CN105777464B

CN105777464B - Hydroxamic acid derivative and preparation method and application thereof

Info

Publication number: CN105777464B
Application number: CN201410855187.3A
Authority: CN
Inventors: 杨玉社; 丁实
Original assignee: Shanghai Institute of Materia Medica of CAS
Current assignee: Shanghai Institute of Materia Medica of CAS
Priority date: 2014-12-26
Filing date: 2014-12-26
Publication date: 2020-09-29
Anticipated expiration: 2034-12-26
Also published as: CN105777464A

Abstract

The invention discloses a hydroxamic acid derivative, a preparation method and application thereof₁M, n, X and R₂Is defined as described in the specification and claims. The hydroxamic acid derivative can inhibit the activity of LpxC deacetylase, has antibacterial activity, can particularly inhibit gram-negative bacteria, and is particularly suitable for preparing medicaments for preventing and/or treating related diseases caused by the gram-negative bacteria.

Description

Hydroxamic acid derivative and preparation method and application thereof

Technical Field

The present invention belongs to the field of pharmaceutical compounds. In particular, the invention relates to a novel class of hydroxamic acid derivatives, or enantiomers, diastereomers, racemates or mixtures thereof, and pharmaceutically acceptable salts thereof, as well as methods for the preparation of the compounds and the use of the compounds as biologically active substances for the preparation of medicaments.

Background

With the wide use of antibacterial drugs, a large number of drug-resistant bacteria appear clinically, and the problem of bacterial drug resistance becomes an important problem threatening the public health of human beings. For gram-negative bacterial infections, in particular diseases caused by escherichia coli (e.coli), pseudomonas aeruginosa (p.aeruginosa) and acinetobacter baumannii (a.baumann ni), therapeutic drugs are very limited.

The outer layer of the gram-negative bacterial cell membrane is composed of Lipopolysaccharide (LPS) and serves as a permeation barrier to prevent antibiotics from entering the interior of the bacteria. Biological studies have shown that lipopolysaccharides are critical for bacterial cell growth and play an important role in The folding of membrane proteins [ The Journal of Biological Chemistry,274(8),1999, 5114-. Each lipopolysaccharide molecule is composed of three major components, an O-type antigen, a core polysaccharide, and a lipid A. Wherein Lipid A is a link connecting lipopolysaccharide with the outer membrane, and is a key structure for maintaining the stability of cell membrane [ J Lipid Res,46 (5); 2005,839-861 ]. The lipid a is synthesized in the cytoplasm on the inner surface of the inner membrane catalyzed by nine specific highly conserved biological enzymes. The first step is acylation of UDP-glucose fatty acid, which is a one-step reversible reaction. The second step is the deacetylation catalyzed by LpxC [ UDP-3-O- (R-3-hydroxymyristoyl) -N-acetylglucosamine deacetylase ] which is the rate-controlling step for biosynthesis of lipid A. If the activity of LpxC deacetylase can be inhibited, the synthesis of lipoid A can be blocked, so that the integrity of bacterial lipopolysaccharide is damaged, and the bacteria die.

LpxC deacetylase is a zinc ion protease, which is lethal to bacteria by increasing or decreasing its content, and is widely present in gram-negative bacteria, has no sequence in common with mammalian protein components, and is not liable to cause side effects. These advantages make it an important target for new anti-gram-negative drugs.

The literature reports various LpxC inhibitors [ Current Medicinal Chemistry,2012,19,2038-2050], most of which have good in vitro antibacterial activity, but few compounds enter clinical research due to poor druggability. Only ACHN-975 by Achaogen entered the first-phase clinic in 2012, but ended the study in 2013 due to injection site problems at the time of administration by injection [ Bioorganic & Medicinal Chemistry Letters 24(2014) 3683-3689 ].

Disclosure of Invention

The invention aims to provide an LpxC inhibitor.

In a first aspect of the invention, there is provided a compound of formula I, an enantiomer, diastereomer, racemate, or mixture thereof, or a pharmaceutically acceptable salt thereof,

in the formula, R₁Is unsubstituted or substituted C₁-C₆Alkyl, said substitution being with a substituent selected from the group consisting of: hydroxyl, amino, halogen, nitro, cyano, mercapto;

m is an integer of 0-2 and is 0, 1 or 2;

n is an integer of 0 to 1;

x is-O-, -S-, -NH-, -NHCO-or-CONH-;

R₂is substituted C₁-C₆Alkyl, said substitution being with a substituent selected from the group consisting of: hydroxy, mercapto, nitro, cyano, -SO₂(halo C)₁-C₃Alkyl), -SO₂(C₁-C₃Alkyl), -CONHOH,

With the proviso that the compound of formula I is not:

4,4' - (1, 3-diacetylene-1, 4-diyl) bis [ N- [ (1S,2R) -2-hydroxy-1- [ (hydroxyamino) acyl ] propyl ] benzamide;

n- [ (1S,2R) -2-hydroxy-1- [ (hydroxyamino) acyl ] propyl ] -N ' - [ (1R,2R) -2-hydroxy-1- [ (hydroxyamino) acyl ] propyl ] - [1,1' -biphenyl ] -4,4' -dicarboxamide;

n- [ (1S) -1- (aminomethyl) -2- (hydroxyamino) -2-oxoethyl ] -4- [2- [4- [2- (hydroxyamino) -2-oxoethoxy ] phenyl ] ethynyl ] -benzamide.

In another preferred embodiment, R₁M, n, X and R₂With the proviso that when X is-CONH-or-NHCO-, R is as defined above₂When the substituent group has two substituent groups, the substituent groups are not hydroxyl and-CONHOH; when X is-O-, R₂The substituent(s) is not-CONHOH.

In another preferred embodiment, the substitution is mono-or poly-substitution. In another preferred embodiment, the substitution is mono-, di-, tri-, or tetra-substitution. In another preferred embodiment, the polysubstituted, disubstituted, trisubstituted or tetrasubstituted radicals are the same or different substituents.

In another preferred embodiment, C₁-C₆The alkyl group has 1,2, 3 or 4 substituents thereon.

In another preferred embodiment, the configuration of each chiral carbon atom in the compound of formula I is independently R-type or S-type.

In another preferred embodiment, R₁Is hydroxy or amino substituted C₁-C₄An alkyl group.

In another preferred embodiment, R₂Is substituted C₁-C₆Alkyl, said substitution being with a substituent selected from the group consisting of: hydroxy, -SO₂CH₃、-SO₂CF₃、-CONHOH、

In another preferred embodiment, R₂Is substituted C₁-C₄Alkyl radical, wherein C₁-C₄The substituents on the alkyl group are selected from: hydroxy, -SO₂CH₃、-SO₂CF₃、-CONHOH、

In another preferred embodiment, the compound of formula I is any one of compounds 1-20 prepared in the examples.

In another preferred embodiment, the pharmaceutically acceptable salt is a hydrochloride, hydrobromide, sulfate, nitrate, phosphate, citrate, methanesulfonate, trifluoroacetate, acetate, oxalate, succinate, malate, tosylate, tartrate, fumarate, glutamate, glucuronate, lactate, glutarate, arginate or maleate.

In a second aspect of the invention, there is provided a process for the preparation of a compound of formula I as described in the first aspect, m is 1 or 2; when n is 1, the method comprises the following steps:

(a) condensing the compound of formula I-1 with the compound of formula I-2 to obtain a compound of formula I-3;

(b) reacting the compound of formula I-3 with the compound of formula I-4 to obtain a compound of formula I-5;

(c) reacting the compound of formula I-5 with hydroxylamine to obtain a compound of formula I,

in each formula, X is as defined above,

m is 0; when n is 0 or 1 and X is-O-or-S-, the method comprises the following steps:

(i) condensing the compound of formula II-1 with the compound of formula II-2 to obtain a compound of formula II-3, wherein q is 1 or 2;

(ii) compounds of formula II-3 with R₂OH reacting to obtain a compound shown in a formula II-4;

(iii) reacting the compound of formula II-4 with hydroxylamine to obtain a compound of formula I,

in the formulae, R₁Is protected or unprotected, unsubstituted or substituted C₁-C₆An alkyl group;

R₂is substituted by C, protected or unprotected₁-C₆An alkyl group;

y is ethynyl or halogen;

each said substitution independently refers to substitution by a group selected from the group consisting of: hydroxy, amino, halogen, nitro, cyano, -SO₂CH₃、-CONHOH、

And when R is₁Is protected, unsubstituted or substituted C₁-C₆Alkyl and/or R₂Being substituted by protected C₁-C₆When alkyl, the process further comprises the step of removing a protecting group selected from: tert-butyloxycarbonyl, p-methoxybenzyl, benzhydryl, benzyl, tert-butyldimethylSilyl, tert-butyl diphenyl silyl, allyl, methoxymethyl, methylthiomethyl, methoxyethoxymethyl and benzyloxymethyl.

In another preferred embodiment, R₁Is protected, unsubstituted or substituted C₁-C₆And during alkyl, the compound shown in the formula II-4 is subjected to protection group removal and then reacts with hydroxylamine to obtain the compound shown in the formula I.

In another preferred embodiment, R₂Being substituted by protected C₁-C₆And in the alkyl process, the compound shown in the formula II-4 reacts with hydroxylamine, and then the protecting group is removed to obtain the compound shown in the formula I.

In a third aspect of the present invention, there is provided a pharmaceutical composition comprising:

a compound of formula I according to the first aspect, enantiomers, diastereomers, racemates or mixtures thereof, or a pharmaceutically acceptable salt thereof; and

a pharmaceutically acceptable carrier.

In a fourth aspect of the invention, there is provided the use of a compound of formula I according to the first aspect or a pharmaceutical composition according to the third aspect for:

(1) preparing a medicament for inhibiting LpxC deacetylase;

(2) preparing a medicament for the prevention and/or treatment of bacterial infections;

(3) preparing a medicament for inhibiting bacterial growth;

(4) LpxC deacetylase inhibitors.

In another preferred embodiment, the bacterium is a gram-negative bacterium.

In another preferred embodiment, the gram-negative bacteria are selected from the group consisting of: escherichia coli, Pseudomonas aeruginosa and Acinetobacter baumannii.

In a fifth aspect of the invention, there is provided a method of reducing the pathogenicity or toxicity of a bacterium, comprising the steps of:

contacting a bacterium with a compound of formula I according to the first aspect 1 or a pharmaceutical composition according to the third aspect, thereby reducing the pathogenicity or toxicity of the bacterium.

In another preferred embodiment, the bacterium is a gram-negative bacterium.

In another preferred embodiment, the method is a non-therapeutic method.

In another preferred embodiment, the method is a therapeutic method.

In another preferred embodiment, said contacting results in an increase or decrease of the content of LpxC deacetylase in the bacterium.

In a sixth aspect of the invention, there is provided a method of inhibiting LpxC deacetylase by administering to a subject in need thereof or to the environment a safe and effective amount of a compound of formula I or a pharmaceutical composition according to the third aspect.

In a seventh aspect of the invention, there is provided an antibacterial method of administering to a subject in need thereof or to the environment a safe and effective amount of a compound of formula I or a pharmaceutical composition according to the third aspect.

In an eighth aspect of the invention, there is provided a method for treating a bacterial infection comprising the steps of: administering to a subject infected with a bacterium a safe and effective amount of a compound of formula I or a pharmaceutical composition of the third aspect.

In another preferred embodiment, the compound of formula I or the pharmaceutical composition of the third aspect is contacted with the bacteria and allowed to act for a period of time, thereby reducing the pathogenicity and/or toxicity of the bacteria.

In the present invention, the subject in need thereof includes a human or non-human mammal, preferably, a human, a mouse or a rat.

In the present invention, the mode of administration to the subject is not particularly limited, and includes, but is not limited to, oral administration, injection, inhalation, and topical application.

In the present invention, the "safe and effective amount" means: the amount of active ingredient (compound of formula I) is sufficient to significantly improve the condition without causing serious side effects.

The hydroxamic acid derivative can inhibit the activity of LpxC deacetylase, has bacteriostatic activity, can inhibit gram-negative bacteria, and is particularly suitable for preparing medicaments for preventing and/or treating related diseases caused by bacteria, particularly gram-negative bacteria.

It is to be understood that within the scope of the present invention, the above-described features of the present invention and those specifically described below (e.g., in the examples) may be combined with each other to form new or preferred embodiments. For reasons of space, they will not be described in detail.

Detailed Description

The present inventors have conducted extensive and intensive studies and, for the first time, have developed an LpxC deacetylase inhibitor having a novel structure, which is a hydroxamic acid derivative. The hydroxamic acid derivative has bacteriostatic activity, and can inhibit gram-negative bacteria. On the basis of this, the present invention has been completed.

Hydroxamic acid derivatives

In the present invention, the hydroxamic acid derivatives, the compounds of formula I and the compounds of formula I have the same meaning and all refer to compounds having the following structure:

wherein R is₁M, n, X and R₂As defined above.

In the present invention, the term "C₁-C₆Alkyl "means a straight or branched chain alkyl group having 1 to 6 carbon atoms, including, without limitation, methyl, ethyl, propyl, isopropyl, butyl, and the like. In the present invention, the term "halogen" refers to fluorine, chlorine, bromine, iodine.

Preparation method

The compound of the present invention can be prepared by the following method, however, the conditions of the method, such as reactants, solvent, acid, base, amount of the compound used, reaction temperature, reaction time, etc., are not limited to the following description. The compounds of the present invention may also be conveniently prepared by optionally combining various synthetic methods described in the present specification or known to those skilled in the art, which combinations may be readily performed by those skilled in the art.

Route one: m is 1 or 2; when n is 1, the method comprises the following steps:

and a second route: m is 0; when n is 0 or 1, the method comprises the following steps:

in the formulae (III), (III) X, R₁、R₂Y, m, n are as defined above.

In a preferred embodiment, the compound of formula I-1 is reacted in a polar solvent with the compound of formula I-2 in the presence of a condensing agent and an organic base at room temperature for 4-16 hours to give the compound of formula I-3. The condensing agent can be 2- (7-azobenzotriazol) -N, N, N ', N' -tetramethylurea Hexafluorophosphate (HATU), 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride (EDCI) and 1-Hydroxybenzotriazole (HOBT). The organic base can be triethylamine and diisopropylethylamine; the polar solvent may be dichloromethane, N-dimethylformamide.

In a preferred embodiment, the compound of formula I-3 and the compound of formula I-4 (Y is ethynyl) are reacted in a mixed solvent under basic conditions under the catalysis of a metal-containing copper catalyst and under the protection of inert gas at room temperature to 40 ℃ for 12-24 hours to obtain the compound of formula I-4. The metal-containing copper catalyst can be copper acetate, and the mixed solvent under alkaline conditions can be a mixed solvent of pyridine and methanol.

In a preferred embodiment, the compound of formula I-3 is reacted with the compound of formula I-4 (Y is halogen) in an inert gas atmosphere at room temperature to 40 ℃ for 2-12 hours in a basic condition and a polar aprotic solvent under the catalysis of a metal-containing palladium catalyst to obtain the compound of formula I-5. The metal-containing palladium catalyst may be bis (triphenylphosphine) palladium dichloride and cuprous iodide. The alkali used in the alkaline condition can be: triethylamine, diisopropylethylamine and pyridine. The polar aprotic solvent may be: 1, 4-dioxane, dimethylformamide and tetrahydrofuran. The inert gas may be nitrogen or argon.

In a preferred embodiment, the compound of formula II-1 is reacted with the compound of formula II-2 in a polar solvent in the presence of a condensing agent and an organic base at room temperature for 4-16 hours to provide the compound of formula II-3. The condensing agent can be 2- (7-azobenzotriazol) -N, N, N ', N' -tetramethylurea Hexafluorophosphate (HATU), 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride (EDCI) and 1-Hydroxybenzotriazole (HOBT). The organic base can be triethylamine and diisopropylethylamine; the polar solvent may be dichloromethane, N-dimethylformamide.

In a preferred embodiment, the compound of formula II-3 is reacted with R in a polar solvent₂And reacting OH in the presence of diethyl azodicarboxylate (DEAD) and triphenylphosphine at room temperature for 0.5-2 hours to obtain the compound of formula II-4. The polar solvent may be tetrahydrofuran, N-dimethylformamide.

In a preferred embodiment, a compound of formula I-5 or a compound of formula II-4 is reacted with an aqueous solution (e.g., 50%) of hydroxylamine in a polar solvent at room temperature to 40 ℃ for 3-18 hours to provide a compound of formula I. The polar solvent may be a mixed solution of methanol and dichloromethane. In a preferred embodiment, part of the compound is not deprotected and the final product is obtained directly after replacement of the methyl ester with hydroxylamine.

In a preferred embodiment, R₂Compounds of formula I-5 or R with protecting groups₂Reacting the product obtained by reacting the compound of formula II-4 with the protecting group with hydroxylamine in an acid solvent at room temperature for 3-12 hours, and removing the protecting group to obtain the compound of formula I. The acidic solvent may be a mixed solution of trifluoroacetic acid and dichloromethane.

In a preferred embodiment, R₁Compounds of formula I-5 having a protecting group (e.g. tert-butyloxycarbonyl) or R₁After the compound of formula II-4 with protecting group (such as tert-butyloxycarbonyl group) is deprotected in acidic solvent, it is reacted with hydroxylamine aqueous solution (such as 50%) in polar solvent at room temperature to 40 deg.C for 3-18 hours,to obtain the compound of formula I. The acidic solvent may be a1, 4-dioxane solution of hydrogen chloride or an ethyl acetate solution. The polar solvent may be a mixed solution of methanol and dichloromethane.

Pharmaceutical composition

The compound shown in the formula I can inhibit the activity of LpxC deacetylase, has antibacterial activity, and can particularly inhibit gram-negative bacteria.

The invention provides a pharmaceutical composition comprising a compound of formula I or a pharmaceutically acceptable salt thereof as an active ingredient; and a pharmaceutically acceptable carrier.

Typically, the pharmaceutical composition contains 1-2000mg of active ingredient per dose, more preferably, 10-200mg of active ingredient per dose. Preferably, said "dose" is a tablet.

"pharmaceutically acceptable carrier" refers to: one or more compatible solid or liquid fillers or gel substances which are suitable for human use and must be of sufficient purity and sufficiently low toxicity. By "compatible" is meant herein that the components of the composition are capable of being combined with the active ingredients of the present invention and with each other without significantly diminishing the efficacy of the active ingredient. Examples of pharmaceutically acceptable carrier moieties are cellulose and its derivatives (e.g. sodium carboxymethylcellulose, sodium ethylcellulose, cellulose acetate, etc.), gelatin, talc, solid lubricants (e.g. stearic acid, magnesium stearate), calcium sulfate, vegetable oils (e.g. soybean oil, sesame oil, peanut oil, olive oil, etc.), polyols (e.g. propylene glycol, glycerol, mannitol, sorbitol, etc.), emulsifiers (e.g. tween, etc.)

) Wetting agents (e.g., sodium lauryl sulfate), coloring agents, flavoring agents, stabilizers, antioxidants, preservatives, pyrogen-free water, and the like.

The mode of administration of the active ingredient or pharmaceutical composition of the present invention is not particularly limited, and representative modes of administration include (but are not limited to): oral, intratumoral, rectal, parenteral (intravenous, intramuscular or subcutaneous), and the like.

Solid dosage forms for oral administration include capsules, tablets, pills, powders and granules.

In these solid dosage forms, the active ingredient is mixed with at least one conventional inert excipient (or carrier), such as sodium citrate or dicalcium phosphate, or with the following: (a) fillers or extenders, for example, starch, lactose, sucrose, glucose, mannitol and silicic acid; (b) binders, for example, hydroxymethylcellulose, alginates, gelatin, polyvinylpyrrolidone, sucrose and acacia; (c) humectants, for example, glycerol; (d) disintegrating agents, for example, agar-agar, calcium carbonate, potato or tapioca starch, alginic acid, certain complex silicates, and sodium carbonate; (e) slow solvents, such as paraffin; (f) absorption accelerators, e.g., quaternary ammonium compounds; (g) wetting agents, such as cetyl alcohol and glycerol monostearate; (h) adsorbents, for example, kaolin; and (i) lubricants, for example, talc, calcium stearate, magnesium stearate, solid polyethylene glycols, sodium lauryl sulfate, or mixtures thereof. In capsules, tablets and pills, the dosage forms may also comprise buffering agents.

The solid dosage forms may also be prepared using coatings and shells, such as enteric coatings and other materials well known in the art. They may contain opacifying agents and the release of the active ingredient in such compositions may be delayed in a certain portion of the digestive tract. Examples of embedding components which can be used are polymeric substances and wax-like substances.

Liquid dosage forms for oral administration include pharmaceutically acceptable emulsions, solutions, suspensions, syrups or tinctures. In addition to the active ingredient, the liquid dosage forms may contain inert diluents commonly employed in the art such as, for example, water or other solvents, solubilizing agents and emulsifiers such as ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, propylene glycol, 1, 3-butylene glycol, dimethylformamide and oils, especially cottonseed, groundnut, corn germ, olive, castor and sesame oils or mixtures of such materials and the like. In addition to these inert diluents, the compositions can also contain adjuvants such as wetting agents, emulsifying and suspending agents, sweetening, flavoring, and perfuming agents.

Suspensions, in addition to the active ingredients, may contain suspending agents as, for example, ethoxylated isostearyl alcohols, polyoxyethylene sorbitol and sorbitan esters, microcrystalline cellulose, aluminum methoxide and agar, or mixtures of these materials, and the like.

Compositions for parenteral injection may comprise physiologically acceptable sterile aqueous or anhydrous solutions, dispersions, suspensions or emulsions, and sterile powders for reconstitution into sterile injectable solutions or dispersions. Suitable aqueous and nonaqueous carriers, diluents, solvents or vehicles include water, ethanol, polyols and suitable mixtures thereof.

The compounds of the present invention may be administered alone or in combination with other therapeutic agents.

When the pharmaceutical composition is used, a safe and effective amount of the compound of formula I of the present invention is suitable for mammals (such as human beings) to be treated, wherein the administration dose is a pharmaceutically-considered effective administration dose, and for a human body with a weight of 60kg, the daily administration dose is usually 1-2000mg, preferably 20-500 mg. Of course, the particular dosage will depend upon such factors as the route of administration, the health of the patient, and the like, and is within the skill of the skilled practitioner.

The features mentioned above with reference to the invention, or the features mentioned with reference to the embodiments, can be combined arbitrarily. All the features disclosed in this specification may be combined in any combination, and each feature disclosed in this specification may be replaced by alternative features serving the same, equivalent or similar purpose. Thus, unless expressly stated otherwise, the features disclosed are merely generic examples of equivalent or similar features.

The invention has the advantages that:

(1) the present invention provides hydroxamic acid derivatives having a novel structure.

(2) The invention provides a preparation method of hydroxamic acid derivatives, which has simple and efficient process.

(3) The invention discovers the new application of the hydroxamic acid derivative for the first time, and can be used for preparing antibacterial drugs, in particular for preparing drugs for inhibiting gram-negative bacteria.

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Experimental procedures without specific conditions noted in the following examples, molecular cloning is generally performed according to conventional conditions such as Sambrook et al: the conditions described in the laboratory Manual (New York: Cold Spring Harbor laboratory Press,1989), or according to the manufacturer's recommendations. Unless otherwise indicated, percentages and parts are by weight.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In addition, any methods and materials similar or equivalent to those described herein can be used in the methods of the present invention. The preferred embodiments and materials described herein are intended to be exemplary only.

In all of the embodiments described herein, the first,¹H-NMR was recorded using a Varian Mercury 300 or AVANCEIII 400 nuclear magnetic resonance apparatus, chemical shifts are expressed in (ppm); the silica gel for separation is 200-300 mesh, and the ratio of the eluent is volume ratio.

Preparation examples

Example 1: preparation of N- ((2S,3R) -3-hydroxy-1- (hydroxyamino) -1-oxybutan-2-yl) -4- ((4- (3- (methylsulfonyl) propoxy) phenyl) 1, 3-butadiynyl-) aniline (compound 1)

(a) 1-iodo-4- (3- (methylsulfonyl) propoxy) benzene

Under the protection of argon, 3-methylsulfonylpropanol (200mg, 1.447mmol) and 4-iodophenol (382mg, 1.737mmol) were dissolved in 10ml of anhydrous tetrahydrofuran, triphenylphosphine (569mg, 2.171mmol) and diethyl azodicarboxylate (378mg, 2.171mmol) were added sequentially with stirring at 0 ℃ for 1h, TLC (PE/EA ═ 2/1) detected that the starting material had reacted, the solution was spin-dried, and column chromatography (PE/EA ═ 5/1-2/1) was performed to obtain 400mg of a white solid with a yield of 81.3%.

¹H NMR(400MHz,Chloroform-d)7.56(d,J＝9.1Hz,2H),6.66(d,J＝9.0Hz,2H),4.08(t,J＝5.8Hz,2H),3.28-3.18(m,2H),2.95(s,3H),2.40–2.28(m,2H).

MS(ESI)m/z:[(M+Na)⁺,263.0].

(b) Trimethyl ((4- (3- (methylsulfonyl) propoxy) phenyl) ethynyl) silane

The compound 1-iodo-4- (3- (methylsulfonyl) propoxy) benzene (400mg, 1.176mmol) prepared in the above (a) and trimethylsilyl acetylene (173mg, 1.765mmol) were dissolved in 10ml of anhydrous tetrahydrofuran under an argon shield, and Ph (PPh) was added₃)₂Cl₂(42mg, 0.059mmol) and CuI (12mg, 0.059mmol), Et₃N (238mg, 2.352mmol), stirred at room temperature for 12 h. TLC (PE/EA: 2/1) detection of disappearance of starting material, solvent spin-dried, and after redissolving with ethyl acetate, washed with saturated aqueous ammonium chloride and saturated aqueous sodium chloride, and dried over anhydrous sodium sulfate. The anhydrous sodium sulfate was removed by filtration, and the solution was subjected to spin-dry column chromatography (PE/EA ═ 5/1-2/1) to give 330mg of a yellow solid in a yield of 90.5%.

¹H NMR(400MHz,Chloroform-d)7.40(d,J＝8.7Hz,2H),6.80(d,J＝8.8Hz,2H),4.11(t,J＝5.8Hz,2H),3.31-3.16(m,2H),2.95(s,3H),2.35(dq,J＝11.4,6.0Hz,2H),0.23(s,9H).

MS(ESI)m/z:[(M+Cl)^-,344.8].

(c) 1-ethynyl-4- (3- (methylsulfonyl) propoxy) benzene

The compound trimethyl ((4- (3- (methylsulfonyl) propoxy) phenyl) ethynyl) silane (330mg, 1.063mmol) prepared in (b) above was dissolved in 10ml of anhydrous tetrahydrofuran, cooled to 0 ℃, tetra-n-butylammonium fluoride (1M,1.3ml) was slowly added, warmed to room temperature, reacted for 1h, monitored by TLC (PE/EA ═ 2/1), and after completion of the reaction, 10ml of water and 30ml of ethyl acetate were added, and the ethyl acetate layer was separated, washed with saturated aqueous sodium chloride solution, and dried over anhydrous sodium sulfate. The anhydrous sodium sulfate was removed by filtration, and the solution was subjected to spin-dry column chromatography (PE/EA ═ 5/1-2/1) to give 228mg of a white solid in a yield of 90.0%.

¹H NMR(400MHz,CDCl₃)7.43(d,J＝8.9Hz,2H),6.82(d,J＝8.9Hz,2H),4.12(t,J＝5.8Hz,2H),3.25(dd,J＝8.7,6.7Hz,2H),3.01(s,1H),2.96(s,3H),2.36(ddt,J＝11.6,7.6,5.7Hz,2H).MS(ESI)m/z:[(M+Na)⁺,263.0].

MS(ESI)m/z:[(M+Na)⁺,261.1].

(d) (2S,3R) -3-hydroxy-2- (4- ((4- (3- (methylsulfonyl) propoxy) phenyl) -1, 3-diacetylen-1-yl) benzoylamino) butyric acid methyl ester

The compound 1-ethynyl-4- (3- (methylsulfonyl) propoxy) benzene (228mg, 0.957mmol) prepared in the above (c) and (2S,3R) -2- (4-ethynylbenzamido) -3-hydroxybutyric acid methyl ester [ Bioorganic & medicinal chemistry 19(2011) 852-860 ] (500mg, 1.914mmol) were dissolved in a mixed solvent of 8ml of anhydrous methanol and 8ml of pyridine, copper acetate (348mg, 1.914mmol) was added under the protection of argon gas, the reaction was stirred at room temperature for 24 hours, TLC (PE/EA ═ 2/1) was monitored for the reaction, and after completion of the reaction, 40ml of ethyl acetate was added and dissolved, pyridine in the solvent was washed with diluted hydrochloric acid (1M), followed by washing with a saturated aqueous sodium chloride solution and drying with anhydrous sodium sulfate. Anhydrous sodium sulfate was removed by filtration, and the solution was subjected to spin-dry column chromatography (PE/EA ═ 5/1-2/1) to give 195mg of a white solid with a yield of 40.1%.

¹H NMR(400MHz,CDCl₃)7.84(d,J＝8.3Hz,2H),7.62(d,J＝8.4Hz,2H),7.51(d,J＝8.8Hz,2H),6.92(d,J＝8.8Hz,1H),6.87(d,J＝8.8Hz,2H),4.84(dd,J＝8.8,2.2Hz,1H),4.50(s,1H),4.16(t,J＝5.8Hz,2H),3.83(s,3H),3.38–3.22(m,2H),2.99(s,3H),2.39(dt,J＝15.5,5.9Hz,2H),1.32(d,J＝6.4Hz,3H).

MS(ESI)m/z:[(M+Na)⁺,520.1].

(e) N- ((2S,3R) -3-hydroxy-1- (hydroxyamino) -1-oxybutan-2-yl) -4- ((4- (3- (methylsulfonyl) propoxy) phenyl) 1, 3-butadiynyl-) aniline

The compound methyl (2S,3R) -3-hydroxy-2- (4- ((4- (3- (methylsulfonyl) propoxy) phenyl) -1, 3-diacetyl-1-yl) benzoylamino) butanoate prepared in the above (d) (195mg, 0.392mmol) was dissolved in a mixed solution of 5ml dichloromethane and 10ml methanol, 50% aqueous hydroxylamine solution (1ml) was added dropwise at 0 ℃, stirred at room temperature for 12 hours, TLC (CH)₂Cl₂MeOH 20/1) to detect the disappearance of the starting material. The solution was spin dried and the dichloromethane slurried three times to obtain a pure product as an off-white solid 98mg with a yield of 50.1%.

¹H NMR(400MHz,DMSO)10.70(s,1H),8.88(s,1H),8.22(d,J＝8.4Hz,1H),7.95(d,J＝8.4Hz,2H),7.71(d,J＝8.4Hz,2H),7.59(d,J＝8.8Hz,2H),7.02(d,J＝8.8Hz,2H),4.91(d,J＝6.4Hz,1H),4.25(dd,J＝8.4,5.6Hz,1H),4.15(t,J＝6.3Hz,2H),4.08–3.97(m,1H),3.31–3.26(m,2H),3.03(s,3H),2.20–2.11(m,2H),1.09(d,J＝6.3Hz,3H).

MS(ESI)m/z:[(M-H)^-,497.0].

Example 2: preparation of N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) -4- ((4- (((S) -3 hydroxy-1- (hydroxylamine) -1-propoxy-2-yl) carbamoyl) phenyl) -1, 3-butadiyn-1-yl) benzamide (Compound 2)

(a) (S) -3-hydroxy-2-amino-propionic acid methyl ester hydrochloride

L-threonine (1.0g, 9.443mmol) was suspended in 20ml methanol, thionyl chloride (1.3g, 10.86mmol) was added at 0 ℃, stirred at room temperature for 24h, and spin dried to give 1.47g of gum in 100% yield.

¹H NMR(400MHz,Deuterium Oxide)4.17(t,J＝3.7Hz,1H),4.00(dd,J＝12.6,4.2Hz,1H),3.89(dd,J＝12.3,3.2Hz,1H),3.75(s,3H).

(b) (S) -2- (4-ethynylbenzoyl) -3-hydroxybutyric acid methyl ester

The compound (S) -3-hydroxy-2-amino-propionic acid methyl ester hydrochloride (256mg, 1.642mmol) prepared in the above (a) and 4-ethynylbenzoic acid (200mg, 1.369mmol) were dissolved in 10ml of N, N-dimethylformamide under argon protection, and 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride (315mg, 1.642mmol), 1-hydroxybenzotriazole (222mg, 1.642mmol) and diisopropylethylamine (708mg, 5.476mmol) were added in this order at 0 ℃. Stirring at room temperature for 20h, and detecting by TLC that the reaction is finished (CH)₂Cl₂MeOH 20/1), 40ml of ethyl acetate was added, and the mixture was washed successively with a saturated aqueous ammonium chloride solution and a saturated aqueous sodium chloride solution and dried over anhydrous sodium sulfate. Filtering to remove anhydrous sodium sulfate, and performing rotary column Chromatography (CH)₂Cl₂MeOH 100/1-80/1) to give 165mg of yellow solid, 44.0% yield.

¹H NMR(400MHz,Chloroform-d)7.82(d,J＝8.0Hz,2H),7.58(d,J＝8.0Hz,2H),7.15(d,J＝7.2Hz,1H),4.89(dt,J＝7.1,3.3Hz,1H),4.10(qd,J＝11.3,5.5Hz,2H),3.85(s,3H),3.24(s,1H),2.63(t,J＝5.8Hz,1H).

MS(ESI)m/z:[(M+H)⁺,248.0].

(c) (2S,3R) -3-hydroxy-2- (4- ((4- (((S) -3-hydroxy-1-methoxy-1-propoxy-2-yl) carbamoyl) phenyl) -1, 3-diacetylen-1-yl) benzoylamino) butyric acid methyl ester

Dissolving the compound (S) -methyl 2- (4-ethynylbenzoyl) -3-hydroxybutyrate (160mg, 0.647mmol) prepared in the step (b) and methyl (2S,3R) -2- (4-ethynylbenzoylamino) -3-hydroxybutyrate (254mg, 0.971mmol) in a mixed solvent of 8ml of anhydrous methanol and 8ml of pyridine, adding copper acetate (348mg, 1.914mmol) under the protection of argon, stirring at room temperature, reacting for 24h, TLC (CH)₂Cl₂MeOH-20/1), after completion of the reaction, 40ml of ethyl acetate was added to dissolve, and pyridine in the solvent was washed off with dilute hydrochloric acid (1M), followed by washing with a saturated aqueous sodium chloride solution and drying over anhydrous sodium sulfate. Filtering to remove anhydrous sodium sulfate, and performing rotary column Chromatography (CH)₂Cl₂MeOH 80/1-20/1) to give 110mg of white solid, 33.6% yield.

¹H NMR(400MHz,DMSO-d₆)8.78(d,J＝7.4Hz,1H),8.47(d,J＝8.2Hz,1H),7.96(d,J＝8.0Hz,4H),7.76(d,J＝7.4Hz,4H),5.08(t,J＝6.2Hz,1H),4.99(d,J＝7.3Hz,1H),4.58–4.48(m,2H),4.19(h,J＝6.8Hz,1H),3.80(t,J＝5.8Hz,2H),3.67(s,3H),3.66(s,3H),1.15(d,J＝6.4Hz,3H).

MS(EI)m/z:(M⁺,506).

(d) N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-propoxy-2-yl) -4- ((4- (((S) -3 hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) carbamoyl) phenyl) -1, 3-butadiyn-1-yl) benzamide

The methyl (2S,3R) -3-hydroxy-2- (4- ((4- (((S) -3-hydroxy-1-methoxy-1-oxobutan-2-yl) carbamoyl) phenyl) -1, 3-butan-1-yl) benzoylamino) butanoate prepared in the above (c) (110mg, 0.216mmol) was dissolved in a mixed solution of 5ml dichloromethane and 10ml methanol, 50% aqueous hydroxylamine solution (1ml) was added dropwise at 0 ℃ and stirred at room temperature for 12 hours, TLC (CH)₂Cl₂MeOH 20/1) to detect the disappearance of the starting material. The solution was spin dried and the dichloromethane slurried three times to obtain a pure product as a off-white solid 100mg with a yield of 91.0%.

¹H NMR(400MHz,DMSO-d₆)10.72(s,1H),10.71(s,1H),8.89(s,1H),8.87(s,1H),8.49(d,J＝7.9Hz,1H),8.24(d,J＝8.4Hz,1H),8.02–7.91(m,4H),7.81–7.70(m,4H),4.99(t,J＝5.8Hz,1H),4.91(d,J＝6.3Hz,1H),4.42(q,J＝6.6Hz,1H),4.26(dd,J＝8.4,5.6Hz,1H),4.09–3.97(m,1H),3.69(hept,J＝5.3Hz,2H),1.10(d,J＝6.3Hz,3H).

MS(ESI)m/z:[(M+H)⁺,508.9].

Example 3: preparation of 4,4' - (1, 2-ethynyl) bis (N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) benzamide) (Compound 3)

(a) (2S,3R) -3-hydroxy-2- (4-iodobenzoyl) butanoic acid methyl ester

The hydrochloride of threonine methyl ester (168mg, 0.991mmol) and 4-iodobenzoic acid (205mg, 0.826mmol) were dissolved in 10ml of N, N-dimethylformamide under argon protection, and 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride (190mg, 0.991mmol), 1-hydroxybenzotriazole (134mg, 0.991mmol), and diisopropylethylamine (427mg, 3.304mmol) were added in this order at 0 ℃. Stirring at room temperature for 20h, and detecting by TLC that the reaction is finished (CH)₂Cl₂MeOH 20/1), 40ml of ethyl acetate was added, and the mixture was washed successively with a saturated aqueous ammonium chloride solution and a saturated aqueous sodium chloride solution and dried over anhydrous sodium sulfate. Filtering to remove anhydrous sodium sulfate, and performing rotary column Chromatography (CH)₂Cl₂MeOH 100/1-80/1) to give 140mg of yellow solid, 38.9% yield.

¹H NMR(400MHz,Chloroform-d)7.81(d,J＝8.4Hz,2H),7.57(d,J＝8.5Hz,2H),6.88(d,J＝8.8Hz,2H),4.80(dd,J＝8.8,2.4Hz,1H),4.47(ddd,J＝6.7,4.5,2.4Hz,1H),3.81(s,3H),2.14(d,J＝4.7Hz,1H),1.29(d,J＝6.4Hz,3H).

MS(ESI)m/z:[(M+H)⁺,386.0].

(b) (2S,2'S,3R,3' R) -2,2'- ((4,4' - (1, 2-ethynyl) bis (benzoyl)) bis (methyl 3-hydroxybutyrate)

Dissolving the compound (2S,3R) -3-hydroxy-2- (4-iodobenzoyl) methyl butyrate (140mg, 0.386mmol) prepared in the step (a) and (2S,3R) -2- (4-ethynylbenzoylamino) -3-hydroxybutyric acid methyl ester (121mg, 0.463mmol) in 15ml of anhydrous tetrahydrofuran solution, adding triethylamine (78mg, 0.772mmol), bis (triphenylphosphine) palladium dichloride (14mg, 0.019mmol) and cuprous iodide (4mg, 0.019mmol) in sequence under the protection of argon gas, reacting for 12h at 40 ℃, and detecting the completion of the reaction by TLC (CH, 3R) -3-hydroxy-2- (4-iodobenzoyl) methyl butyrate)₂Cl₂MeOH 20/1), 40ml of ethyl acetate was added, and the mixture was washed successively with a saturated aqueous ammonium chloride solution and a saturated aqueous sodium chloride solution and dried over anhydrous sodium sulfate.Filtering to remove anhydrous sodium sulfate, and performing rotary column Chromatography (CH)₂Cl₂MeOH 100/1-80/1) to give 90mg of yellow solid in 47.0% yield.

¹H NMR(400MHz,DMSO-d₆)8.43(d,J＝8.1Hz,2H),7.98(d,J＝8.1Hz,4H),7.73(d,J＝8.1Hz,4H),4.99(d,J＝7.5Hz,2H),4.52(dd,J＝8.2,4.2Hz,2H),4.20(td,J＝6.9,4.4Hz,2H),3.67(s,6H),1.14(s,3H)1.18(s,3H).

MS(EI)m/z:(M⁺,496).

(c)4,4' - (1, 2-ethynyl) bis (N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) benzamide)

The compound (2S,2'S,3R,3' R) -2,2'- ((4,4' - (1, 2-ethynyl) bis (benzoyl)) bis methyl-3-hydroxybutyrate (90mg, 0.216mmol) prepared in the above (b) was dissolved in a mixed solution of 5ml dichloromethane and 10ml methanol, 50% aqueous hydroxylamine solution (1ml) was added dropwise at 0 ℃ and stirred at room temperature for 12 hours, TLC (CH)₂Cl₂MeOH 20/1) to detect the disappearance of the starting material. The solution was spin dried and the dichloromethane slurried three times to give a pure product as an off-white solid 80mg with 88.5% yield.

¹H NMR(400MHz,DMSO-d₆)10.69(s,2H),8.87(s,2H),8.19(d,J＝8.5Hz,2H),7.97(d,J＝8.0Hz,4H),7.70(d,J＝8.0Hz,4H),4.92(d,J＝6.3Hz,2H),4.27(dd,J＝8.4,5.5Hz,2H),4.03(q,J＝6.0Hz,2H),1.10(d,J＝6.3Hz,6H).

MS(ESI)m/z:[(M+H)⁺,521.1].

Example 4: preparation of N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) -4- ((4- (3- (methylsulfonyl) propoxy) phenyl) ethynyl) benzamide (compound 4)

(a) (2S,3R) -3-hydroxy-2- (4- ((4- (3- (methylsulfonyl) propoxy) phenyl) ethynyl) benzoyl) butanoic acid methyl ester

The procedure described in (b) of example 3 was repeated using the compound 1-iodo-4- (3- (methylsulfonyl) propoxy) benzene (the product of step (a) of example 1) (237mg, 0.498mmol), (2S,3R) -2- (4-ethynylbenzoylamino) -3-hydroxybutyric acid methyl ester (130mg, 0.696mmol), triethylamine (126mg, 1.245mmol), bis (triphenylphosphine) palladium dichloride (17mg, 0.025mmol) and cuprous iodide (5mg, 0.025mmol), and anhydrous tetrahydrofuran as a solvent to give 200mg of a yellow solid in 84.9% yield.

¹H NMR(400MHz,CDCl₃)7.83(d,J＝8.6Hz,2H),7.58(d,J＝8.6Hz,2H),7.49(d,J＝8.9Hz,2H),6.94–6.80(m,3H),4.83(d,J＝11.1Hz,1H),4.56–4.41(m,1H),4.15(t,J＝5.8Hz,2H),3.80(s,3H),3.27(dd,J＝9.2,6.1Hz,2H),2.97(s,3H),2.42–2.33(m,2H),2.10(d,J＝4.4Hz,1H),1.31(d,J＝6.4Hz,3H).

MS(ESI)m/z:[(M+H)⁺,496.2].

(b) N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) -4- ((4- (3- (methylsulfonyl) propoxy) phenyl) ethynyl) benzamide

Using the compound (2S,3R) -3-hydroxy-2- (4- ((4- (3- (methylsulfonyl) propoxy) phenyl) ethynyl) benzoyl) butyric acid methyl ester (80mg, 0.169mmol) prepared in the above (a) as a starting material, and dichloromethane and methanol as solvents, the method described in (e) in example 1 was performed to obtain 30mg of a white solid with a yield of 37.4%.

¹H NMR(400MHz,DMSO-d₆)10.70(s,1H),8.88(s,1H),8.16(d,J＝8.5Hz,1H),7.94(d,J＝8.4Hz,2H),7.63(d,J＝8.4Hz,2H),7.54(d,J＝8.7Hz,2H),7.02(d,J＝8.8Hz,2H),4.92(d,J＝6.4Hz,1H),4.26(dd,J＝8.5,5.5Hz,1H),4.14(t,J＝6.2Hz,2H),4.03(q,J＝6.2Hz,1H),3.33–3.26(m,2H),3.03(s,3H),2.21–2.11(m,2H),1.10(d,J＝6.3Hz,3H).

MS(ESI)m/z:[(M+H)⁺,475.0].

Example 5: preparation of N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) -4- ((4- (2- (methylsulfonyl) ethoxy) phenyl) ethynyl) benzamide (compound 5)

(a) 1-iodo-4- (2- (methylsulfonyl) ethoxy) benzene

The procedure described in (a) of example 1 was repeated, using the compounds 3-methylsulphonylethanol (200mg, 1.610mmol), 4-iodophenol (425mg, 1.932mmol), triphenylphosphine (633mg, 2.415mmol) and diethyl azodicarboxylate (420mg, 2.415mmol) as starting materials and anhydrous tetrahydrofuran as solvent, to give 411mg of a white solid in 78.3% yield.

¹H NMR(400MHz,Chloroform-d)7.60(d,J＝9.0Hz,2H),6.69(d,J＝9.0Hz,2H),4.41(t,2H),3.44(t,J＝5.3Hz,2H),3.05(s,3H).

MS(ESI)m/z:[(M+Cl)^-,360.5].

(b) (2S,3R) -3-hydroxy-2- (4- ((4- (2- (methylsulfonyl) ethoxy) phenyl) ethynyl) benzoyl) butanoic acid methyl ester

Using the compound 1-iodo-4- (3- (methylsulfonyl) ethoxy) benzene (411mg, 0.984mmol) prepared in the above (a), methyl (2S,3R) -2- (4-ethynylbenzoylamino) -3-hydroxybutyrate (280mg, 1.073mmol), triethylamine (298mg, 2.952mmol), bis (triphenylphosphine) palladium dichloride (35mg, 0.049mmol) and cuprous iodide (10mg, 0.049mmol), anhydrous tetrahydrofuran as a solvent, the method described in (b) in example 3 was followed to obtain 328mg of a yellow solid in a yield of 72.5%.

¹H NMR(400MHz,Chloroform-d)7.85(d,J＝8.3Hz,2H),7.61(d,J＝8.2Hz,2H),7.54(d,J＝8.7Hz,2H),6.93(d,J＝8.8Hz,2H),4.86(dd,J＝8.7,2.4Hz,1H),4.65–4.36(m,3H),3.84(s,3H),3.49(t,J＝5.3Hz,2H),3.11(s,1H),1.33(d,J＝6.4Hz,3H).

MS(ESI)m/z:[(M+H)⁺,459.9].

(c) N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) -4- ((4- (2- (methylsulfonyl) ethoxy) phenyl) ethynyl) benzamide

Using the compound (2S,3R) -3-hydroxy-2- (4- ((4- (3- (methylsulfonyl) ethoxy) phenyl) ethynyl) benzoyl) butyric acid methyl ester (100mg, 0.217mmol) prepared in the above (b) as a starting material, and dichloromethane and methanol as solvents, according to the method described in (e) in example 1, 30mg of a white solid was obtained with a yield of 30.0%.

¹H NMR(400MHz,DMSO)10.69(s,1H),8.87(s,1H),8.15(d,J＝8.5Hz,1H),7.94(d,J＝8.4Hz,2H),7.63(d,J＝8.4Hz,2H),7.55(d,J＝8.8Hz,2H),7.07(d,J＝8.9Hz,2H),4.92(d,J＝6.4Hz,1H),4.40(t,J＝5.7Hz,2H),4.26(dd,J＝8.4,5.6Hz,1H),4.03(dd,J＝12.2,6.1Hz,1H),3.65(t,J＝5.6Hz,2H),3.09(s,3H),1.09(d,J＝6.3Hz,3H).

MS(ESI)m/z:[(M+H)⁺,460.8].

Example 6: preparation of (S) -N- (3-amino-1- (hydroxylamine) -3-methyl-1-oxybutan-2-yl) -4- ((4- (2- (methylsulfonyl) ethoxy) phenyl) ethynyl) benzamide (Compound 6)

(a) (S) -3- ((tert-Butoxycarbonyl) amino) -3-methyl-2- (4- ((4- (2- (methylsulfonyl) ethoxy) phenyl) ethynyl) benzamide) butyric acid methyl ester

The procedure described in (b) in example 3 was repeated using the compound 1-iodo-4- (3- (methylsulfonyl) ethoxy) benzene (the product of step (a) in example 5) (209mg, 0.641mmol), (S) -3- ((tert-butoxycarbonyl) amino) -2- (4-ethynylbenzamide) -3-methylbutanoic acid methyl ester (WO2013170030A1) (200mg, 0.534mmol), triethylamine (162mg, 1.602mmol), bis (triphenylphosphine) palladium dichloride (37mg, 0.053mmol) and cuprous iodide (10mg, 0.053mmol), anhydrous tetrahydrofuran as a solvent to give 280mg of a yellow solid in 91.6% yield.

¹H NMR(400MHz,Chloroform-d)9.13(s,1H),7.98–7.87(m,2H),7.65–7.55(m,2H),7.54–7.47(m,2H),6.90(d,J＝8.8Hz,2H),4.74(d,J＝8.0Hz,1H),4.70(s,1H),4.48(dd,J＝5.8,4.9Hz,2H),3.75(s,3H),3.49–3.42(m,2H),3.08(d,J＝0.8Hz,3H),1.53(s,3H),1.49(s,3H),1.46(s,9H).

MS(ESI)m/z:[(M+H)⁺,572.7].

(b) (S) -3-amino-3-methyl-2- (4- ((4- (2- (methylsulfonyl) ethoxy) phenyl) ethynyl) benzamide) butyric acid methyl ester

Dissolving the compound (S) -3- ((tert-butoxycarbonyl) amino) -3-methyl-2- (4- ((4- (2- (methylsulfonyl) ethoxy) phenyl) ethynyl) benzamide) methyl butyrate (280mg, 0.489mmol) prepared in the step (a) in 10ml of 1, 4-dioxane solution, dropwise adding 5ml of 1, 4-dioxane hydrogen chloride solution, stirring at room temperature for 5 hours, detecting the completion of the reaction by TLC (PE/EA ═ 2/1), after spin-drying the solvent, adding 40ml of ethyl acetate to dissolve, washing off residual acid with saturated aqueous sodium bicarbonate solution, washing with saturated aqueous sodium chloride solution, and drying the ethyl acetate layer with anhydrous sodium sulfate. Filtered and rotary-dried to obtain 185mg of solid with the yield of 80.1 percent.

¹H NMR(400MHz,DMSO-d6)8.41(s,1H),7.91(d,J＝8.1Hz,2H),7.64(d,J＝8.0Hz,2H),7.56(d,J＝8.4Hz,2H),7.07(d,J＝8.5Hz,2H),4.42(s,1H),4.40(d,J＝5.2Hz,2H),3.66(s,3H),3.64(d,2H),3.09(s,3H),1.15(s,3H),1.13(s,3H).

MS(ESI)m/z:[(M+H)⁺,473.1]

(c) (S) -N- (3-amino-1- (hydroxylamine) -3-methyl-1-oxybutan-2-yl) -4- ((4- (2- (methylsulfonyl) ethoxy) phenyl) ethynyl) benzamide

Using the compound (S) -3-amino-3-methyl-2- (4- ((4- (2- (methylsulfonyl) ethoxy) phenyl) ethynyl) benzamide) methyl butyrate (185mg, 0.391mmol) prepared in the above (b) as a starting material, dichloromethane and methanol as solvents, the method described in (e) in example 1 was followed to obtain 60mg of a white solid with a yield of 32.4%.

¹H NMR(400MHz,DMSO-d₆)11.19(s,1H),9.26(s,1H),8.63(d,J＝9.3Hz,1H),7.99(d,J＝8.2Hz,2H),7.65(d,J＝8.0Hz,2H),7.55(d,J＝8.7Hz,2H),7.07(d,J＝8.8Hz,2H),4.70(d,J＝9.3Hz,1H),4.40(t,J＝5.6Hz,2H),3.65(s,2H),3.09(s,3H),1.35(s,3H),1.31(s,3H).

MS(ESI)m/z:[(M+H)⁺,474.1]

Example 7: preparation of (S) -N- (3-amino-1- (hydroxylamine) -3-methyl-1-oxybutan-2-yl) -4- ((4- (3- (methylsulfonyl) propoxy) phenyl) ethynyl) benzamide (Compound 7)

(a) (S) -3- ((tert-Butoxycarbonyl) amino) -3-methyl-2- (4- ((4- (2- (methylsulfonyl) propoxy) phenyl) ethynyl) benzamide) butyric acid methyl ester

The procedure described for (b) in example 3 was repeated using 1-iodo-4- (3- (methylsulfonyl) propoxy) benzene (product of step (a) in example 5) (218mg, 0.641mmol), (S) -3- ((tert-butoxycarbonyl) amino) -2- (4-ethynylbenzamide) -3-methylbutanoic acid methyl ester (200mg, 0.534mmol), triethylamine (162mg, 1.602mmol), bis (triphenylphosphine) palladium dichloride (37mg, 0.053mmol) and cuprous iodide (10mg, 0.053mmol), and anhydrous tetrahydrofuran as a solvent to give 260mg of a yellow solid in 82.9% yield.

¹H NMR(400MHz,Chloroform-d)9.13(s,1H),7.94(d,J＝8.1Hz,2H),7.61(d,J＝8.1Hz,2H),7.51(d,J＝8.4Hz,2H),6.89(d,J＝8.4Hz,2H),4.82–4.67(m,2H),4.17(t,J＝5.8Hz,2H),3.77(s,3H),3.42–3.15(m,2H),2.99(s,3H),2.44–2.34(m,2H),1.55(s,3H),1.51(s,3H),1.48(s,9H).

MS(ESI)m/z:[(M+Na)⁺,609.2].

(b) (S) -3-amino-3-methyl-2- (4- ((4- (2- (methylsulfonyl) propoxy) phenyl) ethynyl) benzamide) butyric acid methyl ester

Dissolving methyl (S) -3- ((tert-butoxycarbonyl) amino) -3-methyl-2- (4- ((4- (2- (methylsulfonyl) propoxy) phenyl) ethynyl) benzamide) butyrate (260mg, 0.443mmol) prepared in the step (a) in 10ml of 1, 4-dioxane solution, dropwise adding 5ml of 1, 4-dioxane hydrogen chloride solution, stirring at room temperature for 5 hours, detecting the completion of the reaction by TLC (PE/EA ═ 2/1), after spin-drying the solvent, adding 40ml of ethyl acetate to dissolve, washing off residual acid with saturated aqueous sodium bicarbonate solution, washing with saturated aqueous sodium chloride solution, and drying the ethyl acetate layer with anhydrous sodium sulfate. Filtration and spin-drying gave 170mg of solid in 78.9% yield.

¹H NMR(400MHz,DMSO)8.54(s,1H),7.93(d,J＝8.3Hz,2H),7.64(d,J＝8.4Hz,2H),7.54(d,J＝8.8Hz,2H),7.02(d,J＝8.8Hz,2H),4.53(d,J＝3.2Hz,1H),4.14(t,J＝6.2Hz,2H),3.67(s,3H),3.31–3.23(m,2H),3.03(s,3H),2.26–2.08(m,2H),1.20(s,3H),1.19(s,3H).

MS(ESI)m/z:[(M+H)⁺,487.0].

(c) (S) -N- (3-amino-1- (hydroxylamine) -3-methyl-1-oxybutan-2-yl) -4- ((4- (2- (methylsulfonyl) propoxy) phenyl) ethynyl) benzamide

Using (S) -3-amino-3-methyl-2- (4- ((4- (2- (methylsulfonyl) propoxy) phenyl) ethynyl) benzamide) methyl butyrate (170mg, 0.349mmol) prepared in the above (b) as a raw material, and dichloromethane and methanol as solvents, according to the method described in (e) in example 1, 60mg of a white solid was obtained with a yield of 35.3%.

¹H NMR(300MHz,DMSO-d6)11.24(d,J＝5.2Hz,1H),9.28(d,J＝13.9Hz,1H),8.55(d,J＝9.4Hz,1H),8.04(s,2H),7.95(d,J＝8.1Hz,2H),7.63(d,J＝8.0Hz,2H),7.52(d,J＝8.1Hz,2H),7.00(d,J＝9.2Hz,2H),4.69(d,J＝9.1Hz,1H),4.32–3.97(m,2H),3.25(d,J＝8.2Hz,2H),3.01(s,3H),2.11(s,2H),1.33(s,3H),1.28(s,3H).

MS(ESI)m/z:[(M+H)⁺,488.0].

Example 8: preparation of N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) -4- ((4- ((5-hydroxy-4-oxa-1, 4-dihydropyridin-2-yl) methyl ester) phenyl) ethynyl) benzamide (Compound 8)

(a)2- ((4-iodophenyl) methylene) -4, 5-bis ((4-methoxybenzyl) oxy) pyridine

The procedure described in (a) of example 1 was repeated using (4, 5-bis ((4-methoxybenzyl) oxy) -2-pyridyl) methanol (WO2013150296A1) (500mg, 1.311mmol), 4-iodophenol (346mg, 1.573mmol), triphenylphosphine (516mg, 1.967mmol) and diethyl azodicarboxylate (343mg, 1.967mmol) as starting materials and anhydrous tetrahydrofuran as a solvent to give 400mg of a white solid in 52.3% yield.

¹H NMR(400MHz,Chloroform-d)8.11(s,1H),7.53(d,J＝9.1Hz,2H),7.33–7.28(m,4H),7.04(s,1H),6.88(d,J＝2.3Hz,2H),6.86(d,J＝2.3Hz,2H),6.71(d,J＝8.9Hz,2H),5.10(s,2H),5.08(s,2H),5.03(s,2H),3.82(s,3H),3.80(s,3H).

MS(ESI)m/z:[(M+H)⁺,584.4].

(b) (2S,3R) -2- (4- ((4- ((4, 5-bis ((4-methoxybenzyl) oxy) -2-pyridinyl) methoxy) phenyl) ethynyl) benzamide) -3-hydroxybutyric acid methyl ester

The procedure described for (b) in example 3 was repeated using the compound 2- ((4-iodophenyl) methylene) -4, 5-bis ((4-methoxybenzyl) oxy) pyridine (400mg, 0.686mmol) of the above-mentioned compound (a), (2S,3R) -2- (4-ethynylbenzoylamino) -3-hydroxybutyric acid methyl ester (215mg, 0.823mmol), triethylamine (208mg, 2.058mmol), bis (triphenylphosphine) palladium dichloride (24mg, 0.034mmol) and cuprous iodide (7mg, 0.034mmol), and anhydrous tetrahydrofuran as a solvent to give 300mg of a yellow solid in a yield of 61.0%.

¹H NMR(400MHz,CDCl₃)8.13(s,1H),7.82(d,J＝8.3Hz,2H),7.58(d,J＝8.3Hz,2H),7.47(d,J＝8.7Hz,2H),7.31(t,J＝8.9Hz,4H),7.06(s,1H),6.92(d,J＝8.8Hz,2H),6.87(m,5H),5.11(s,2H),5.10(s,4H),4.83(dd,J＝8.6,2.1Hz,1H),4.52–4.43(m,1H),3.81(s,9H),1.25(d,J＝2.5Hz,3H).

MS(ESI)m/z:[(M+H)⁺,739.4].

(c)4- ((4- ((4, 5-bis ((4-methoxybenzyl) oxy) -2-pyridinyl) methoxy) phenyl) ethynyl) -N- ((2S,3R) -3 hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) benzamide

The procedure described in (e) of example 1 was repeated using methyl (2S,3R) -2- (4- ((4- ((4, 5-bis ((4-methoxybenzyl) oxy) -2-pyridinyl) methoxy) phenyl) ethynyl) benzamide) -3-hydroxybutyrate, prepared in the above-mentioned (b), as a starting material (300mg, 0.419mmol) and dichloromethane and methanol as solvents to give 200mg of a white solid in 66.5% yield.

¹H NMR(400MHz,DMSO)10.71(s,1H),8.87(s,1H),8.20(s,1H),8.16(d,J＝8.3Hz,1H),7.94(d,J＝8.4Hz,2H),7.63(d,J＝8.4Hz,2H),7.53(d,J＝9.0Hz,2H),7.35(dd,J＝10.4,8.2Hz,4H),7.30(s,1H),7.08(d,J＝8.1Hz,2H),6.93(dd,J＝8.7,4.2Hz,4H),5.14(s,2H),5.10(s,2H),5.08(s,2H),4.28–4.24(m,1H),4.06–4.00(m,1H),3.76(s,3H),3.75(s,3H),1.10(d,J＝6.0Hz,3H).

MS(ESI)m/z:[(M+H)⁺,718.0].

(d) N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) -4- ((4- ((5-hydroxy-4-oxa-1, 4-dihydropyridin-2-yl) methyl ester) phenyl) ethynyl) benzamide

The compound 4- ((4- ((4, 5-bis ((4-methoxybenzyl) oxy) -2-pyridinyl) methoxy) phenyl) ethynyl) -N- ((2S,3R) -3 hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) benzamide (200mg, 0.279mmol) prepared in (c) above was dissolved in 10ml of dry dichloromethane, 0.2ml of trifluoroacetic acid was added dropwise at 0 ℃, after completion of the addition, the mixture was allowed to stand at room temperature and stirred for 5h, TLC (CH)₂Cl₂MeOH ═ 10:1) detection reaction was complete, spin dried, and slurried with ethyl acetate three times to give a solid in 82.7% yield.

¹H NMR(400MHz,DMSO-d₆)10.70(s,1H),8.15(d,J＝8.4Hz,1H),7.95(d,J＝8.1Hz,2H),7.65(s,1H),7.63(d,J＝8.1Hz,2H),7.56(d,J＝8.3Hz,3H),7.09(d,J＝8.5Hz,2H),6.65(s,1H),5.07(s,2H),4.32–4.23(m,1H),4.09–3.99(m,1H),1.10(d,J＝6.2Hz,3H).

MS(ESI)m/z:[(M+H)⁺,478.0].

Example 9: preparation of 4- ((4- ((1, 5-dihydroxy-4-oxa-1, 4-dihydropyridin-2-yl) methoxy) phenyl) ethynyl) -N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) benzamide (Compound 9)

(a)1, 5-bis (benzhydryloxy) -2- ((4-iodophenoxy) methyl) pyridin-4 (1H) -one

The procedure described in (a) of example 1 was repeated, using the compounds 1, 5-bis (benzhydryloxy) -2- (hydroxymethyl) pyridin-4 (1H) -one [ Journal of medicinal Chemistry 56(2013) 5541-one 5552] (500mg, 1.021mmol) and 4-iodophenol (270mg, 1.225mmol), triphenylphosphine (402mg, 1.532mmol) and diethyl azodicarboxylate (267mg, 1.532mmol) as starting materials, and anhydrous tetrahydrofuran as a solvent, to give 390mg of a white solid in 55.2% yield.

¹H NMR(400MHz,Chloroform-d)7.75–7.26(m,20H),7.19–7.15(m,2H),6.98(s,1H),6.43(d,J＝3.2Hz,2H),6.40(s,1H),6.22(s,1H),5.88(s,1H),4.50(s,2H).

MS(ESI)m/z:[(M+H)⁺,714.2].

(b) (2S,3R) -2- (4- ((4- ((1, 5-bis (benzhydryloxy) -4-oxa-1, 4-dihydropyridin-2-yl) methoxy) phenyl) ethynyl) benzamido) -3-hydroxybutyric acid methyl ester

Using the compound 1, 5-bis (benzhydryloxy) -2- ((4-iodophenoxy) methyl) pyridin-4 (1H) -one (390mg, 0.564mmol) of the above-mentioned compound (a), (methyl 2S,3R) -2- (4-ethynylbenzoylamino) -3-hydroxybutyric acid (177mg, 0.677mmol), triethylamine (171mg, 1.692mmol), bis (triphenylphosphine) palladium dichloride (20mg, 0.028mmol) and cuprous iodide (6mg, 0.028mmol), anhydrous tetrahydrofuran as a solvent, the procedure described in (b) of example 3 gave 300mg of a yellow solid in a yield of 64.5%.

¹H NMR(400MHz,Chloroform-d)7.96(d,J＝8.3Hz,2H),7.79(d,J＝8.3Hz,1H),7.55(d,J＝8.3Hz,2H),7.48–7.25(m,20H),7.19–7.16(m,2H),6.96(s,1H),6.66(d,J＝8.7Hz,2H),6.45(s,1H),6.02(s,1H),5.88(s,1H),4.78(dd,J＝8.2,3.2Hz,1H),4.60–4.50(m,2H),4.47(dd,J＝6.5,3.3Hz,1H),3.80(s,3H),1.29(d,J＝6.4Hz,3H).

MS(ESI)m/z:[(M+H)⁺,825.0].

(c)4- ((4- ((1, 5-bis (benzhydryloxy) -4-oxa-1, 4-dihydropyridin-2-yl) methoxy) phenyl) ethynyl) -N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) benzamide

The procedure described in (e) of example 1 was repeated using methyl (2S,3R) -2- (4- ((4- ((1, 5-bis (benzhydryloxy) -4-oxa-1, 4-dihydropyridin-2-yl) methoxy) phenyl) ethynyl) benzamido) -3-hydroxybutyric acid ester (300mg, 0.363mmol) prepared in (b) above as a starting material and dichloromethane and methanol as solvents to give 200mg of a white solid in 66.7% yield.

¹H NMR(400MHz,DMSO-d₆)10.70(s,1H),8.88(s,1H),8.16(d,J＝8.4Hz,1H),7.95(d,J＝8.4Hz,2H),7.85(s,1H),7.64(d,J＝8.4Hz,2H),7.48(d,J＝8.7Hz,2H),7.44–7.30(m,16iH),7.24–7.21(m,4H),6.78(d,J＝8.9Hz,2H),6.47(s,1H),6.39(s,1H),6.02(s,1H),4.92(d,J＝6.3Hz,1H),4.76(s,2H),4.27(dd,J＝8.5,5.5Hz,1H),4.12(q,J＝5.3Hz,1H),4.03(q,J＝6.1Hz,1H),3.17(d,J＝5.2Hz,3H),1.10(d,J＝6.3Hz,3H).

MS(ESI)m/z:[(M-H)^-,824.2].

(d)4- ((4- ((1, 5-dihydroxy-4-oxa-1, 4-dihydropyridin-2-yl) methoxy) phenyl) ethynyl) -N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) benzamide

The procedure described in (d) of example 8 was repeated, using 4- ((4- ((1, 5-bis (benzhydryloxy) -4-oxa-1, 4-dihydropyridin-2-yl) methoxy) phenyl) ethynyl) -N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) benzamide (200mg, 0.242mmol) prepared in (c) above as the starting material, dichloromethane as the solvent, and trifluoroacetic acid as the debenzylating agent, to give 110mg of a solid in 82.7% yield.

¹H NMR(600MHz,DMSO)10.72(s,1H),8.90(s,1H),8.18(d,J＝8.1Hz,1H),7.95(d,J＝7.8Hz,2H),7.92(s,1H),7.64(d,J＝7.7Hz,2H),7.56(d,J＝7.8Hz,2H),7.10(d,J＝8.1Hz,2H),6.93(s,1H),5.22(s,2H),4.28–4.25(m,1H),4.06–4.00(m,1H),1.10(d,J＝5.7Hz,3H).

MS(ESI)m/z:[(M+H)⁺,494.1].

Example 10: preparation of 4- ((4- ((1, 5-dihydroxy-4-oxa-1, 4-dihydropyridin-2-yl) methoxy) phenyl) -1, 3-butadiyn-1-yl) -N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) benzamide (Compound 10)

(a)1, 5-bis (benzhydryloxy) -2- ((4- ((trimethylsilyl) ethynyl) phenoxy) methylene) pyridin-4 (1H) -one

The procedure described in (b) of example 3 was followed using the compound 1, 5-bis (benzhydryloxy) -2- ((4-iodophenoxy) methyl) pyridin-4 (1H) -one (product of step (a) of example 9) (390mg, 0.564mmol), trimethylsilylacetylene (66mg, 0.677mmol), triethylamine (171mg, 1.692mmol), bis (triphenylphosphine) palladium dichloride (20mg, 0.028mmol) and cuprous iodide (6mg, 0.028mmol), anhydrous tetrahydrofuran as a solvent to give 300mg of a yellow solid in 80.4% yield.

¹H NMR(400MHz,Chloroform-d)7.75–7.26(m,20H),7.19–7.15(m,2H),6.98(s,1H),6.43(d,J＝3.2Hz,2H),6.40(s,1H),6.22(s,1H),5.88(s,1H),4.50(s,2H),0.23(s,9H).

MS(ESI)m/z:[(M+H)⁺,662.2].

(b)1, 5-bis (benzhydryloxy) -2- ((4-ethynylphenoxy) methylene) pyridin-4 (1H) -one

The procedure described in (c) of example 1 was repeated using 1, 5-bis (benzhydryloxy) -2- ((4- ((trimethylsilyl) ethynyl) phenoxy) methylene) pyridin-4 (1H) -one (300mg, 0.453mmol) as the above-mentioned compound (a) as a starting material, tetra-n-butylammonium fluoride (1M, 0.6ml) as a desilylation reagent, and tetrahydrofuran as a solvent to give 240mg of a white solid in 89.8% yield.

¹H NMR(400MHz,Chloroform-d)7.75–7.26(m,20H),7.19–7.15(m,2H),6.98(s,1H),6.43(d,J＝3.2Hz,2H),6.40(s,1H),6.22(s,1H),5.88(s,1H),4.50(s,2H),3.01(s,1H).

MS(ESI)m/z:[(M+H)⁺,662.2].

(c) (2S,3R) -2- (4- ((4- ((1, 5-bis (benzhydryloxy) -4-oxa-1, 4-dihydropyridin-2-yl) methoxy) phenyl) -1, 3-diacetylen-1-yl) benzamide) -3-hydroxybutyric acid methyl ester

The procedure described in (d) of example 1 was repeated using the compound 1, 5-bis (benzhydryloxy) -2- ((4-ethynylphenoxy) methylene) pyridin-4 (1H) -one prepared in the above-mentioned (b) (240mg, 0.407mmol), (2S,3R) -2- (4-ethynylbenzoylamino) -3-hydroxybutyric acid methyl ester (213mg, 0.813mmol), and copper acetate (122mg, 0.813mmol) as starting materials and methanol and pyridine as mixed solvents to give 138mg of a white solid in a yield of 40.0%.

¹H NMR(400MHz,Chloroform-d)7.84(d,J＝8.3Hz,2H),7.75–7.26(m,22H),7.19–7.15(m,2H),6.98(s,1H),6.43(d,J＝3.2Hz,2H),6.40(s,1H),6.22(s,1H),5.88(s,1H),4.84(dd,J＝8.8,2.2Hz,1H),4.60(s,1H),4.50(s,2H),3.83(s,3H),1.32(d,J＝6.4Hz,3H).

MS(ESI)m/z:[(M+H)⁺,849.3].

(d)4- ((4- ((1, 5-bis (benzhydryloxy) -4-oxa-1, 4-dihydropyridin-2-yl) methoxy) phenyl) -1, 3-diacetylen-1-yl) -N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) benzamide

The procedure described in (e) of example 1 was repeated using methyl (2S,3R) -2- (4- ((4- ((1, 5-bis (benzhydryloxy) -4-oxa-1, 4-dihydropyridin-2-yl) methoxy) phenyl) -1, 3-butan-1-yl) benzamide) -3-hydroxybutyrate prepared in (c) above as a starting material (138mg, 0.163mmol) and dichloromethane and methanol as solvents to give 120mg of a white solid in a yield of 87.0%.

¹H NMR(400MHz,DMSO-d₆)10.70(s,1H),8.88(s,1H),8.16(d,J＝8.4Hz,1H),7.85(d,J＝8.4Hz,2H),7.85(s,1H),7.66(d,J＝8.4Hz,2H),7.48(d,J＝8.7Hz,2H),7.44–7.30(m,16H),7.24–7.21(m,4H),6.78(d,J＝8.9Hz,2H),6.47(s,1H),6.39(s,1H),6.02(s,1H),4.92(d,J＝6.3Hz,1H),4.76(s,2H),4.27(dd,J＝8.5,5.5Hz,1H),4.12(q,J＝5.3Hz,1H),4.03(q,J＝6.1Hz,1H),3.17(d,J＝5.2Hz,3H),1.10(d,J＝6.3Hz,3H).

MS(ESI)m/z:[(M+H)⁺,850.3].

(e)4- ((4- ((1, 5-dihydroxy-4-oxa-1, 4-dihydropyridin-2-yl) methoxy) phenyl) -1, 3-butadiyn-1-yl) -N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) benzamide

The procedure described in (d) of example 8 was repeated using 4- ((4- ((1, 5-bis (benzhydryloxy) -4-oxa-1, 4-dihydropyridin-2-yl) methoxy) phenyl) -1, 3-diacetylen-1-yl) -N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) benzamide (120mg, 0.141mmol) prepared in (d) above as a starting material and dichloromethane and methanol as solvents to give 58mg of a white solid in 80.2% yield.

¹H NMR(600MHz,DMSO)10.72(s,1H),8.90(s,1H),8.18(d,J＝8.1Hz,1H),7.95(d,J＝7.8Hz,2H),7.92(s,1H),7.66(d,J＝7.7Hz,2H),7.56(d,J＝7.8Hz,2H),7.10(d,J＝8.1Hz,2H),6.93(s,1H),5.22(s,2H),4.28–4.25(m,1H),4.06–4.00(m,1H),1.10(d,J＝5.7Hz,3H).MS(ESI)m/z:[(M+H)⁺,494.1].

MS(ESI)m/z:[(M+H)⁺,518.1].

Example 11: preparation of N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxobutan-2-yl) -4- ((4- ((5-hydroxy-4-oxa-1, 4-dihydropyridin-2-yl) methoxy) phenyl) -1, 3-butan-1-yl) benzamide (Compound 11)

(a)4, 5-bis ((4-methoxybenzyl) oxy) -2- ((4- ((trimethylsilyl) ethynyl) phenoxy) methylene) pyridine

The procedure described in (b) of example 3 was followed using the compound 2- ((4-iodophenyl) methylene) -4, 5-bis ((4-methoxybenzyl) oxy) pyridine (product of step (a) of example 8) (420mg, 0.720mmol), trimethylsilylacetylene (106mg, 1.080mmol), triethylamine (218mg, 2.160mmol), bis (triphenylphosphine) palladium dichloride (25mg, 0.036mmol) and cuprous iodide (7mg, 0.036mmol), and anhydrous tetrahydrofuran as a solvent to give 350mg of a yellow solid in 87.8% yield.

¹H NMR(400MHz,Chloroform-d)8.13(s,1H),7.40(d,J＝8.4Hz,2H),7.34(d,J＝8.4Hz,2H),7.31(d,J＝8.3Hz,2H),7.06(s,1H),6.94–6.84(m,6H),5.12(s,2H),5.11(s,2H),5.09(s,2H),3.84(s,3H),3.83(s,3H),0.26(s,9H).

MS(ESI)m/z:[(M+H)⁺,554.0].

(b)2- ((4-ethynylphenyl) methylene) -4, 5-bis ((4-methoxybenzyl) oxa) pyridine

The procedure described in (c) of example 1 was repeated using 350mg, 0.632mmol of 4, 5-bis ((4-methoxybenzyl) oxy) -2- ((4- ((trimethylsilyl) ethynyl) phenoxy) methylene) pyridine (compound (a) above as a starting material, 1M, 0.8ml of tetra-n-butylaminofluoride (1M, 0.8ml) as a desilylation agent, and tetrahydrofuran as a solvent to give 270mg, 88.8% yield as a white solid.

¹H NMR(400MHz,Chloroform-d)8.15(s,1H),7.43(d,J＝8.5Hz,2H),7.33(dd,J＝10.5,8.5Hz,4H),7.07(s,1H),6.89(d,J＝8.1Hz,6H),5.13(s,2H),5.11(s,2H),5.10(s,2H),3.84(s,3H),3.83(s,3H),3.03(s,1H).

MS(ESI)m/z:[(M+H)⁺482.0].

(c) (2S,3R) -2- (4- ((4- ((4, 5-bis ((4-methoxybenzyl) oxy) pyridin-2-yl) methoxy) phenyl) -1, 3-diacetylen-1-yl) benzamide) -3-hydroxybutyric acid methyl ester

The procedure described in (d) in example 1 was repeated using 270mg, 0.561mmol of the compound 2- ((4-ethynylphenyl) methylene) -4, 5-bis ((4-methoxybenzyl) oxa) pyridine prepared in (b) above, (2S,3R) -methyl 2- (4-ethynylbenzamido) -3-hydroxybutyrate (293mg, 1.121mmol) and copper acetate (168mg, 1.121mmol) as starting materials and methanol and pyridine as mixed solvents to give 162mg of a white solid in a yield of 38.9%.

¹H NMR(300MHz,DMSO-d₆)8.41(d,J＝8.1Hz,1H),8.17(s,1H),7.92(d,J＝8.4Hz,2H),7.70(d,J＝8.3Hz,2H),7.56(d,J＝8.7Hz,2H),7.33(dd,J＝8.6,7.7Hz,4H),7.27(s,1H),7.06(d,J＝8.8Hz,2H),6.91(dd,J＝8.7,3.2Hz,4H),5.12(s,2H),5.07(s,4H),4.96(d,J＝7.4Hz,1H),4.48(dd,J＝8.2,4.2Hz,1H),4.21–4.13(m,1H),3.74(s,3H),3.73(s,3H),3.64(s,3H),1.13(d,J＝6.4Hz,3H).

MS(ESI)m/z:[(M+H)⁺,741.0].

(d)4- ((4- ((4, 5-bis ((4-methoxybenzyl) oxy) pyridin-2-yl) methoxy) phenyl) -1, 3-diacetylen-1-yl) -N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) benzamide

The procedure described in (e) of example 1 was repeated using methyl (2S,3R) -2- (4- ((4- ((4, 5-bis ((4-methoxybenzyl) oxy) pyridin-2-yl) methoxy) phenyl) -1, 3-diacetyl-1-yl) benzamide) -3-hydroxybutyric acid, compound prepared in (c), as a starting material (162mg, 0.219mmol) and dichloromethane and methanol as solvents to give 138mg of a white solid in 85.0% yield.

¹H NMR(400MHz,DMSO-d₆)10.69(s,1H),8.87(s,1H),8.22–8.18(m,2H),7.95(d,J＝8.0Hz,2H),7.71(d,J＝8.1Hz,2H),7.58(d,J＝8.4Hz,2H),7.35(dd,J＝10.2,8.3Hz,4H),7.29(s,1H),7.08(d,J＝8.5Hz,2H),6.97–6.89(m,4H),5.14(s,2H),5.09(s,4H),4.90(d,J＝6.7Hz,1H),4.26(dd,J＝8.5,5.5Hz,1H),4.03(q,J＝6.2Hz,1H),3.76(s,3H),3.75(s,3H),1.09(d,J＝6.3Hz,3H).

MS(ESI)m/z:[(M+H)⁺,742.1].

(e) N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) -4- ((4- ((5-hydroxy-4-oxa-1, 4-dihydropyridin-2-yl) methoxy) phenyl) -1, 3-butadiyn-1-yl) benzamide

The procedure described in (d) of example 8 was repeated using 4- ((4- ((4, 5-bis ((4-methoxybenzyl) oxy) pyridin-2-yl) methoxy) phenyl) -1, 3-diacetylen-1-yl) -N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) benzamide (138mg, 0.186mmol) prepared in (d) above as a starting material and dichloromethane and methanol as solvents to give 65mg of a white solid in 69.7% yield.

¹H NMR(400MHz,DMSO-d6)10.70(s,1H),8.21(d,J＝8.4Hz,1H),7.98(s,1H),7.95(d,J＝8.1Hz,2H),7.71(d,J＝8.0Hz,2H),7.63(d,J＝8.2Hz,2H),7.11(d,J＝8.5Hz,2H),7.08(s,1H),5.24(s,2H),4.26(dd,J＝8.4,5.5Hz,1H),4.10–3.94(m,1H),1.09(d,J＝6.2Hz,3H).

MS(ESI)m/z:[(M+H)⁺,502.1].

Example 12: preparation of N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) -4- (3- (methylsulfonyl) propoxy) benzamide (Compound 12)

(a) (2S,3R) -3-hydroxy-2- (4-hydroxybenzamide) butanoic acid methyl ester

The procedure of example 2(b) was repeated using p-hydroxybenzoic acid (114mg, 0.826mmol), threonine methyl ester hydrochloride (168mg, 0.991mmol), 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride (190mg, 0.991mmol), 1-hydroxybenzotriazole (134mg, 0.991mmol), and diisopropylethylamine (427mg, 3.304mmol) as a starting material and N-N-dimethylformamide as a solvent to give 157mg of a white solid in a yield of 75.2%.

¹H NMR(300MHz,CD₃OD)7.78(d,J＝8.4Hz,2H),6.85(d,J＝8.4Hz,2H),4.66(d,J＝3.3Hz,1H),4.37(dq,J＝3.3,6.6Hz,1H),3.75(s,3H),1.22(d,J＝6.6Hz,3H)；

MS(ESI)m/z:[(M-H)^-,252.0].

(b) (2S,3R) -3-hydroxy-2- (4- (3- (methylsulfonyl) propoxy) benzamide) butyric acid methyl ester

The procedure of example 1(a) was repeated using the compound (2S,3R) -3-hydroxy-2- (4-hydroxybenzamide) butyric acid methyl ester (157mg, 0.620mmol) prepared in the above (a), 3-methylsulfonylpropanol (129mg, 0.930mmol), triphenylphosphine (325mg, 1.240mmol) and diethyl azodicarboxylate (216mg, 1.240mmol) as starting materials and anhydrous tetrahydrofuran as a solvent to give 160mg of a white solid in a yield of 69.1%.

¹H NMR(400MHz,Chloroform-d)7.82(d,J＝8.7Hz,2H),6.99(d,J＝8.7Hz,1H),6.90(d,J＝8.8Hz,2H),4.80(dd,J＝8.7,2.5Hz,1H),4.50–4.38(m,1H),4.15(t,J＝5.8Hz,2H),3.79(s,3H),3.32–3.22(m,2H),2.98(s,3H),2.86(d,J＝5.2Hz,1H),2.44–2.31(m,2H),1.28(d,J＝6.4Hz,3H).

MS(ESI)m/z:[(M+H)⁺,374.0].

(c) N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) -4- (3- (methylsulfonyl) propoxy) benzamide

The method described in (e) in example 1 was repeated using the compound (2S,3R) -3-hydroxy-2- (4- (3- (methylsulfonyl) propoxy) benzamide) methyl butyrate (160mg, 0.428mmol) prepared in (b) above as a starting material and dichloromethane and methanol as solvents to give 138mg of a white solid in 86.0% yield.

¹H NMR(400MHz,DMSO-d₆)10.65(s,1H),8.84(s,1H),7.93–7.80(m,3H),7.03(d,J＝8.5Hz,2H),4.89(d,J＝6.3Hz,1H),4.25(dd,J＝8.4,5.3Hz,1H),4.16(t,J＝6.2Hz,2H),4.02(q,J＝6.1Hz,1H),3.32–3.26(m,2H),3.03(s,3H),2.21–2.11(m,2H),1.08(d,J＝6.3Hz,3H).

MS(ESI)m/z:[(M-H)^-,373.1].

Example 13: preparation of N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) -4- (3- (methylsulfonyl) ethoxy) benzamide (Compound 13)

(a) (2S,3R) -3-hydroxy-2- (4- (3- (methylsulfonyl) ethoxy) benzamide) butyric acid methyl ester

The procedure described in example 1(a) was followed, starting from the compound methyl (2S,3R) -3-hydroxy-2- (4-hydroxybenzamide) butanoate (product of step (a) of example 12) (157mg, 0.620mmol), 3-methylsulphonylethanol (154mg, 1.240mmol) and triphenylphosphine (325mg, 1.240mmol), diethyl azodicarboxylate (216mg, 1.240mmol) and anhydrous tetrahydrofuran as solvent, to give 150mg of a white solid in 67.3% yield.

¹H NMR(400MHz,Chloroform-d)7.86(d,J＝8.8Hz,2H),6.96(d,J＝8.7Hz,2H),6.91(d,J＝8.8Hz,1H),4.83(dd,J＝8.7,2.4Hz,1H),4.55–4.44(m,3H),3.82(s,3H),3.50(t,J＝5.3Hz,2H),3.10(s,3H),1.31(d,J＝6.4Hz,3H).

MS(ESI)m/z:[(M+Cl)^-,393.9].

(b) N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) -4- (3- (methylsulfonyl) ethoxy) benzamide

The method described in (e) in example 1 was repeated using the compound methyl (2S,3R) -3-hydroxy-2- (4- (3- (methylsulfonyl) ethoxy) benzamide) butyrate (150mg, 0.417mmol) prepared in the above (a) as a starting material and dichloromethane and methanol as solvents to give 120mg of a white solid in a yield of 79.8%.

¹H NMR(400MHz,DMSO-d₆)10.65(s,1H),8.85(s,1H),7.98–7.83(m,3H),7.08(d,J＝8.8Hz,2H),4.90(d,J＝6.2Hz,1H),4.42(t,J＝5.7Hz,2H),4.26(dd,J＝8.5,5.4Hz,1H),4.02(q,J＝6.0Hz,1H),3.66(t,J＝5.7Hz,2H),3.09(s,3H),1.08(d,J＝6.3Hz,3H).

MS(ESI)m/z:[(M-Cl)^-,358.9].

Example 14: preparation of N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) -4'- (3- (methylsulfonyl) propoxy) - [1,1' -biphenyl ] -4-carboxamide (Compound 14)

(a) (2S,3R) -3-hydroxy-2- (4 '-hydroxy- [1,1' -biphenyl ] -4-formyl) butanoic acid methyl ester

The procedure of example 2(b) was repeated using 4 '-hydroxy- [1,1' -biphenyl ] -4-carboxylic acid (177mg, 0.826mmol), threonine methyl ester hydrochloride (168mg, 0.991mmol), 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride (190mg, 0.991mmol), 1-hydroxybenzotriazole (134mg, 0.991mmol) and diisopropylethylamine (427mg, 3.304mmol) as the starting materials and N-N-dimethylformamide as the solvent to give 180mg of a white solid in 66.2% yield.

¹H NMR(400MHz,DMSO)9.70(s,1H),8.25(d,J＝8.2Hz,1H),7.95(d,J＝8.3Hz,2H),7.72(d,J＝8.3Hz,2H),7.59(d,J＝8.6Hz,2H),6.88(d,J＝8.6Hz,2H),5.00(d,J＝7.8Hz,1H),4.52(dd,J＝8.2,4.1Hz,1H),4.24–4.15(m,1H),3.67(s,3H),1.16(d,J＝6.4Hz,3H).

MS(ESI)m/z:[(M+H)⁺,330.0]

(b) (2S,3R) -3-hydroxy-2- (4'- (3-methylsulfonyl) propoxy) - [1,1' -biphenyl ] -4-formyl) butanoic acid methyl ester

Using methyl (2S,3R) -3-hydroxy-2- (4 '-hydroxy- [1,1' -biphenyl ] -4-formyl) butanoate, which was the compound prepared in the above (a) (180mg, 0.547mmol), 3-methylsulfonylpropanol (151mg, 1.094mmol), triphenylphosphine (287mg, 1.094mmol), and diethyl azodicarboxylate (191mg, 1.094mmol) as starting materials, and anhydrous tetrahydrofuran as a solvent, according to the method described in example 1(a), 150mg of a white solid was obtained in a yield of 61.0%.

¹H NMR(400MHz,Chloroform-d)7.92(d,J＝8.3Hz,2H),7.63(d,J＝8.3Hz,2H),7.56(d,J＝8.7Hz,1H),7.01(d,J＝8.7Hz,2H),6.99(d,J＝8.7Hz,2H),4.87(dd,J＝8.7,2.4Hz,1H),4.49(td,J＝6.9,3.5Hz,1H),4.18(t,J＝5.8Hz,2H),3.83(s,3H),3.37–3.26(m,2H),3.00(s,3H),2.45(d,J＝3.7Hz,1H),2.43–2.36(m,2H),1.33(d,J＝6.4Hz,3H).

MS(ESI)m/z:[(M+H)⁺,449.9].

(c) N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) -4'- (3- (methylsulfonyl) propoxy) - [1,1' -biphenyl ] -4-carboxamide

The procedure described in (e) of example 1 was repeated using methyl (2S,3R) -3-hydroxy-2- (4'- (3-methylsulfonyl) propoxy) - [1,1' -biphenyl ] -4-formyl) butanoate (150mg, 0.334mmol) prepared in the above (b) as a starting material, and dichloromethane and methanol as solvents to give 100mg of a solid in 66.7% yield.

¹H NMR(400MHz,DMSO-d₆)10.69(s,1H),8.87(s,1H),8.04(d,J＝8.3Hz,1H),7.97(d,J＝8.4Hz,2H),7.75(d,J＝8.4Hz,2H),7.71(d,J＝8.7Hz,2H),7.07(d,J＝8.7Hz,2H),4.93(d,J＝6.5Hz,1H),4.29(dd,J＝8.5,5.3Hz,1H),4.16(t,J＝6.2Hz,2H),4.04(h,J＝6.1Hz,1H),3.34–3.27(m,2H),3.04(s,3H),2.22–2.12(m,2H),1.10(d,J＝6.3Hz,3H).

MS(ESI)m/z:[(M-H)^-,448.9].

Example 15: preparation of N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) -4'- (3- (methylsulfonyl) ethoxy) - [1,1' -biphenyl ] -4-carboxamide (Compound 15)

(a) (2S,3R) -3-hydroxy-2- (4'- (3-methylsulfonyl) ethoxy) - [1,1' -biphenyl ] -4-formyl) butanoic acid methyl ester

The procedure of example 1(a) was repeated using the compound methyl (2S,3R) -3-hydroxy-2- (4 '-hydroxy- [1,1' -biphenyl ] -4-formyl) butanoate (product of step (a) of example 16) (204mg, 0.620mmol), 3-methylsulfonylethanol (154mg, 1.240mmol) and triphenylphosphine (325mg, 1.240mmol), diethyl azodicarboxylate (216mg, 1.240mmol) as starting materials and anhydrous tetrahydrofuran as a solvent to give 190mg of a white solid in a yield of 70.4%.

¹H NMR(400MHz,Chloroform-d)7.92(d,J＝8.3Hz,2H),7.63(d,J＝8.3Hz,2H),7.56(d,J＝8.7Hz,1H),7.01(d,J＝8.7Hz,2H),6.99(d,J＝8.7Hz,2H),4.87(dd,J＝8.7,2.4Hz,1H),4.49(td,J＝6.9,3.5Hz,1H),4.42(t,J＝5.7Hz,2H),3.83(s,3H),3.66(t,J＝5.7Hz,2H),3.00(s,3H),2.45(d,J＝3.7Hz,1H),1.33(d,J＝6.4Hz,3H).

MS(EI)m/z:(M⁺,435).

(b) Preparation of N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) -4'- (3- (methylsulfonyl) ethoxy) - [1,1' -biphenyl ] -4-carboxamide

The procedure described in (e) of example 1 was repeated using methyl (2S,3R) -3-hydroxy-2- (4'- (3-methylsulfonyl) ethoxy) - [1,1' -biphenyl ] -4-formyl) butanoate (190mg, 0.436mmol) prepared in the above (b) as a starting material, and dichloromethane and methanol as solvents to give 120mg of a solid in a yield of 63.1%.

¹H NMR(400MHz,DMSO-d₆)10.69(s,1H),8.87(s,1H),8.04(d,J＝8.3Hz,1H),7.97(d,J＝8.4Hz,2H),7.75(d,J＝8.4Hz,2H),7.71(d,J＝8.7Hz,2H),7.07(d,J＝8.7Hz,2H),4.93(d,J＝6.5Hz,1H),4.42(t,J＝5.7Hz,2H),4.29(dd,J＝8.5,5.3Hz,1H),4.04(h,J＝6.1Hz,1H),3.66(t,J＝5.7Hz,2H)，3.04(s,3H),1.10(d,J＝6.3Hz,3H).

MS(EI)m/z:(M⁺,436).

Example 16: preparation of (S) -N- (3-amino-1- (hydroxylamine) -3-methyl-1-oxybutan-2-yl) -4'- (3- (methylsulfonyl) propoxy) - [1,1' -biphenyl ] -4-carboxamide (Compound 16)

(a) (S) -3- ((tert-Butoxycarbonyl) amino) -2- (4 '-hydroxy- [1,1' -biphenyl ] -4-carboxamido) -3-methylbutanoic acid methyl ester

Using 4 '-hydroxy- [1,1' -biphenyl ] -4-carboxylic acid (177mg, 0.826mmol), (S) -methyl 2-amino-3- ((tert-butoxycarbonyl) amino) -3-butanoate (WO201231298A2) (244mg, 0.991mmol), 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride (190mg, 0.991mmol), 1-hydroxybenzotriazole (134mg, 0.991mmol), diisopropylethylamine (427mg, 3.304mmol) as a starting material, and N-N-dimethylformamide as a solvent, the procedure described in example 2(b) was followed to give 200mg of a white solid in 54.7% yield.

¹H NMR(400MHz,Chloroform-d)9.07(s,1H),7.99(d,J＝8.4Hz,2H),7.64(d,J＝8.4Hz,2H),7.57(d,J＝8.7Hz,2H),6.97(d,J＝8.7Hz,2H),4.78(d,J＝8.3Hz,1H),4.72(s,1H),3.74(s,3H),1.53(s,3H),1.49(s,3H),1.46(s,9H).

MS(EI)m/z:(M⁺,442)

(b) (S) -methyl 3- ((tert-butoxycarbonyl) amino) -3-methyl-2- (4'- (3- (methylsulfonyl) propoxy) - [1,1' -biphenyl ] -4-carboxamido) butanoate

Using methyl (S) -3- ((tert-butoxycarbonyl) amino) -2- (4 '-hydroxy- [1,1' -biphenyl ] -4-carboxamido) -3-methylbutyrate (200mg, 0.452mmol) which was the compound prepared in the above-mentioned (a), 3-methylsulfonylpropanol (151mg, 1.094mmol), triphenylphosphine (287mg, 1.094mmol), and diethyl azodicarboxylate (191mg, 1.094mmol) as starting materials, and anhydrous tetrahydrofuran as a solvent, according to the procedure described in example 1(a), 180mg of a white solid was obtained in a yield of 70.8%.

¹H NMR(400MHz,Chloroform-d)9.07(s,1H),7.99(d,J＝8.4Hz,2H),7.64(d,J＝8.4Hz,2H),7.57(d,J＝8.7Hz,2H),6.97(d,J＝8.7Hz,2H),4.78(d,J＝8.3Hz,1H),4.72(s,1H),4.16(t,J＝5.8Hz,2H),3.74(s,3H),3.36–3.11(m,2H),2.97(s,J＝0.7Hz,3H),2.43–2.16(m,2H),1.53(s,3H),1.49(s,3H),1.46(s,9H).

MS(ESI)m/z:[(M+Na)+,585.2].

(c) (S) -3-amino-3-methyl-2- (4'- (3- (methylsulfonyl) propoxy) - [1,1' -biphenyl ] -4-carboxamide) butanoic acid methyl ester

Using methyl (S) -3- ((tert-butoxycarbonyl) amino) -3-methyl-2- (4'- (3- (methylsulfonyl) propoxy) - [1,1' -biphenyl ] -4-carboxamido) butanoate (180mg, 0.320mmol), which was the compound prepared in the above (b), as a starting material, and 1, 4-dioxane of hydrogen chloride as a solvent, 126mg of a solid was obtained in 85.0% yield by the method described in example 7 (b).

¹H NMR(400MHz,Chloroform-d)7.89(d,J＝8.2Hz,2H),7.61(d,J＝8.2Hz,2H),7.54(d,J＝8.7Hz,2H),7.46(d,J＝8.4Hz,1H),7.05–6.83(m,2H),4.59(d,J＝8.3Hz,1H),4.16(t,J＝5.8Hz,2H),3.78(d,J＝0.8Hz,3H),3.38–3.16(m,2H),2.97(s,3H),2.43–2.16(m,3H),1.26(s,3H),1.23(s,3H).

MS(ESI)m/z:[(M+H)+,463.1].

(d) (S) -N- (3-amino-1- (hydroxylamine) -3-methyl-1-oxybutan-2-yl) -4'- (3- (methylsulfonyl) propoxy) - [1,1' -biphenyl ] -4-carboxamide

The procedure described in (e) in example 1 was repeated using the compound (S) -3-amino-3-methyl-2- (4'- (3- (methylsulfonyl) propoxy) - [1,1' -biphenyl ] -4-carboxamide) butyric acid methyl ester (126mg, 0.320mmol) prepared in the above (c) as a starting material and dichloromethane and methanol as solvents to give 80mg of a solid in a yield of 63.5%.

¹H NMR(400MHz,DMSO)8.12(s,1H),7.93(d,J＝7.9Hz,2H),7.73(d,J＝8.0Hz,2H),7.69(d,J＝8.9Hz,2H),7.06(d,J＝8.2Hz,2H),6.29(s,2H),4.36(s,1H),4.15(t,J＝6.2Hz,2H),3.30(s,2H),3.03(s,3H),2.17(t,J＝7.8Hz,2H),1.14(s,3H),1.06(s,3H).

MS(ESI)m/z:[(M+H)+,464.0].

Example 17: preparation of N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) -4- ((5-hydroxy-4-oxa-1, 4-dihydropyridin-2-yl) methoxy) benzamide (Compound 17)

(a) (2S,3R) -2- (4- ((4, 5-bis ((4-methoxybenzyl) oxy) pyridin-2-yl) methoxy) benzoyl) -3-hydroxybutyric acid methyl ester

Using the compound methyl (2S,3R) -3-hydroxy-2- (4-hydroxybenzamide) butanoate (product of step (a) of example 12) (157mg, 0.620mmol), (4, 5-bis ((4-methoxybenzyl) oxy) -2-pyridyl) methanol (WO2013150296A1) (354mg, 0.930mmol), triphenylphosphine (325mg, 1.240mmol), diethyl azodicarboxylate (216mg, 1.240mmol) as a starting material and anhydrous tetrahydrofuran as a solvent, 300mg of a white solid was obtained in a yield of 78.5% as described in example 1 (a).

¹H NMR(400MHz,DMSO)8.19(s,1H),8.07(s,1H),7.88(d,J＝8.8Hz,2H),7.36(d,J＝13.0Hz,5H),7.11(d,J＝8.8Hz,2H),6.92(s,4H),5.14(s,2H),5.10(d,J＝5.3Hz,4H),4.94(s,1H),4.48(s,1H),4.16(s,1H),3.74(s,6H),3.65(s,3H),1.13(s,3H).

MS(ESI)m/z:[(M+H)⁺,617.1]

(b)4- ((4, 5-bis ((4-methoxybenzyl) oxy) pyridin-2-yl) methoxy) -N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) benzamide

The procedure described in (e) of example 1 was repeated using methyl (2S,3R) -2- (4- ((4, 5-bis ((4-methoxybenzyl) oxy) pyridin-2-yl) methoxy) benzoyl) -3-hydroxybutyrate (300mg, 0.486mmol) prepared in the above (a) as a starting material and dichloromethane and methanol as solvents to give 240mg of a solid in 80.0% yield.

¹H NMR(400MHz,DMSO-d₆)10.63(s,1H),8.83(s,1H),8.19(s,1H),7.86(t,J＝9.0Hz,1H),7.42–7.27(m,4H),7.09(d,J＝8.8Hz,2H),6.92(dd,J＝8.6,5.2Hz,4H),5.13(s,2H),5.09(s,4H),4.88(s,1H),4.23(s,1H),4.01(s,1H),3.74(s,6H),1.08(s,3H).

MS(ESI)m/z:[(M+H)⁺,618.0].

(c) N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) -4- ((5-hydroxy-4-oxa-1, 4-dihydropyridin-2-yl) methoxy) benzamide

The procedure described in (d) of example 8 was repeated using the compound 4- ((4, 5-bis ((4-methoxybenzyl) oxy) pyridin-2-yl) methoxy) -N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) benzamide prepared in (b) above (240mg, 0.389mmol) as a starting material and dichloromethane and methanol as solvents to give 100mg of a white solid in a yield of 68.2%.

¹H NMR(400MHz,DMSO-d₆)10.64(s,1H),8.85(s,1H),7.97(s,1H),7.89(s,3H),7.11(d,J＝8.8Hz,3H),5.25(s,2H),4.25(s,1H),4.01(s,1H),1.99(d,J＝7.4Hz,1H),1.06(s,3H).

MS(ESI)m/z:[(M+H)⁺，378.0].

Example 18: preparation of 4- ((1, 5-dihydroxy-4-oxa-1, 4-dihydropyridin-2-yl) methoxy) -N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) benzamide (Compound 18)

(a) (2S,3R) -2- (4- ((1, 5-bis (benzhydryloxy) -4-oxa-1, 4-dihydropyridin-2-yl) methoxy) benzamide) -3-hydroxybutyric acid methyl ester

Using the compound methyl (2S,3R) -3-hydroxy-2- (4-hydroxybenzamide) butanoate (product of step (a) of example 12) (157mg, 0.620mmol), 1, 5-bis (benzhydryloxy) -2- (hydroxymethyl) pyridin-4 (1H) -one [ Journal of medicinal Chemistry 56(2013)5541-5552] (607mg, 1.240mmol), triphenylphosphine (325mg, 1.240mmol), diethyl azodicarboxylate (216mg, 1.240mmol) as a starting material and anhydrous tetrahydrofuran as a solvent, 350mg of a white solid was obtained in a yield of 77.9% as described in example 1 (a).

¹H NMR(400MHz,DMSO-d₆)8.11(d,J＝8.2Hz,1H),7.85–7.79(m,3H),7.46–7.33(m,14H),7.30(dq,J＝6.5,3.6,2.9Hz,2H),7.24–7.19(m,4H),6.83(d,J＝8.8Hz,2H),6.46(s,1H),6.38(s,1H),6.03(s,1H),5.76(s,1H),4.94(d,J＝7.6Hz,1H),4.77(s,2H),4.47(dd,J＝8.2,4.1Hz,1H),4.17(ddd,J＝7.7,6.3,4.1Hz,1H),3.65(s,3H),1.14(d,J＝6.3Hz,2H).

MS(ESI)m/z:[(M+H)⁺,725].

(b)4- ((1, 5-bis (benzhydryloxy) -4-oxa-1, 4-dihydropyridin-2-yl) methoxy) -N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) benzamide

The procedure described in example 1 (e) was repeated using the compound methyl (2S,3R) -2- (4- ((1, 5-bis (benzhydryloxy) -4-oxa-1, 4-dihydropyridin-2-yl) methoxy) benzamide) -3-hydroxybutyric acid ester prepared in the above-mentioned (a) (350mg, 0.482mmol) as a starting material and dichloromethane and methanol as solvents to give 250mg of a solid in a yield of 71.4%.

¹H NMR(400MHz,DMSO-d₆)10.64(s,1H),8.85(s,1H),7.96–7.73(m,4H),7.45–7.34(m,13H),7.33–7.28(m,2H),7.25–7.17(m,4H),6.81(d,J＝8.8Hz,2H),6.46(s,1H),6.39(s,1H),6.02(s,1H),4.88(d,J＝6.4Hz,1H),4.77(s,2H),4.25(dd,J＝8.5,5.4Hz,1H),4.02(q,J＝6.1Hz,1H),1.08(d,J＝6.3Hz,3H).

MS(ESI)m/z:[(M+Na)⁺,748.1].

(c)4- ((1, 5-dihydroxy-4-oxa-1, 4-dihydropyridin-2-yl) methoxy) -N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) benzamide

The procedure described in (d) of example 8 was repeated using the compound 4- ((1, 5-bis (benzhydryloxy) -4-oxa-1, 4-dihydropyridin-2-yl) methoxy) -N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) benzamide prepared in (b) above (250mg, 0.344mmol) as a starting material and dichloromethane and methanol as solvents to give 100mg of a white solid in a yield of 73.9%.

¹H NMR(400MHz,DMSO-d₆)10.66(s,1H),10.24(d,J＝2.5Hz,2H),8.84(s,4H),8.03–7.81(m,2H),7.11(d,J＝8.7Hz,1H),6.95(s,1H),5.25(s,2H),4.23(s,1H),4.02(s,1H),1.07(s,3H).

MS(ESI)m/z:[(M+H)⁺,394.0].

Example 19: preparation of N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) -4'- ((5-hydroxy-4-oxa-1, 4-dihydropyridin-2-yl) methoxy) - [1,1' -biphenyl ] -4-carboxamide (Compound 19)

(a) (2S,3R) -2- (4'- ((4, 5-bis ((4-methoxybenzyl) oxy) pyridin-2-yl) methoxy) - [1,1' -biphenyl ] -4-ylcarbonyl) -3-hydroxybutyric acid methyl ester

The procedure described in example 1(a) was repeated using the compound methyl (2S,3R) -3-hydroxy-2- (4 '-hydroxy- [1,1' -biphenyl ] -4-formyl) butanoate (product of step (a) of example 16) (204mg, 0.620mmol), (4, 5-bis ((4-methoxybenzyl) oxy) -2-pyridyl) methanol (354mg, 0.930mmol), triphenylphosphine (325mg, 1.240mmol), and diethyl azodicarboxylate (216mg, 1.240mmol) as starting materials and anhydrous tetrahydrofuran as a solvent to give 310mg of a white solid in a yield of 72.2%.

¹H NMR(400MHz,DMSO)8.27(d,J＝8.2Hz,1H),8.20(s,1H),7.97(d,J＝8.4Hz,2H),7.77(d,J＝8.4Hz,2H),7.70(d,J＝8.8Hz,2H),7.37(d,J＝8.6Hz,2H),7.34(d,J＝8.6Hz,2H),7.31(s,1H),7.13(d,J＝8.8Hz,2H),6.92(dd,J＝8.6,2.0Hz,4H),5.14(s,2H),5.10(d,J＝7.6Hz,4H),4.99(d,J＝7.7Hz,1H),4.52(dd,J＝8.2,4.1Hz,1H),4.25–4.14(m,1H),3.74(s,3H),3.72(s,3H),3.67(s,3H),1.16(d,J＝6.4Hz,3H).

MS(ESI)m/z:[(M+H)⁺,692.9].

(b)4'- ((4, 5-bis ((4-methoxybenzyl) oxy) pyridin-2-yl) methoxy) -N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) - [1,1' -biphenyl ] -4-benzamide

The procedure described in (e) of example 1 was repeated using methyl (2S,3R) -2- (4'- ((4, 5-bis ((4-methoxybenzyl) oxy) pyridin-2-yl) methoxy) - [1,1' -biphenyl ] -4-ylcarbonyl) -3-hydroxybutyrate (310mg, 0.447mmol) prepared in (a) above as a starting material and dichloromethane and methanol as solvents to give 270mg of a solid in 87.1% yield.

¹H NMR(400MHz,DMSO-d₆)10.68(s,1H),8.86(s,1H),8.19(s,1H),8.02(d,J＝8.6Hz,1H),7.96(d,J＝8.5Hz,2H),7.75(d,J＝8.4Hz,2H),7.69(d,J＝8.8Hz,2H),7.37(d,J＝8.7Hz,2H),7.34(d,J＝8.7Hz,2H),7.31(s,1H),7.12(d,J＝8.8Hz,2H),6.92(dd,J＝8.7,2.0Hz,4H),5.14(s,2H),5.09(s,4H),4.92(d,J＝6.4Hz,1H),4.29(dd,J＝8.5,5.3Hz,1H),4.04(q,J＝6.1Hz,1H),3.74(s,3H),3.72(s,3H),1.10(d,J＝6.3Hz,3H).

MS(ESI)m/z:[(M+H)⁺,694.1].

(c) N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) -4'- ((5-hydroxy-4-oxa-1, 4-dihydropyridin-2-yl) methoxy) - [1,1' -biphenyl ] -4-carboxamide

The procedure described in (d) of example 8 was repeated using 4'- ((4, 5-bis ((4-methoxybenzyl) oxy) pyridin-2-yl) methoxy) -N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) - [1,1' -biphenyl ] -4-benzamide (270mg, 0.389mmol) prepared in the above-mentioned (b) as a starting material and dichloromethane and methanol as solvents to give 100mg of a white solid in a yield of 68.2%.

¹H NMR(400MHz,DMSO)10.69(s,1H),8.04(d,J＝8.5Hz,1H),7.98(d,J＝8.1Hz,2H),7.94(s,1H),7.75(t,J＝7.8Hz,4H),7.16(d,J＝8.6Hz,2H),7.05(s,1H),5.24(s,2H),4.29(dd,J＝8.4,5.5Hz,1H),4.08–4.02(m,1H),1.11(d,J＝6.2Hz,3H).

MS(ESI)m/z:[(M+H)⁺,454.2].

Example 20: preparation of 4'- ((1, 5-dihydroxy-4-oxa-1, 4-dihydropyridin-2-yl) methoxy) -N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) - [1,1' -biphenyl ] -4-carboxamide (Compound 20)

(a) (2S,3R) -2- (4'- ((1, 5-bis (benzhydryloxy) -4-oxa-1, 4-dihydropyridin-2-yl) methoxy) - [1,1' -biphenyl ] -4-ylbenzoylamino) -3-hydroxybutyric acid methyl ester

The procedure described in example 1(a) was repeated using the compound methyl (2S,3R) -3-hydroxy-2- (4 '-hydroxy- [1,1' -biphenyl ] -4-formyl) butanoate (product of step (a) of example 16) (304mg, 0.620mmol), 1, 5-bis (benzhydryloxy) -2- (hydroxymethyl) pyridin-4 (1H) -one (607mg, 1.240mmol), triphenylphosphine (325mg, 1.240mmol), diethyl azodicarboxylate (216mg, 1.240mmol) as a starting material, and anhydrous tetrahydrofuran as a solvent to give 350mg of a white solid in a yield of 69.4%.

¹H NMR(400MHz,CDCl₃)8.02(d,J＝8.3Hz,2H),7.76(d,J＝8.3Hz,1H),7.58(d,J＝8.4Hz,2H),7.43(d,J＝8.7Hz,2H),7.33(d,J＝8.7Hz,2H),7.17(s,1H),7.06(d,J＝8.7Hz,2H),6.89(d,J＝8.7Hz,2H),6.85(d,J＝8.7Hz,2H),6.75(d,J＝8.7Hz,2H),6.48(s,1H),4.99(s,2H),4.98(s,2H),4.83(dd,J＝8.5,3.0Hz,1H),4.62(s,2H),4.53–4.46(m,1H),3.80(s,3H),3.78(s,3H),3.77(s,3H),1.34(d,J＝6.4Hz,3H).

MS(ESI)m/z:[(M+Na)⁺,731.2].

(b)4'- ((1, 5-bis (benzhydryloxy) -4-oxa-1, 4-dihydropyridin-2-yl) methoxy) -N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) - [1,1' -biphenyl ] -4-carboxamide

The procedure described in (e) of example 1 was repeated using methyl (2S,3R) -2- (4'- ((1, 5-bis (benzhydryloxy) -4-oxa-1, 4-dihydropyridin-2-yl) methoxy) - [1,1' -biphenyl ] -4-ylbenzoylamino) -3-hydroxybutyric acid ester prepared in (a) above (350mg, 0.436mmol) as a starting material and dichloromethane and methanol as solvents to give 280mg of a solid in 80.1% yield.

¹H NMR(400MHz,DMSO)10.68(s,1H),8.86(s,1H),8.11(s,1H),8.03(d,J＝8.4Hz,1H),7.98(d,J＝8.3Hz,2H),7.76(d,J＝8.4Hz,2H),7.71(d,J＝8.3Hz,2H),7.39(d,J＝7.0Hz,4H),7.05(d,J＝8.5Hz,2H),6.98(d,J＝5.6Hz,2H),6.96(d,J＝5.7Hz,2H),6.19(s,1H),5.28(s,2H),5.05(s,2H),4.96(s,2H),4.92(d,J＝6.4Hz,1H),4.30(dd,J＝8.2,5.6Hz,1H),4.09–4.02(m,1H),3.77(s,3H),3.76(s,3H),1.11(d,J＝6.3Hz,3H).

MS(ESI)m/z:[(M-H)^-,708.0]

(c)4'- ((1, 5-dihydroxy-4-oxa-1, 4-dihydropyridin-2-yl) methoxy) -N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) - [1,1' -biphenyl ] -4-carboxamide

The procedure described in (d) of example 8 was repeated, using 4'- ((1, 5-bis (benzhydryloxy) -4-oxa-1, 4-dihydropyridin-2-yl) methoxy) -N- ((2S,3R) -3-hydroxy-1- (hydroxylamine) -1-oxybutan-2-yl) - [1,1' -biphenyl ] -4-carboxamide (280mg, 0.349mmol) prepared in the above-mentioned (b) as a starting material and dichloromethane and methanol as solvents, to give 100mg of a white solid in a yield of 61.0%.

¹H NMR(400MHz,DMSO)10.69(s,1H),8.03(d,J＝8.5Hz,1H),7.97(d,J＝7.9Hz,2H),7.80(s,1H),7.75(d,J＝8.2Hz,2H),7.71(d,J＝8.3Hz,2H),7.12(d,J＝8.4Hz,2H),6.84(s,1H),5.20(s,2H),4.34–4.25(m,1H),4.09–3.98(m,1H),1.11(d,J＝6.2Hz,3H).

MS(ESI)m/z:[(M-H)^-,468.1].

Biological activity assay

1. Experiment for inhibiting bacteria

The test method comprises the following steps: the MIC (Minimum inhibitory concentration) value of each compound was measured three times by the following method.

The method used 96-well plates and LB medium containing 5% DMSO. The compounds were prepared at different concentrations and 100. mu.L were placed in 96-well plates (Corning Costar3596, flat bottom with lid, polystyrene wells). In the two-fold dilution series, the ranges are 0.0005-1. mu.g/mL, 0.0025-5. mu.g/mL, and 0.014-5. mu.g/mL. Bacterial cells, grown to an OD600 of 0.6, were diluted 100-fold with fresh LB medium and 100 μ L of the diluted cells were added to each well. These inoculated plates were incubated at 37 ℃ for 22 h. After the incubation is finished, 50uL of 1mg/mL 3- (4, 5-dimethylthiazole-2) -2, 5-diphenyl tetrazolium bromide (MTT) is added, and the plate is incubated for 3 hours. The MIC values were based on the lowest concentration with no significant discoloration (from yellow to black).

The positive control drug is CHIR-090 which is a classical LpxC inhibitor and can effectively inhibit the growth of pseudomonas aeruginosa and escherichia coli.

As can be seen from the data in Table 2, the compound of the present invention has very good biological activity, such as strong in vitro inhibition activity of the compounds 4,5, 6 and 7 against Pseudomonas aeruginosa and Escherichia coli, and particularly the compound 4 has significantly better bacteriostatic activity than the positive drug CHIR-090.

TABLE 2 inhibitory Activity data (unit: μ g/ml) of some of the compounds against Pseudomonas aeruginosa and Escherichia coli

2. In vitro liver microsome stability test of the present invention

The test method comprises the following steps: SD rat liver microsomes and ICR mouse liver microsomes were used for this experiment. The incubation method is as follows: the microsomes were placed in 0.1M tris (hydroxymethyl) aminomethane/hydrochloric acid buffer (pH 7.4) to a final concentration of 0.33mg/ml microsomal protein, followed by addition of the cofactor MgCl₂(5mM), test compound (final concentration of 0.1. mu.M, cosolvent 0.01% DMSO, 0.005% BSA) and NADPH (1mM), incubated at 37 ℃ for 60 min. The reaction is started upon addition of liver microsomes, test compounds or NADPH. Samples were taken at 0, 7, 17, 30 and 60min of incubation and the enzymatic reaction was stopped by precipitation of the protein by addition of methanol. After centrifugation, the samples were analyzed by LC/MS/MS. The method evaluates the metabolic stability of the test compound by measuring its in vitro half-life and hepatic microsomal clearance.

TABLE 3 data for partial compounds in vitro liver microsome stability experiments

As can be seen from the data in Table 3, the compounds 4 and 5 of the present invention have very good stability in the in vitro liver microsome stability test, and are significantly better than the control drug CHIR-090.

All documents referred to herein are incorporated by reference into this application as if each were individually incorporated by reference. Furthermore, it should be understood that various changes and modifications of the present invention can be made by those skilled in the art after reading the above teachings of the present invention, and these equivalents also fall within the scope of the present invention as defined by the appended claims.

Claims

1. A compound of formula I, enantiomers, diastereomers, racemates or mixtures thereof, or a pharmaceutically acceptable salt thereof,

in the formula, R₁Is substituted C₁-C₆Alkyl, said substitution being with a substituent selected from the group consisting of: hydroxy, amino;

m is 1;

n is 1;

x is-O-;

R₂is-SO₂(C₁-C₃Alkyl) substituted C₁-C₆An alkyl group.

2. The compound of formula I according to claim 1, wherein the configuration of each chiral carbon atom in the compound of formula I is independently R-or S-form.

3. A compound of formula I according to claim 1, wherein R is₁Is hydroxy or amino substituted C₁-C₄An alkyl group.

4. A compound of formula I according to claim 1, wherein R is₂is-SO₂CH₃Substituted C₁-C₆An alkyl group.

5. A compound of formula I according to claim 1, wherein R is₂is-SO₂CH₃Substituted C₁-C₄An alkyl group.

6. The compound of formula I according to claim 1, wherein the compound of formula I is:

or

7. A process for the preparation of a compound of formula I according to claim 1, comprising the steps of:

wherein X is defined as in claim 1,

in the formulae, R₁As protected or unprotected, substituted C₁-C₆Alkyl, said substitution being with a substituent selected from the group consisting of: hydroxy, amino;

R₂is-SO protected or unprotected₂(C₁-C₃Alkyl) substituted C₁-C₆An alkyl group;

y is ethynyl or halogen;

and when R is₁Is protected, substituted C₁-C₆Alkyl and/or R₂To be protected-SO₂(C₁-C₃Alkyl) substituted C₁-C₆When alkyl, the process further comprises the step of removing a protecting group selected from: tert-butyloxycarbonyl, p-methoxybenzyl, benzhydryl, benzyl, tert-butyldimethylsilyl, tert-butyldiphenylsilyl, allyl, methoxymethyl, methylthiomethyl, methoxyethoxymethyl, benzyloxymethyl.

8. A pharmaceutical composition, comprising:

a compound of formula I according to claim 1, enantiomers, diastereomers, racemates or mixtures thereof, or a pharmaceutically acceptable salt thereof; and

a pharmaceutically acceptable carrier.

9. Use of a compound of formula I according to claim 1 or a pharmaceutical composition according to claim 8 for:

(1) preparing a medicament for inhibiting LpxC deacetylase;

(3) preparing the medicine for inhibiting the growth of bacteria.

10. The use of claim 9, wherein the bacterial infection is a gram-negative bacterial infection.

11. The use according to claim 10, wherein the gram-negative bacteria are selected from the group consisting of: escherichia coli, Pseudomonas aeruginosa and Acinetobacter baumannii.

12. A method for reducing the pathogenicity or toxicity of a bacterium for an in vitro non-therapeutic purpose, comprising the steps of:

contacting a bacterium with a compound of formula I according to claim 1 or a pharmaceutical composition according to claim 8, thereby reducing the pathogenicity or toxicity of the bacterium.

13. The method of claim 12, wherein the bacteria is a gram negative bacteria.

14. The method of claim 13, wherein the gram-negative bacteria are selected from the group consisting of: escherichia coli, Pseudomonas aeruginosa and Acinetobacter baumannii.

15. The method of claim 12, wherein said contacting results in an increase or decrease in the amount of LpxC deacetylase in the bacterium.

16. A method for inhibiting LpxC deacetylase for in vitro non-therapeutic purposes, by administering a compound of formula I as defined in claim 1 or a pharmaceutical composition as defined in claim 8 to a subject in need thereof or to the environment.

17. An in vitro non-therapeutic antibacterial method of administering a compound of formula I according to claim 1 or a pharmaceutical composition according to claim 8 to a subject in need thereof or to the environment.