PEPTIDIC THROMBIN INHIBITOR COMPOUND TECHNICAL FIELD The present invention relates to a novel thrombin inhibitor compound represented by the following formula (1) : a pharmaceutically acceptable salt, hydrate, solvate, and isomer thereof, in which A represents -CH2CO2R1 wherein R1 represents hydrogen, C1-C6-alkyl, C3-C7-cycloalkyl, C5-C10-ar-C1-C6-alkyl, or Cs-Clo-aryl, B represents H, OH, R2, OR, OC (O) R2, OC (O) NHR, OC (O) OR2, C (O) OR2, C(O)R2,C(O)NHR2,C(O)NR22,OP(O)(OR3)2, or C (O) O (CHR4) OC (O) R, wherein Rl and B are not hydrogen at the same time, Ra and Rs independently of one another represent nitro, or represent C1-C6-alkyl unsubstituted or mono-to poly-substituted by substituents selected from a group consisting of halogen, hydroxy and Cl-C6-alkoxy, or represent (CH2)n-C3-C7-cycloalkyl, (CH2)n-heteroaryl, or (CH2) n-heterocycle (n=0, 1,2, 3) (wherein heteroaryl or heterocycle means 5 or 6 membered ring having one or two hetero atoms selected from a group consisting of nitrogen, oxygen and sulfur), or represent phenyl unsubstituted or mono-to poly-substituted by substituents selected from a group consisting of halogen, hydroxy and Ci-Ce-alkoxy, or represent C5-C10-ar-C1-C6-alkyl, C5-C10-aryl or Cl-C6-alkyl-N (R4) 2, m denotes an integer of 1,2, 3 or 4,

R3 represents hydrogen or C-C6-alkyl, and R4 represents hydrogen or Cl-C3-alkyl, which has a good inhibitory effect against thrombosis and can be orally administered.

The present invention also relates to a process for preparing the compound of formula (1) as defined above, to a composition for the therapeutic and/or prophylactic treatment of various diseases associated with thrombin inhibition mechanism, which composition comprises the compound of formula (1) as an active ingredient, and to a method of treatment thereof.

BACKGROUND ART It is generally known that coagulation is the result of a complex series of enzymatic reactions. The final step in this series of reactions is the conversion of prothrombin to the active enzyme thrombin. Thrombin thus produced activates platelets, converts fibrinogen into fibrin monomers, which polymerize spontaneously into fibrin polymers, and activates factor XIII, which in turn crosslinks the polymers to form insoluble fibrin. Furthermore, thrombin activates factor V and factor VIII, which participate in the blood coagulation process, to more facilitate the blood coagulation reaction. Inhibitors of thrombin would therefore be expected to act as an effective anticoagulant, and at the same time, to prevent and treat various thrombosis by inhibiting the aggregation of platelets and the formation and stabilization of fibrin.

Heparin is now used most widely as an injectable anticoagulant, of which activity is based on a mechanism of indirectly inhibiting thrombin by binding antithrombin. Also, heparin shows a low effect against arterial thrombosis, and further has such a demerit that patients should be carefully observed during the treatment due to low stability with respect

to bleeding. In addition, coumarine, the most widely used anticoagulant in the form of oral preparation, is an antagonist of vitamin K-dependent serine proteases. However, it has such disadvantages that it becomes effective in a certain period (6-24 hours) from the administration and also requires careful observation of patients due to the same undesirable bleeding.

Low molecular weight thrombin inhibitors have been highlighted as a therapeutic agent against thrombosis, and so many studies have been made (USP 4,258, 192; USP 4,201, 863 ; Biochemistry 1984,23, 85-90; J. Med. Chem. 1990,33, 1729 ; Circulation 1994, 90, 1-231 ; WO 93/11152; WO 94/29336; J. Med. Chem. 1997,40, 1565).

Further, a new thrombin inhibitor, which can be orally administered as well as absorbed into blood in a high concentration when orally administered, has been published in WO 00/39124.

During the consecutive study about the thrombin inhibitors disclosed in WO 00/39124, however, the present inventors have discovered that the inhibitors show high absorptivity and therapeutic effect before food ingestion, but highly reduced bioavailability after food ingestion, when the drug is orally administered. Thus, the present inventors extensively studied to improve this problem, developed an effective prodrug of the compound disclosed in WO 00/39124, and then completed the present invention.

It was also identified that the prodrug according to the present invention contributes to the enhancement of bioavailability as described in USP 5,965, 692. That is, in the pharmacokinetic experiment on dogs and trypsin inhibitory experiment, the prodrug of the present invention shows similar bioavailability but no trypsin inhibitory activity when compared with the parent drugs of WO 00/39124. Since the compound of the present invention has a decreased trypsin inhibitory effect, it is possible to reduce probable side effects including indigestion which are caused by the inhibition of trypsin or other

serine proteases in the gastrointestinal tract by the orally administered active thrombin inhibitors. The compound of the invention takes the form of a prodrug which is inactive per se, but upon oral or parenteral administration is metabolized in the body to form an active thrombin inhibitor. Accordingly, it makes it possible to diminish inter-or intra-individual difference in bioavailability, to dissolve the difficulty in the determination of time interval of treatment from too high (bleeding) or low (formation of thrombosis) plasma concentration, and to reduce the side effects.

DISCLOSURE OF THE INVENTION Therefore, it is an object of the present invention to provide a compound of the following formula (1) : a pharmaceutically acceptable salt, hydrate, solvate, or isomer thereof, in which A represents-CH2CO2R'wherein R'represents hydrogen, Cs-C6-alkyl, C3-C7-cycloalkyl, C5-C10-ar-C1-C6-alkyl, or C5-C10-aryl, B represents H, OH, R2, oR2, OC (O) R2, OC (O) NHR2, OC (O) OR2, C (O) OR2, C(O)R2,C(O)NHR2,C(O)NR22,OP(O)(OR3)2, or C (O) O (CHR4) mOC (O) R59 wherein R'and B are not hydrogen at the same time, R2 and Rs independently of one another represent nitro, or represent C1-C6-alkyl unsubstituted or mono-to poly-substituted by substituents selected from a group consisting of halogen, hydroxy and Cl-C6-alkoxy, or represent (CH2) n-C3-C7-cycloalkyl,

(CH2) n-heteroaryl, or (CH2) n-heterocycle (n=0, 1,2, 3) (wherein heteroaryl or heterocycle means 5 or 6 membered ring having one or two hetero atoms selected from a group consisting of nitrogen, oxygen and sulfur), or represent phenyl unsubstituted or mono-to poly-substituted by substituents selected from a group consisting of halogen, hydroxy and C1-C6-alkoxy, or represent C5-C) o-ar-C)-C6-alkyl, Cs-Cjo-aryl or Cl-C6-alkyl-N (R4) 2, m denotes an integer of 1, 2, 3 or 4, R3 represents hydrogen or Cl-C6-alkyl, and R4represents hydrogen or C,-C3-alkyl, which has a good inhibitory effect against thrombosis and can be orally administered.

In the definitions of substituents for the compound of formula (1) of the present invention, the term"alkyl"when used alone or in a composite term such as"alkyloxy" means straight-chain or branched hydrocarbon radical including for example methyl, ethyl, isopropyl, isobutyl, and t-butyl, and the carbon number of alkyl may be enlarged to the extent that any person skilled in the art to which the present invention pertains can expect.

Among the compound of formula (1) of the present invention, a preferred one includes those wherein A represents -CH2CO2R1, wherein R1 represents hydrogen or Cl-C6-alkyl.

Among the compound of formula (1) of the present invention, a preferred one also includes those wherein B represents H, OH, C (O) OR2, OC (O) R2, C (O) R2, C (O) NHR2, C (O) NR22, OP (O) (OR3) 2 or C (O) O (CHR4) mOC (O) R5, wherein R2 and Rs independently of one another represent C,-C6-alkyl unsubstituted or mono-to poly-substituted by substituents selected from a group consisting of halogen, hydroxy and C-C6-alkoxy, or represent (CH2) n-C3-C7-cycloalkyl, (CH2) n-heteroaryl, or (CH2) n-heterocycle (n=0, 1, 2, 3) (wherein heteroaryl or heterocycle means 5 or 6 membered ring having one or two hetero atoms selected from a group consisting of nitrogen, oxygen and sulfur), or represent phenyl unsubstituted or mono-to poly-substituted by substituents selected from a group consisting

of halogen and Cl-C6-alkoxy, or represent C5-Clo-ar-Cl-C6-alkyl or Cl-C6-alkyl-N (R4) 2, m denotes an integer of 1,2, 3 or 4, R3 represents Cl-C6-alkyl, and R4 represents hydrogen or Cl-C3-allcyl.

A particularly preferred one includes those wherein A represents-CH2CO2RI, wherein R'represents hydrogen, ethyl or t-butyl, B represents H, OH, C (O) OR2, OC (O) R2, C (O) R2, C (O) NHR2, C (O) NR22, OP (O) (OR3) 2 or C (O) O (CHR4) mOC (O) R5, wherein R2 and R5 independently of one another represent methyl, ethyl, isopropyl, isobutyl, t-butyl or neopentyl each of which is unsubstituted or mono-to poly-substituted by substituents selected from a group consisting of fluoro, chloro, hydroxy and methoxy, or represent (CH2)n-C3-C6-cycloalkyl (n=0,1, 2,3), imidazole, (CH2)2-morpholine, or CH2-pyridine, or represent phenyl unsubstituted or mono-to poly-substituted by substituents selected from a group consisting of fluoro and methoxy, or represent benzyl or- (CH2) 2-N (CH3) 2, m denotes an integer of 1, 2,3 or 4, R3 represents ethyl, and R4 represents hydrogen or methyl.

Typical examples of the compound of formula (1) according to the present invention include the following.

Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-OH ; H2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-OH ; EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph ; EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C(O)OCH2CCl3 ; HO2CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-C (O) OCH2CCl3 ; tBuO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C (O) OCH2CCl3 ; tBu02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-C (O) OCH2CH3 ; Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-C (O) OCH2CH3 ; H2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C(O) OCH2CH3; H2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C(O)OCH2Ph ; EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C(O) OCH2Ph;

HO2CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-C (O) OCH2iPr ; Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-C (O) OCH2iPr ; tBuO2CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-C (O) OCH2iPr ; H02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-C (O) OCH (CH3) OC (O) CH3; EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C (O) OCH (CH3) OC (O) CH3; tBu02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-C (O) OCH (CH3) OC (O) CH3; HO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C (O) OCH2CH20CH3 ; EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C(O)OCH2CH2OCH3 ; HO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C (O) OPh-4-F; EtO2CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-C (O) OPh-4-F; EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-OC (O) CH3; H02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-C (O) OCH2CF3 ; EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C(O)OCH2CF3 ; EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C(O) OPh-4-OCH3; HO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C(O)OCH2CH2F ; EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C(O)OCH2CH2F ; EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C(O) OCH20C (O) CH3; HO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C(O)OCH2Cyh ; Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-C (O) OCH2Cyh ; HO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C(O)OCH2CH2Cyh ; EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C(O) OCH2CH2Cyh; EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C (O)-Imid ; EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C(O)OCH2CH2-Mor ; EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C(O)OCH2-3-Pyr ; EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C(O)NHCH2CH2OH ; Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-C (O) N (CH2CH20H) 2; Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-C (O) OCH2CH2N (CH3) 2 ; EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C(O)OCH2Cypr ; EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C(O)OCH2Cypen ;

EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C (O) CH2tBu ; Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-C (O) OCyh; EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C (O) OCH2Cyb ; EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C(O)CH3; EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C (O) CH2CH3 ; Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-C (O) iPr ; Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-OC (O) iPr ; Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-OC (O) CH2CH3 ; EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-OC (O) tBu ; Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-OP (O) (OCH2CH3) 2 ; and Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-C (O) NHCH2iPr.

A particularly preferred compound among the above typical examples includes the following.

Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-OH ; EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C(O)OCH2iPr ; Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-OC (O) CH3; EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C(O)OCH2Cyh; EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C (O) OCH2CH2Cyh ; Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-C (O) OCH2-3-Pyr ; and EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C (O) CH3.

The compound of formula (1) according to the present invention can also form a pharmaceutically acceptable salt. Such salt includes non-toxic acid addition salt containing pharmaceutically acceptable anion, for example, a salt with inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, hydrobromic acid, hydriodic acid, etc. , a salt with organic carboxylic acids such as tartaric acid, formic acid, citric acid, acetic acid, trichloroacetic acid, trofluoroacetic acid, gluconic acid, benzoic acid, lactic acid, fumaric acid, maleic acid, etc. , or a salt with sulfonic acids such as

metlianesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, naphthalenesulfonic acid, etc.

Furthermore, the compound of the present invention may have asymmetric carbon atoms in the structure, and so may exist in the form of R or S isomer or individual diastereomers, or mixtures thereof including racemates. Thus, the present invention also includes all of these isomers and their mixtures in its scope.

The compound of formula (1) of the present invention can be prepared, characterized in that (a) a compound represented by the following formula (2): wherein B is as defined above and P represents an amino-protecting group, preferably t-butoxycarbonyl (boc), is reacted in a solvent with HCl gas to give a compound represented by the following formula (3): wherein B is as defined above, and the compound of formula (3) thus produced is reacted in a solvent in the presence of a base and a catalyst with a compound represented by the following formula (4):

A-L (4) wherein A is as defined above and L represents a leaving group, preferably halogen, to give the compound of formula (1), or (b) a compound represented by the following formula (la) or (lb) :

wherein A is as defined above, is reacted in a solvent in the presence of a base with a carbonate, an anhydride or a halide to give a compound represented by the following formula (lc) :

wherein B'represents B except H and OH, which has an alkyl or acyl group.

Therefore, it is another object of the present invention to provide the above process for preparing the compound of formula (1).

As preferable examples of the base and catalyst in the above process (a), diisopropylethylamine (DIPEA) and sodium iodide (NaI) may be mentioned, respectively, and methylene dichloride may be mentioned as the solvent. After the reaction is completed, a quenching agent, such as preferably hexamethylenetetramine (hexamine), may be added to the reaction solution in order to remove the unreacted reactant, whereby such a side reaction as introducing two A groups into the amine group is suppressed.

The carbonate, anhydride or halide to introduce the group B'into the compound of formula (la) or (lb) may be in the form of X-B', RCOB', ROCOB', or XCOB' (wherein X represents halogen and R represents alkyl), and the halide, anhydride or ester group is removed after the substitution reaction.

Specific examples of the above process are depicted in the following Reaction Schemes 1 and 2, and the abbreviations used therein are explained below.

TEA: Triethylamine MDC : Methylenedichloride DIPEA: Diisopropylethylamine hexamine: Hexamethylenetetramine [Process 1] Compounds (9) and (10) may be prepared according to the processes as described in WO 00/39124. Compound (10) may be N-alkylated with various reactants and then reacted with hydroxylamine to give an amidoxime compound such as Compound (12).

This Compound (12) may be a prodrug per se as well as be used as a starting material for preparing other prodrugs. That is, various alkylation or acylation reactions may be subjected to Compound (12) to give Compound (13). Otherwise, the amidoxime of Compound (12) may be converted into an amidine, which is then alkylated or acylated to give Compound (15). Furthermore, the protecting group of Compound (14) may be removed by HC1 gas, and the resulting compound, Compound (16), may be alkylated or

acylated to give Compound (17). Alkyl (Rl and B'), carbonate, anhydride (mixed acid anhydride), etc. as mentioned here will be more specifically described in the following examples. In the following reaction schemes, B'X means alkyl or acylhalide, and alkyl means straight-chain or branched alkyl including methyl, ethyl, isopropyl, isobutyl, and t-butyl as stated before.

Reaction Scheme 1 PhPh H L-CHI-COI < N N.... ,, q N"DIPEA/Nal. R'O, C" 9 10 Rt O O p MDC 9 10 PhvPh Ph, Ph Carbonateoranhydride TEAIEtOH ^ N N S N-OH o halide etc _ R'O CNNNB' NHzOH. HCI R OZC O O NH2 Organic solvenubase zu '12 Ph Ph Ph Ph Carbonate or anhydride 12 AcOIMeOH ^ N'N , NH ohalideetc R102CN NN S NB ROC N g H 2. Hz (guPd-C H O p (NH Organic sovenGbase O O NHi 14 15 Ph,. Ph ph ph Ph Ph Carbonateoranhydride PhPh H HO C H g HO C N O 0 NH2 Organic solvent/base H z 17 16

[Process 2] The Compound (9) prepared in Process 1 may be reacted with hydroxylamine to give an amidoxime compound, Compound (18), which is then alkylated or acylated in a variety of ways to give Compound (19). Then, the amino-protecting group, Boc, is removed [such a protecting group may be removed by conventionally known methods such as a reaction with HCl gas, hydrogenation, or a reaction using trifluoroacetic acid (TFA)], and the amine compound may be alkylated or acylated to give Compound (13).

Reaction Scheme 2 Ph Ph : f ., jT-n Carbonate or anhydride D H Carbonate or anhydride or halide etc NHUH. rlU ! 0 0 NH Organic sotvent/base 18 18 Ph Ph -1 H \ 1. HClin MDC BocNH N ii N g N B 2. L-CHrCO2-R' DIPEA/Nal NH2 hexamine MDC 19 The compound of formula (1) prepared according to the process of the present invention may be converted into its salt. After the reaction is completed, the product may be isolated and purified by conventional work up processes such as chromatography, recrystallization, etc.

However, the processes for preparing the compound according to the present invention are not limited to those as explained above, and can be easily selected by optionally combining various synthetic ways described in the present specification or known in the art. And such a combination may be easily carried out by one of ordinary skill in the art.

The above processes according to the present invention will be more specifically explained in the following examples. However, it should be understood that the scope of the present invention is not limited in any manner by these examples.

[Medical and Pharmaceutical Use] The compound of the present invention is useful because it is metabolized in the body to form a compound which possesses pharmacological activity. In particular, the

compound of the invention is inactive to thrombin per se, but can be metabolized in the body to form a potent inhibitor of thrombin, for example as demonstrated in the experiments described below.

The compound of the invention is inactive to thrombin per se, and so shows an ICso Thrombin Clotting Time (TT) of I tM or more as determined in Experiment 1 below.

The compound of the invention is thus expected to be useful in those conditions where inhibition of thrombin is required, but such side effects as bleeding in the intestinal tract, indigestion, etc. need to be suppressed.

Therefore, the present invention relates to a composition for the therapeutic and/or prophylactic treatment of various diseases associated with thrombin inhibition mechanism, which comprises the compound of formula (1) as an active ingredient.

More specifically, the present invention relates to a composition for the therapeutic and/or prophylactic treatment of thrombosis and hypercoagulability in blood and tissues of animals including humans.

It is known that hypercoagulability may lead to thrombo-embolic diseases.

Thrombo-embolic diseases include activated protein C resistance, such as the factor V-mutation, and inherited or acquired deficiencies in antithrombin III, protein C, protein S, heparin cofactor II. Other conditions known to be associated with hypercoagulability and thrombo-embolic disease include circulating antiphospholipid antibodies (Lupus anticoagulant), homocysteinemia, heparin induced thrombocytopenia and defects in fibrinolysis. Thus, the compound of the invention can be used for the therapeutic and/or prophylactic treatment of these conditions.

The compound of the invention is further useful for the treatment of conditions where there is an undesirable excess of thrombin without signs of hypercoagulability, for

example neurodegenerative diseases such as Alzheimer's disease.

Particular diseases which may be mentioned include venous thrombosis, pulmonary embolism, arterial thrombosis (e. g. , myocardial infarction, unstable angina, thrombosis-based cerebral stroke, and peripheral arterial embolism) and systemic embolism usually from the atrium during arterial fibrillation or from the left ventricle after transmural myocardial infarction.

Moreover, the compound of the invention is expected to have utility for the prophylaxis of re-occlusion after percutaneous trans-luminal angioplasty, thrombolysis and coronary bypass operations; the prevention of re-thrombosis after microsurgery and vascular surgery in general.

Further utilities include the therapeutic and/or prophylactic treatment of disseminated intravascular coagulation caused by bacteria, multiple trauma, intoxication or any other mechanism; anticoagulant treatment when blood is in contact with foreign surfaces in the body such as vascular grafts, vascular stents, vascular catheters, mechanical and biological prosthetic valves, or any other medical device; and anticoagulant treatment when blood is in contact with medical devices outside the body such as during cardiovascular surgery using a heart-lung machine or in haemodialysis.

In addition to its effects on the coagulation process, thrombin is known to activate a large number of cells such as neutrophils, fibroblasts, endothelial cells and smooth muscle cells. Therefore, the compound of the invention may be also useful for the therapeutic and/or prophylactic treatment of idiopathic and adult respiratory distress syndrome, pulmonary fibrosis following treatment with radiation or chemotherapy, septic shock, septicemia, inflammatory responses, which include, but are not limited to, acute or chronic atherosclerosis such as coronary arterial disease, cerebral arterial disease, peripheral arterial disease, reperfusion damage, and restenosis after percutaneous

trans-luminal angioplasty.

The compound of the invention that inhibits trypsin and/or thrombin may be also useful for the treatment of pancreatitis.

Considering the interrelation between the thrombin inhibitory mechanism and the various diseases as explained above, the compound of the invention can be specifically used for the therapeutic and/or prophylactic treatment of antiphospholipid antibodies, homocysteinemia, heparin induced thrombocytopenia, venous thrombosis, pulmonary embolism, arterial thrombosis, myocardial infarction, unstable angina, thrombosis-based cerebral stroke, peripheral arterial embolism, systemic embolism, septic shock, and pancreatitis, and prophylaxis of re-occlusion, and prevention of re-thrombosis.

According to the further aspect of the present invention, there is provided a method of treatment of a condition where inhibition of thrombin is required which method comprises administration of a therapeutically effective amount of the compound of formula (1), pharmaceutically acceptable salt, hydrate, solvate, or isomer thereof as defined above, to a person suffering from, or susceptible to such a condition. The compound of the invention will normally be administered orally, buccally, rectally, dermally, nasally, tracheally, bronchially, by injection route, or via inhalation.

The compound of the invention may be also co-administered with any anticoagulant having a different mechanism of action, such as the antiplatelet agents acetylsalicylic acid, ticlopidine, clopidogrel, thromboxane receptor and/or synthetase inhibitors, fibrinogen receptor antagonists, prostacyclin minetics, phosphodiesterase inhibitors, ADP-receptor antagonists, and thrombin receptor antagonists.

The compound of the invention may further be combined and/or co-administered with thrombolytics such as tissue plasminogen activator (natural or recombinant),

streptokinase, urokinase, prourokinase, anisolated streptokinase plasminogen activator complex (ASPAC), animal salivary gland plasminogen activators, and the like, for the treatment of thrombotic diseases, in particular myocardial infarction.

Another further aspect of this invention provides a pharmaceutical formulation including the compound of formula (1) as defined before, or a pharmaceutically acceptable salt, hydrate, solvate, or isomer thereof, in admixture with a pharmaceutically acceptable auxiliaries (adjuvant), diluent or carrier.

Depending upon disorder of a patient to be treated and route of administration, the active compound may be administered at varying doses. A typically suitable daily dose of the compound of the invention in the therapeutic treatment is about 0. 001-100mg/kg body weight at peroral administration and 0. 001-50mg/kg body weight at parenteral administration.

The compound of the invention has the advantage to improve pharmacokinetic properties after oral and parenteral administration. Injections, for example, sterilized aqueous or oily suspension for injection, can be prepared according to the known procedure using suitable dispersing agent, wetting agent, or suspending agent. Solvents that can be used for preparing injections include water, Ringer's fluid and isotonic NaCl solution, and also sterilized fixing oil may be conveniently used as the solvent or suspending media. Any non-stimulative fixing oil including mono-, di-glyceride may be used for this purpose. Fatty acid such as oleic acid may also be used for injections. As the solid preparation for oral administration can be mentioned capsules, tablets, pills, powders, granules, etc. , preferably capsules and tablets. It is also desirable for tablets and pills to be formulated into enteric-coated preparation. The solid preparations may be prepared by mixing the active compound of formula (1) of the invention with at least one carrier selected from a group consisting of inactive diluents such as sucrose, lactose, starch, etc. , lubricants such as magnesium stearate, disintegrating agent, and binding agent.

A noticeable characteristic of the compound of formula (1) of the invention is that it shows improved bioavailability after food ingestion. As can be seen from Experiment 4 below, the compound of the invention exhibits up to about 100 times improved bioavailability as much as those of WO 00/39124.

Further, the compound of the invention has the feature that it is inactive per se to thrombin, trypsin and other serine proteases. The compound thus remains inactive in the gastrointestinal tract (see Experiments 1 and 2). Therefore, the compound of the invention can be used without the potential side effects such as bleeding and indigestion resulting from inhibition of trypsin, which may be caused by orally administered anticoagulants which are active per se. Furthermore, local bleeding associated with the parenteral administration of a thrombin inhibitor may be avoided by using the compound of the invention. Therefore, the compound of the invention may also have useful pharmacological properties such as more efficacious, less toxic, longer acting, having a broader range of activity, fewer side effects, more easily absorbed, etc. than other compounds known in the prior art (see Experiment 3).

The present invention will be more specifically explained in the following examples and experiments. However, it should be understand that these examples and experiments are intended to illustrate the present invention but not in any manner to limit the scope of the present invention.

The abbreviations and terms used in the nomenclature of the following examples are: Boc: t-butoxycarbonyl Br: bromo Bu: butyl tBu : t-butyl

Cl: chloro Cyb: cyclobutyl Cyh : cyclohexyl Cypr: cyclopropyl Cypen: cyclopentyl Dpa: diphenylalanine Et: ethyl F: fluoro Imid: imidazole iPr : isopropyl Mor: morpholine Ph : phenyl Pro: proline Pyr: pyridine thioph: thiophene Synthesis of starting compounds The following starting compounds were prepared by referring to the methods disclosed in IPA WO 00/39124 and Korean Patent Appln. No. 10-2001-0017840. <BR> <BR> <P> Boc-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph,<BR> Boc-D-Dpa-Pro-NH-CH2-5- (2-CN)-thioph,<BR> H02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph<BR> tBuO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-CN)-thioph,<BR> tBuO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph, Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-CN)-thioph, and 5-aminomethylthiophene-2-carbonitrile hydrochloride.

Example 1 Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-OH a) Preparation of EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-CN)-thioph HCI-D-Dpa-Pro-NH-CH2-5- (2-CN)-thioph (20g, 40. 40mmol) was dissolved in dichloromethane (60nle) and sodium iodide (1. 21g, 8. 08mmol) and ethylbromoacetate (927g, 161. 6mmol) were added thereto at 5°C. Diisopropylethylamine (13. 05g, 101. Ommol) was added dropwise while maintaining the temperature of 10°C or less. The reaction solution was stirred for about 9 hours, hexamethylenetetraamine (16.99g, 121.2mmol) was added, and the mixture was stirred again for about 10 hours. The reaction solution was washed with water (60m#), 2% aqueous hydrochloric acid solution (301lé) and 5% aqueous sodium hydrogen carbonate solution (30mu). The solvent was removed by distillation to give the title compound as a residue. b) Preparation of EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-OH The compound prepared in step a) was dissolved in ethanol (180vint) and hydroxylamine hydrochloride (10.39g, 149. 5mmol) was added thereto at 5#10°C. Triethylamine (13.90g, 137.4mmol) was added while maintaining the temperature of 10°C or less. Completion of reaction was confirmed by HPLC, the reaction solvent, ethanol, was removed by evaporation, and the residue was extracted with dichloromethane/water. The organic layer was washed with aqueous sodium chloride solution, dried over anhydrous sodium sulfate, and filtered to give the title compound as a residue. Thus obtained compound was dissolved in ethanol (180lnQ) and refluxed. The resulting solid was filtered to give the pure title compound (16. 2mmol, 9.33g) in a yield of 40%.

'H-NMR (400MHz, CDC13) S 8.65 (broad, 1H), 8. 22 (t, 1H), 7.43 (d, 2H), 7.36 (t, 2H), 7. 30-7. 08 (m, 6H), 7.01 (d, 1H), 6. 83 (d, 1H), 4.90 (s, 2H), 4.59 (dd, 1H), 4.52 (dd, 1H), 4.36 (d, 1H), 4.28 (m, 2H), 4.08 (m, 2H), 3.35 (m, 3H), 2.74 (dd, 1H), 1.98 (m, 2H), 1.81 (m, 1H), 1. 36 (m, 2H), 1.22 (t, 3H) LC-MS; [M+H] =578 Example 2 Preparation of H02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-OH The compound prepared in step b) of Example l (lg, 1. 73mmol) was dissolved in acetonitrile (long,) and stirred at room temperature. Then, 1N-aqueous sodium hydroxide solution (lOniC) was added dropwise thereto at room temperature. After 30 minutes, completion of reaction was confirmed by HPLC, and the reaction was stopped.

Acetonitrile was distilled under reduced pressure, and the reaction solution was adjusted to pH 6 by IN-aqueous hydrochloric acid solution. The resulting solid was filtered to give the title compound (900mg, 1. 64mmol) in a yield of 94%.

'H-NMR (400MHz, DMSO-d6) S 9. 57 (broad, 1H), 8.41 (t, 1H), 7. 49-7. 05 (m, 11H), 6.84 (d, 1H), 5.84 (s, 2H), 4.41 (m, 2H), 4.26 (dd, 1H), 4.12 (d, 1H), 3.93 (m, 1H), 3.00 (m, 1H), 1.73 (m, 1H), 1.58 (m, 2H), 1.35 (m, 1H) LC-MS ; [M+H] =550 Example 3 Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph

The compound prepared in step b) of Example 1 (4.26g, 7. 37mmol) was dissolved in methanol (21g) and the temperature of the reaction solution was lowered to 5°C. Acetic anhydride (0. 75g, 7. 38mmol) was added dropwise thereto. After 30 minutes, completion of reaction was confirmed by HPLC. The reaction solution was warmed to room temperature, and 5% palladium/carbon (0. 89g) was added. The reaction solution was stirred for about 18 hours under hydrogen bubbling to complete the reaction. The reaction solution was filtered and distilled to remove the solvent, and the residue was purified by column chromatography (50% ethyl acetate/hexane) to give the title compound (6. 26mmol, 3.52g) in a yield of 85.0%.

'H-NMR (500MHz, CDC13) 6 8.12 (broad, 1H), 7.43 (d, 2H), 7.36 (t, 2H), 7. 30-7. 12 (m, 6H), 7.01 (d, 1H), 6.83 (d, 1H), 4.85 (s, 2H), 4.52 (dd, 1H), 4.50 (dd, 1H), 4.32 (d, 1H), 4.25 (m, 2H), 4.08 (m, 2H), 3.31 (m, 3H), 2.72 (dd, 1H), 2.01 (m, 2H), 1.78 (m, 1H), 1.35 (m, 2H), 1.22 (t, 3H) LC-MS; [M+H] =562 Example 4 Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2CC13 a) Preparation of 4-nitrophenyl 2,2, 2-trichloroethyl carbonate

Trichloroethyl chloroformate (3.2g, 15. 0mmol) and 4-nitrophenol (2g, 14.4 mmol) were dissolved in dichloromethane (201nu), the mixture was stirred at 0°C, and triethylamine (1. 6g, 15. 8mmol) was slowly added dropwise. The mixture was stirred at 0°C, washed with water (5. 0m#), 1N-aqueous sodium hydroxide solution (5. 0mQ) and aqueous sodium chloride solution (5. 01nu) in order, dried over anhydrous sodium sulfate, filtered, and distilled under reduced pressure. The residue was purified by column chromatography (100% chloroform) to give the title compound (3.4g, 10. 8mmol) in a yield of 75. 0%. b) Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2CC13 The compound prepared in Example 3 (500mg, 0. 734mmol) was dissolved in dimethylformamide (10m#), and the compound prepared in step a) (230mg, 0. 734mmol) was added. Potassium carbonate (224mg, 1.69mmol) was added thereto, and the mixture was stirred for 10 minutes at 0°C and warmed to room temperature. After completion of reaction was confirmed by HPLC, the reaction solution was washed with saturated aqueous sodium hydrogen carbonate solution (20m#), water (20ring) and saturated aqueous sodium chloride solution (20}) in order, dried over anhydrous sodium sulfate, filtered, and distilled under reduced pressure. The residue was purified by column chromatography (50% ethyl acetate/hexane) to give the title compound (492mg, 0.668mmol) in a yield of 75.0%.

'H-NMR (400MHz, DMSO) 6 9.15 (broad, 1H), 8.37 (t, 1H), 7.85 (d, 1H), 7.43 (d, 2H), 7.27 (t, 2H), 7. 25-7. 08 (m, 6H), 6.98 (d, 1H), 4.85 (s, 2H), 4.42 (ddd, 2H), 4.36 (m, 1H), 4.13 (d, 1H), 4.03 (q, 2H), 3.97 (dd, 1H), 3.51 (m, 1H), 3.02 (q, 1H), 1. 83 (m, 1H), 1.61 (m, 2H), 1. 35 (m, 1H) LC-MS ; [M+H] =736 Example 5 Preparation of HO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph- C (O) OCH2CC13 HO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph(500mg, 0. 73mmol) and potassium carbonate (120mg, 0. 87mmol) were added to a mixture of tetrahydrofuran (2. 5n)/water (2. 5all), and the compound prepared in step a) of Example 4 (230mg, 0. 73mmol) was slowly added thereto at 0°C over 10 minutes. The mixture was stirred at 0°C for 15 minutes, warmed to room temperature, and then stirred for 4 hours to complete the reaction. The solvent in the reaction solution was completely removed by evaporation, and the residue was diluted with dichloromethane (3m). This mixture was adjusted to pH 4#5 using 0. 5N aqueous hydrochloric acid solution to transfer the reactants to the organic layer. The reactants in the organic layer maintained a solid state, which was then filtered to give the title compound (140mg, 0. 20mmol) in a yield of 27. 7%.

'H NMR (400MHz, CDC13) 5 9.23 (bs, 2H), 8. 06 (t, 1H), 7.99 (d, 1H), 7. 47-7. 18 (m, 12H), 6.78 (d, 1H), 4. 77 (s, 2H), 4.60 (m, 1H), 4.39 (m, 1H), 4.32 (m, 2H), 4.16 (m, 1H), 3.45 (m, 2H), 3.28 (s, 2H), 2.63 (m, 1H), 1.98 (m, 1H), 1.73 (m, 1H), 1.32 (m, 1H) LC-MS; [M+H] =710 Example 6 Preparation of tBuO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph- C (O) OCHZCC13

tBuO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph (360mg, 0. 554mmol) was added to dimethylformamide (7. 2lnQ), to which was added the compound prepared in step a) of Example 4 (174mg, 0.554 mmol). Potassium carbonate (115mg, 0. 831mmol) was added and the resulting mixture was stirred for 15 minutes at 0°C, and then stirred for 5 hours at room temperature. After completion of reaction was confirmed by HPLC, solvent was completely removed by evaporation, and the residue was purified by column chromatography (50% ethyl acetate/hexane) to give the title compound (331mg, 0.432mmol) in a yield of 78.0%.

'H-NMR (400MHz, CDCl3) 6 9.31 (broad, 1H), 8.04 (m, 1H), 7. 60-7. 10 (m, I OH), 6.94 (d, 1H), 4.81 (dd, 2H), 4.55 (qd, 2H), 4. 26 (m, 2H), 4.10 (m, 1H), 3. 25 (m, 3H), 2. 66 (m, 1H), 2.07 (m, 1H), 1.67 (m, 2H), 1.40 (s, 9H), 1.25 (m, 2H) LC-MS; [M+H] =764 Example 7 Preparation of tBuO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph- C (O) OCH2CH3 a) Preparation of ethyl 4-nitrophenyl carbonate Ethyl chloroformate (1. 33lnQ, 13. 97mmol) was reacted according to the same procedure as step a) of Example 4 to give the title compound (1. 97g, 9.34mmol) in a yield

of 67%. b) Preparation of tBuO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph- C (O) OCH2CH3 The compound prepared in step a) (143mg, 0. 678mmol) was reacted according to the same procedure as Example 6 to give the title compound (178mg, 0.269mmol) in a yield of 40%.

IH-NMR (400MHz, CDC13) õ 7.75 (t, 1H), 7.44 (d, 1H), 7. 15-7. 41 (m, 10H), 6. 92 (d, 1H), 4.57 (d, 2H), 4. 29 (m, 2H), 4.20 (m, 3H), 3.25 (m, 3H), 2.68 (m, 1H), 2.14 (m, 1H), 1.75 (m, 1H), 1. 34#1. 41 (m, 12H) LC-MS; [M+H] =662 Example 8 Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2CH3 The compound prepared in step a) of Example 7 was reacted according to the same procedure as step b) of Example 4 to give the title compound (Yield 60%).

'H-NMR (400MHz, CDC13) # 7.95 (t, 1H), 7.47 (d, 1H), 7. 13-7. 41 (m, 10H), 6.95 (d, 1H), 4.55 (ddd, 2H), 4.24 (m, 4H), 4.05 (m, 2H), 3.77 (m, 1H), 3.32 (m, 3H), 2.75 (m, 1H), 2.12 (m, 1H), 1.87 (m, 1H), 1.75 (m, 1H), 1.41 (m, 2H), 1.35 (t, 3H), 1. 23 (t, 3H) LC-MS; [M+H] =634

Example 9 Preparation of H02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2CH3 The compound prepared in step a) of Example 7 (62mg, 0.294mmol) was reacted according to the same procedure as Example 5 to give the title compound (108mg, 0. 17mmol) in a yield of 60%.

'H-NMR (400MHz, DMSO-d6) S 9.0 (br, 1H), 8.47 (t, 1H), 7.78 (d, 1H), 6. 97-7. 46 (m, 10H), 6.76 (d, 1H), 4. 30-4. 46 (m, 3H), 3. 91-4. 10 (m, 5H), 1.71 (m, 1H), 1.59 (m, 2H), 1.31 (m, 1H), 1. 18 (t, 3H) LC-MS; [M+H] =607 Example 10 Preparation of H02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2Ph a) Preparation of benzyl 4-nitrophenyl carbonate Benzylchloroformate (1. 99m#, 13. 97mmol) was reacted according to the same procedure as step a) of Example 4 to give the title compound (2.3g, 8. 42mmol) in a yield of 60%.

b) Preparation of HO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C (O) OCH2Ph The compound prepared in step a) (248mg, 0. 906mmol) was reacted according to the same procedure as Example 5 to give the title compound (459mg) in a yield of 76%.

'H-NMR (400MHz, DMSO-d6) S 8. 85 (broad, 1H), 8.27 (t, 1H), 7.60 (d, 1H), 7. 40-6. 90 (m, 15H), 6.76 (d, 1H), 4.85 (s, 2H), 4.21 (ddd, 2H), 4.19 (m, 1H), 3.90 (d, 1H), 3.71 (dd, 1H), 2. 78 (m, 1H), 1. 50 (m, 1H), 1. 38 (m, 2H), 1.08 (m, 1H) LC-MS; [M+H] =668 Example 11 Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2Ph The compound prepared in step a) of Example 10 (80.2mg, 0. 294mmol) was reacted according to the same procedure as step b) of Example 4 to give the title compound (121mg, 0. 174mmol) in a yield of 59%.

'H-NMR (400MHz, CDCl3) S 7.91 (m, 1H), 7. 13-7. 46 (m, 16H), 6.93 (d, 1H), 5.17 (s, 2H), 4.55 (ddd, 2H), 4.21 (m, 3H), 4.00 (m, 2H), 3.29 (m, 3H), 2.67 (m, 1H), 2.10 (m, 1H), 1.87 (m, 1H), 1.70 (m, 2H), 1.39 (m, 1H), 1.18 (t, 3H) LC-MS; [M+H] =696 Example 12 Preparation of H2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph- C (O) OCH2iPr a) Preparation of isobutyl 4-nitrophenyl carbonate Isobutyl chloroformate (2. 0m#, 15. 42mmol) was reacted according to the same procedure as step a) of Example 4 to give the title compound (2. 21g, 9.25mmol) in a yield of 60%. b) Preparation of HO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C(O)OCH2iPr The compound prepared in step a) (220mg, 0. 937mmol) was reacted according to the same procedure as Example 5 to give the title compound (400mg, 0. 580mmol) in a yield of 67%.

IH-NMR (400MHz, DMSO-d6) S 9.010 (br, 2H), 8.479 (t, 1H, J=6. 0Hz), 7.806 (d, 1H, J=4Hz), 7.473 (d, 2H, J=7. 6Hz), 7.298 (t, 2H, J=7. 2Hz), 7. 226-7. 124 (m, 6H), 6. 985 (d, 1H, J=3. 6Hz), 4. 485-4. 299 (m, 3H), 4.125 (d, 1H, J=10. 4Hz), 3.942 (dd, 1H, J=5. 6Hz, 6. 8Hz), 3.781 (d, 1H, J=6. 8Hz), 3. 559-3. 503 (m, 1H), 3. 045-2. 986 (m, 1H), 1. 930-1. 846 (m, 1H), 1. 749-1. 703 (m, 1H), 1. 632-1. 578 (m, 2H), 1. 365-1. 307 (m, 1H), 0.900 (d, 6H, J=6. 8Hz) LC-MS; [M+H] =634 Example 13 Preparation of EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph- C (O) OCH2iPr

The compound prepared in step a) of Example 12 (96mg, 0.401mmol) was reacted according to the same procedure as step b) of Example 4 to give the title compound (100mg, 0. 151mmol) in a yield of 47%.

'H-NMR (400MHz, DMSO-d6) 6 9.010 (br, 2H), 8.448 (t, 1H), 7.805 (d, 1H), 7.458 (d, 2H), 7.291 (t, 2H), 7. 221-7. 131 (m, 6H), 6.980 (d, 1H), 4. 479-4. 314 (m, 3H), 4.114 (d, 1H), 3.935 (d, 2H), 3. 995-3. 924 (m, 1H), 3.779 (d, 2H), 3. 523-3. 469 (m, 1H), 3. 035-2. 945 (m, 1H), 2. 095-2. 102 (m, 1H), 1. 934-1. 876 (m, 1H), 1. 798-1. 689 (m, 1H), 1. 621-1. 534 (m, 2H), 1. 395-1. 295 (m, 1H), 1.151 (t, 3H), 0. 898 (d, 6H) LC-MS; [M+H] =662 Example 14 Preparation of tBuO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph- C (O) OCH2iPr The compound prepared in step a) of Example 12 (360mg, 1. 51mmol) was reacted according to the same procedure as Example 6 to give the title compound (250mg, 0. 362mmol) in a yield of 24%.

'H-NMR (400MHz, DMSO-d6) 8 9.012 (br, 2H), 8.449 (t, 1H, J=5. 2Hz), 7. 806 (d, 1H, J=3. 2Hz), 7.456 (d, 2H, J=7. 6Hz), 7.295 (t, 2H, J=7. 4Hz), 7. 217-7. 132 (m, 6H),

6.989 (d, 1H, J=2. 8Hz), 4. 468-4. 329 (m, 3H), 4.103 (d, 1H, J=10. 4Hz), 4.035 (q, 1H, J=3. 6Hz), 3.779 (d, 2H, J=6. 4Hz), 3. 532-3. 477 (m ; 1H), 3.229 (s, 2H), 3. 021-2. 954 (m, 1H), 1. 984 (b, 1H), 1. 926-1. 862 (m, 1H), 1. 752-1. 669 (m, 1H), 1. 638-1. 502 (m, 2H), 1.366 (m, 10H), 0.898 (d, 6H, J=6. 4Hz) LC-MS; [M+H] =690 Example 15 Preparation of H02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH (CH3) OC (O) CH3 a) Preparation of I-f [ (4-nitrophenoxy) carbonyl] oxy} ethyl acetate The title compound (1. 05g, 3.90mmol) was obtained according to the same procedure as described in JMC, 1999,42 (19), 3994 in a yield of 90%. b) Preparation of H02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH (CH3) OC (O) CH3 The compound prepared in step a) (116mg, 0. 37mmol) was reacted according to the same procedure as Example 5 to give the title compound (180mg) in a yield of 69%.

'H NMR (400MHz, CDCl3) S 9.16 (bs, 2H), 8.59 (t, 1H, J=5.8Hz), 7.86 (d, 1H, J=4. 0Hz), 7.47 (d, 2H, J=7.6Hz), 7.30 (t, 2H, J=7.6Hz), 7. 22-7. 13 (m, 8H), 7.00 (d, 1H, J=3.6Hz), 6.72 (q, 1H, J=5.2Hz), 4.38 (m, 3H), 4.12 (d, 1H, J=10.4Hz), 3.93 (dd, 1H, J1=7. 6Hz, J2=4.4Hz), 3.53 (m, 1H), 3.11 (s, 2H), 3.00 (m, 1H), 2.02 (s, 3H), 1.70 (m, 1H), 1.61 (m, 2H), 1.42 (d, 3H, J=5.2Hz), 1.34 (m, 1H) LC-MS; [M+H] =664

Example 16 Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH (CH3) OC (O) CH3

The compound prepared in step a) of Example 15 (230mg, 0.85mmol) was reacted according to the same procedure as step b) of Example 4 to give the title compound (140mg) in a yield of 28%.

'H-NMR (400MHz, DMSO-d6) # 9.169 (b, 2H), 8.464 (t, 1H), 7.861 (d, 1H), 7. 461 (d, 2H), 7.294 (t, 2H), 7. 223-7. 134 (m, 6H), 6.997 (d, 1H), 6.717 (q, 1H), 4. 481-4. 326 (m, 3H), 4.117 (d, 1H), 4.038 (q, 2H), 3.930 (q, 1H), 3. 529-3. 475 (m, 1H), 3. 033-2. 975 (m, 1H), 2.021 (s, 4H), 1. 749-1. 588 (m, 3H), 1.420 (d, 3H), 1. 364-1. 276 (m, 1H), 1.152 (t, 3H) LC-MS; [M+H] =692 Example 17 Preparation of tBuO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph- C (O) OCH (CH3) OC (O) CH3

The compound prepared in step a) of Example 15 (380mg, 1. 52mmol) was reacted

according to the same procedure as Example 6 to give the title compound (180mg, 0. 73mmol) in a yield of 48%.

'H-NMR (400MHz, DMSO-d6) # 9.182 (b, 2H), 8. 467 (t, 1H), 7.888 (d, 1H), 7. 463 (d, 2H), 7.301 (t, 2H), 7. 225-7. 137 (m, 6H), 7.000 (d, 1H), 6.723 (q, 1H), 4. 483-4. 336 (m, 3H), 4.110 (d, 1H), 3.924 (q, 1H), 3. 559-3. 483 (m, 1H), 3.233 (t, 2H), 3. 028-2. 968 (m, 1H), 2.025 (s, 4H), 1. 747-1. 518 (m, 3H), 1.425 (d, 3H), 1.370 (m, 10H) TOF MS ES+: [M+H]=742 Example 18 Preparation of H02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2CH20CH3 a) Preparation of 2-methoxyethyl 4-nitrophenyl carbonate 4-Nitrophenyl chloroformate (4.03g, 20. 0mmol) was dissolved in dichloromethane (20nlQ), and 2-methoxyethanol (1. 52g, 20. 0mmol) and triethylamine (2. 02g, 20. 0mmol) dissolved in dichloromethane (15m#) were slowly added dropwise thereto at 0°C. After completion of reaction, the reaction mixture was washed with water (201nu), aqueous sodium chloride solution (louez and 5% aqueous sodium hydrogen carbonate solution (10m#), dried over anhydrous sodium sulfate, and distilled to give the title compound (Yield 37%).

'H NMR (400MHz, CDC13) # 8. 29 (m, 2H), 7.40 (m, 2H), 4.44 (td, 2H), 3.71 (td, 2H), 3.45 (s, 3H)

b) Preparation of HO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph- C (O) OCH2CH20CH3 The compound prepared in step a) (219mg, 0. 906mmol) was reacted according to the same procedure as Example 5 to give the title compound (376mg) in a yield of 65%.

1H-NMR (400MHz, DMSO-d6) 8 9.03 (s, 2H), 8.52 (t, 1H), 7.82 (d, 1H), 7. 50-7. 10 (m, 10H), 6.99 (d, 1H), 4.43 (m, 2H), 4.34 (dd, 1H), 4.11 (m, 3H), 3.94 (t, 1H), 3.26 (d, 6H), 3.01 (q, 1H), 1.73 (m, 1H), 1.60 (m, 2H), 1.35 (m, 1H) LC-MS; [M+H] =636 Example 19 Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2CH20CH3 The compound prepared in step a) of Example 18 (177mg, 0. 734mmol) was reacted according to the same procedure as step b) of Example 4 to give the title compound (242mg) in a yield of 50%.

'H-NMR (400MHz, DMSO-d6) 8 9.03 (s, 2H), 8.47 (t, 1H), 7. 82 (d, 1H), 7. 50 ~ 7. 00 (m, 10H), 6.98 (d, 1H), 4.45 (dd, 1H), 4. 38 (m, 2H), 4.11 (m, 3H), 4.04 (q, 2H), 3.95 (m, 1H), 3.54 (m, 3H), 3.27 (s, 3H), 3.00 (m, 1H), 2.05 (m, 1H), 1.73 (m, 1H), 1.58 (m, 2H), 1.35 (m, 1H), 1.15 (t, 3H) LC-MS; [M+H] =664

Example 20 Preparation of HO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C (O) OPh- 4-F a) Preparation of bis (4-fluorophenyl) carbonate 4-Fluorophenol (4. 0g, 35. 68mmol) and triphosgene (1. 77g, 5. 95mmol) were dissolved in dichloromethane (40m#), and triethylamine (3.61g, 35.68mmol) was slowly added dropwise thereto at 0°C. After 10 minutes, completion of reaction was confirmed.

Then, the reaction mixture was washed with water (40all) and aqueous sodium chloride solution(20m#) in order, dried over anhydrous sodium sulfate, and distilled to give the title compound (4.24g, 16. 9mmol) in a yield of 95%.

1H NMR (400MHz, CDCl3) # 7.24 (m, 4H), 7.10 (t, 4H) b) Preparation of HO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C (O) OPh-4-F The compound prepared in step a) (240mg, 0.937mmol) was reacted according to the same procedure as Example 5 to give the title compound (380mg, 0.565mmol) in a yield of 60%.

IH-NMR (400MHz, DMSO-d6) S 9.161 (d, 2H), 8. 513 (t, 1H, J=5. 8Hz), 7.883 (d, 1H, J=4Hz), 7.474 (d, 2H, J=7. 6Hz), 7.316 (t, 2H, J=7. 0Hz), 7. 298-7. 140 (m, 10H), 7.019 (d, 1H, J=4. 0Hz), 4. 504-4. 316 (m, 3H), 4.128 (d, 1H, J=10. 4 Hz), 3.944 (t, 1H, J=6. 4Hz), 3. 580-3. 509 (m, 1H), 3.023 (dd, 1H, J=7. 2Hz, 16. 8Hz), 1. 774-1. 707 (m, 1H), 1.612 (q, 2H, J=6. 4Hz), 1. 377-1. 399 (m, 1H) LC/MS ; [M+H] =672

Example 21 Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-C (O) OPh- 4-F

The compound prepared in step a) of Example 20 (96mg, 0.401mmol) was reacted according to the same procedure as step b) of Example 4 to give the title compound (100mg, 0. 151mmol) in a yield of 47%.

'H-NMR (400MHz, DMSO-d6) # 9.010 (br, 2H), 8.476 (t, 1H, J=6. 0Hz), 7.881 (d, 1H, J=3.6Hz), 7.459 (d, 2H, J=6. 8Hz), 7.293 (t, 2H, J=7. 6Hz), 7. 224-7. 147 (m, 10H), 7.014 (d, 1H, J=3.6Hz), 4. 493-4. 332 (m, 3H), 4.117 (d, 1H, J=10. 4Hz), 4.035 (m, 2H), 3.943 (dd, 1H, J=5. 2Hz, 7.8Hz), 3. 509-3. 438 (m, 1H), 3. 042-2. 984 (m, 1H), 2. 071-2. 016 (m, 1H), 1. 750-1. 704 (m, 1H), 1. 623-1. 567 (m, 2H), 1. 361-1. 305 (m, 1H), 1.152 (t, 3H, J=6. 8Hz) LC-MS; [M+H] =700 Example 22 Preparation of EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-OC(O)CH3

The compound prepared in step b) of Example 1 (200mg, 0. 346mmol) was

dissolved in methanol (2. 2ll1Q) and stirred at 0°C. Acetic anhydride (38. 5mg, 0.377mmol) was added thereto and the resulting mixture was stirred for 10 minutes at 0°C. The solvent was distilled under reduced pressure. The residue was diluted with dichloromethane (501118), washed with saturated aqueous sodium hydrogen carbonate solution (20m#), water (20me) and aqueous sodium chloride solution (20m#) in order, dried over anhydrous sodium sulfate, filtered, and distilled under reduced pressure to give the title compound (210mg, 0.339mmol) in a yield of 97%.

IH NMR (400MHz, CDC13) # 7.88 (t, 1H), 7. 15-7. 40 (m, 11H), 6.89 (d, 1H), 5.13 (br, 2H), 4.52 (ddd, 2H), 4.24 (m, 3H), 4.04 (m, 2H), 3.31 (m, 3H), 2.69 (m, 1H), 2.22 (s, 3H), 2.09 (m, 1H), 1.74 (m, 2H), 1.45 (m, 1H), 1.22 (t, 3H) LC-MS; [M+H] =620 Example 23 Preparation of H02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2CF3 a) Preparation of 4-nitrophenyl 2,2, 2-trifluoroethyl carbonate 2, 2, 2-Trifluoroethanol (2. 0g, 20. 0mmol) was reacted according to the same procedure as step a) of Example 18 to give the title compound (2. 0g) in a yield of 38%.

'H NMR (400MHz, CDCI3) 6 8. 28 (m, 2H), 7.41 (m, 2H), 4.63 (m, 2H) b) Preparation of H02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2CF3

The compound prepared in step a) (240mg, 0.906mmol) was reacted according to the same procedure as Example 5 to give the title compound (330mg) in a yield of 55%.

'H-NMR (400MHz, DMSO-d6) 8 9.38 (broad, 1H), 9.12 (broad, 1H), 8.57 (t, 1H), 7.91 (d, 1H), 7. 50-7. 05 (m, 10H), 7.02 (d, 1H), 4.67 (q, 3H), 4.50 (dd, 1H), 4.41 (d, 3H), 4.34 (dd, 1H), 4.13 (d, 2H), 3.93 (m, 2H), 3.00 (m, 2H), 2.09 (s, 1H), 1. 85 (m, 1H), 1.73 (m, 2H), 1.33 (m, 1H) LC-MS; [M+H] =660 Example 24 Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2CF3 The compound prepared in step a) of Example 23 (195mg, 0.734mmol) was reacted according to the same procedure as step b) of Example 4 to give the title compound (200mg) in a yield of 40%.

'H-NMR (400MHz, DMSO-d6) S 9.11 (broad, 1H), 8. 87 (broad, 1H), 8.26 (s, 1H), 7.68 (s, 1H), 7. 40-6. 90 (m, 9H), 6. 78 (s, 1H), 4.44 (d, 2H), 4.18 (m, 3H), 3.88 (d, 1H), 3.80 (d, 2H), 3.71 (s, 1H), 2.78 (m, 1H), 1.82 (m, 1H), 1.49 (m, 1H), 1.38 (m, 2H), 1.10 (m, 1H), 0.95 (t, 3H) LC-MS; [M+H] =688 Example 25 Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-C (O) OPh- 4-OCH3 a) Preparation of bis (4-methoxyphenyl) carbonate 4-Methoxyphenol (l. 0g, 4. 96mmol) was reacted according to the same procedure as step a) of Example 20 to give the title compound (500mg, 1. 82mmol) in a yield of 37%.

'H NMR (400MHz, CDCl3) 6 6.99 (d, 4H), 6.70 (d, 4H), 3.60 (s, 6H) b) Preparation of EtO2CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-C (O) OPh- 4-OCH3 The compound prepared in step a) (80. 5mg, 0.294mmol) was reacted according to the same procedure as step b) of Example 4 to give the title compound (80mg, 0. 112mmol) in a yield of 38%.

'H NMR (400MHz, CDCI3) 5 7.98 (t, 1H), 7.52 (d, 1H), 7. 18-7. 27 (m, 10H), 7.10 (d, 2H), 6.98 (d, 1H), 6.91 (d, 2H), 4.61 (ddd, 2H), 4.27 (m, 3H), 4.07 (m, 2H), 3.81 (s, 3H), 3.34 (m, 3H), 2.72 (m, 1H), 2.08 (m, 1H), 1.71 (m, 2H), 1.35 (m, 1H), 1.25 (t, 3H) LC-MS; [M+H] =712 Example 26 Preparation of H02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2CH2F

a) Preparation of 2-fluoroethyl 4-nitrophenyl carbonate 2-Fluoroethanol (4. 0g, 19.84mmol) was reacted according to the same procedure as step a) of Example 18 to give the title compound (2.13g, 9. 3mmol) in a yield of 46.9%.

'H NMR (400MHz, CDC13) 6 8. 30 (d, 2H), 7.41 (d, 2H), 4.78 (m, 1H), 4.66 (m, 1H), 4. 58 (m, 1H), 4. 51 (m, 1H) b) Preparation of HO2CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2CH2F The compound prepared in step a) (208mg, 0. 906mmol) was reacted according to the same procedure as Example 5 to give the title compound (371mg) in a yield of 66%.

IH-NMR (400MHz, DMSO-d6) S 9.08 (s, 2H), 8.55 (t, 1H), 7.85 (d, 1H), 7. 50-7. 10 (m, 10H), 7.00 (d, 1H), 4.67 (d, 1H), 4.57 (d, 1H), 4. 48-4. 02 (m, 6H), 3.93 (m, 1H), 3.00 (m, 1H), 1.72 (m, 1H), 1.62 (m, 2H), 1.34 (m, 1H), 1.08 (q, 1H) LC-MS; [M+H] =624 Example 27 Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2CH2F

The compound prepared in step a) of Example 26 (123mg, 0. 537mnol) was reacted according to the same procedure as step b) of Example 4 to give the title compound (210mg, 0. 322mmol) in a yield of 60. 2%.

'H NMR (400MHz, CDCI3) 6 7.92 (t, 1H), 7.44 (d, 1H), 7. 20-7. 39 (m, 10H), 6. 94 (d, 1H), 4.73 (m, 1H), 4. 60-4. 70 (m, 2H), 4. 44-4. 50 (m, 1H), 4. 38 (dt, 2H), 4.24 (m, 3H), 4.04 (m, 2H), 3.31 (m, 3H), 2.70 (m, 1H), 2.07 (m, 1H), 1.69 (m, 2H), 1. 35 (m, IH), 1.22 (t, 3H) LC-MS; [M+H] =652 Example 28 Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH20C (O) CH3 a) Preparation of f [ (4-nitrophenoxy) carbonyl] oxy} methyl acetate Acetoxymethyl chloroformate (500mg, 3.28mmol) was reacted according to the same procedure as step a) of Example 15 to give the title compound (720mg, 2.82mmol) in a yield of 86%. b) Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH20C (O) CH3 The compound prepared in step a) (200mg, 0. 78mmol) was reacted according to the same procedure as step b) of Example 4 to give the title compound (376mg, 0. 52mmol) in a yield of 67%.

'H-NMR (400MHz, DMSO-d6) 6 9.20 (b, 2H), 8.46 (t, 1H), 7.85 (d, 1H), 7.46 (d, 2H), 7.29 (t, 2H), 7.20 (m, 6H), 6.99 (d, 1H), 6.72 (s, 2H), 4.40 (m, 3H), 4.12 (d, 1H), 4.04 (q, 2H), 3.93 (q, 1H), 3.50 (m, 1H), 3.00 (m, 1H), 2.02 (s, 4H), 1.60 (m, 3H), 1.32 (m, 1H), 1.15 (t, 3H) LC-MS; [M+H] =678 Example 29 Preparation of H02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2Cyh a) Preparation of cyclohexylmethyl 4-nitrophenyl carbonate Cyclohexylmethanol (2.28g, 20. 0mmol) was reacted according to the same procedure as step a) of Example 18 to give the title compound (4.97g) in a yield of 89%.

'H NMR (400MHz, CDCI3) # 8.27 (m, 2H), 7.38 (m, 2H), 4.10 (d, 2H), 1.79 (m, 6H), 1. 25 (m, 3H), 1.06 (m, 2H) b) Preparation of H02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2Cyh The compound prepared in step a) (262mg, 0. 937mmol) was reacted according to the same procedure as Example 5 to give the title compound (476mg) in a yield of 75%.

IH-NMR (400MHz, DMSO-d6) 8 8.36 (t, 1H), 7.61 (d, 1H), 7.29 (d, 2H), 7.11 (t, 2H), 7. 02-6. 85 (m, 6H), 4. 50 (m, 1H), 4.15 (ddd, 2H), 4.02 (d, 1H), 3.70 (t, lH), 3. 58 (d, 2H), 2. 79 (m, 1H), 1.47 (m, 5H), 1.40 (m, 4H), 1.08 (m, 1H), 0.95 (m, 3H), 0. 73 (m, 2H)

LC-MS; [M+H] =674 Example 30 Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2Cyh

The compound prepared in step a) of Example 29 (293mg, 1. 05mmol) was reacted according to the same procedure as step b) of Example 4 to give the title compound (300mg) in a yield of 41%. lH-NMR (400MHz, DMSO-d6) 6 9.04 (s, 2H), 8.48 (t, 1H), 7. 83 (d, 1H), 7.46 (d, 2H), 7.30 (t, 2H), 7. 23-7. 11 (m, 6H), 6.98 (d, 1H), 4.41 (ddd, 2H), 4.37 (m, 1H), 4.12 (d, 1H), 4.04 (m, 3H), 3.94 (dd, 1H), 3.81 (d, 2H), 3.34 (d, 1H), 3.00 (q, 1H), 1.68 (m, 6H), 1.61 (m, 3H), 1.34 (m, 1H), 1.17 (m, 7H), 0.96 (m, 2H) LC-MS; [M+H] =702 Example 31 Preparation of H02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2CH2Cyh

a) Preparation of cyclohexylethyl 4-nitrophenyl carbonate

2-Cyclohexylethanol (2.56g, 20. 0mmol) was reacted according to the same procedure as step a) of Example 18 to give the title compound (5.17g) in a yield of 88%.

'H NMR (400MHz, CDC13) 8.27 (m, 2H), 7.38 (m, 2H), 4.33 (t, 2H), 1.69 (m, 7H), 1.45 (m, 1H), 1.20 (m, 3H), 0.99 (m, 2H) b) Preparation of H02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2CH2Cyh The compound prepared in step a) (275mg, 0. 937mmol) was reacted according to the same procedure as Example 5 to give the title compound (540mg) in a yield of 84%.

'H-NMR (400MHz, DMSO-d6) S 8. 86 (broad, 1H), 8.43 (t, 1H), 7.61 (d, 1H), 7.32 (d, 2H), 7.16 (t, 2H), 7. 07-6. 93 (m, 6H), 6.76 (d, 1H), 4.60 (m, 1H), 4.19 (m, 3H), 4.11 (m, 1H), 3.79 (t, 3H), 3. 69 (t, 2H), 2.79 (m, 1H), 1.42 (m, 8H), 1.25 (q, 2H), 1.08 (m, 2H), 0.94 (m, 3H), 0. 66 (q, 2H) LC-MS; [M+H] =688 Example 32 Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2CH2Cyh The compound prepared in step a) of Example 31 (308mg, 1. 05mmol) was reacted according to the same procedure as step b) of Example 4 to give the title compound (362mg) in a yield of 48%.

'H-NMR (400MHz, DMSO-d6) S 9.04 (s, 2H), 8.47 (t, 1H), 7.82 (d, 1H), 7.45 (d, 2H), 7.29 (t, 2H), 7. 25-7. 08 (m, 6H), 4.40 (ddd, 2H), 4.38 (m, 1H), 4.11 (d, 1H), 4.02 (m, 4H), 3.94 (dd, 1H), 3.00 (m, 1H), 1.65 (m, 8H), 1.48 (m, 2H), 1.33 (m, 2H), 1.15 (m, 6H), 0.90 (m, 2H) LC-MS; [M+H] =716 Example 33 Preparation of EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C (O)-Imid Carbonyldiimidazole (290mg, 1. 79mmol) was reacted according to the same procedure as step b) of Example 4 to give the title compound (713mg, 1. 09mmol) in a yield of 61%.

IH NMR (400MHz, CDCl3) S 9.74 (br, 1H), 8. 38 (s, 1H), 8.03 (t, 1H), 7.60 (d, 1H), 7.58 (d, 1H), 7. 17-7. 40 (m, 10H), 7.03 (s, 1H), 6.96 (d, 1H), 4.53 (ddd, 2H), 4.25 (m, 3H), 4.06 (m, 2H), 3.35 (m, 3H), 2.73 (m, 1H), 2.11 (m, 1H), 1. 78 (m, 2H), 1.32 (m, 1H), 1.20 (t, 3H) LC-MS; [M+H] =656 Example 34 Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2CH2-Mor

a) Preparation of 2-morpholin-4-ylethyl 4-nitrophenyl carbonate 4- (2-Hydroxyethyl) morpholine (651mg, 4. 96mmol) was reacted according to the same procedure as step a) of Example 18 to give the title compound (1. 43g) in a yield of 97%.

'H NMR (400MHz, CDC13) 6 8.32 (m, 2H), 7.56 (m, 2H), 4.35 (t, 2H), 3.58 (m, 4H), 2.64 (t, 2H), 2.47 (m, 4H) b) Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2CH2-Mor The compound prepared in step a) (586mg, 1. 98mmol) was reacted according to the same procedure as step b) of Example 4 to give the title compound (767mg) in a yield of 54%.

'H-NMR (400MHz, DMSO-d6) S 8.99 (broad, 2H), 8.45 (t, 1H), 7.81 (d, 1H), 7.46 (d, 2H), 7.29 (t, 2H), 7.21 (d, 4H), 7.17 (m, 4H), 6.98 (d, 1H), 4.41 (ddd, 2H), 4. 11 (t, 2H), 4.07 (d, 1H), 4.03 (m, 2H), 3.94 (dd, 1H), 3.57 (t, 4H), 3.50 (m, 1H), 3.31 (m, 1H), 3.00 (m, 1H), 2.41 (m, 4H), 2.05 (m, 1H), 1.74 (m, 1H), 1.60 (m, 2H), 1.34 (m, 1H), 1.15 (t, 3H), 1.10 (m, 1H) LC-MS; [M+Na] =741 Example 35 Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2-3-Pyr

a) Preparation of 3-pyridylmethyl 1H-imidazole-1-carboxylate 3-Pyridinemethanol (4g, 36. 65mmol) was added to tetrahydrofuran (40in and stirred at 0°C. Carbonyldiimidazole (5.94g, 36. 65mmol) dissolved in tetrahydrofuran (40mu,) was slowly added dropwise thereto while being stirred. The solvent was distilled under reduced pressure and the residue was stirred in diethylether to give the title compound (2. 5g, 12. 02mmol) in a yield of 32.8%.

IH NMR (400MHz, CDCl3) 6 8.72 (s, 1H), 8.65 (d, 1H), 8.13 (s, 1H), 7.78 (d, 1H), 7.41 (s, 1H), 7. 36 (m, 1H), 7.06 (d, 1H), 5.42 (s, 2H) b) Preparation of EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C(O)OCH2- 3-Pyr The compound prepared in step a) (370mg, 1. 78mmol) was reacted according to the same procedure as step b) of Example 4 to give the title compound (780mg, 1. 1 lmmol) in a yield of 63%.

'H NMR (400MHz, CDC13) # 8.69 (s, 1H), 8.54 (d, 1H), 7.93 (t, 1H), 7.77 (d, 1H), 7.45 (d, 1H), 7. 20-7. 39 (m, 10H), 6.94 (d, 1H), 5.19 (s, 2H), 4.54 (ddd, 2H), 4.25 (m, 3H), 4.02 (m, 2H), 3.29 (m, 3H), 2.71 (m, 1H), 2.12 (m, 1H), 1.72 (m, 2H), 1.41 (m, 1H), 1.19 (t, 3H) LC-MS; [M+HI=697 Example 36 Preparation of EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph- C (O) NHCH2CH20H

The compound prepared in Example 33 (200mg, 0. 31mmol) was dissolved in dichloromethane (3m#) and stirred. Ethanolamine (15yt, 0. 46mmol) was added and the mixture was stirred under reflux for about 12 hours. The solvent was distilled under reduced pressure and the residue was purified by column chromatography (10% methanol/dichloromethane) to give the title compound (114mg, 0. 18mmol} in a yield of 56.7%.

'H NMR (400MHz, CDCl3) 6 7. 93 (d, 1H), 7. 15-7. 41 (m, 10H), 6.89 (d, 1H), 4.51 (ddd, 2H), 4.27 (m, 3H), 4.05 (m, 2H), 3.69 (m, 4H), 3.34 (m, 4H), 2.73 (m, 1H), 2. 08 (m, 2H), 1.75 (m, 1H), 1.35 (m, 1H), 1.23 (t, 3H) LC-MS; [M+H] =649 Example 37 Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) N (CH2CH20H) 2 The compound prepared in Example 33 (196mg, 0. 30mmol) was dissolved in chloroform (liftez and stirred. 2, 2-Diethanolamine (60mg, 0. 60mmol) and triethylamine (60, use,, 0.36 mmol) were added and the mixture was stirred under reflux overnight.

Chloroform was distilled under reduced pressure and the residue was purified by column

chromatography (Silica gel, MC: MeOH=10: 1) to give the title compound (123mg, 0. 18mmol) in a yield of 59%.

'H-NMR (400MHz, DMSO-d6) 8 8. 43 (t, 1H), 7.67 (d, 1H), 7. 13-7. 34 (m, 10H), 6.93 (d, 1H), 4.69 (m, 2H), 4.35 (m, 3H), 4.10 (m, 1H), 4.01 (m, 2H), 3.93 (m, 1H), 3.50 (m, 6H), 2.95 (m, 1H), 2.05 (m, 1H), 1.61 (m, 3H), 1.29 (m, 1H), 1.14 (t, 3H) LC-MS; [M+H] =693 Example 38 Preparation of EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph- C (O) OCH2CH2N (CH3) 2 a) Preparation of 2- (dimethylamino) ethyl 1H-imidazole-3-carboxylate N, N-dimethylethanolamine (2. 0g, 22.44mmol) was reacted according to the same procedure as step a) of Example 35 to give the title compound, which was then used for preparing the following compound without further purification. b) Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2CH2N (CH3) 2 The compound prepared in step a) (300mg, mixture, excess) was reacted according to the same procedure as step b) of Example 4 to give the title compound (239mg, 0. 354mmol) in a yield of 40%.

'H NMR (400MHz, CDC13) 6 7.90 (t, 1H), 7.44 (d, 1H), 7. 15-7. 41 (m, 10H), 6.94 (d, 1H), 4.50 (ddd, 2H), 4.24 (m, 4H), 4.04 (m, 2H), 3.31 (m, 3H), 2.64 (m, 1H), 2.29

(s, 6H), 2.10 (m, 1H), 1.74 (m, 1H), 1.42 (m, 1H), 1.21 (t, 3H) LC-MS; [M+H] =677 Example 39 Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2Cypr a) Preparation of cyclopropylmethyl 4-nitrophenyl carbonate Bis (4-nitrophenyl) carbonate (3.1g, 10. 19mmol) and cyclopropylmethanol (2. 0g, 27. 7mmol) were dissolved in dichloromethane, and triethylamine (l. Sg, 10.19mmol) was added dropwise. After completion of reaction was confirmed, the mixture was purified by silica gel column chromatography (Eluent : EtOAc/n-hexane=1/9) to give the title compound (1. 24g, 5.23mmol) in a yield of 51%. b) Preparation of EtO2CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2Cypr The compound prepared in step a) (211mg, 0. 891mmol) was reacted according to the same procedure as step b) of Example 4 to give the title compound (328mg, 0. 497mmol) in a yield of 56%.

'H NMR (400MHz, CDC13) 8 7.93 (t, 1H), 7.47 (d, 1H), 7. 16-7. 42 (m, 10H), 6.96 (d, 1H), 4.50 (ddd, 2H), 4.25 (m, 3H), 4.06 (m, 2H), 3.97 (d, 2H), 3.32 (m, 3H), 2.71 (m, 1H), 2.11 (m, 1H), 1. 74 (m, 2H), 1.44 (m, 1H), 1.23 (t, 3H), 0.57 (m, 2H), 0.33 (m, 1H) LC-MS; [M+H] =660

Example 40 Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2Cypen a) Preparation of cyclopentylmethyl 4-nitrophenyl carbonate Bis (4-nitrophenyl) carbonate (4. 0g, 13. 14mmol) and cyclopentylmethanol (2.80g, 27. 96mmol) were reacted according to the same procedure as step a) of Example 39 to give the title compound (1. 56g, 5. 89mmol) in a yield of 45%. b) Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2Cypen The compound prepared in step a) (234mg, 0. 891mmol) was reacted according to the same procedure as step b) of Example 4 to give the title compound (379mg, 0. 55 lmmol) in a yield of 62%.

1H NMR (400MHz, CDC13) 6 7.93 (t, 1H), 7.46 (d, 1H), 7. 17-7. 42 (m, 1OH), 6.95 (d, IH), 4.55 (ddd, 2H), 4.26 (m, 3H), 4. 05 (m, 4H), 3.32 (m, 3H), 2, 71 (m, 1H), 2. 31 (m, 1H), 2.12 (m, 1H), 1. 21-1. 82 (m, 14H) LC-MS; [M+H] =688 Example 41 Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) CH2tBu a) Preparation of 4-nitrophenylpivalate t-Butylacetylchloride (1m#, 7.20mmol) and 4-nitrophenol (lg, 6. 99mmol) were dissolved in dichloromethane (20its) and stirred at 0°C. Triethylamine (lent, 7. 21mmol) was slowly added dropwise thereto and stirred for 2 hours. The reaction mixture was washed with water (5mA), IN-aqueous sodium hydroxide solution (SlnQ) and aqueous sodium chloride solution (511lu), dried over anhydrous sodium sulfate, filtered, and distilled under reduced pressure to give the title compound (1. 2g, 4. 98mmol) in a yield of 69.2%.

'H NMR (400MHz, CDCI3) 5 8. 28 (d, 2H), 7.28 (d, 2H), 2.49 (s, 2H), 1.16 (s, 9H) b) Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-C (O) CH2tBu The compound prepared in step a) (215mg, 0. 891mmol) was reacted according to the same procedure as step b) of Example 4 to give the title compound (237mg, 0. 359mmol) in a yield of 40%.

'H NMR (400MHz, CDC13) 6 7.92 (t, 1H), 7. 20-7. 39 (m, 11H), 6.95 (d, 1H), 4.55 (ddd, 2H), 4.25 (m, 3H), 4.04 (m, 2H), 3.30 (m, 3H), 2.67 (m, 1H), 2.35 (s, 2H), 2.08 (m, 1H), 1.74 (m, 2H), 1.41 (m, 1H), 1.21 (t, 3H), 1.06 (s, 9H) LC-MS; [M+H] =660 Example 42 Preparation of EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C(O) OCyh

a) Preparation of cyclohexyl 4-nitrophenyl carbonate Bis (4-nitrophenyl) carbonate (1. 57g, 5. 15mmol) and cyclohexanol (lg, 9.98 mmol) were reacted according to the same procedure as step a) of Example 39 to give the title compound (1. 24g, 4.34mmol) in a yield of 84%. b) Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph-C (O) OCyh The compound prepared in step a) (234mg, 0. 891mmol) was reacted according to the same procedure as step b) of Example 4 to give the title compound (375mg, 0.545mmol) in a yield of 61%.

'H NMR (400MHz, CDC13) 6 7.91 (t, 1H), 7.48 (d, 1H), 7. 16-7. 42 (m, 10H), 6. 92 (d, 1H), 4. 64 (m, 2H), 4.52 (ddd, 2H), 4.25 (m, 3H), 4.05 (m, 2H), 3.32 (m, 3H), 2.71 (m, 1H), 2.10 (m, 1H), 1.98 (m, 2H), 1. 25-1. 81 (m, 8H), 1.24 (t, 3H) LC-MS; [M+H] =688 Example 43 Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2Cyb a) Preparation of cyclobutylmethyl 4-nitrophenyl carbonate Cyclobutylmethanol (1. 63g, 18. 9mmol) and 4-nitrophenylchloroformate (3.80g,

18.9mmol) were reacted according to the same procedure as step a) of Example 4 to give the title compound (3. 51g) in a yield of 74%.

'H NMR (400MHz, CDC13) 6 8.27 (m, 2H), 7.39 (m, 2H), 4.27 (d, 2H), 2.75 (hep, 1H), 2.13 (m, 2H), 1.95 (m, 2H), 1.87 (m, 2H) b) Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) OCH2Cyb The compound prepared in step a) (143mg, 0. 569mmol) was reacted according to the same procedure as step b) of Example 4 to give the title compound (282mg) in a yield of 73%.

'H-NMR (400MHz, DMSO-d6) 6 9.01 (broad, 2H), 8.49 (t, 1H), 7.80 (d, 1H), 7.29 (t, 2H), 7.18 (m, 8H), 6.98 (d, 1H), 4.39 (dd, dd, dd, 3H), 4.11 (d, 2H), 4.05 (q, 2H), 3.97 (d, 2H), 3.95 (dd, 1H), 3.50 (m, 1H), 3.31 (m, 2H), 3.00 (dd, 1H), 2.58 (hep, 1H), 2.01 (m, 3H), 1.84 (m, 2H), 1.73 (m, 3H), 1.60 (m, 2H), 1.33 (m, 1H), 1.15 (t, 3H) LC-MS; [M+H] =674 Example 44 Preparation of EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C (O) CH3 a) Preparation of 4-nitrophenyl acetate Acetic anhydride (l. Og, 16. 65mmol) was dissolved in dichloromethane (30all), triethylamine (2.03g, 20. 06mmol) was added thereto, and the mixture was cooled to 0°C.

1-Ethyl-3- (3-dimethylaminopropyl) carbodiimide (3.84g, 20. 06mmol) was added and stirred

for 10 minutes. After stirring, 4-nitrophenol (2.32g, 16. 68mmol) was added, and the mixture was stirred for 2 hours at 0#10°C. After completion of reaction was confirmed, the reaction mixture was washed with water (30mont), saturated aqueous sodium hydrogen carbonate solution (20nez and aqueous sodium chloride solution (15m. ) in order, and dried over anhydrous sodium sulfate. The solvent was removed by evaporation and the residue was purified by column chromatography (ethyl acetate/hexane/dichloromethane=1/9/1) to give the title compound (1. 5g, 8. 3mmol) in a yield of 50%.

'H NMR (400MHz, CDC13) 6 8.30 (m, 2H), 7. 44 (m, 2H), 2. 33 (s, 3H) b) Preparation of EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C (O) CH3 The compound prepared in step a) (129mg, 0.712mmol) was reacted according to the same procedure as step b) of Example 4 to give the title compound (190mg) in a yield of 44%.

IH-NMR (400MHz, DMSO-d6) 6 8.45 (t, 1H), 7.81 (d, 1H), 7.46 (d, 2H), 7.30 (t, 2H), 7. 25-7. 08 (m, 6H), 6.99 (d, 1H), 4.40 (ddd, 2H), 4. 38 (m, 1H), 4.12 (d, 1H), 4.04 (m, 2H), 3.94 (dd, 1H), 3.51 (m, 1H), 3.00 (dd, 1H), 2.04 (s, 3H), 1.74 (m, 1H), 1.60 (m, 2H), 1.35 (m, 1H), 1.16 (t, 3H) LC-MS; [M+H] =604 Example 45 Preparation of Et02CCHrD-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) CH2CH3

a) Preparation of 4-nitrophenylpropionate Propionic anhydride (2g, 15. 37mmol) was dissolved in dichloromethane (50lnQ) and stirred at 0°C. 4-Nitrophenol (2.2g, 15.37mmol) was added thereto and stirred.

Triethylamine (2. 2all, 15. 86mmol) was slowly added dropwise thereto and the mixture was stirred for 3 hours at 0°C. The reaction mixture was washed with water (20m. ), IN-aqueous sodium hydroxide solution (201nQ) and aqueous sodium chloride solution (20m#), dried over anhydrous sodium sulfate, and filtered to give the title compound (1. 7g, 8. 54mmol) in a yield of 55.6%. b) Preparation of EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C(O)CH2CH3 The compound prepared in step a) (710mg, 3.57mmol) was reacted according to the same procedure as step b) of Example 4 to give the title compound (1. 43g, 2.32mmol) in a yield of 65%.

'H NMR (400MHz, CDC13) 5 7.93 (t, 1H), 7. 15-7. 44 (m, 11H), 6.92 (d, 1H), 4.51 (ddd, 2H), 4.25 (m, 3H), 4.05 (m, 2H), 3.31 (m, 3H), 2.71 (m, 1H), 2.49 (q, 2H), 2.10 (m, 1H), 1.74 (m, 2H), 1.41 (m, 1H), 1.22 (t, 3H), 1.15 (t, 3H) LC-MS; [M+H] =618 Example 46 Preparation of EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C(O)iPr a) Preparation of 4-nitrophenyl isobutyrate Isobutyryl chloride (2g, 15. 37mmol) was dissolved in dichloromethane (50m#) and stirred at 0°C. 4-Nitrophenol (2.7g, 18.6mmol) was added, triethylamine (2. 6m#, 18. 7mmol)

was slowly added dropwise thereto, and the mixture was stirred for 3 hours at 0°C. The reaction mixture was washed with water (201nQ), lN-aqueous sodium hydroxide solution (20m#) and aqueous sodium chloride solution (201nu), dried over anhydrous sodium sulfate, filtered, and distilled under reduced pressure to give the title compound (1. 9g, 8.9mmol) in a yield of 58%. b) Preparation of EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-C(O)iPr The compound prepared in step a) (760mg, 3. 57mmol) was reacted according to the same procedure as step b) of Example 4 to give the title compound (1. 12g, 1.77mmol) in a yield of 50%.

'H NMR (400MHz, CDC13) S 7.99 (t, 1H), 7.50 (d, 1H), 7. 16-7. 39 (m, 10H), 6. 96 (d, 1H), 4. 59 (ddd, 2H), 4.26 (m, 3H), 3. 96-4. 11 (m, 2H), 3. 57 (m, 1H), 3. 30 (m, 3H), 2.72 (m, 1H), 2.12 (m, 1H), 1.74 (m, 2H), 1.43 (m, 1H), 1.22 (m, 9H) LC-MS; [M+H] =632 Example 47 Preparation of EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-OC (O) iPr The compound prepared in step a) of Example 46 (732mg, 3. 50mmol) was reacted according to the same procedure as Example 22 to give the title compound (1. 97g) in a yield of 87%.

'H-NMR (400MHz, DMSO-d6) 8 8. 42 (t, 1H), 7. 49-7. 10 (m, 11H), 6.92 (d, 1H), 6. 77 (s, 2H), 4.43 (dd, 1H), 4.38 (d, 1H), 4.32 (dd, 1H), 4.11 (d, 1H), 4.03 (m, 2H),

3.94 (q, 1H), 3.50 (m, 1H), 3.00 (m, 1H), 2.72 (m, 1H), 2.05 (m, 1H), 1.72 (m, 1H), 1.60 (m, 2H), 1.34 (m, 1H), 1.14 (m, 9H) LC-MS; [M+H] =648 Example 48 Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- OC (O) CH2CH3

Propionic anhydride (547mg, 3. 50mmol) was reacted according to. the same procedure as Example 22 to give the title compound (884mg) in a yield of 40%.

IH-NMR (400MHz, DMSO-d6) 6 8.40 (t, 1H), 7. 50-7. 10 (m, 11H), 6. 91 (d, 1H), 6.78 (s, 1H), 4.42 (dd, 1H), 4.37 (m, 1H), 4. 32 (dd, 1H), 4.11 (d, 1H), 4.03 (m, 2H), 3.94 (q, 1H), 3.49 (m, 1H), 3.00 (m, 1H), 2.42 (m, 2H), 2.05 (m, 1H), 1.72 (m, 1H), 1.60 (m, 2H), 1.34 (m, 1H), 1.16 (t, 3H), 1. 07 (t, 3H) LC-MS; [M+H] =634 Example 49 Preparation of EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph-OC(O)tBu

Pivalic anhydride (338mg, 1. 51mmol) was reacted according to the same procedure

as Example 22 to give the title compound (891mg) in a yield of 89%.

'H-NMR (400MHz, DMSO-d6) # 8.43 (t, 1H), 7. 50-7. 10 (m, 11H), 6.92 (d, 1H), 6. 62 (s, 1H), 4.35 (m, 3H), 4.12 (d, 1H), 4.05 (m, 2H), 3.94 (q, 1H), 3.50 (m, 1H), 3.00 (m, 1H), 2.05 (m, 1H), 1.75 (m, 1H), 1.60 (m, 2H), 1.34 (m, 1H), 1.23 (s, 9H), 1.16 (t, 3H) LC-MS; [M+H] =662 Example 50 Preparation of EtO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph- OP (O) (OCH2CH3) 2 Diethylchlorophosphonate (l. 1m#, 7. 85mmol) was reacted according to the same procedure as Example 22 to give the title compound (3.6g, 5.04mmol) in a yield of 71%.

'H NMR (400MHz, CDCl3) 6 7.90 (t, 1H), 7. 15-7. 41 (m, 11H), 6.90 (d, 1H), 5.14 (s, 2H), 4.52 (ddd, 2H), 4.25 (m, 7H), 4.03 (m, 2H), 3.30 (m, 3H), 2.69 (m, 1H), 2.05 (m, 1H), 1.72 (m, 2H), 1.40 (m, 1H), 1.36 (t, 3H), 1.21 (t, 6H) LC-MS; [M+H] =714 Example 51 Preparation of Et02CCH2-D-Dpa-Pro-NH-CH2-5- (2-amd)-thioph- C (O) NHCH2iPr Isobutylamine (100µ#, 0. 99mmol) was reacted according to the same procedure as Example 36 to give the title compound (475mg, 0. 69mmol) in a yield of 69%.

1H NMR (400MHz, CDC13) S 7. 88 (t, 1H), 7. 15-7. 41 (m, 11H), 6.90 (d, 1H), 5.55 (t, 2H), 4.51 (ddd, 2H), 4.28 (m, 3H), 4.03 (m, 2H), 3.27 (m, 3H), 3.03 (m, 2H), 2.72 (m, 1H), 2.15 (m, 1H), 1.74 (m, 3H), 1.45 (m, 1H), 1.24 (t, 3H), 0.93 (d, 6H) LC-MS; [M+H] =661 Experiment 1 Determination of Thrombin Clotting Time To human thrombin (T 6769, Sigma, concentration: 1.4 NIH units/m#) in buffer solution (100µ#, pH 7.4) was added inhibitor solution (1000,), which was then incubated for 1 minute. Pooled normal citrated human plasma (100µ#) was then added and the clotting time was measured in an automatic device (Diagnostica Stago. ST ART-4). The clotting time in seconds was plotted against the inhibitor concentration, and the ICsoTT was determined by interpolation. ICsoTT means the concentration of inhibitor that doubles the thrombin clotting time for human plasma.

The compounds of Examples 1 to 51 were all tested according to the above procedure and were all found to exhibit an ICsoTT value of 1. OGM or more. That is, they are inactive to thrombin per se. For reference, IC5oTT value of HO2CCH2-D-Dpa-Pro- NH-CH2-5- (2-amd)-thioph is 0. 02 uM.

Experiment 2

Determination of Biological Activity of Thrombin Inhibitors Thrombin inhibitory effect of the compound of formula (1) was identified by determination of a dissociation constant Ki represented by the following Equation 1: <BR> <BR> <BR> <BR> <BR> Ki=#E#>/[E<BR> . in which [E] means a concentration of the free enzyme, [I] means a concentration of the unbound inhibitor, and [EI] means a concentration of the enzyme-inhibitor complex, according to the known method described in literatures (see, Methods in Enzymology V. 80 p341-361; Biochemistry 27, p2144-2151, 1988).

The dissociation constant Ki denotes the degree of dissociation of the enzyme-thrombin inhibitor complex. Accordingly, a low dissociation constant means a high binding property of thrombin inhibitor to enzyme, and therefore, is estimated that the thrombin inhibitor has high inhibitory activity for thrombin. Such dissociation constant can be determined by reacting thrombin with a certain substrate which develops a color when it is hydrolyzed by the action of thrombin, and then measuring the degree of color development as a function of time by means of spectrophotometry.

In the present experiment, Chromozym TH (Tosyl-Gly-Pro-Arg-4-nitroanilide acetate) is used as the substrate for thrombin, which develops a color by the action of thrombin. Chromozym TH is hydrolyzed by thrombin to produce yellow para-nitroanilide.

Accordingly, the amount of yellow para-nitroanilide thus produced can be measured as the change of absorbance with the lapse of time to determine the thrombin inhibitory activity of the compound of the invention. That is, the enzyme activity can be determined from

the rate of change in absorbance and then can be directly connected with the ability of the thrombin inhibitor to inhibit the enzyme activity.

The inhibitory activity for trypsin of the compound of the invention was measured according to the same method as above for determination of thrombin inhibitory activity.

As the substrate, 500ptM solution of N-benzoyl-Val-Gly-Arg-p-nitroanilide hydrochloride (20,) was used, and the inhibitors were used in various concentrations between 0 and 100, uM. Trypsin was dissolved in 0. 1N HCl and then diluted with Tris buffer to 1µg/ml# solution just before the experiment, 20, ue of which was used. The total volume of the reaction solution was 200, LtQ, the same volume as that used in the experiment for thrombin, and the other processes were substantially identical to those for thrombin. The Km value used in the calculation of Ki value was determined to 160 aM according to the same method as for thrombin.

The inhibitory activity of the compound of the invention for thrombin and trypsin as determined according to the above method was represented by the Ki value. As a result, it was identified that the Ki values of all the compounds were 50nM or more for thrombin, whereas 1 uM or more for trypsin. Specifically, the Ki values for trypsin measured for the compounds'of Examples 22 and 30 were represented in the following Table 1.

Table 1 Drug Parent*'Example 22 Example 30 Trypsin inhibitory constant (nM) 0. 30 21333 21019 Note) *1 : HO2CCH2-D-Dpa-Pro-NH-CH2-5-(2-amd)-thioph Experiment 3 Pharmacokinetic test

Absorptivity upon oral administration of the compound of the invention was determined by measuring the drug concentration in blood according to the following procedure. Male dogs were fasted for 18 hours and fed. One hour after food ingestion, the drug was orally administered. Here, the drug was prepared by making a 1% (10 mg/m#) solution of the example compound with using HPCD (hydroxypropyl-p- cyclodextrin) as a dissolution aid. Bloods were collected from the dogs at given time intervals, which were then extracted with methylene chloride and reversely extracted again with diluted hydrochloric acid solution. The drug concentration in blood was measured by HPLC.

The pharmacokinetic parameters of the compound of the invention were calculated from the drug concentration in blood as measured above and are represented in the following Table 2.

Table 2 Pharmacokinetic parameters in dogs orally administered (10 mg/kg, solution, fed) Example Cmax (: g/) TmaX (min) AUC (g-min/mA) Parent*'0. 52 30 76 1 0.73 30 85 22 0.72 80 121 30 0.30 100 63 In the above Table 2 Cmax means the maximum blood concentration, Tmax means the time to reach the maximum blood concentration, and AUC means the integration value under the curve of time versus blood concentration.

Experiment 4

The results of Experiment 3 were converted to bioavailability (%) and are represented in the following Table 3.

Table3 Bioavailability (%) Parent*'Example 13 Example 22 Example 30 When administered after fast (A) When administered 4.4 3.4 9 4 after ingestion (B) Bioavailability Rate 10 48 32 1000 (B/A)

As can be seen from Table 3, the compound of Example 22 of the invention showed higher bioavailability rate as well as more increased absolute bioavailability after food ingestion than the Parent compound. In the case of the compound of Example 30, its absolute bioavailability after fast was not high. After food ingestion, however, its absolute bioavailability was increased to the same level as the Parent compound, and bioavailability rate thereof was also improved by one hundred times as much as the Parent compound.