WO1997010247A1 - Clavulanic acid derivatives for treating atherosclerosis - Google Patents

Abstract

Clavulanic acid derivatives of structure (I) in which R1 is OH, OCOR3, OCHO, O(CH¿2)nOR?5, OC¿1-12?alkyl, O(CH2)nCO2R?5¿, -S(O)¿p?C1-12alkyl, S(CH2)qPh, S(O)r(CH2)nPh, N3, NR?6R7¿ or (a); R2 is O(CH¿2?)nPh in which the phenyl ring may optionally be substituted, O(CH2)nnaphthyl, O(CH2)nCOPh, O(CH2)nSPh, OCH(Ph)C1-6alkyl, OC1-6alkyl, NR?10(CH¿2)qPh, NR10(CH2)nCOPh, N(R8)O(CH2)nPh; R3 is C¿1-12?alkyl, C2-12alkenyl, optionally substituted phenyl, CH(Ph)2, biphenyl, (CH2)nPh, (CH2)nHet, (CH2)nCO2R?8, (CH¿2)nC3-6cycloalkyl, C(R9)3, adamantyl, naphthyl, C3-6cyclohexyl, (CH2)nPh(CH2)nPh or PhOPh; R5 is hydrogen or C¿1-6?alkyl; one of R?6 and R7¿ is hydrogen or C¿1-6?alkyl, and the other is CHO, CH2Ph, COC1-6alkyl, COPh, COCH2NHCOC1-6alkyl or NHCOOCH2Ph; R?8¿ is hydrogen or C¿1-6?alkyl; R?9¿ is hydrogen or halogen; R10 is hydrogen, hydroxy, C¿1-6?alkyl or OCOCH3; m is 1 or 2; n is 1 to 8; p is 0, 1 or 2; q is 0 to 6 and r is 0, 1 or 2; and salts, hydrates and solvates thereof are inhibitors of Lp PLA2 and of use in therapy, in particular for treating atherosclerosis.

Description

CLAVULANIC ACID DERIVATIVES FOR TREATING ATHEROSCLEROSIS

The present invention relates to certain novel clavulanic acid derivatives, processes for their preparation, intermediates useful in their preparation, pharmaceutical compositions containing them and their use in therapy, in particular in the treatment of atherosclerosis.

The sequence of the enzyme Lipoprotein Associated Phospholipase A2 (Lp- PLA2), the isolation and purification thereof, isolated nucleic acids encoding the enzyme, recombinant host cells transformed with DNA encoding the enzyme are described in patent application WO 95/00649 (SmithKline Beecham pic). Suggested therapeutic uses for inhibitors of the enzyme included atherosclerosis, diabetes, rheumatoid arthritis, stroke, myocardial infarction, reperfusion injury and acute and chronic inflammation. A later patent application (WO 95/09921. Icos Corporation) and a related publication in Nature (Tjoelker et al. vol 374. 6 April 1995, 549) describe the same enzyme, although calling it by the name 'Platelet Activating Factor Acetyl Hydrolase' (PAF acetyl hydrolase) and suggest that it may have potential as a therapuetic protein for regulating pathological inflammatory events.

Lp-PLA2 is responsible for the conversion of phosphatidylcholine to lysophosphatidylcholine, during the conversion of low density lipoprotein (LDL) to its oxidised form. The enzyme is known to hydrolyse the sn-2 ester of oxidised phosphatidylcholine to give lysophosphatidylcholine and an oxidatively modified fatty acid. Both products of Lp-PLA2 action are biologically active with lysophosphatidylcholine. a component of oxidised LDL, known to be a potent chemoattractant for circulating monocytes. As such, lysophosphatidylcholine is thought play a significant role in atherosclerosis by being responsible for the accumulation of cells loaded with cholesterol ester in the arteries. Inhibition of the Lp-PLA2 enzyme would therefore be expected to stop the build up of these macrophage enriched lesions (by inhibition of the formation of lysophosphatidylcholine and oxidised free fatty acids) and so be useful in the treatment of atherosclerosis. The increased lysophosphatidylcholine content of oxidatively modified LDL is also thought to be responsible for the endothelial dysfunction observed in patients with atherosclerosis. Inhibitors of Lp-PLA2 could therefore prove beneficial in the treatment of this phenomenon. A Lp-PLA2 inhibitor could also find utility in other disease states that exhibit endothelial dysfunction including diabetes, hypertension, angina pectoris and after ischaemia and reperfusion. Lp-PLA2 inhibitors may also have a general application in any disorder that involves activated monocytes. macrophages or lymphocytes, as all of these cell types express Lp-PLA₂. Examples of such disorders include psoriasis.

Lp-PLA2 inhibitors may also have a general application in any disorder that involves lipid peroxidation in conjunction with Lp-PLA2 activity to produce the two injurious products, lysophosphatidylcholine and oxidatively modified fatty acids. Such conditions include the aforementioned conditions atherosclerosis, diabetes, rheumatoid arthritis, stroke, inflammatory conditions of the brain such as Alzheimer's Disease, myocardial infarction, reperfusion injury, sepsis and acute and chronic inflammation. Further such conditions include various neuropsychiatric disorders such as schizophrenia. Recently published International patent applications WO 96/13484 and WO 96/19451 (SmithKline Beecham pic) disclose two series of substituted azetidin-2-ones which are inhibitors of Lp PLA -

We have now identified a further series of compounds which have been found to act as inhibitors of Lp-PLA2-

The present invention provides in a first aspect compounds of structure (I):

in which:

O

R ! is OH, OCR³, OCHO. O(CH₂)_nOR⁵. OC \ . \ 2alkyl, O(CH₂)_n O2R⁵,

_<C4 -S(O)pCι_i2alkyl, S(CH₂)_qPh. S(O)_r(CH₂)_nPh. N₃, NR⁶R⁷ or -^ ;

R2 is O(CH2)_nPh in which the phenyl ring may optionally be substituted, O(CH₂)_nnaphthyl. O(CH₂)_nCOPh. O(CH₂)_nSPh. OCH(Ph)C₁_₆alkyl, OC galkyl, NRlO(CH₂)_qPh. NRl°(CH₂)_nCOPh, N(R8)O(CH₂)_nPh;

R³ is Cι_i2 lkyl. C2-i2alkenyl, optionally substituted phenyl, CH(Ph)2, biphenyl, (CH₂)_nPh. (CH₂)_nHet. (CH2)_nCO₂R⁸. (CH2)_nC3-6cycloalkyl, C(R9)₃. adamantyl. naphthyl. C3_₆cyclohexyl, (CH₂)_nPh CH2)_nPh or PhOPh; R⁵ is hydrogen or Cj . galkyl;

. ? - one of R⁶ and R⁷ is hydrogen or Cj. galkyl, and the other is CHO. C Ph. COCi.galkyl,

COPh. COCH2NHCOC1.₆alkyl or NHCOOCH Ph;

R⁸ is hydrogen or C \. galkyl;

R" is hydrogen or halogen: R¹⁰ is hydrogen, hydroxy. Cj .galkyl or OCOCH3; m is 1 or 2; n is 1 to 8: p is 0. 1 or 2; q is 0 to 6 and r is 0. 1 or 2; and salts, hydrates and solvates thereof.

Preferably R¹ is OH. OCOR³ or NR6R7. Most preferably R¹ is NHCOCH3.

Preferably R^<- is O CH2)_n h- in which n is 1 to 8, in particular 6. Preferably R³ is Cj.galkyl. Most preferably R³ is methyl.

Preferably R³ is hydrogen.

Preferably, one of R^ and R⁷ is hydrogen and the other is COCj. alkyl, in particular COCH3.

Preferably R⁸ is hydrogen. Preferably one group R^ is hydrogen and the other two are halogen, in particular chlorine.

Preferably R^ is hydrogen.

Preferably, m is 2.

Preferably, n is 6. Preferably, p is 2.

Preferably, q is 0 to 6. Most preferably q is 0 or 1.

Preferably, r is 0. 1 or 2. Most preferably r is 2.

The term optionally substituted phenyl ring as used herein shall be taken to include phenyl rings substituted by 1 to 3 substituents selected from C ] .galkyl, C \ . galkoxy. amino. C \ .galkylthio. halogen, cyano. hydroxy. carbamoyl. carboxy, C \ . galkanoyl or trifluoromethyl. Cj .g and Cj .galkyl groups (either alone or as part of another group) can be straight or branched.

Compounds of structure (I) can form salts, in particular pharmaceutically acceptable acid addition salts with suitable organic and inorganic acids the nature of which will be apparent to persons skilled in the art. For example, pharmaceutically acceptable salts can be formed by reaction with hydrochloric, sulphuric, or phosphoric acids: aliphatic, aromatic or heterocyclic sulphonic acids or carboxylic acids such as for example, citric, maleic or fumaric acids.

The compounds of structure (I) can be prepared staπing. for example, from potassium clavulanate by processes analogous to those known to those skilled in the an as described in the specific examples hereinafter. Compounds of the present invention are inhibitors of the enzyme iipoprotein associated phospholipase A2 (Lp-PLA2) and as such are expected to be of use in therapy, in particular in the treatment of atherosclerosis. In a further aspect therefore the present invention provides a compound of formula (I) for use in therapy. The compounds of formula (I) are inhibitors of lysophosphatidylcholine production by Lp-PLA2 and may therefore also have a general application in any disorder that involves endothelial dysfunction, for example atherosclerosis, diabetes, hypertension, angina pectoris and after ischaemia and reperfusion. In addition, compounds of formula (I) may have a general application in any disorder that involves lipid peroxidation in conjunction with enzyme activity, for example in addition to conditions such as atherosclerosis and diabetes, other conditions such as rheumatoid arthritis, stroke, inflammatory conditions of the brain such as Alzheimer's Disease, myocardiai infarction, reperfusion injury, sepsis, and acute and chronic inflammation. Further such conditions include various neuropsychiatric disorders such as schizophrenia. Further applications include any disorder that involves activated monocytes, macrophages or lymphocytes, as all of these cell types express Lp-PLA₂. Examples of such disorders include psoriasis.

Accordingly, in a further aspect, the present invention provides for a method of treating a disease state associated with activity of the enzyme Lp-PLA₃ which method involves treating a patient in need thereof with a therapeutically effective amount of an inhibitor of the enzyme. The disease state may be associated with the increased involvement of monocytes, macrophages or lymphocytes: with the formation of lysophosphatidylcholine and oxidised free fatty acids: with lipid peroxidation in conjunction with Lp PLA2 activity: or with endothelial dysfunction. Compounds of the present invention may also be of use in treating the above mentioned disease states in combination with anti-hyperiipidaemic or anti-atherosclerotic or anti-diabetic or anti-anginal or anti-inflammatory or anti-hypertension agents. Examples of the above include cholesterol synthesis inhibitors such as statins, anti- oxidants such as probucol. insulin sensitisers. calcium channel antagonists, and anti- inflammatory drugs such as NSAIDs.

In therapeutic use. the compounds of the present invention are usually administered in a standard pharmaceutical composition. The present invention therefore provides in a further aspect pharmaceutical compositions comprising a compound of structure (I) or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier. The compounds of structure (I) and their pharmaceutically acceptable salts which are active when given orally can be formulated as liquids, for example syrups, suspensions or emulsions, tablets, capsules and lozenges.

A liquid formulation will generally consist of a suspension or solution of the compound or pharmaceutically acceptable salt in a suitable liquid carrier(s) for example, ethanol. glycerine, non-aqueous solvent, for example polyethylene glycol. oils, or water with a suspending agent, preservative, flavouring or colouring agent.

A composition in the form of a tablet can be prepared using any suitable pharmaceutical carrier(s) routinely used for preparing solid formulations. Examples of such carriers include magnesium stearate. starch, lactose, sucrose and cellulose. A composition in the form of a capsule can be prepared using routine encapsulation procedures. For example, pellets containing the active ingredient can be prepared using standard carriers and then filled into a hard gelatin capsule: alternatively, a dispersion or suspension can be prepared using any suitable pharmaceutical carrier(s), for example aqueous gums, celluloses, silicates or oils and the dispersion or suspension then filled into a soft gelatin capsule.

Typical parenteral compositions consist of a solution or suspension of the compound or pharmaceutically acceptable salt in a sterile aqueous carrier or parenterally acceptable oil. for example polyethylene glycol. polyvinyl pyrrolidone, lecithin, arachis oil or sesame oil. Alternatively, the solution can be lyophilised and then reconstituted with a suitable solvent just prior to administration.

A typical suppository formulation comprises a compound of formula (I) or a pharmaceutically acceptable salt thereof which is active when administered in this way, with a binding and/or lubricating agent such as polymeric glycols. gelatins or cocoa butter or other low melting vegetable or synthetic waxes or fats.

Preferably the composition is in unit dose form such as a tablet or capsule. Each dosage unit for oral administration contains preferably from 1 to 250 mg (and for parenteral administration contains preferably from 0.1 to 25 mg) of a compound of the formula (I) or a pharmaceutically acceptable salt thereof calculated as the free base. The daily dosage regimen for an adult patient may be. for example, an oral dose of between 1 mg and 500 mg, preferably between 1 mg and 250 mg. or an intravenous, subcutaneous, or intramuscular dose of between 0.1 mg and 100 mg, preferably between 0.1 mg and 25 mg, of the compound of the formula (I) or a pharmaceutically acceptable salt thereof calculated as the free base, the compound being administered 1 to 4 times per day. Suitably the compounds will be administered for a period of continuous therapy, for example for a week or more.

- 3 The following examples serve to illustrate the invention.

Unless otherwise stated all compounds have the 3R. 5R. Δ2.8Z stereochemistry.

Example 1: R² = O(CH₂)₆-(4- F)Ph. R¹ = OH 6-(4-Fluorophenyl)hexyl clavulanate

(a) 6-(4-Fluorophenyl)hexyl bromide

6-Bromohexanoyl chloride (125 g , 0.585mol) was added over 5 minutes to a suspension of aluminium chloride (71.6 g, 0.537mol) in CH2CI2 (1000ml) whilst keeping the temperature at 20-25°C. The mixture was treated with fluorobenzene (46.5 g, 0.484mol) dropwise over 10 minutes. After stirring at room temperature for 19 hours, triethylsilane (139.4 g, 1.2mol) was added over 10 minutes keeping the temperature below 35°C. The mixture was stirred at room temperature for 60 minutes then poured into ice water ( 11), extracted with diethyl ether ( 1.51). The organic layer was washed with water (x5), brine (x2). dried (MgSO₄) and evaporated in vacuo. The residue was distilled under reduced pressure to give a clear oil (111.9 g), boiling point 1 16-126°C/0.1mbar. Purification by column chromatography on silica gel using hexane as eluant gave the product as a colourless oil (99.8 g, 80%).

(b) 6-(4-Fluorophenyl)hexyl clavulanate.

A mixture of 6-(4-fluorophenyl)hexyl bromide (1.56 g, όmmol) and potassium clavulanate (0.95 g. όmmol) in dimethvlformamide (DMF. 60ml) was stirred at room temperature for 18 hours. The mixture was evaporated to dryness and pardoned between ethyl acetate (100ml) and water (50ml). The organic layer was separated, washed with brine (x2). dried (MgSO ) and evaporated to an oil which was purified by column chromatography on silica gel using 2:1 hexane/ethyl acetate as the eluting solvents, yielding the product as a yellow oil (0.7 g, 46%). Found: C. 63.3: H. 6.4; N. 3.6% C20H24FNO5 requires: C. 63.7: H. 6.4 ; N, 3.7%

The following compounds. Examples 2-39. were prepared as above using the appropriate benzyl bromide or alkyl bromide or iodide which was commercially available or prepared by the method described above. Example 2: R² = OCH₃. R¹ = OH Methyl clavulanate. Yield = 83%. pale yellow oil. Found: C. 50.5: H, 5.2: N. 6.5% C₉H, ,NO₅ requires: C. 50.7; H. 5.2: N. 6.6% Example 3: R²= OC₆H_{I 3}, R¹ = OH n-Hexyl clavulanate. Yield = 68%. yellow oil. Found: C, 59.2: H. 7.5; N. 5.1% C,₄H_{2 ]}NO₅ requires: C. 59.4: H, 7.5: N. 4.9% Example 4: R²= OC,₈H₃₇. R¹ = OH n-Octadecyl clavulanate. Yield = 3.5%, cream solid, m.p. 72-74°C. Found: C. 69.0: H, 10.0: N, 3.3%

C₂₆H₄₅NO₅ requires: C. 69.1 : H. 10.0; N, 3.1% Example 5: R²= OCH₂Ph, R¹ = OH Benzyl clavulanate. Yield = 70%. Yellow oil. Found: C. 61.5; H. 5.3; N. 5.0% C ₁₅H,₅NO₅(0.2H₂0) requires: C. 61.5; H, 5.3; N. 4.8% Example 6: R²= OCH₂-(4-NO₂)Ph. R¹ = OH

4-Nitrobenzyl clavulanate. Yield = 60%, yellow solid, m.p. 1 14-1 15°C. Found: C, 53.7; H. 4.2; N, 8.3% C₁₅H₁₄N₂O₇ requires: C. 53.9; H. 4.2; N, 8.4% Example 7: R²= OCH₂-(4-Cl)Ph, R¹ = OH

4-Chlorobenzyl clavulanate. Yield = 68.7%, colourless solid, m.p. 94°C.

Found: C, 55.8; H. 4.3; N, 4.4: Cl. 10.8%

C₁₅H₁₄ClNO₅ requires: C. 55.7: H. 4.4; N, 4.3; Cl. 1 1.0%

Example 8: R²= OCH₂-(4-CH3)Ph. R¹ = OH 4-Methylbenzyl clavulanate. Yield = 38%. colourless solid, m.p. 71 -75°C.

Found: C. 63.4; H. 5.7; N. 4.6%

C₁₆H,₇NO₅ requires: C. 63.4; H. 5.6: N, 4.6%

Example 9: R = OCH₂-(4-Br)Ph, R¹ = OH

4-Bromobenzyl clavulanate. Yield = 56%. colourless solid, m.p.107-108°C. Found: C. 48.9; H, 3.9; N. 3.9: Br. 22.1%

C₁₅H,₄BrNO₅ requires: C. 48.9: H. 3.8: N. 3.8; Br. 21.7%

Example 10: R = OCH₂-(4-OCH₃)Ph, R¹ = OH

4-Methoxybenzyl clavulanate. Yield = 23%. yellow oil.

Found: C. 59.9; H, 5.4: N. 4.3% C₁₆H₁₇NO₆ requires: C. 60.2; H. 5.4; N, 4.4%

Example 11: R²= OCH₂-(4-(CH₃)₃)Ph. R¹ = OH 4-tert-Butylbenzyl clavulanate. Yield = 41%. yellow oil.

Found: C. 66.0: H. 6.8: N, 3.8%

C₁₉H₂ ιNO₅ requires: C. 66.1; H. 6.7: N. 4.1%

Example 12: R = OCH₂-(4-Ph)Ph. R¹ = OH 4-Biphenylmethyl clavulanate. Yield = 63%. yellow oil.

Found: C. 68.4; H. 5.2: N. 4.1%

C₂₁H,₉NO₅(0.2H₂O) requires: C. 68.3; H. 5.3: N. 3.8%

Example 13: R²= OCH₂ -1 -Naphthyl, R¹ = OH

(1 -Naphthyl )methyl clavulanate. Yield = 70%. yellow oil. Found: C. 66.9: H. 5.1 : N. 3.9%

C,₉H₁₇NO₅ requires: C. 67.3. H, 5.1: N, 4.1%

Example 14: R = OCH₂-(4-OH. 3.5-di-tert-butyl)Ph. R¹ = OH

3.5-Di-t-butyl-4-hydroxybenzyi clavulanate. Yield = 2.6%. foam.

Found: C. 66.0: H. 7.6: N. 3.4% C₂₃H_{3 1}NO₆ requires: C. 66.2: H. 7.5; N, 3.4%

Example 15: R²= OCH₂-(2,4-diCl)Ph. R¹ = OH

2.4-Dichlorobenzyl clavulanate. Yield = 32%. colourless solid, m.p. 73-74°C.

'H NMR-(CDC1₃) δ 3.09 (d, J= 16.7Hz, IH. 6β-H). δ 3.50 (dd. J=2.6. 16.7Hz, lH, 6α-H), δ 4.22 (m, 2H. 9,9'-H). δ 4.92 (t. J=7.0Hz, IH. 8-H), δ 5.10 (d, J=0.96Hz. I H. 3-H), δ 5.26-5.28 (2xd. J=12.8Hz, 2H. CH₂Ar), δ 5.70 (d, J=2.6Hz. IH. 5-H). δ 7.29

(m, 2H. Ar-H). δ 7.44 (d, J=2.0Hz. IH. Ar-H).

Example 16: R²= OCH₂-(2,6-diCl)Ph. R¹ =OH

2.6-DichIorobenzyl clavulanate. Yield = 46%. colourless solid, m.p. 1 1 1°C.

Found: C. 50.2: H. 3.7: N. 3.9: Cl. 20.0% C₁₅H₁₃Cl₂NO₅ requires: C. 50.3: H. 3.7; N. 3.9: Cl. 19.8%

Example 17: R = OCH₂-(2.5-diCl)Ph. R¹ =OH

2,5-Dichlorobenzyl clavulanate. Yield 7.5%. colourless solid, m.p. 1 10°C.

Found: C. 50.3: H. 3.8; N, 4.0; Cl. 19.5%

Cι₅H_{I 3}Cl₂NO₅ requires: C. 50.3: H. 3.7; N, 3.9: Cl. 19.8 % Example 18: R = OCH₂-(2,4-diCl)Ph. R¹ = OH

2,4-Dichlorobenzyl clavulanate. Yield = 40%. colourless solid, m.p. 61-62°C.

Found: C. 50.3: H. 3.8: N. 3.9%

C₁₅H_{! 3}Cl₂NO₅ requires: C, 50.3: H, 3.7; N. 3.9%

Example 19: R = OCH₂-(2,3-diCl)Ph. R¹ = OH 2.3-Dichlorobenzyl clavulanate. Yield = 26%. colourless solid, m.p. 71°C. Found: C. 50.4: H. 3.8: N. 3.9% C₁₅H₁₃Cl₂NO5 requires: C. 50.3; H. 3.7; N. 3.9% Example 20: R²= O(CH₂)₅CO-(4-Cl)Ph, Rl = OH 6-(4-Chlorophenyl)-5-oxo-hexyl clavulanate. Yield = 33%. yellow oil. Found: C. 58.1 ; H. 5.5; N. 3.3; Cl. 9.9% C₂₀H₂₂CINO₆(0.08CH₂C1₂) requires: C. 58.2; H. 5.4: N. 3.4; Cl. 9.9% Example 21: R = OCH(CH₃)Ph. R¹ = OH R.S-1-Phenylethyl clavulanate. Yield = 47%. pale yellow oil. Found: C, 63.1 : H. 5.7: N. 4.6% C₁₆H₁₇NO₅ requires: C. 63.4; H, 5.7; N, 4.6% Example 22: R²= O(CH₂)₃Ph, R ' = OH

3-Phenylpropyl clavulanate. Yield = 56%. colourless oil. Found: C. 64.5: H. 6.1 ; N. 4.6% C₁₇H₁₉NO₅ requires: C. 64.3; PL 6.0: N, 4.4% Example 23: R²= O(CH₂)₈Ph. R¹ = OH 8-Phenyloctyl clavulanate. Yield = 32%. colourless oil. Found: C, 68.4; H, 7.5; N, 3.6 % C₂₂H₂₉NO₅ requires: C. 68.2; H. 7.5; N, 3.6% Example 24: R = O(CH₂)₆-(4-Br)Ph, R¹ = OH 6-(4-Bromophenyl)hexyl clavulanate. Yield = 43%, yellow oil. Found: C, 54.8; H, 5.5; N, 3.5; Br. 18.5%

C₂oH₂₄BrNO₅ requires: C. 54.8; H, 5.5; N, 3.2; Br. 18.2% Example 25: R = O(CH₂)₆Ph, R¹ = OH 6-Phenylhexyl clavulanate. Yield = 51%, yellow oil. Found: C. 66.7: H. 7.0; N. 3.9% C₂₀H₂₅NO₅ requires: C. 66.8: H. 7.0: N. 3.9% Example 26: R²= O(CH₂)₆-(4-Cl)Ph, R¹ = OH 6-(4-Chlorophenyl)hexyl clavulanate. Yield = 39%, yellow oil. Found; C, 59.4; H, 6.1; N, 3.2%

C₂₀H₂₄C1NO₅(O.5H₂O) requires: C, 59.2; H, 6.2; N, 3.5% Example 27: R = O(CH₂)₆-(4-C₄H₉)Ph, R¹ = OH

6-(4-n-Butylphenyl)hexyl clavulanate. Yield = 33%, yellow oil. Found: C, 68.9: H, 7.9; N, 3.5% C₂₄H₃₃NO₅ requires: C. 69.4; H. 8.0: N, 3.4% Example 28: R²= O(CH₂)₆-(2.4-diCl)Ph. R¹ = OH 6-(2,4-Dichlorophenyl)hexyl clavulanate. Yield = 30%. yellow oil. Found: C, 56.0: H. 5.5; N. 3.4; Cl. 16.1% C₂₀H₂₃Cl₂NO₅(0.083EtOAc) requires: C. 56.1: H. 5.5; N. 3.2; Cl. 16.3%

Example 29: R²= O(CH₂)₆-(2,4-diCH₃)Ph. R¹ = OH

6-(2.4-Dimethylphenyl)hexyl clavulanate. Yield = 23%. yellow oil.

Found: C. 68.2; H, 7.5; N. 3.5% C₂₂H₂₉NO₅ requires: C. 68.2: H. 7.5; N. 3.6%

Example 30: R²= O(CH₂)₅-(2.4-diCl)Ph. R¹ = OH

5-(2,4-Dichlorophenyl)pentyl clavulanate. Yield = 18%. pale yellow solid. m.p. 61-62°C

Found: C. 55.2; H. 5.1; N, 3.4; Cl. 16.7% C₁₉H₂₁C1₂NO₅(0.02C₆H₁₄) requires: C. 55.2; H. 5.2; N. 3.4; Cl. 17.1%

Example 31: R²= O(CH₂)₄-(4-CH₃)Ph. R¹ = OH

4-(4-Methyiphenyl)butyl clavulanate. Yield = 47%. pale yellow oil.

Found; C. 65.8; H. 6.7: N, 3.9%

C,₉H₂₃NO, requires: C. 66.1; H. 6.7 N. 4.1% Example 32: R²= O(CH₂)₄-(4-OCH₃)Ph. R¹ = OH

6-(4-Methoxyphenyl)butyl clavulanate. Yield = 57%, yellow oil.

Found: C, 62.9; H. 6.4; N. 3.7%

C₁₉H₂₃NO₆ requires: C, 63.2; H. 6.4; N, 3.9%

Example 33: R = O(CH₂)₄-(4-Ph)Ph, R¹ = OH 4-(4-Biphenyl)butyl clavulanate. Yield = 56%, colourless solid, m.p. 86-88°C.

Found: C. 70.5; H, 6.2: N, 3.5%

C₂₄H₂₅NO₅ requires: C.70.8: H. 6.2; N, 3.4%

Example 34: R²= O(CH₂)₆-(4-OH)Ph. R¹ = OH

6-(4-Hydroxyphenyl)hexyl clavulanate. Yield = 2.8%. colourless solid, m.p. 62-63°C. Found: C. 63.8: H. 6.5: N. 3.8%

C₂₀H₂₅NO₆ requires: C. 64.0: H. 6.7: N. 3.7%

Example 35: R = O(CH₂)₆-(4-OCH₃)Ph. R¹ = OH

6-(4-Methoxyphenyl)hexyl clavulanate. Yield = 17%, yellow oil

Found: C, 64.6; H, 7.1 ; N, 3.6% C₂₁H₂₇NO₆ requires: C. 64.8; H, 7.0; N. 3.6%

Examle 36: R = O(CH₂)₆S-(4-OH)Ph, R¹ = OH

6-(4-Hydroxyphenyl)thiohexyl clavulanate (a) 6-Bromohexyl clavulanate

A mixture of 1.6-dibromohexane (15.37 g. 63mmol) and potassium clavulanate (3 g, 12. όmmol) in DMF (100ml) was stirred at room temperature for 20 hours. The mixture was evaporated in vacuo and partioned between ethyl acetate (50ml) and water (50ml). The organic layer was separated, washed with water, brine, dried (MgSO₄) and evaporated to an oil. which was purified by column chromatography on silica gel using 1 : 1 pet ether/ethyl acetate as the eluting solvents, yielding the product as a yellow oil (3.8 g, 83%). (b) 6-(4-Hydroxyphenyl)thiohexyl clavulanate.

A mixture of 6-bromohexyl clavulanate ( 1 g, 2.8mmol). 4-hydroxythiophenol (0.35g. 2.8mmol) and potassium carbonate (0.4 g. 2.8mmol) was stirred in acetone (50ml) for 20 hours, filtered and evaporated to a brown oil. The oil was purified by column chromatography on silia gel using 1 : 1 pet ether/ethyl acetate as the eluting solvents, yielding the product as a colourless oil (0.136 g, 12%). Found: C. 58.5; H. 6.4; N, 3.2%

C₂₀H₂₅NO₆S(0.09H₂O) requires: C. 58.9; H. 6.2; N. 3.4% Example 37: R²= O(CH₂)₅S-(4-OH.3.5-di-tert-butyl)Ph. R¹ = OH 5-(4-Hydroxy-3.5-di-tert-butylphenylthio)pentyl clavulanate (a) 5-Bromopentyl clavulanate

A mixture of 1.5-dibromopentane (28.73 g, 0.125 mol) and potassium clavulanate (6 g, 0.025 mol) in DMF (200ml) was stirred at room temperature for 20 hours. The mixture was evaporated in vacuo and partitioned between ethyl acetate (100ml) and water (100ml). The organic layer was separated, washed with water, brine, dried (MgSO₄) and evaporated to an oil, which was purified by column chromatography on silica gel using 1 : 1 pet ether/ethyl acetate as the eluting solvents, yielding the product as a yellow oil (5.92 g, 68%). (b) 5-(4-Hydroxy-3.5-di-tert-butylphenyithio)pentyl clavulanate

A mixture of 5-bromopentyl clavulanate (0.69 g. 2mmol). 4-hydroxy-3.5-di-tert- butylthiophenoi (0.95g. 4mmoi) and potassium carbonate (0.27 g, 2mmol) was stirred in acetone (50ml) for 20 hours, filtered and evaporated to an oil. The oil was purified by column chromatography on silica gel using 1 : 1 pet ether/ethyl acetate as the eluting solvents, yielding the product as a yellow oil (0.70 g, 69%). Found: C. 63.8; H, 7.9; N, 2.4;, S. 6.0% C₂₇H₃₉NO₆S requires: C. 64.1 ; H, 7.8: N, 2.8; S. 6.3% Example 38: R²= O(CH₂)₅SPh. R¹ = OH 5-Phenylthiopentyl clavulanate

A mixture of 5-bromopentyl clavulanate (Example 37a)( 1.0 g, 2.8 mmol), thiophenol (0.35 g. 3.2mmol) and potassium carbonate (0.4 g. 2.8mmol) was stirred in acetone (50ml) for 20 hours, filtered and evaporated to a brown oil. The oil was purified by column chromatography on silica gel using pet ether/ethyl acetate as the eluting solvents, yielding the product as a yellow oil (0.44 g, 40%).

Found: C. 60.3; H. 6.2: N. 3.8%

C_{I 9}H₂₃NO₅S requires: C. 60.5: H.6.1 ; N. 3.7%

Example 39: R²= OCH(C₅H, ,)Ph. R¹ = OH

(RS)-2-Phenylhexyi (3R.5R)-clavulanate.

Examples 40-49 were prepared following the general procedures in J. Chem. Soc. Perkin Trans 1 1984. pp 635-650.

Example 40: R²= NH(CH₂)₆Ph. R¹ = OH N-6-Phenylhexyl clavulanamide

(a) Phenylhexyl iodide

Phenylhexyl bromide (82g. 0.34mol) and sodium iodide (157 g. 1.05mol) were stirred together in acetone (800ml) for 20 hours. The reaction mixture was evaporated to dryness and the residue was extracted with hexane. filtered and the filtrate was evaporated to dryness to yield the product as a pale yellow oil (97.9 g, 99%).

(b) Phenylhexyl phthalimide

Phenylhexyl iodide (25 g. 0.087mol) was dissolved in dry DMF (125ml) and potassium phthalimide (32.9 g, 0.178mol) was added and the mixture stirred at 100°C for 20 hours. Mixture was evaporated and the residue was treated with water ( 150ml) and washed with ethyl acetate (150ml, 100ml). The organic extracts were combined, washed with brine, dried (MgSO₄) and evaporated to a yellow solid which was purified by column chromatography on silica gel using 3:1 pet ether/ethyl acetate as the eluting solvents, yielding the product as a colourless oil which solidifies on standing (23.7 g, 88.7%) m.p. 56-57°C. (c) Phenylhexylamine

Phenylhexyl phthalimide (27.1 lg, 0.088mol) was dissolved in ethanol (750ml) and hvdrazine monohvdrate (12.9ml. 0.256mol) was added and the mixture was stirred at reflux for 19 hours. The reaction was filtered, evaporated to dryness and azeotroped with water (x2) and ethanol. Residue was mixed with diethyl ether, the solid was removed by filtration and the filtrate was evaporated to a yellow oil (10.3g). The solid was stirred with 2NNaOH (200ml) and ethyl acetate (200ml) and the mixture was filtered and the organic layer washed with brine, dried (MgSO₄) and evaporated to a yellow oil (6.2 g). The two oils were combined and distilled in three batches using a Kugelrohr apparatus at 155°C/0.15mbar to give the product as a colourless oil (13.45 g , 86%). (d) N-6-Phenylhexyl clavulanamide

A solution of benzyl clavulanate (4.26 g. 0.0147mol) in dry tetrahydrofuran (THF) (50ml ) was hydogenated over 10% palladium on carbon ( 1.1 g) for 5 minutes at 25°C at 20psi. The catalyst was filtered off and the filtrate and solutions of dicyclohexylcarbodi¬ imide (DCC) (2.53 g. 0.01226moi) in dry CH₂C1₂ (175ml) and 6-phenylhexylamine (2.07 g, 0.01 17mol) in dry CH₂C1₂ (175ml) were mixed together quickly. The mixture was evaporated to near dryness and CH₂C1₂ (175ml) was added. After stirring for 1 hour at room temperature the suspension was cooled, filtered and the filtrate evaporated to dryness. The residue was purified by column chromatography on silica gel using 2:1 ethyl acetate/hexane as the eluting solvents, yielding the crude product as a colourless solid (3.33 g. 80%). 1.03 g was further purified by chromatography and recrystallisation from diethyl ether to give an analytical sample as a colourless solid (0.24 g) m.p. 97-98° C.

Found: C. 67.0: H. 7.1: N. 8.0% ^C ₂0^H2₆ ^N ₂°₄ requires: C. 67.0: H.7.3; N, 7.8% Example 41: R²= NH(CH₂)₆-(4-F)Ph, R¹ = OH N-6-(4-Fluorophenyl)hexyl clavulanamide. Yield = 14.8% . cream solid. m.p. 106°C.

Found: C. 63.8; H, 6.6; N, 7.5% C₂₀H₂₅FN₂O₄ requires: C, 63.8; H, 6.7; N. 7.4% Example 42: R = N(CH₃)(CH₂)₆-(4-F)Ph, R¹ = OH N-Methyl-6-(4-fluorophenyl)hexyl clavulanamide (a) N-Methyl-N-6-(4-fluorophenyl)hexylamine

6-(4-Fluorophenyl)hexyl bromide (5 g, 0.0193 mol I was stirred at reflux in 33% methylamine in ethanol (100ml) for 1.5h. The mixture was evaporated to dryness and the residue was stirred with ether and the white solid was collected by filtration (5.14 g), dissolved in IN NaOH (100ml) and extracted with diethyl ether (2x75ml). The organic extracts were combined, washed with brine (75ml). dried (MgSO₄) and evaporated to give the product as a light brown oil (3.98 g, 99%). (b) N-Methyl-6-(4-fluorophenyi)hexyl clavulanamide

Clavulanic acid (derived from benzyl calvulanate (5.18 g, 0.0179mol)as described in Example 40d) and N-methyl N-6-(4-fluorophenyl)hexylamine (3g, 0.0143mol) were reacted with DCC (3.07 g. 0.0149 mol) as described in Example 40d. Repeated column chromatography on silica gel using 2: 1 ethyl acetate/hexane-ethyl acetate as the eluting solvents yielded the product as a paie yellow oil (3.62g, 52%). A small sample was further purified for analysis.

Found: C. 64.3; H. 7.1 ; N. 6.7%

C₂,H2₇FN₂O₄(0.045EtOAc. 0.053Et₂O) requires: C. 64.5; H. 7.1; N. 7.0% Example 43: R²= N(CH₃)(CH₂)₆- (4-C₄H₉)Ph. R¹ = OH

N-Methyl-6-(4-n-butyiphenyl)hexyl clavulanamide. Yield = 15%. colourless oil.

Found: C. 69.7: H. 8.3: N. 6.4%

C₂₅H₃₆N₂O₄ requires: C. 70.1 : H. 8.5: N. 6.5%

Example 44: R²= N(CH₃)CH₂Ph. Rl = OH N-Methyl benzyl clavulanamide. Yield = 12%, foam.

Found: C. 63.8: H, 6.1 ; N. 9.4%

C,₆H_{1 8}N₂O₄ requires: C. 63.6; H. 6.0: N. 9.3%

Example 45: R²= NH(CH₂)₄Ph. R¹ = OH

N-4-Phenylbutyl clavulanamide. Yield = 17%. colourless solid, m.p. 74-76°C. Found: C. 65.4; H, 6.6: N. 8.4%

C₁₈H₂₂N₂O₄ requires: C. 65.4: H. 6.7; N, 8.5%

Example 46: R²= NHCH₂Ph. R¹ = OH

N-Benzyl clavulanamide. Yield = 14%, colourless solid, m.p. 140-142°C.

Found: C. 62.2; H. 5.6; N. 9.8% C,₅Hι₆N₂O₄ requires: C. 62.5; H. 5.6: N. 9.7%

Example 47: R²= NHO(CH₂)₆-(4-C₄H₉)Ph. R¹ = OH

N-6-(4-n-Butylphenyl)hexyloxy clavulanamide

(a) 6-(4-n-Butylphenyl)hexyloxy phthalimide

6-(4-n-Butylphenyl)hexyl bromide (2 g. 0.00673mol) and N-hydroxyphthalimide (1.1 g, 0.00674moi) and triethylamine (1.4ml. 0.01 mol) were mixed together in DMF (25ml) and stirred at 100°C for 6.5 hours. The mixture was evaporated to dryness and partitioned between water (50ml), brine (50ml) and ethyl acetate (75ml). The organic layer was separated and washed with 10% Na₂CO₃, brine (x2), dried (MgSO₄) and evaporated to a brown oil which was purified by column chromatography on silica gel using 1 : 1 CH₂Cl₂/hexane as the eluting solvents, yielding the product as a colourless solid (1.89 g. 74%) m.p. 36-39°C.

(b) 6-(4-n-Butylphenyl)hexyloxyamine

6-(4-n-Butylphenyl)hexyloxy phthalimide (1.83 g, 0.00482mol) was dissolved in glacial acetic acid (5ml) and 60%HBr (7ml) was added. The mixture was stirred at reflux for 10 minutes, cooled and diluted with IN NaOH (100ml) and extracted with ethyl acetate (2x75ml). The organic extracts were combined, washed with brine, dried (MgSO ) and evaporated to a brown oil which was purified by column chromatography on silica gel using 15: 1 CH₂Cl₂/methanol as the eluting solvents yielding the product as an oil (0.94 g. 78%) (c) N-6-(4-n-Butylphenyl)hexyloxy clavulanamide A solution of benzyl clavulanate (1.2 g, 0.00415mol) in dry THF (35ml) was hydrogenated over 10% palladium on carbon (0.36 g) for 20 minutes at 25°C at 40psi.

The catalyst was filtered off and the filtrate and solutions of DCC (0.84 g, 0.00407mol) in dry CH₂C1₂ ( 100ml) and 6-(4-n-butylphenyl)hexyloxyamine (0.9 g, 0.00361mol) in dry

CH₂C1₂ (100ml) were mixed quickly together. The mixture was evaporated to near dryness and CH₂C1₂ ( 100ml) was added. After stirring for 90 minutes at room temperature the suspension was filtered and the filtrate evaporated to dryness.

Purification by repeat column chromatography on silica gel eluting with ethyl acetate/hexane and recrystallisation from ethyl acetate/hexane yielded the product as a white solid (0.29 g. 18.7%) m.p. 91 -92°C. Found: C. 66.8; H. 7.7; N. 6.5%

C₂₄H₃₄N₂O₅ requires: C. 67.0: H. 8.0; N. 6.5%

Example 48: R = NHOCH₂Ph. R¹ = OH

N-Benzyloxy clavulanamide. Yield = 13.3%. colurless solid, m.p. l33-134°C.

Found: C. 59.1 ; H, 5.3; N, 9.2% C₁₅H,₆N₂O₅ requires: C, 59.2; H, 5.3; N, 9.2%

Example 49: R²= NHO(CH₂)₅Ph. R! = OH

N-5-Phenylpentyloxy clavulanamide. Yield(crude) = 62%, colourless solid.

A sample was further purified for analysis. Colourless solid, m.p. 78-80°C.

Found: C 63.3; H. 6.6: N.7.8% C₁₉H₂₄N₂O₅ requires: C. 63.3: H. 6.7; N. 7.8%

Example 50: R²= NH-(4-CH₃)Ph, R¹ = OH

N-4-Tolyl clavulanamide

Solutions of potassium clavulanate (3 g, 0.0126mol) in water (19ml), p-toluidine hydrochloride (1.5 g, 0.0104mol) in water (19ml) and l-cyclohexyl-3-(2- moφholinoethyl)-N-methylcarbodi-imidinium toluene-p-sulphonate (3.93 g 0.00928mol) in dioxane-water ( 19ml:38ml) were mixed at 0°C with stirring. After stirring for 80 minutes at 0-2°C. the precipitated toluamide was collected by filtration. The solid was recrystallised from ethyl acetate yielding the product as a white solid (0.47 g. 15.7%) m.p. 198-200°C. Found: C. 62.4: H. 5.6: N, 9.9%

C ₁₅H₁₆N₂O₄ requires: C, 62.5; H. 5.6: N. 9.7% Example 51: R²= NHCH₂COPh. R¹ = OH N-Benzoylmethyl clavulanamide

Benzyl clavulanate (4.8 g. 0.0166mol) in dry THF (75ml) was hydrogenated over 10% palladium on carbon ( 1.2 g) for 15 minutes at 25°C at 40psi. The catalyst was removed by filtration and washed with THF (75ml) and the filtrate was cooled to -50°C under nitrogen and treated with pyridine ( 1.45ml. 0.0179mol) and isobutyl chloroformate (2.4ml. 0.0185mol). The reaction was stirred at -50 to -30°C for 40 minutes and then cooled to -40°C and N.N-diisopropylethylamine (3.1ml. 0.0178mol) was added. α-Aminoacetophenone hydrochloride (5.7 g, 0.0332mol) was added as a solid over 35 minutes and the reaction was stirred at -30°C for 90 minutes and poured into water

(200ml) and extracted with ethyl acetate (200ml. 2x100ml). The organic extracts were combined, washed with IN HCl. brine (x2). dried (MgSO₄) and evaporated to an orange solid which was dissolved in CH₂C1₂ (50ml) and purified on a short silica gel column eluting with CH₂C1₂ (50ml) and ethyl acetate (50ml). The filtrate was evaporated to dryness and the residue was mixed with hexane and the resulting cream solid was collected ( 1.19 g, 23%). 1 OOmg was further purified by column chromatography on silica gel eluting with ethyl acetate and recrystallisation from ethyl acetate to give an analytical sample, colourless solid, m.p.l64-165°C (32mg). Found: C. 60.0: H. 5.1 : N. 8.8% C,₆H₁₆N₂O₅(0.18H₂O. O.OUEtOAc) requires: C. 60.1; H. 5.2; N, 8.7% Example 52 : R²= OCH₃. R ^J = OH Methyl (3R. 5R. E) clavulanate Example 53: R²= O(CH₂)₆Ph. R¹ = OCOCH₃ 6-Phenylhexyl O-acetylclavulanate 6-Phenylhexyl clavulanate (0.94 g, 2. όmmol) was dissolved in dry dichloromethane (CH C1₂) (20ml). The solution was cooled to -30°C and treated with pyridine (0.21 g, 27mmol) followed by the dropwise addition of acetyl chloride (0.21 g, 27mmol) in CH₂C1₂ (20ml). Stirring was continued at -30°C for 60 minutes and the reaction mixture was poured into IN HCl (25ml). extracted with CH₂C1 (15ml) and the combined organic layers were washed with brine, dried (MgSO ) and evaporated to a yellow oil, which was purified by column chromatography on silica gel using 2:1 pet ether/ethyl acetate as the eluting solvents, yielding the product as a colourless oil (0.40 g, 38%). Found: C, 65.7: H, 6.7; N. 3.6% C₂₂H₂₇NO₆ requires: C. 65.8: H. 6.8: N. 3.5% The following compounds. Examples 54-95. were prepared as above using the appropriate acid chloride.

Example 54: R²= OCH₂-(4-NO₂)Ph. R¹ = OCO-(4-Ph)Ph 4-Nitrobenzyl O-(4-biphenylcarbonyl)clavulanate. Yield = 52%. pale yellow solid m.p. 1 19-120°C

Found: C. 65.1; H. 4.5: N. 5.6%

C₂₈H₂₂N₂O₈ requires: C. 65.4; H, 4.3; N, 5.4%

Example 55: R = O(CH₂)₆-(4-Br)Ph. R¹ = OCOCH₃ 6-(4-Bromophenyl)hexyl O-acetylclavulanate. Yield = 83%, yellow oil.

Found: C. 54.7; H, 5.5; N. 3.2; Br. 16.9%

C₂₂H₂₆BrNO₆ requires: C. 55.0: H. 5.5; N, 2.9; Br. 16.6%

Example 56: R = O(CH₂)₆-(4-Br)Ph. Rl = OCO-(4-Ph)Ph

6-(4-Bromophenyl)hexyl O-(4-biphenylcarbonyl)clavulanate. Yield = 32%. colourless solid, m.p. 94-95°C.

Found: C. 63.9; H, 5.3; N. 2.5; Br, 13.1%

C₃₃H₃₂BrNO₆ requires: C. 64.1. H, 5.2; N, 2.3; Br. 12.9%

Example 57: R²= O(CH₂)₆-(4-C₄H₉)Ph. R¹ = OCOCH₃

6-(4-n-Butylphenyl)hexyl O-acetylclavulanate. Yield = 76%. pale yellow oil. Found: C. 68.1 ; H, 7.5; N, 3.1%

C₂₆H₃₅NO₆ requires: C, 68.3; H, 7.7; N, 3.1%

Example 58: R = O(CH₂)₆-(4-C₄H₉)Ph, R¹ = OCOPh

6-(4-Butylphenyl)hexyl O-benzoylclavulanate. Yield = 67%. yellow oil.

Found: C. 71.6: H, 7.2; N. 2.8% C₃₁H₃₇NO₆ requires: C. 71.7; H. 7.2: N. 2.7%

Example 59: R²= O(CH₂)₆-(4-CI)Ph. R¹ = OCOCH₃

6-(4-Chlorophenyl)hexyl O-acetylclavulanate. Yield = 50%. yellow oil.

Found: C, 59.7; H, 6.0; N. 3.3; Cl. 8.8%

C₂₂H₂₆CINO₆(0.06CH₂C1₂) requires: C. 60.1; H. 6.0: N. 3.2; Cl, 9.0% Example 60: R²= OCH₂-(2,4-diCl)Ph. R¹ = OCOPh

2,4-Dichlorobenzyl O-benzoylclavulanate. Yield = 18%. colourless solid, m.p. 79°C. Found: C. 57.1 : H, 3.8: N. 3.0: Cl. 15.5% C₂₂H₁₇Cl₂NO₆ requires: C. 57.2; H. 3.7; N. 3.0: Cl. 15.3% Example 61: R²= OCH₂-(2.4-diCl)Ph. Rl= OCOCH₃ 2.4-Dichlorobenzyl O-acetylclavulanate. Yield = 45%. colourless solid, m.p. 57-58°C Found: C. 51.0: H, 3.9: N. 3.6: Cl. 17.6% C_{I 7}H₁₅Cl₂NO₆ requires: C. 51.0: H. 3.8: N. 3.5; Cl. 17.7%

Example 62: R²= OCH₂Ph. R¹ = OCOCH₃

O-Acetyl benzyl clavulanate. Yield = 75%. yellow oil.

Found: C. 61.9: H. 5.3: N, 4.8% C_{I 7}H,₇NO₆ requires: C. 61.6; H. 5.2; N, 4.2%

Example 63: R²= OCH₂Ph. R¹ = OCO-(4-Ph)Ph

Benzyl O-(4-biphenylcarbonyl)clavulanate. Yield = 33%. glass.

Found: C. 71.3: H. 5.1 : N. 3.1%

C₂₈H₂₃NO₆(0.032CH₂Cl₂)requires: C. 71.3: H. 4.9; N. 3.0% Example 64: R= OCH₂Ph. R = OCOPh

O-Benzoyl benzyl clavulanate. Yield = 47%, pale yellow oil.

Found: C. 66.5; H. 5.1 : N. 3.5%

C₂₂H,₉NO₆ requires: C. 66.2: H. 4.9: N. 3.6%

Example 65: R²= OCH₂Ph. R¹ = OCO(CH₂)₂Ph Benzyl O-phenpropionyiclavulanate. Yield = 56%>, pale yellow oil.

Found: C. 68.7: H, 5.6: N. 3.4%

C₂₄H₂₃NO₆ requires: C. 68.4; H. 5.5; N. 3.3%

Example 66: R = OCH₂Ph, Rl = OCOCH₂Ph

Benzyl O-phenylacetylclavulanate. Yield = 38%, pale yellow oil. Found: C, 67.7; H, 5.3: N. 3.3%

C₂₃H₂₁NO₆ requires: C. 67.8; H, 5.2; N, 3.4%

Example 67: R²= OCH₂Ph. R¹ = OCO(CH₂)₄CH₃

Benzyl O-hexanoylclavulanate. Yield = 72%. yellow oil.

Found: C. 64.8; H. 6.5: N. 3.6% C₂₁H₂₅NO₆ requires: C. 65.0: H. 6.5; N. 3.6%

Example 68: R²= OCH₂Ph. R¹ = OCO(CH₂)₈CH=CH₂

Benzyl O-(10-undecanoyl)clavulanate. Yield = 71%, pale yellow oil.

Found: C. 68.8; H, 7.5: N. 3.1%

C₂₆H₃₃NO₆ requires: C. 68.6: H. 7.3; N, 3.1% Example 69: R²= OCH₂Ph. R 1 = OCO-( 1 -adamantyl)

Benzyl O-(l-adamantylcarbonyl)clavulanate. Yield = 44%. pale yellow oil.

Found: C. 67.1; H. 6.6: N, 3.0%

C₂₆H₂₉NO₆(0.2CH₂C1₂) requires: C. 67.2: H. 6.3; N, 3.0%

Example 70: R = OCH₂Ph. R^J = OCOCH₂-(2-thienyl) Benzyl O-(2-thienylacetyl)clavulanate. Yield = 74%, pale yellow oil.

Found: C. 60.5: H. 4.7; N. 3.2% C₂₁H_{] 9}NO₆S(0.1CH₂C1₂) requires: C. 60.3; H. 4.6: N. 3.3%

Example 71: R²= OCH₂Ph. R¹ = OCO(CH₂)₂CO₂Et

Benzyl O-(ethylsuccinoyl)clavulanate. Yield = 52%. pale yellow oil.

Found: C. 60.5: H. 5.6: N. 3.1% C₂₁H₂₃NO₈ requires: C. 60.4; H. 5.6; N. 3.4%

Example 72: R= OCH₂Ph. R^l = OCO-(4-CN)Ph

Benzyl O-(4-cyanobenzoyl)clavulanate. Yield = 52%. thick yellow oil.

Found: C, 64.9: H. 4.4; N. 6.4%

C₂₃H_{1 8}N₂O₆(0.1CH₂C1₂) requires: C. 65.0; H, 4.3; N. 6.6% Example 73: R²= OCH₂Ph. R¹ = OCO-(4-NO₂)Ph

Benzyl O-(4-nitrobenzoyl)clavulanate. Yield = 49%. pale yellow oil.

Found: C. 59.5; H, 4.3; N, 6.0%

C₂₂H_{] 8}N₂O₈(0.1CH₂C1₂) requires: C. 59.4: H. 4.1 : N. 6.3%

Example 74: R = OCH₂Ph. R^[ = OCOCH(Ph)₂ Benzyl O-(diphenylacetyl)clavulanate. Yield = 53%. pale yellow glass.

Found: C. 70.9; H, 5.3; N. 2.8%

C₂₉H₂₅NO₆(0.1CH₂C1₂) requires: C. 71.0; H. 5.2: N. 2.9%

Example 75: R²= OCH₂Ph. R ^[ = OCO(CH₂)₇CH₃

Benzyl O-nonoylclavulanate. Yield = 81%, pale yellow oil. Found: C. 66.9; H, 7.1; N, 3.2%

C₂₄H_{3 ]}NO₆ requires: C, 67.1 : H, 7.3; N, 3.3%

Example 76: R = OCH₂Ph. R^J = OCO(CH₂)₂-C₅H₉

Benzyl O-(3-cyclopentylpropionyl)clavulanate. Yield = 34%. pale yellow oil.

Found: C. 66.5: H. 6.6; N. 3.6% C₂₃H₂₇NO₆ requires: C. 66.8: H. 6.6; N. 3.4%

Example 77: R²= OCH₂Ph, Rl = OCO-(CH₂)₅Ph

Benzyl O-(6-phenylhexyl)clavulanate. Yield = 33%, pale yellow oil.

Found: C. 70.0; H, 6.4; N, 3.3%

C₂₇H₂₉NO₆ requires: C. 70.0: N. 6.3: N. 3.0% Example 78: R²= OCH₂Ph. R¹ = OCO-(l -naphthyl)

Benzyl O-(l-naphthoyl)clavulanate. Yield = 39%. pale yellow oil. Found: C. 69.3; H, 4.9; N. 3.2% C₂₆H_{2 I}NO₆(0.4H₂O) requires: C. 69.4; H. 4.9: N. 3.1% Example 79: R²= OCH₂Ph. R¹ = OCOC₆H, , Benzyl O-(cyclohexylcarbonyl)clavulanate. Yield = 46%. pale yellow oil. Found: C. 66.3: H, 6.4: N. 3.2% C₂₂H₂₅NO₆ requires: C. 66.2: H. 6.3: N. 3.5%

Example 80: R²= OCH₂Ph. R^J = OCO(4-CH₂Ph)Ph

Benzyl O-(4-benzylbenzoyl)clavulanate. Yield = 40%. pale yellow oil.

Found: C. 70.2: H. 5.3; N, 2.6% C₂₉H₂₅NO₆(0.15CH₂C1₂) requires: C, 70.6; H. 5.1 : N. 2.8%

Example 81 : R²= OCH₂Ph. Rl = OCO(4-O-Ph)Ph

Benzyl O-(phenoxybenzoyl)clavulanate. Yield = 24%. cream solid, m.p. 83-85°C.

Found: C. 68.2: H. 4.8: N. 2.9%

C₂₈H₂₃NO₇(0.125CH₂C1₂) requires: C, 68.1; H. 4.7: N. 2.8% Example 82: R = NH(CH₂)₆Ph. Rl = OCOCH₃

N-6-Phenylhexyl O-acetylclavulanamide, Yield = 77%. colourless solid. m.p. 62-63°C

Found: C. 65.7: H. 6.9: N. 7.0%

C₂₂H₂₈N₂O₅ requires: C. 66.0; H. 7.1 ; N. 7.0% Example 83 : R = (CH₂)₆-(4-OCH₃)Ph. R * = OCOCH₃

6-(4-Methoxyphenyl)hexyl O-acetylclavulanate. Yield = 23%. colourless oil.

Found: C. 64.0; H. 6.9; N. 3.4%

C₂₃H₂₉NO₇ requires: C. 64.0; H. 6.8; N. 3.3%

Example 84: R²= NHO(CH₂)₅Ph. R¹ = OCOCH₃ N-5-Phenylpentyloxy O-acetylclavulanamide, Yield = 54%, yellow oil.

Found: C. 62.4: H, 6.6; N, 7.1%

C₂₁H₂₆N₂O₆ requires: C. 62.7; H. 6.5: N. 7.0%

Example 85: R = NH(CH₂)₆-(4-F)Ph. Rl = OCOCH₃

N-6-(4-Flurophenyl)hexyl O-acetylclavulanamide. Yield = 30%. colourless solid, m.p. 64-65°C.

Found: C. 63.0: H, 6.4; N. 6.9%

C₂₂H₂₇FN₂O₅ requires: C, 63.1 : H. 6.5; N, 6.7%

Example 86: R²= N(CH₃)(CH₂)₆-(4-F)Ph, Rl = OCOCH₃

N-Methyl-6-(4-fluorophenyl)hexyl O-acetylclavulanamide, Yield = 73%, colouriess oil. Found: C, 63.6; H, 7.1: N, 6.3%

C₂₃H₂₉FN₂O₅ requires: C, 63.9; H. 6.8; N. 6.5% Example 87: R²= O(CH₂)₅CO-(4-Cl)Ph, Rl = OCOCH₃ O-Acetyl 6-(4-chlorophenyl)-6-oxo-hexyl clavulanate. Yield = 64%. yellow oil. Found: C. 57.6: H. 5.4: N. 3.0; Cl. 8.7% C₂₂H₂₄C1NO₇(0.75CH₂C1₂) requires: C. 58.1 : H. 5.3: N. 3.1 : Cl. 8.9% Example 88: R²= O(CH₂)₆-(4-F)Ph. R = OCOCH₃ 6-(4-Fluorophenyl)hexyl O-acetylclavulanate. Yield = 46%. colourless oil. Found: C. 62.9: H. 6.3; N. 3.1% C₂₂H₂₆FNO₆ requires: C. 63.0: H. 6.3; N. 3.3% Example 89: R²= O(CH₂)₆-(4-Cl)Ph. R^! = OCOCHCl₂ 6-(4-Chlorophenyl)hexyl O-dichloroacetylclavulanate. Yield = 79%. yellow oil. Found: C. 52.6; H. 4.9: N. 2.7% C₂₂H₂₄Cl₃NO₆ requires: C. 52.4; H. 4.8; N. 2.8% Example 90: R = OCH₂-(3.4-diCl)Ph. Rl = OCOPh 3.4-Dichlorobenzyl O-benzoylclavulanate, Yield = 50%, yellow oil. Found: C. 57.1 ; H. 3.9; N. 2.9; Cl. 15.2%

C₂₂H₁₇Cl₂NO₆ requires: C. 57.2; H, 3.7; N. 3.0; Cl. 15.3% Example 91: R = OCH₂-(3.4-diCl)Ph. R¹ = OCOCH₃ 3.4-Dichlorobenzyl O-acetylclavulanate. Yield = 74%. pale yellow oil. Found: C. 51.1 ; H. 3.9: N. 3.5: Cl. 17.2% C₁₇H,₅Cl₂NO₆(0.06Et₂O) requires: C. 51.2; H. 3.9; N. 3.5; Cl. 17.5% Example 92: R²= N(CH₃)(CH₂)₆-(4-C₄H₉)Ph, R^! = OCOPh

N-Methyl-6-(4-n-butylphenyl)hexyl O-benzoylclavulanamide. Yield = 50%, colourless oil. Found: C, 72.1; H, 7.5; N. 5.1% C₃₂H₄₀N₂O₅ requires: C. 72.1 : H. 7.6; N, 5.3% Example 93: R²= NHO(CH₂)₆-(4-C₄H₉)Ph, R¹ = OCOCH₃

N-6-(4-n-Butylphenyl)hexyloxy O-acetylclavulanamide. Yield = 43%. colourless solid, m.p. 67-68°C.

Found: C. 65.7; H, 7.4; N, 6.1% C₂₆H₃₆N₂O₆ requires: C. 66.1 : H. 7.7: N, 5.9% Example 94: R²= N(CH₃)(CH₂)₆-(4-C₄H₉)Ph. R¹ = OCOCH₃

N-Methyl-6-(4-n-butylphenyl)hexyl O-acetylclavulanamide. Yield = 44%. colourless oil. Found: C. 69.1 ; H. 8.1 ; N. 5.9% C₂₇H₃₈N₂O₅ requires: C. 68.9; H. 8.1 ; N, 6.0% Example 95: R²= OCH₂Ph. Rl = OCOCHCl₂ Benzyl O-dichloroacetylclavulanate. Yield = 82%(crude) Analytical sample, yellow oil. Found: C, 51.6; H. 4.0: N. 3.5%

C ,₇H_{] 5}C1₂NO₆(0.13C₆H₁₄) requires: C. 51.9; H.4.1 : N. 3.4% Example 96: R²= N(OH)(CH₂)₆-(4-F)Ph, R^J = OCOCH₃ N-Hydroxy-N-6-(4-fluorophenyl)hexyl O-acetylclavulanamide (a) Benzyl O-acetylclavulanate Benzyl clavulanate (4 g. 0.0138mol) was dissolved in dry CH₂C1₂ (75ml). The solution was cooled to -30°C under nitrogen and treated with pyridine (1.3ml. 0.01607mol) and acetyl chloride (lml. 0.0141mol). The reaction was stirred at -30°C to -10°C over 2 hours and poured into 0.5N HCl (100ml) and CH₂C1₂ (50ml). The organic layer was removed, washed with brine, dried (MgSO₄) and evaporated to a yellow oil which was purified by column chromatography on silica gel using 2:1 hexane/ethyl acetate as the eluting solvents, yielding the product as an oil (4.14 g. 90%).

(b) Ethyl 2-(6-(4-fluorophenyl)hexyl)-3-methyl-isoxazol-5-one-4-carboxylate

A solution of ethyl 5-hydroxy-3-methyl-4-isox-ιzolecaroxylate. sodium salt, hemihydrate (4.9 g, 0.0242mol) in dry DMF (20ml) was treated with 6-(4- fluorophenyl)hexyl bromide (7.4 g, 0.0242mol) and stirred at 120°C for 1 hour, poured into water (300ml) and extracted with CH₂C1₂ (3x75ml). The organic extracts were combined, washed with water, dried (MgSO₄) and evaporated to an orange oil which was purified by column chromatography on silica gel using 1 : 1 ethyl acetate/hexane as the eluting solvents, yielding the product as a cream solid (6.1 1 g, 72%) m.p. 69-71 °C.

(c) N-6-(4-fluorophenyl)hexyl hydroxylamine

Ethyl 2-(6-(4-fluorophenyl)hexyl)-3-methyl-isoxazol-5-one-4-carboxylate (5.8 g, 0.0166mol) was dissolved in water (15ml), glacial acetic acid (15ml) and cHCl (15ml), stirred at reflux for 19 hours and evaporated to dryness. The residue was dissolved in water (50ml) and basified with 2N NaOH to pH14 and extracted with ethyl acetate

(2x75ml), dried (MgSO₄) and evaporated to an orange oil, triturated with hexane and the solid product was collected by filtration, yielding the product as a cream solid (2.28 g, 65%) m.p. 74-75°C.

(d) N-Hydroxy-N-6-(4-fluorophenyl)hexyl O-acetylclavulanamide Benzyl O-acetyl clavulanate (2.45 g. 0.00739mol) was hydrogenated in dry THF

(50ml) over 10% palladium on carbon (1 g) for 7 minutes at 25°C at 20psi. The reaction mixture was filtered to remove catalyst and THF (50ml) was added. The filtrate and solutions of DCC (1.27 g, 0.006 lόmol) in dry CH₂C1₂ (100ml) and N-6-(4- fluorophenyl)hexyl hydroxylamine (1.25 g, 0.00592mol) in dry CH₂C1₂ (100ml) were mixed together quickly. The mixture was evaporated to near dryness and CH₂C1₂

(100ml) was added. After stirring for 90 minutes at room temperature the mixture was filtered and evaporated to an oil which was purified by column chromatography on silica gel using hexane/ethyl acetate as the eluting solvents, yielding the product as a yellow oil (0.183 g, 7.1%) Found: C, 60.8; H, 6.4; N, 6.3%

C₂₂H₂₇FN₂O₆ requires: C, 60.8: H. 6.3: N. 6.5% Example 97: R²= N(OCOCH₃)(CH₂)₆-(4-F)Ph. R^] = OCOCH₃ N-Acetoxy-N-6-(4-fluorophenyl)hexyl O-acetylclavulanamide

A solution of N-Hydroxy-N-6-(4-fluorophenyl)hexyl O-acetylclavulanamide (1 g, 0.0023mol) in dry CH₂C1₂ (60ml). cooled to -30°C under nitrogen, was treated with pyridine (0.21 ml. 0.0026mol) followed a solution of acetyl chloride (0.18 g,

0.002306mol) in CH₂C1₂ (5ml). The reaction was stirred at -30°C to 0°C over 90 minutes, poured into brine (100ml) with CH₂C1₂ (50ml). The organic layer was separated, dried (MgSO ) and evaporated to a yellow oil which was purified by column chromatography on silica gel using hexane/ethyl acetate as the eluting solvents, yielding the product as a yellow oil (0.49 g. 45%). Found: C. 60.3; H. 6.2; N, 5.7% C₂₄H₂₉FN₂O₇ requires: C. 60.5; H. 6.1 ; N. 5.9% Example 98: R²= N(OCOCH₃)(CH₂)₆-(4-C₄H₉)Ph. R = OCOCH₃ N-Acetoxy-6-(4-n-butylphenyl)hexyl O-acetyiclavulanamide (a) N-Hydroxy-N-6-(4-n-butylphenyl)hexyl clavulanamide

Clavulanic acid (derived from benzyl clavulanate (0.6 g, 0.00207) as described in Example 40d) and N-6-(4-n-butylphenyl)hexyl hydroxylamine (prepared as described for Example 96b) were treated with DCC (0.42 g, 0.00203mol) as described in Example 96d Purification of the residue by column chromatography on silica gel using hexane/ethyl acetate as the eluting solvents, gave the product as an oil (0.15g, 29%) (b) N-Acetoxy-6-(4-n-butylphenyl)hexyl O-acetylclavulanamide

N-Hydroxy-N-6-(4-n-butylphenyl)hexyl clavulanamide (0.14 g, 0.000325) was dissolved in dry CH₂C1₂ (20ml). The solution was cooled to -30°C under nitrogen and treated with pyridine (0.03ml. 0.00037mol) and a solution of acetyl chloride (0.023ml. 0.000323mol) in CH₂C1₂ (1ml). stirred at -30°C for 1 hour, poured into brine (50ml) and extracted with CH₂C1₂ (30ml). The organic layer was dried (MgSO₄) and evaporated to an oil which was purified by column chromatography on silica gel using 3: 1 hexane/ethyl acetate as the eluting solvents, yielding the product as a pale yellow oil (0.059 g, 70%) Found: C, 64.9; H, 7.3; N, 5.1% C₂₈H₃₈N₂O₇ requires: C. 65.3; H. 7.4: N, 5.4% Example 99: R²= NHO(CH₂)₆Ph. R¹ = OCOCH₃ N-6-Phenyihexyloxy O-acetylclavulanamide. Yield = 42%. colourless solid, m.p. 70-71°C.

A solution of benzyl O-acetylclavulanate (Example 96a) ( 1.4 g, 0.00422 mol) in dry THF (42ml) was hydrogenated over 10% palladium on carbon (0.56 g) for 5 minutes at 25°C at 20psi. The catalyst was filtered off and the filtrate and solutions of DCC

(0.73 g. 0.00354mol) in dry CH₂CI₂ (65ml) and 6-phenylhexyloxyamine (prepared as for Example 47b) (0.65 g, 0.00336mol) in dry CH₂C1₂ (65ml) were mixed together quickly.

The reaction mixture was evaporated to near dryness and CH CI₂ (65ml) was added.

After stirring at room temperature for 1.5 hours the suspension was cooled, filtered and the filtrate was evaporated to dryness. The residue was purified by coiumn chromatography on silica gel using hexane/ethyl acetate as the eluting solvents and recrystaliisation from ethyl acetate/hexane gave the product as a colourless solid (0.59 g,

42%) m.p. 70-71°C.

Found: C. 62.6; H, 6.5: N. 6.8%

C₂₂H₂₈N₂O₆(0.23H₂O) requires: C. 62.8; H, 6.8; N, 6.7% Example 100: R = O(CH₂)₆-(4-F)Ph, Rl= OCHO

6-(4-Fluorophenyl)hexyl O-formylclavulanate

98-100% Formic acid (0.12ml. 0.00318mol) was added to acetic anhydride

(0.25ml. 0.00265mol) at 0°C. The mixture was then stirred at 50°C for 90 minutes, cooled to 0°C. (THF) (1ml) was added followed by 6-(4-fluorophenyl)hexyl clavulanate (0.5 g. 0.00132mol) in dry THF (1 l) and the reaction was stirred at room temperature for 4 hours. The reaction mixture was evaporated and purified by column chromatography on silica gel using 3: 1 hexane/ethyl acetate as the eluting solvents, yielding the product as a yellow oil (0.23 g, 43%).

Found: C. 62.2; H. 6.2; N, 3.4% C₂ιH₂₄FNO₆ requires: C. 62.2: H. 6.0; N, 3.5%

Example 101: R² = O(CH2)6Ph. R¹ = N(CH3)CH2Ph

6-Phenylhexyi 9-N-benzyl-N-methyldeoxy clavulanate

6-Phenylhexyl O-dichloroacetylclavulanate (lg, 2mmol) was dissolved in DMF

(20ml) at 0°C and treated with N-benzylmethylamine (0.46g, 3.8mmol) dropwise. The mixture was stirred for 3 hours then poured into ethyl acetate (40 ml), washed with water

(x3). brine (x2). dried (MgSO4) and evaporated to a yellow oil which was purified by repeat coiumn chromatography on silica gel using 1 : 1 pet ether/ethyl acetate as the eluting solvents, yielding the product as a yellow oil (0.037 g, 4%).

Found: C. 71.6: H. 7.4: N, 5.6% C₂₈H₃₄N₂O₄(0.04H₂O) requires: C. 71.6; H, 7.5; N. 6.0%

Example 102: R² = O(CH₂)₆-(4-F)Ph. R¹ = NHCHO

6-(4-Fluorophenyl)hexyl 2-(2-formamidoethylidene)-clavam-3-carboxylate

(a) N-Formyl benzyl carbamate

Benzyl carbamate (20g, 0.1323mol) and N.N-dimethylformamide dimethylacetal (52ml. 0.391mol) were heated together at 120°C for 15 minutes. The methanol was removed and the reaction mixture was heated at 100°C for 1 hour, cooled and filtered to give a colourless solid (21.2 g) m.p. 80-82°C. which was mixed with 70% aqueous glacial acetic acid (100ml) and stirred at room temperature for 1 hour, poured into water (500ml) and extracted with ethyl acetate (2x250ml). The organic extracts were combined, washed with water, brine, dried (MgSO₄) and evaporated in vacuo. The residue was mixed with water, filtered and the solid was recrystallised from ethanol/water to give the product as colourless needles (12.97 g. 55%). m.p. 65°C. (b) 6-(4-Fluorophenyl)hexyl-2-(2-formamidoethylidene)-clavam-3-carboxylate

A solution of 6-(4-flurophenyl)hexyl clavulanate (3 g. 0.00795mol) in dry THF (90ml). stirred at 10°C under nitrogen, was treated with triphenylphosphine (2.4 g, 0.00915mol) and N-formyl benzyl carbamate (2.85 g, 0.0159mol).

Diethylazodicarboxylate ( 1.59 g, 0.00913mol) in dry THF (30ml) was added over 20 minutes and the reaction mixture was stirred at room temperature for 21 hours and evaporated to an orange oil which was purified by column chromatography on silica gel using 2:1 hexane/ethyl acetate as the eluting solvents to give a yellow oil (4.06 g). This oil was hydrogenated in dry THF (50ml) over 10% palladium on carbon (2 g) for 60 minutes at 25°C at 40psi. The reaction mixture was filtered to remove catalyst, evaporated to an oil which was purified by column chromatograhy on silica gel eluting with hexane/ethyl acetate as the eluting solvents, yielding the product as a yellow oil (0.146 g, 4.5%). Found: C. 61.9: H, 6.2; N, 6.8%

C₂₁H₂₅FN₂O₅ requires: C, 62.3; H, 6.2; N, 6.9% Example 103: R² = O(CH₂)₆Ph, R¹ = NHCHO 6-Phenylhexyl-2-(2-formamidoethylidene)-clavam-3-carboxylate

Potassium cyanate (6.19 g. 0.0763mol) in water (5ml) and toluene (75ml) was cooled to -5° C. 5N H₂SO₄ ( 12.5ml) was added to the vigorously stirred solution over 5 minutes keeping the temperature below 0°C. The toluene layer was decanted off. dried (MgSO ) and cooled to -10 °C and added to a solution of 6-phenylhexyl clavulanate (1 g, 0.00278mol) and triphenyl phosphine (0.93 g, 0.00354mol) in dry THF (20ml) stirred at -10°C. Diethylazodicarboxylate (0.62ml, 0.00394mol) was added at -10°C and the reaction mixture was stirred at room temperature for 1 hour, filtered and evaporated in vacuo. The residue was dissolved in dry CH₂C1₂ (25ml) and cooled to 10°C. Pyridine (0.56ml. 0.00692mol) and formic acid (0.25ml. 0.00663mol) were added and the reaction was srirred at room temperature for 1 hour and diluted with CH₂C1₂ (75ml). The reaction mixture was washed with 0.5N HCl. water. 10% NaHCO₃. brine, dried MgSO₄ and evaporated to a brown oil which was purified by column chromatography on silica gel eluting with ethyl acetate and recrystallisation from diethyl ether to give the product as a colourless solid (0.037 g, 3.4%), m.p. 53-54°C.

Found: C. 65.1; H. 6.6: N. 7.4% C₂,H₂₆N₂O₅ requires: C. 65.3: H. 6.8; N, 7.3% Examples 104 and 105: R² = O(CH₂)₆Ph, R^] = NHCOCH₃

(i) 6-Phenylhexyl (3R. 5R. Z)-2-(2-acetamidoethylidene)-clavam-3-carboxylate and (ii) 6-Phenylhexyl (3R. 5R. E)-2-(2-acetamidoethylidene)-clavam-3-carboxylate (a) N-Acetyl benzyl carbamate

To a suspension of benzyl carbamate (20 g. 0.1323mol) in dry benzene (20ml) was added acetyl chloride (21ml. 0.2953mol)and the mixture was stirred at 75°C for 20 hours. Acetyl chloride (5ml. 0.0703mol) was added and the reaction mixture was stirred at 75°C for 1 hour and then evaporated to dryness. The residue was azeotroped with ethyl acetate (x2) and the resulting yellow solid was recrystallised from ethyl acetate/hexane to give the product as a colourless solid (18.49 g. 72%), m.p.l06-108°C (b) (i) 6-Phenylhexyl (3R. 5R. Z)-2-(2-acetamidoethylidene)-clavam-3-carboxylate and (ii) 6-Phenylhexyl (3R. 5R, E)-2-(2-acetamidoethylidene)-clavam-3-carboxylate

A solution of 6-phenylhexyl clavulanate (4.5 g, 0.0125mol) in dry THF (100ml), stirred at 10°C under nitrogen, was treated with triphenylphosphine (3.78 g, 0.0I44mol) and N-acetyl benzyl carbamate (2.9 g, 0.015mol). Diethylazo dicarboxylate (2.51 g, 0.0144mol) in dry THF (30ml) was added over 10 minutes. The reaction mixture was then stirred at room temperature for 5 hours and evaporated to an oil which was purified by column chromatography on silica gel using hexane/ethyl acetate as the eluting solvents, yielding a crude oil (0.96 g). This oil was hydrogenated in dry THF (30ml) over 10% palladium on carbon (0.5 g) for 60 minutes at 25°C at 40psi. The reaction was filtered to remove catalyst, evaporated to an oil which was purified by column chromatograhy on siiica gel eluting with 2:1 ethyl acetate/hexane as eluting solvents. Recrystallisation from ether/hexane of the appropriate column fractions gave: i) as a colourless solid (0.222g, 4.45%), m.p. 64-65°C. Found: C. 65.6; H, 6.9; N. 7.0% C₂₂H₂₈N₂O₅ requires: C. 66.0; H.7.1; N. 7.0%

(ii) as a colourless solid (0.02g. 0.4%) m.p. 64-65°C

Found: C. 65.8: H. 6.9; N. 7.1%

C₂₂H₂₈N₂O₅ requires: C. 66.0; H. 7.1 : N. 7.0%

The following compounds. Examples 106-109. were prepared as described above in Example 104 Example 106: R² = O(CH₂)₆-(4-F)Ph. R¹ = NHCOCH₃

6-(4-Fluorophenyl)hexyl-2-(2-acetamidoethylidene)-clavam-3-carboxylate. Yield = 34%, colourless solid, m.p. 73-74°C. Found: C. 63.2: H. 6.4; N. 6.7%

C₂₂H₂₇FN₂O₅ requires: C. 63.2; H. 6.5; N. 6.7%

Example 107: R² = O(CH₂)₆-(4-Cl)Ph. Rl = NHCOCH₃

6-(4-Chlorophenyl)hexyl-2-(2-acetamidoethylidene)-clavam-3-carboxylate. Yield = 5%, colourless solid, m.p. 69-72°C. Found: C. 61.2: H. 6.2; N. 6.5%

C₂₂H₂₇ClN₂O₅ requires: C. 60.8; H, 6.3; N. 6.4%

Example 108: R² = O(CH₂)₆-(4-C₄H₉)Ph. Rl = NHCOCH₃

6-(4-n-Butylphenyl)hexyl (3R. 5R. Z)-2-(2-acetamidoethylidene)clavam-3-carboxyiate,

Yield = 20%. colourless solid, m.p. 80-82°C. Found: C. 68.2; H. 7.8; N. 6.4%

C₂₆H₃₆N₂O₅ requires: C. 68.4: H. 8.0; N. 6.1%BRL-23845

Example 109: R² = OCH₂Ph. R¹ = NHCOCH₃

Benzyl (3R, 5R, Z)-2-(2-acetamidoethylidene)-clavam-3-carboxylate. Yield = 3%, colourless solid, m.p. 134-135°C Found: C. 61.8; H, 5.5; N, 8.4%

C_{I 7}H_{I 8}N₂O₅ requires: C, 61.8; H. 5.5; N, 8.5%

Example 110: R² = OCH₂Ph. Rl = NHCOPh

(i) Benzyl (3R, 5R, Z)-2-(2-benzamidoethylidene)-cIavam-3-carboxylate and Example 111 R² = OCH₂Ph. R 1 = NHCOPh

(ii) Benzyl (3R. 5R. E)-2-(2-benzamidoethylidene)-clavam-3-carboxylate

(a) N-Benzoyl benzyl carbamate

A suspension of benzoyl isocyanate (1.5 g, 0.0102mol) in dry benzene (8ml) was treated with a solution of benzyl alcohol (1.1 g, 0.0102mol) in benzene (5ml) and the reaction mixture was heated at 80°C for 30 minutes. After cooling the product was filtered from hexane as a colourless solid (1.45 g, 57%) m.p.1 18-120°C.

(b) A solution of benzyl clavulanate (2.19 g, 0.00757mol) in distilled THF (40ml) was treated with triphenvlphosphine (2.28 g, 0.0087mol), N-benzoyl benzyl carbamate (3.38 g, 0.0132mol) and a solution of diethylazodicarboxylate (1.5 g, 0.00861 mol) in THF (10ml) was added over 1 minute. After stirring at room temperature for 24 hours the reaction mixture was evaporated to a yellow oil which was purified by repeat column chromatography on silica gel using 3: 1 hexane/ethyl acetate as the eluting solvents, yielding a yellow oil (1.21 g). This oil was hydrogenated in dry THF (30ml) over 10% palladium on carbon (0.5 g) for 60 minutes at 25°C at 40psi. The reaction mixture was filtered and treated with a solution of sodium bicarbonate (0.14 g. 0.000167mol) in water (40ml) and the mixture freeze dried to give a brown solid which was dissolved in DMF (35ml) and treated with benzyl bromide (1 g, 0.00585mol). After stirring at room temperature for 6 hours the reaction mixture was evaporated to an oil. mixed with diethyl ether, filtered and the filtrate was washed with brine, dried (MgSO ), evaporated to a brown oil which was purified by column chromatography on silica gel using hexane/ethyl acetate as the eluting solvents. Recrystallisation of the appropriate fractions from ethyl acetate/hexane gave the products: (i) colourless solid (0.104 g, 12.5%) m.p.l43-144°C Found: C. 67.4; H. 5.3; N, 7.2% C₂₂H₂₀N₂O₅ requires: C. 67.3: H. 5.1 ; N. 7.1% (ii) colouriess solid (0.019g. 2.4 %) m.p. 160-162°C Found: C. 67.5: H. 5.3; N. 7.2%

^C22^H2₀ ^N2°₅ requires: C. 67.3: H. 5.1; N. 7.1%

Example 112: R² = O(CH₂)₆-(4-C₄H₉)Ph. Rl = NHCOPh

6-(4-n-Butyiphenyl)hexyl (3R, 5R. Z)-2-(2-benzamidoethylidene)-clavam-3-carboxylate,

Yield = 31%. colourless solid, m.p. 87-89°C, prepared as described in Example 111 above. Found: C. 71.5; H. 7.2; N. 5.4% ^c3.H₃₈N₂O₅ requires: C. 71.8; H. 7.4; N, 5.4%

Example 113: R² = NH(CH₂)₆Ph. R^l = NHCOCH₃

N-6-Phenylhexyl-2-(2-acetamidoethylidene)-clavam-3-carboxamide

Benzyl (3R. 5R. Z)-2-(2-acetamidoethylidene)-clavam-3-carboxylate (0.38 g, 0.001 15mol) in dry THF (20ml) was hydogenated over 10%) palladium on carbon (0.15 g) for minutes at 25°C at 20psi. The reaction mixture was filtered and the catalyst was washed with THF (30ml) and CH₂C1₂ (30ml). The combined filtrates and solutions of DCC (0.20 g.0.00097mol) in dry CH₂C1₂ (20ml) and 6-phenylhexylamine (0.165 g, 0.00093 lmol) in dry CH C1₂ (20ml) were mixed together quickly. The reaction mixture was evaporated to near dryness and CH₂C1₂ (20ml) was added. After stirring at room temperature for 1.5 hours the reaction mixture was cooled, filtered and the filtrate was evaporated to an oil which was purified by column chromatography on silica gel using ethyl acetate/ ethanol as the eluting solvents and recrystallisation from ethyl acetate/pet ether, yielding the product as a colourless solid (0.102 g. 28%) m.p. l45-146°C.

Found: C. 66.1 ; H. 7.1 ; N. 10.6% C₂₂H₂₉N₃O₄ requires: C. 66.1 ; H. 7.3; N, 10.5%

Example 114: R² -= NHO(CH₂)₅Ph. NHCOCH₃

N-5-Phenyipentyloxy-2-(2-acetamidoethylidene)-clavam-3-carboxamide

2-(2-acetamidoethylidene)-clavam-3-carboxylic acid (derived from benzyl (3R. 5R. Z)-2-(2-acetamidoethylidene)-clavam-3-carboxylate (0.7 g) as described in Example 1 13a) was treated with DCC (0.43 g) and 5-phenylpentyloxyamine (0.34 g) as described in Example 1 13a to give the product as a colourless soiid (0.217 g, 29%) m.p. 126-129°C. Found: C. 63.0; H. 6.7; N. 10.5% C₂,H₂₇N₃O₅ requires: C. 62.8; H. 6.8: N,10.5%

Example 115: R² = OCH₂-(2.4-diCl)Ph, R¹ = NHCOCH₂NHCOCH₃ 2.4-Dichlorobenzyl (3R. 5R)-9-deoxy-9-(2-N-acetylglycinamido)clavulanate

Sodium (3R. 5R) 9-deoxy -9-(2-N-acetylgycinamido)cIavulanate (0.125 g, 0.000391 mol) and 2.4-dichlorobenzyl bromide (0.282 g, 0.001175mol) were stirred together in DMF (7.5ml) for 18 hours. The reaction was evaporated to dryness and the residue was partitioned between ethyl acetate (50ml) and water (25ml) and filtered to remove solid. The organic layer was dried (MgSO₄), combined with the solid and evaporated in vacuo to give a solid which was washed with diethyl ether and recrystallised from ethyl acetate to give the product as colourless solid (0.09 g. 50%) m.p. 180-181°C.

Found: C. 49.9; H, 4.3; N, 9.1%

C₁₉H,₉Cl₂N₃O₆ requires: C. 50.0; H, 4.2; N, 9.2%

Example 116: R² = OCH₂-(2.4-diCl)Ph, R¹ = NHCOCH₂NHCOCH₃

2.4-DichIorobenzyl (3S, 5S)-9-deoxy-9-(2-N-acetylglycinamido)clavulanate Sodium (3S. 5S)-9-deoxy-9-(2-N-acetylglycinamido)clavulanate (0.135 g,

0.0042mol) and (0.30 g, 0.00125mol) were stirred together in DMF (7.5ml) for 21 hours. The reaction mixture was evaporated to an orange oil which was partitioned between ethyl acetate (75ml) and water (30ml). The organic layer was washed with brine, dried (MgSO₄) and evaporated to a clourless solid which was washed with diethyl ether to remove 2,4-dichlorobenzyl bromide. The residue was recrystallised from ethyl acetate to give the product as a colourless solid (0.097 g, 50%) m.p. 183-184 °C. Found: C. 50.0: H. 4.0: N. 9.4% C₁₉H_{] 9}Cl₂N₃O₆ requires: C. 50.0: H. 4.2; N, 9.2% Example 117: R² = OCH₂Ph. R^J = NHCOCH₃ Benzyl (3S. 5S. Z)-2-(2-acetamidoethylidene)-clavam-3-carboxylate (a) Benzyl (3S. 5S)-9-deoxy-9-(2-N-acetylglycinamido)clavulanate Sodium (3S. 5S)-9-deoxy-9-(2-N-acetylglycinamido)clavulanate (125 g, 0.033mol) and benzyl bromide (50ml. 0.42mol) were stirred together in DMF (1.11) for 24 hours. Ethy acetate (1.11) was added and the reaction mixture was filtered and evaporated in vacuo to a brown oil which was purified by column chromatography on silica gel using chloroform/ethanol as the eluting solvents. Recrystallisation from ethyl acetate/ether gave the product as a light brown solid (12.9 g, 25%) m.p. 138-140°C. (b) Benzyl (3S. 5S. Z)-2-(2-acetamidoethylidene)-clavam-3-carboxylate

A solution of benzyl (3S. 5S)-9-deoxy-9-(2-N-acetylglycinamido)-clavulanate (0.48 g, 1.25mmol) in CH₂C1₂ (25ml), cooled to -5°C, was treated with a solution of pyridine (0.99 g, 12.5mmol) in CH₂C1₂ (2ml) folowed by thionyl chloride (0.59 g,

5mmol) in CH₂C1₂ (2ml). The reaction mixture was stirred at 5°C for 10 minutes and at room temperature for 50 minutes, cooled to 5°C and treated with 2-aminothiophenol (1.25 g, lOmmoi) in CH₂C1₂ (2ml) and stirred at 5°C for 1 hour. Pyridine (1.98 g, 25mmol) and acetyl chloride (1.57 g. 20mmol) were added to the reaction mixture and it was stirred at room temperature for 1 hour. The reaction mixture was diluted with

CH₂C1₂ (25ml) and washed with 0.5M HCl. water. sat.NaHCO₃, brine, dried (MgSO₄) and evaporated to a red tar which was purified by column chromatography on silica gel eluting with ethyl aceate and then 20: 1 CHCl₃/methanoi to give an orange oil. Trituration with diethyl ether yielded the product as a light brown solid (0.033 g, 8%) m.p. 129-132°C.

Found: C, 61.1; H, 5.5; N, 8.5%

C₁₇H₁₈N₂O₅(0.026EtOAc. 0.17H₂0) requires: C. 61.2; H. 5.6; N, 8.3%

Example 118: R² = O(CH₂)₆-(4-C₄H₉)Ph. Rl = NHCOCH₃

6-(4-n-Butylphenyi)hexyl (3S. 5S. Z)-2-(2-acetamidoethylidene)-clavam-3-carboxylate and Example 119: R² = O(CH₂)₆-(4-C₄H₉)Ph. R^J = NHCOCH₃

6-(4-n-Butylphenyl)hexyl (3S. 5S)-2-(2-acetamidoethyl)-clavam-3-carboxylate

Benzyl (3S, 5S, Z)-2-(2-acetamidoethylidene)-clavam-3-carboxylate (0.21 g, 0.636mmol) in THF (20ml) was hydrogenated over 10% palladium on carbon (0.63 g) for 1.5 hours. The reaction mixture was filtered to remove catalyst and treated with a solution of NaHCO₃ (54mg, 0.643mmol) in water (5ml). The THF was removed in vacuo and the remaining solution was freeze dried to give an oil which was dissolved in DMF (15ml) and treated with 6-(4-n-butylphenyl)hexyl bromide (0.4 g, 1.35mmol) and the reaction mixture was stirred at room temperature for 20 hours and evaporated to an oil. This oil was purified by column chromatography on silica gel using hexane/ethyl acetate as the eluting solvents and evaporation of the appropriate fractions gave the products

(i) as a brown oil (0.005g, 1.7%).

'H NMR-(CDC1₃) δ 0.92 (t, J=7.3Hz. 3H, CH₃), δ 1.37 (m, 6H. CH₂). δ 1.59 (m, H,

CH₂). δ 1.96 (s, 3H. COCH₃), ό 2.57 (t, J=7.6Hz, 4H. CH₂), δ (3.08 (d, J=15Hz, IH, 6β-H), δ 3.50 (dd, J=2.15Hz. IH. 6α-H). δ 3.94 (t, J=6.8Hz, 2H, 9,9^*-H), δ 4.16 (m. IH, COCH₂), δ 4.75 (t. J=7Hz. IH. 8-H). δ 5.01 (s, IH. 3-H). δ 5.52 (m, IH. NH), δ 5.79 (d. J=2Hz. IH.

5-H). δ 7.09 (s, 4H. Ar-H)

(ii) as a colourless oil (0.079 g, 27%)

'H NMR-(CDC1₃) δ 0.90 (t, J=7.3Hz, 3H. CH₃), δ 1.36 (m. 6H. CH₂), δ 1.56 (m, 6H, CH₂), δ 1.88 (m, 1 H. 8'-H). δ 1.97 (s, 3H. COCH₃), δ 2.06 ( m. 1 H, 8-H), δ 2.57 (t, J=7.6Hz, 4H,

CH₂), δ 2.92 (dd, J=4.12.6Hz. IH. 6β-H), δ 3.40 (m. 3H. 6α-H. 9,9'-H). δ 4.13 (m, 3-H.

CO₂CH₃), δ 4.33 (m, IH. 2-H), δ 4.64 (d, J=6.4Hz. 3-H), δ 5.31 (d. J=4Hz, 5-H), δ 5.55 (d,

J=2.4Hz. 5-H). δ 5.79 (m. IH. NH), δ 7.09 (s, 4H. Ar-H)

Example 120: R² = OCH₂Ph. Rl = NHCOCH₂NHCOCH₃ Benzyl (3R. 5R)-9-deoxy-9-(2-N-acetylglycinamido)clavulanate

Example 121: R² = OCH₂Ph, Rl = NHCOCH₂NHCOCH₃

Benzyl (3S. 5S)-9-deoxy-9-(2-N-acetylglycinamido)clavulanate

Example 122: R² = OCH₂Ph, R¹ = NHCO₂CH₂Ph

Benzyl 9-N-benzyloxycarbonylamino deoxyclavulanate Example 123: R² = OCH₂-(4-Br)Ph, R¹ = NHCOCH₃

4-Bromobenzyl (2S. 5S, Z)-2-(2-acetamidoethylidene)-clavam-3-carboxylate

Example 124: R² = OCH₂Ph. R¹ = O(CH₂)₂OH

Benzyl O-(2'-hydroxyethyl)clavulanate

Example 125: R² = OCH₂Ph. Rl = N₃ Benzyl (3R. 5R. Z)-2-(2-azidoethylidene)clavam-3-carboxylate

Example 126: R² = OCH₂Ph. Rl = O(CH₂)₅CH₃

Benzyl O-n-hexylclavulanate, Yield = 1 1.5%, yellow oil.

A solution of benzyl clavulanate (0.58 g, 0.002mol) in dry CH₂C1₂ (30ml) was treated with hexyl iodide (0.428 g, 0.003mol). silver(I)oxide (0.47 g, 0.002mol) and powdered 4A° molecular sieves (2.2 g). The reaction mixture was stirred in the dark for

19 hours, filtered, evaporated in vacuo and the residue was purified by column chromatography on silica gel, yielding the product as a yellow oil (0.086 g, 11.5%).

Found: C. 67.5: H. 7.2; N. 4.0%

C₂|H₂₇NO₅ requires: C. 67.5: H. 7.3; N, 3.8% Example 127: R² = OCH₂Ph. R¹ = OCH₃

O-Methyl benzyl clavulanate. Yield = 42%, pale yellow oil. Found: C. 63.8; H. 5.9; N. 4.7%

C|₆H,₇NO₅ requires: C. 63.4: H, 5.6: N. 4.6%

Example 128: R² = OCH₂Ph. R¹ = OTHP

Benzyl O-2-pyranosylclavulanate. Yield = 81%. colourless oil. Found: C. 62.3; H. 6.2; N. 3.5%

C₂₀H₂₃NO₆(0.17CH₂C1₂) requires: C. 62.5: H. 6.1 : N. 3.6%

Example 129: R² = OCH₃, R^J = OCH₃

Methyl O-methylclavulanate

Example 130: R² = OCH₂-(4-NO₂)Ph. Rl = OTHP 4-Nitrobenzyl O-tetrehydropyran-2'-yl)clavulanate

Example 131: R² = OCH₂Ph, Rl = OCH₂CO₂Et

Benzyl O-(carboxymethyl)clavulanate. Yield = 4%, oil.

Found: C. 59.6: H. 5.6: N. 3.2%

C ι₉H_{2 I}NO₇(0.1CH₂Cl₂) requires: C. 59.7; H. 5.6: N. 3.6% Example 132: R² = O(CH₂)₆-(4-C₄H₉)Ph. R^J = SCH₃

6-(4-Butylphenyl)hexyl (3R. 5R. Z)-2-methylthioethylidene-clavam-3-carboxylate (a) 6-(4-n-Butylphenyl)hexyl bromide

6-Bromohexanoyl chloride (29.34 g, 0.14mol) in dry CH₂C1₂ (30ml) was added over 5 minutes to a suspension of aluminium chloride (16.13 g, 0.12 mol) in CH₂C1₂ (80ml) whilst keeping the temperature at 20-23 °C. The mixture was stirred at room temperature for 30 minutes and treated with a solution of n-butylbenzene (14.9 g, 0.11 mol) in CH C1₂ (30ml). After stirring at room temperature for 20 hours, triethylsilane

(32 g, 0.28 mol) was added at 23-25°C over 10 minutes. The mixture was stirred at room temperature for 60 minutes then poured into ice water (200ml). The organic layer was separated, dried (MgSO- and evaporated in vacuo. The residue was distilled under reduced pressure to give a clear oil (28.35 g, 87%). boiling point 140-143 °C/0.2mbar. (b) 6-(4-n-Butylphenyl)hexyl clavulanate

A mixture of 6-(4-n-butylphenyl)hexyl bromide (7.48 g, 25mmol) and potassium clavulanate (5 g. 21 mmol) in DMF (200ml) was stirred at room temperature for 20 hours. The mixture was evaporated to dryness and partitioned between ethyl acetate (200ml) and water (200ml). The organic layer was separated, washed with water, brine, dried (MgSO4) and evaporated to an oil which was purified by column chromatography on silica gel using 2:1 pet ether/ethyl acetate as the eluting solvents, yielding the product as an orange oil (2.09 g, 24%). (c) 6-(4-n-Butylphenyl)hexyl O-dichloroacetylclavulanate

- jj - 6-(4-n-butylphenyl)hexyl clavulanate ( 1.88 g, 4.5mmol) was dissolved in dry dichloromethane (40ml). the solution was cooled to -30°C and treated with pyridine (0.44ml) and a solution of dichloroacetyl chloride (0.46ml) in CH₂C1₂ (10ml) dropwise over 10 minutes. Stirring was continued at -30°C for 60 minutes, the reaction mixture was poured into IN HCl (50ml). extracted with dichloromethane (25ml) and the combined organic layers washed with brine (x2).dried (MgSO_t) and evaporated to an oil which was purified by column chromatography on silica gel using 5:1 pet ether/ethyl acetate as the eluting solvents, yielding the product as a yellow oil (1.24 g, 52%). (d) 6-(4-n-Butylphenyl)hexyl (3R. 5R, Z)-2-methylthioethylidene clavam-3 -carboxylate A solution of 6-(4-n-butylphenyl)hexyl O-dichloroacetylclavulanate ( 1.59 g,

3mmol) in DMF (10ml) was cooled to -60°C and treated dropwise with a solution of sodium thiomethoxide (0.198 g. 3mmol) in DMF (30ml) over 10 minutes. The reaction mixture was stirred at -50°C for 30 minutes and at room temperature for 90 minutes. The reaction was cooled to -50°C and sodium thiomethoxide (0.065 g) was added, stirred at room temperature for 45 minutes, evaporated in vacuo to an orange oil which was partitioned between ethyl acetate and water. The organic layer was washed with brine, dried (MgSO₄) and evaporated to an oil which was purified by column chromatography on silica gel using 7: 1 hexane/ethyl acetate as the eluting solvents, yielding the product as a yellow oil (0.41 g, 30%). Found: C, 67.7; H, 8.0; N, 3.0%

C₂₅H₃₅NO₄S requires: C. 67.4: H, 7.9; N, 3.1% Example 133: R² = O(CH₂)₆-(4-C₄H₉)Ph, Rl = SOCH₃

6-(4-n-Butylphenyl)hexyl (3R. 5R. Z)-2-methylsulphinylethylidene-clavam-3-carboxylate 6-(4-n-Butylphenyl)hexyl (3R.5R.Z)-2-methylthioethylidene clavam-3- carboxylate (0.32 g, 0.72mmol) was dissolved in CH₂C1₂ (30ml) and cooled to -60°C and MCPBA (0.25 g, 0.72mmol) in CH₂C1₂ (25ml) was added over 10 minutes. The reaction was stirred at -60°C for 30 minutes and allowed to warm to room temperature over 60 minutes. The reaction mixture was washed with aq Na₂SO₃, aq NaHCO₃, water, dried (MgSO ), and evaporated to an oil which was purified by column chromatography on silica gel using ethyl acetate/ethanol as the eluting solvents, yielding the product as a colourless oil (0.13 g, 39%).

1H NMR-(CDC1₃) δ 0.92 (t. J=7.3Hz. 3H. CH₃), δ 1.35 (m, 6H. CH₂), δ 1.60 (m, 6H, CH₂), δ 2.51 (d. J=2.3Hz. 3H. SOCH₃), δ2.57 (t, J=7.5hZ. 4H. CH₂), δ 3.09 (d, J=17Hz, IH, 6β-H), δ 3.51 (m. 3H. 9.9'-H. 6α-H), δ 4.17 (t, J=6.6Hz, 3H. CO₂CH₂), δ 4.80 (q, J=9.2, 1 1.1 Hz, IH. 8-H), δ 5.12 (s, IH. 3-H), δ 5.73 (dd, J=2.71Hz.lH. 5-H), δ 7.08 (s, 5H. Ar-H). Example 134: R² = O(CH₂)₆-(4-C₄H₉)Ph. R¹ = SO₂CH₃

6-(4-n-Butylphenyl)hexyl (3R. 5R. Z)-2-methylsulphonylethylidene-clavam-3-carboxylate

6-(4-n-butylphenyl)hexyl (3R. 5R. Z)-2-methylthioethylidene clavam-3- carboxylate (0.2 g, 0.45mmol) was dissolved in CH₂C1₂ (25ml) and cooled in an ice bath. A solution of mCPBA (0.62 g. 1.8mmol) in CH₂C1 (25ml) was added over 10 minutes and the mixture stirred for 90 minutes in an ice bath. After warming to room temperature the mixture was washed with 5% Na2SO3. saturated NaHCO3, water, dried (MgSO4) and evaporated to a yellow oil. which was purified by column chromatography on silica gel using 3 :2 pet ether/ethyl acetate as the eluting solvents, yielding the product as a colourless oil (0.1 1 g, 51 %).

Found: C. 62.7; H, 7.3; N, 3.1% C₂₅H₃₅NO₆S requires: C. 62.9; H. 7.4; N. 2.9%

1 H NMR-(CDC1 ) δ 0.92 (t. J=6.9 Hz. 3H. CH₃) , 1.40 (m, 4H. CH2) - 1.6 (m. 8H. CH2),

2.57 (t. J=6.7 Hz. 4H. CH -Ph) . 2.8 (s. 3H. SO₂CH₃) .3.1 (d. J=16.8Hz. IH. 6β-H) , 3.5 (dd J=2.8.16.8Hz. IH. 6 -H) . 3.8 (d. J=7.5Hz. 2H. CH2 9.9'-H) .4.15 (t. J=3.8Hz.

2H OCH₂) . 4.85 (t, J=7.5Hz. IH. 8-H) . 5.14 (s. IH. 3-H) , 5.77 (d. J=2.8. IH. 5-H) ,

7.08 (bs. 4H. Ar-H)

The following compounds. Examples 135-137. were prepared as described above.

Example 135: R² = O(CH₂)₆Ph. R^l = SCH₃

6-Phenylhexyl (3R. 5R, Z)-2-methylthioethylidene clavam-3-carboxylate.

Yield = 14%. yellow oil.

Found: C. 64.5: H. 7.0; N. 3.4% C₂₁H₂₇NO₄S requires: C. 64.8: H. 7.0: N. 3.6%

Example 136: R² = O(CH₂)₆Ph. Rl = SO₂CH₃

6-Phenylhexyl (3R.5R.Z)-2-methylsulphonylethylidene clavam-3-carboxylate.

Yield = 68.7%. pale yellow oil.

Found: C. 59.3: H, 6.3: N. 3.0: S. 7.4% C_{2 I}H₂₇NO₆S(0.064CH₂C1₂) requires: C. 59.3; H. 6.4; N. 3.3; S, 7.5%

Example 137: R² = O(CH₂)₆-(4-Br)Ph. Rl = SO₂CH₃

6-(4-Bromophenyl)hexyl (3R. 5R. Z)-2-methylsulphonylethylidene clavam-3 -carboxylate,

Yield = 37%). colourless oil.

!H NMR-(CDC1₃) δ 1.35 (m. 4H. CH₂) . 1.6 (m. 4H. CH₂) . 2.56 (t. J=7.5Hz. 2H. CH₂-Ph) . 2.82 (s, 3H. SCH3) . 3.1 (d. J=16.8Hz. IH. 6β-H) , 3.59 (dd. J=16.8.

2.75Hz. IH. 6α-H) , 3.8 (d. J=8Hz. 2H. CH₂ 9.9') , 4.17 (t. J=6.5Hz. 2H. CO₂CH₂) ,

4.85 (t. J=8Hz. IH, 8-H) . 5.14 (s. IH. 3-H). 5.77 (d. J=2.75. IH. 5-H) ,7.06 (d. J=8.25Hz. 2H. Ar-H). 7.37 (d. J=8.25. 2H. Ar-H)

Example 138: R² = OCH₂Ph. R¹ = SPh

Benzyl (3R, 5R. Z)-2-phenylthioethylidene-clavam-3-carboxylate

Sodium hydride (0.08 g. 0.002mol) was suspended in dry DMF (10ml) and cooled in an ice bath. Thiophenol (0.21ml. 0.00205mol) was added over 2 minutes and the reaction was stirred at room temperature for 15 minutes and than cooled in an ice bath.

Benzyl O-dichloroacetylclavulanate (0.8 g, 0.002mol) in DMF (5ml) was added and the reaction was stirred at room temperature for 1 hour and was then evaporated to a brown oil which was purified by column chromatography on silica gel using 3: 1 hexane/ethyl acetate, yielding the product as a colourless oil (0.138 g. 18%).

Found: C, 66.0; H. 5.2; N. 3.3%

C₂₁H₁₉NO₄S requires: C. 66.1 : H. 5.0; N. 3.7%

Example 139: OCH₂-(2.4-diCI)Ph. R¹ = SCH₂Ph

2.4-Dichlorobenzyl (3R. 5R. Z)-2-benzylthioethyIidene-clavam-3-carboxylate. 2.4-Dichlorobenzyl O-dichloroacetylclavulanate (2.35 g, 0.005mol) was dissolved in dry DMF (25ml) and benzyl mercaptan (0.93 g, 0.0075moi) was added. The mixture was cooled to -60°C and triethylamine (0.67ml. 0.0048mol) was added over 5 minutes.

The reaction was stirred at -50 to -60°C for 60 minutes and then allowed to warm to room temperature, poured into diethyl ether (200ml) and washed with water (x3), brine, dried (MgSO ) and evaporated to a yellow oil which was purified by column chromatography on silica gel using 5: 1 hexane/ethyl acetate as the eluting solvents, yielding the product as a colourless oil. (1.53 g, 69%).

Found: C. 56.9: H. 4.2: N. 2.8; S. 7.0%

C₂₂H_]9Cl₂NO₄S requires: C. 56.9: H. 4.1; N. 3.0: S. 6.9% Example 140: R² = OCH₂-(2.4-diCl)Ph. R¹ = SOCH₂Ph

2,4-Dichlorobenzyl (3R. 5R. Z)-2-benzylsulphinylethylidene-clavam-3-carboxylate.

2,4-Dichlorobenzyl (3R. 5R. Z)-2-benzylthioethylidene-clavam-3-carboxylate (Example 140)

(0.695 g, 1.5mmol) was dissolved in CH₂C1₂ (25ml) and cooled to -60°C. MCPBA (0.51 g, 1.5mmol) in CH₂C1 (40ml) was added over 20 minutes and the suspension was stirred at -60°C for 1 hour and then allowed to warm to room temperature. The reaction was washed with dilute Na₂SO₃, NaHCO₃ (x2). water, brine, dried (MgSO ) and evaporated to an oil which was purified by repeat column chromatography on silica gel using hexane/ethyl acetate as the eluting solvents, yielding the product as a colourless oil (0.225 g. 31%). Found: C. 55.0. H, 4.5: N. 2.6: Cl. 13.5; S, 6.4% C₂₂H,₉Cl₂NO₅S(0.42EtOAc) requires: C, 55.0; H. 4.4; N. 2.7; Cl, 13.7; S, 6.2% Example 141: R² = OCH₂-(2.4-diCl)Ph, R¹ = SO₂CH₂Ph 2.4-Dichlorobenzyl (3R. 5R. Z)-2-benzylsulphonylethylidene-clavam-3-carboxylate. 2.4-Dichlorobenzyl (3R. 5R. Z)-2-benzyithioethylidene-clavam-3-carboxylate (Example 140) (0.35 g, 0.75mmol) was dissolved in CH₂C1 (30ml) and cooled in an ice bath. MCPBA (1.04 g, 3mmol) in CH₂C1₂ (25ml) was added over 10 minutes and the reaction was stirred in the ice bath for 90 minutes and was then allowed to warm to room temperature. The reaction was washed with dilute NaτSO . NaHCO₃ (x2), water, dried (MgSO₄) and evaporated to an oil which was purified by column chromatography on silica gel using hexane/ethyl acetate as the eluting solvents, yielding the product as a colourless oil Recrystallisation from ethyl acetate gave the product as a colourless solid (0.15 g, 40%) m.p. 1 15-1 16°C.

Found: C. 53.1 : H, 4.0: N. 2.9; Cl. 14.0; S. 6.7%

C₂₂H₁₉Cl₂NO₆S requires: C. 53.2: H. 3.9: N. 2.8; Cl. 14.3; S. 6.5%

The following compounds. Examples 142-146 were prepared as described above in Examples 138-141.

Example 142: R² = OCH₂Ph, R^J = S(CH₂)₅CH3

Benzyl (3R. 5R. Z)-2-hexylthioethylidene-clavam-3-carboxylate. Yield = 31%, colourless oil. Found: C, 64.7: H, 6.8; N, 3.6; S, 8.0%

C₂₁H₂₇NO₄S requires: C, 64.8; H, 7.0; N, 3.6; S, 8.2%.

Example 143: R² = OCH₂Ph. Rl = SO₂(CH₂)₅CH₃

Benzyl (3R. 5R. Z)-2-hexylsulponylethylidene-clavam-3-carboxylate. Yield = 36%. colourless oil. Found: C. 59.2: H, 6.3: N. 2.9: S. 7.9%

C_{2 ]}H₂₇NO₆S(0.03CH₂C1₂) requires: C. 59.6; H. 6.4; N, 3.3; S. 7.6%

Example 144: R² = OCH₂Ph, Rl = SCH₂Ph

Benzyl (3R, 5R. Z)-2-benzylthioethylidene-clavam-3-carboxylate. Yield = 29%, colourless oil. Found: C. 66.7: H, 5.4; N. 3.4; S. 8.2%

C₂₂H_{2 ]}NO₄S requires: C. 66.8: H. 5.4; N. 3.5; S. 8.1%

Example 145: R² = OCH₂Ph. Rl = SOCH₂Ph

Benzyl (3R. 5R. Z)-2-benzylsulpinylethylidene-clavam-3-carboxylate. Yield = 23%. colourless oil. Found: C. 63.5: H, 5.4; N. 3.0%

C₂₂H_{2 ]}NO₅S(0.08EtOAc. 0.18H₂O) requires: C. 63.6: H. 5.3; N. 3.3% Example 146: R² = OCH₂Ph. R¹ = SO₂CH Ph

Benzyl (3R. 5R. Z)-2-benzylsulponylethylidene-clavam-3-carboxylate. Yield = 68%, colourless oil.

Found: C. 60.7: H, 5.0; N. 3.2% C₂₂H₂₁NO₆S(0.05CH₂C1₂. 0.24H₂O) requires: C. 60.7: H. 5.0: N. 3.2%

Example 147: R² = O(CH₂)₆-Ph. R¹ = NHCOPh

6-(phenyl)hexyl (3R. 5R. Z)-2-(2-benzoylaminoethylidene)clavam-3-carboxylate and

Example 148: R² = O(CH₂)₆-Ph. Rl = NHCOPh 6-(phenyl)hexyl (3R. 5R. E)-2-(2-benzoylaminoethylidene)clavam-3-carboxylate a. 6-(phenyl)hexyl (3R, 5R. Z)-2-(2-azidoethylene)clavam-3-carboxylate 6-(phenyl)hexyl clavulanate (10 g) in didthyl ether ( 100 ml) was treated with pyridine and thionyl chloride at -60°C to -40°C for 0.3 h. After aqueous work-up the organic extracts were evaporated and the residue dissolved in acetone ( 100 ml) and treated with NaN₃ ( 1 .07g) in water ( 10 ml) for lh. After acidification, and washing of the organic solution with water the organic extracts were evaporated, and chromatographed to give 6-(phenyl)hexyl (3R, 5R, Z)- 2-(2-azidoethylidene)clavam-3-carboxylate (0.96 g). b. 6-(Phenyl)hexyl (3R, 5R. Z)-2-(2-azidoethylene)clavam-3-carboxylate (0.96 g)was dissolved in THF (30 ml) and treated with Zn dust ( 1.63 g) and 2N HCl. keeping the pH between 2.5 and 3. After stirring for 2h the mixture was neutralised, filtered and extracted with ethyl acetate. The organic extracts were washed with brine . dried and concentrated to

30 ml. cooled to -40 to -50C and treated with pyridine and benzoyl chloride. After aqueous work-up the organic extracts were evaporated and chromatographed to give the title compounds as cream solids. (i) 6-(phenyl)hexyl (3R. 5R. Z)-2-(2-benzoylaminoethylidene)clavam-3-carboxylate. 0.56 g, m.p. 93-94°C

(i) 6-(phenyl)hexyl (3R. 5R. E)-2-(2-benzoylaminoethylidene)clavam-3-carboxylate. 0.05 g, m.p. 106-107°C

Example 149 R² = O(CH₂)₆-Ph. R¹ = NHCOCH3 6-(Phenyl)hexyl (3S. 5S. Z)-2-(2-acetamidoethylene)clavam-3-carboxylate a. 6-(Phenyl)hexyl (3S. 5S. Z)-2-(2-N-acetylglycinamidoethylene)clavam-3-carboxylate

(4.6 g) was prepared from sodium (3S. 5S)-9-deoxy-9-(2-N- acetylglycinamido)clavulanate ( 40 g) and 6-phenylhexyliodide (16.8 g) by the method described in Example 1 16 and was isolated as a yellow solid. b. 6-(Phenyl)hexyl (3S. 5S. Z)-2-(2-N-acetylglycinamidoethylene)clavam-3-carboxylate

(2.3 g) in dichloromethane (125 ml) at -10C was treated with pyridine (3.95 g) in dichloromethane (10 ml) and thionyi chloride (2.38 g) in dichloromethane ( 10 ml), then the mixture stirred at room temperature for lh. The mixture was cooled to -IOC. and treated with 2-aminothiophenol (5 g), stirred for 1 h. and treated with pyridine (7.9 g) and acetyl chloride (6.3 g) in a total of 40 ml of dichloromethane. After stirring at room temperature for 1 h and aqueous work-up the title compound was isolated as a yellow semi-solid after chromatography (0.05 g)

DATA

1. Screen for Lp-PLA2 inhibition.

Enzyme activity was determined by measuring the rate of turnover of the artificial substrate (A) at 37 °C in 50mM HEPES (N-2-hydroxyethylpiperazine-N'-2- ethanesulphonic acid) buffer containing 150mM NaCl. pH 7.4.

(A) Assays were performed in 96 well titre plates.

Lp-PLA2 was pre-incubated at 37 °C with vehicle or test compound for 10 min in a total volume of 180 μl. The reaction was then initiated by the addition of 20 μl lOx substrate (A) to give a final substrate concentration of 20 μM. The reaction was followed at 405 nm for 20 minutes using a plate reader with automatic mixing. The rate of reaction was measured as the rate of change of absorbance.

Results: The majority of compounds of Examples 1 -149 had IC₅₀s in the range 0.002-50 μM with many (e.g. Examples 25-30. 55-57, 59-61. 64-77. 87-91. 99-102, 106-108) having IC₅₀s < 0.1 μM whilst Examples 53, 56. 71. 87. 88 and 137 have IC₅₀s < 0.01 μM.

Claims

Claims

1. A compound of structure (I):

in which: R¹ is OH, OCOR³ OCHO, O(CH₂)_nOR⁵. OC_{1 - 12}alkyl, O(CH₂)_nCO₂R⁵, -S(O)_pC _{1 - 12}alkyl, S(CH₂)_qPh, S(O)_r(CH₂)_nPh. N₃, NR⁶R⁷ or ;

R² is O(CH₂)_nPh in which the phenyl ring may optionally be substituted,

O(CH₂)_nnaphthyl, O(CH₂)_nCOPh. O(CH₂)_nSPh. OCH(Ph)C_{1 - 6}alkyl, OC_{1 - 6}alkyl, NR¹⁰(CH₂)_qPh, NR ¹⁰(CH₂)_nCOPh, N(R⁸)O(CH₂)_nPh;

R³ is C_{1 - 12}alkyl, C_{2- 12}alkenyl, optionally substituted phenyl, CH(Ph)2, biphenyl,

(CH₂)_nPh, (CH₂)_nHet, (CH₂)_nCO₂R⁸, (CH₂)_nC_3-6cycloalkyl, C(R⁹)₃, adamantyl, naphthyl, C_3-6cyclohexyl, (CH₂)_nPh(CH₂)_nPh or PhOPh;

R⁵ is hydrogen or C_{1 - 6}alkyl;

one of R⁶ and R⁷ is hydrogen or C_{1 -6}alkyl, and the other is CHO, CH₂Ph. COC _{1 -6}alkyl,

COPh. COCH₂NHCOC_{1 - 6}alkyl or NHCOOCH₂Ph;

R⁸ is hydrogen or C _{1 -6}alkyl;

R9 is hydrogen or halogen;

R¹⁰ is hydrogen, hydroxy, C_{1 - 6}alkyl or OCOCH₃;

m is 1 or 2; n is 1 to 8; p is 0, 1 or 2; q is 0 to 6 and r is 0, 1 or 2;

and salts, hydrates and solvates thereof.

2. A compound as claimed in claim 1 in which R¹ is OH, OCOR³ or NR⁶R⁷.

3. A compound as claimed in claim 1 or 2 in which R² is O(CH₂)_nPh, in which n is 1 to 8.

4. A compound as claimed in any one of claims 1 to 3 in which R³ is C_{1 - 12}alkyl-

5. A compound as claimed in any one of claims 1 to 4 in which R³ is hydrogen.

6. A compound as claimed in any one of claims 1 to 5 in which one of R" and R⁷ is hydrogen and the other is COC_{1 - 6}alkyl.

7. A compound as claimed in any one of claims 1 to 6 in which R° is hydrogen.

8. A compound as claimed in any one of claims 1 to 7 in which one group R⁹ is hydrogen and the other two are halogen, in particular chlorine.

9. A compound as claimed in any one of claims 1 to 8 in which R¹⁰ is hydrogen.

10. A compound as claimed in any one of claims 1 to 9 in which m is 2.

1 1. A compound as claimed in any one of claims 1 to 10 in which n is 6.

12. A compound as claimed in any one of claims 1 to 1 1 in which p is 2.

13. A compound as claimed in any one of claims 1 to 12 in which q is 0 to 6.

14. A compound as claimed in any one of claims 1 to 13 in which r is 0, 1 or 2.

15. A compound as claimed in claim 1 in which:

R² = O(CH₂)₆-(4- F)Ph, R¹ = OH:R² = OCH₃. R¹ = OH;

R²= OC₆H₁₃. R¹ = OH:

R²= OC₁₈H₃₇. R¹ = OH;

R²= OCH₂Ph, R¹ = OH;

R²= OCH₂-(4-NO₂)Ph, R¹ = OH;

R²= OCH₂-(4-Cl)Ph, R¹ = OH;

R²= OCH₂-(4-CH3)Ph, R¹ = OH;

R²= OCH₂-(4-Br)Ph, R¹ = OH;

R²= OCH₂-(4-OCH₃)Ph, R¹ = OH;

R²= OCH₂-(4-(CH₃)₃)Ph, R¹ = OH;

R²= OCH₂-(4-Ph)Ph, R¹ = OH;

R²= OCH₂ -1 -Naphthyl, R¹ = OH;

R²= OCH₂-(4-OH, 3,5-di-tert-butyl)Ph, R¹ = OH; R²= OCH₂-(2,4-diCl)Ph, R¹ = OH;

R²= OCH₂-(2,6-diCl)Ph, R¹ =OH;

R²= OCH₂-(2,5-diCl)Ph, R¹ =OH;

R²= OCH₂-(2,4-diCl)Ph, R¹ = OH;

R²= OCH₂-(2,3-diCl)Ph, R¹ = OH;

R²= O(CH₂)₅CO-(4-Cl)Ph, R¹ = OH;

R²= OCH(CH₃)Ph, R¹ = OH;

R²= O(CH₂)₃Ph, R¹ = OH;

R²= O(CH₂)₈Ph, R¹ = OH;

R²= O(CH₂)₆-(4-Br)Ph, R ¹ = OH;

R²= O(CH₂)₆Ph, R¹ = OH;

R²= O(CH₂)₆-(4-Cl)Ph, R¹ = OH:

R²= O(CH₂)₆-(4-C₄H₉)Ph, R¹ = OH;

R²= O(CH₂)₆-(2,4-diCl)Ph, R¹ = OH;

R²= O(CH₂)₆-(2,4-diCH₃)Ph, R¹ = OH;

R²= O(CH₂)₅-(2,4-diCl)Ph, R^J = OH;

R²= O(CH₂)₄-(4-CH₃)Ph, R¹ = OH;

R²= O(CH₂)₄-(4-OCH₃)Ph, R¹ = OH;

R²= O(CH₂)₄-(4-Ph)Ph, R¹ = OH;

R²= O(CH₂)₆-(4-OH)Ph, R¹ = OH;

R²= O(CH₂)₆-(4-OCH₃)Ph, R¹ = OH;

R²= O(CH₂)₆S-(4-OH)Ph, R¹ = OH;

R²= O(CH₂)₅S-(4-OH,3,5-di-tert-butyl)Ph, R¹ = OH; R²= O(CH₂)₅SPh, R¹ = OH;

R²= OCH(C₅H_{1 1} )Ph, R¹ = OH;

R²= NH(CH₂)₆Ph, R¹ = OH;

R²= NH(CH₂)₆-(4-F)Ph, R¹ = OH;

R²= N(CH₃)(CH₂)₆-(4-F)Ph, R¹ = OH;

R²= N(CH₃)(CH₂)₆- (4-C₄H₉)Ph, R¹ = OH;

R²= N(CH₃)CH₂Ph, R¹ = OH;

R²= NH(CH₂)₄Ph, R¹ = OH;

R²= NHCH₂Ph, R¹ = OH;

R²= NHO(CH₂)₆-(4-C₄H₉)Ph, R¹ = OH;

R²= NHOCH₂Ph, R¹ = OH;

R²= NHO(CH₂)₅Ph, R¹ = OH;

R²= NH-(4-CH₃)Ph, R¹ = OH; R²= NHCH₂COPh, R¹ = OH;

R²= OCH₃, R¹ = ( 3H;

R²= O(CH₂)₆Ph, R¹ = OCOCH₃;

R²= OCH₂-(4-NO₂)Ph, R¹ = OCO-(4-Ph)Ph; R²= O(CH₂)₆-(4-Br)Ph, R¹ = OCOCH₃;

R²= O(CH₂)₆-(4-Br)Ph, R¹ = OCO-(4-Ph)Ph;

R²= O(CH₂)₆-(4-C₄H₉)Ph, R¹ = OCOCH₃;

R²= O(CH₂)₆-(4-C₄H₉)Ph, R¹ = OCOPh;

R²= O(CH₂)₆-(4-Cl)Ph, R¹ = OCOCH₃; R²= OCH₂-(2,4-diCl)Ph, R¹ = OCOPh;

R²= OCH₂-(2,4-diCl)Ph, R¹= OCOCH₃;

R²= OCH₂Ph, R¹ = OCOCH₃;

R²= OCH₂Ph, R¹ = OCO-(4-Ph)Ph;

R= OCH₂Ph, R¹ = OCOPh:

R²= OCH₂Ph, R¹ = OCO(CH₂)₂Ph;

R²= OCH₂Ph, R¹ = OCOCH₂Ph;

R²= OCH₂Ph, R¹ = OCO(CH₂)₄CH₃;

R²= OCH₂Ph, R¹ = OCO(CH₂)₈CH=CH₂;

R²= OCH₂Ph, R¹ = OCO-(1-adamantyl); R²= OCH₂Ph, R¹ = OCOCH₂-(2-thienyl);

R²= OCH₂Ph, R¹ = OCO(CH₂)₂CO₂Et;

R= OCH₂Ph, R¹ = OCO-(4-CN)Ph;

R² = OCH₂Ph, R¹ = OCO-(4-NO₂)Ph;

R²= OCH₂Ph, R¹ = OCOCH(Ph)₂;

R²= OCH₂Ph, R¹ = OCO(CH₂)₇CH₃;

R²= OCH₂Ph, R¹ = OCO(CH₂)₂-C₅H₉;

R²= OCH₂Ph, R¹ = OCO-(CH₂)₅Ph;

R²= OCH₂Ph, R¹ = OCO-(1 -naphthyl);

R²= = OCH₂Ph, R¹ = OCOC₆H_n;

R²= = OCH₂Ph, R¹ = OCO(4-CH₂Ph)Ph;

R²= = OCH₂Ph, R¹ = OCO(4-O-Ph)Ph;

R²= = NH(CH₂)₆Ph, R¹ = OCOCH₃;

R²= = (CH₂)₆-(4-OCH₃)Ph, R¹ = OCOCH₃;

R²= = NHO(CH₂)₅Ph, R¹ = OCOCH₃;

R²= = NH(CH₂)₆-(4-F)Ph, R¹ = OCOCH₃;

R²= = N(CH₃)(CH₂)₆-(4-F)Ph, R¹ = OCOCH₃; R²= O(CH₂)₅CO-(4-Cl)Ph, R¹ = OCOCH₃;

R²= O(CH₂)₆-(4-F)Ph, R¹ = OCOCH₃;

R²= O(CH₂)₆-(4-Cl)Ph, R¹ = OCOCHCl₂;

R²= OCH₂-(3,4-diCl)Ph, R¹ = OCOPh;

R²= OCH₂-(3.4-diCl)Ph, R¹ = OCOCH₃;

R²= N(CH₃)(CH₂)₆-(4-C₄H₉)Ph, R¹ = OCOPh:

R²= NHO(CH₂)₆-(4-C₄H₉)Ph, R¹ = OCOCH₃;

R²= N(CH₃)(CH₂)₆-(4-C₄H₉)Ph, R¹ = OCOCH₃;

R²= OCH₂Ph, R¹ = OCOCHCl₂;

R²= N(OH)(CH₂)₆-(4-F)Ph, R¹ = OCOCH₃ ;

R²= N(OCOCH₃)(CH₂)₆-(4-F)Ph, R¹ = OCOCH₃;

R²= N(OCOCH₃)(CH₂)₆-(4-C₄H₉)Ph, R¹ = OCOCH₃;

R²= NHO(CH₂)₆Ph, R¹ = OCOCH₃;

R²= O(CH₂)₆-(4-F)Ph, R¹= OCHO;

R² = O(CH₂)₆Ph, R¹ = N(CH₃)CH₂Ph;

R² = O(CH₂)₆-(4-F)Ph, R¹ = NHCHO;

R² = O(CH₂)₆Ph, R¹ = NHCHO;

R² = O(CH₂)₆Ph, R¹ = NHCOCH₃;

R² = O(CH₂)₆-(4-F)Ph, R¹ = NHCOCH₃;

R² = O(CH₂)₆-(4-Cl)Ph, R¹ = NHCOCH₃ ;

R² = O(CH₂)₆-(4-C₄H₉)Ph, R¹ = NHCOCH₃;

R² = OCH₂Ph, R¹ = NHCOCH₃;

R² = OCH₂Ph, R¹ = NHCOPh:

R² = OCH₂Ph, R¹ = NHCOPh:

R² = O(CH₂)₆-(4-C₄H₉)Ph, R¹ = NHCOPh;

R² = NH(CH₂)₆Ph, R¹ = NHCOCH₃;

R² = NHO(CH₂)₅Ph, NHCOCH₃;

R² = OCH₂-(2,4-diCl)Ph, R¹ = NHCOCH₂NHCOCH₃;

R² = OCH₂-(2,4-diCl)Ph, R¹ = NHCOCH₂NHCOCH₃; R² = OCH₂Ph, R¹ = NHCOCH₃;

R² = O(CH₂)₆-(4-C₄H₉)Ph, R¹ = NHCOCH₃;

R² = OCH₂Ph, R¹ = NHCOCH₂NHCOCH₃;

R² = OCH₂Ph, R¹ = NHCOCH₂NHCOCH₃;

R² = OCH₂Ph, R¹ = NHCO₂CH₂Ph;

R² = OCH₂-(4-Br)Ph, R ¹ = NHCOCH₃ ;

R² = OCH₂Ph, R¹ = O(CH₂)₂OH: R² = OCH₂Ph, R¹ = N₃;

R² = OCH₂Ph, R¹ = O(CH₂)₅CH₃;

R² = OCH₂Ph, R¹ = OCH₃;

R² = OCH₂Ph, R¹ = OTHP;

R² = OCH₃, R¹ = OCH₃;

R² = OCH₂-(4-NO₂)Ph, R¹ = OTHP:

R² = OCH₂Ph, R¹ = OCH₂CO₂Et;

R² = O(CH₂)₆-(4-C₄H₉)Ph, R¹ = SCH₃;

R² = O(CH₂)₆-(4-C₄H₉)Ph, R¹ = SOCH₃;

R² = O(CH₂)₆-(4-C₄H₉)Ph, R¹ = SO₂CH₃ ;

R² = O(CH₂)₆Ph, R¹ = SCH₃;

R² = O(CH₂)₆Ph, R¹ = SO₂CH₃;

R² = O(CH₂)₆-(4-Br)Ph, R¹ = SO₂CH₃;

R² = OCH₂Ph, R¹ = SPh;

OCH₂-(2,4-diCl)Ph, R¹ = SCH₂Ph;

R² = OCH₂-(2,4-diCl)Ph, R¹ = SOCH₂Ph;

R² = OCH₂-(2,4-diCl)Ph, R¹ = SO₂CH₂Ph;

R² = OCH₂Ph, R¹ = S(CH₂)₅CH3;

R² = OCH₂Ph, R¹ = SO₂(CH₂)₅CH₃;

R² = OCH₂Ph, R¹ = SCH₂Ph;

R² = OCH₂Ph, R¹ = SOCH₂Ph;

R² = OCH₂Ph, R¹ = SO₂CH₂Ph;

R² = O(CH₂)₆-Ph, R¹ = NHCOPh; and

R² = O(CH₂)₆-Ph, R¹ = NHCOCH₃

16. A pharmaceutical composition comprising a compound according to any one of the preceding claims and a pharmaceutically acceptable carrier.

17. A compound according to claim 1 for use in therapy.

18. The use of a compound of structure (I) as defined in claim 1 in the manufacture of a medicament for treating as defined in claim 1 in the manufacture of a medicament for treating atherosclerosis.

19. The use of a compound of structure (I) as defined in claim 1 in the manufacture of a medicament for treating diabetes, hypertension, angina pectoris, after ischaemia. reperfusion. rheumatoid arthritis, stroke, myocardial infarction, reperfusion injury, sepsis, and acute and chronic inflammation, inflammatory conditions of the brain such as Alzheimer's Disease, neuropsychiatric disorders such as schizophrenia, and psoriasis.