (Va), a stereoisomer, tautomer, or pharmaceutically acceptable salt thereof:wherein R3and s are as defined in claim 49.

53. A compound as claimed in any one of claims 48 to 52 which is a compound of formula (V) in which the thiazolyl ring and the group -C(O)R4are trans to one another, or a compound of formula (Va) in which the thiazolyl ring and the group -C(O)OH are trans to one another, or a tautomer, or pharmaceutically acceptable salt thereof.

54. A compound as claimed in any one of claims 28 to 53, wherein said compound has the following structure, or a stereoisomer, tautomer, or pharmaceutically acceptable salt thereof:

55. A compound as claimed in claim 54, wherein said compound is selected from Compound Nos. 5, 8, 15, 16, 17, 18, 20, 21, 25, 28, 1 , 4, 6, 25, 27, 22, 23 and 2 in which the 5-membered heteroaromatic ring is positioned trans to the -C(O)OH group, their tautomers and their pharmaceutically acceptable salts.

56. A compound as claimed in any one of claims 28 to 55 for use as a medicament.

57. A pharmaceutical composition comprising a compound as claimed in any one of claims 28 to 55, together with one or more pharmaceutically acceptable carriers, excipients or diluents.

58. Use of a compound as defined in any one of claims 1 and 4 to 27 in the manufacture of a medicament for use in preventing, inhibiting or treating a condition or disorder which is mediated by urocanate reductase.

59. Use as claimed in claim 58, wherein said condition or disorder is a gastrointestinal disorder or condition, a cardiovascular disease or disorder, or a metabolic disorder.

60. Use as claimed in claim 58, wherein said condition or disorder is primary sclerosing cholangitis (PSC), myocardial fibrosis, heart failure, type 2 diabetes or pre-diabetes.61 . A method of preventing, inhibiting or treating a condition or disorder which is mediated by urocanate reductase, said method comprising the step of administering to a patient in need thereof(e.g. a human subject) a pharmaceutically effective amount of a compound as defined in any one of claims 1 and 4 to 27.

62. A method as claimed in claim 61 , wherein said condition or disorder is a gastrointestinal disorder or condition, a cardiovascular disease or disorder, or a metabolic disorder.

63. A method as claimed in claim 61 , wherein said condition or disorder is primary sclerosing cholangitis (PSC), myocardial fibrosis, heart failure, type 2 diabetes or pre-diabetes.

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