WO1999020617A1

WO1999020617A1 - Antiinflammatory thiadiazolyl ureas which act as lfa-1 and mac-1 inhibitors

Info

Publication number: WO1999020617A1
Application number: PCT/US1998/021630
Authority: WO
Inventors: Ronald B. Gammill; Susan Vander Velde; Mark Allen Mitchell; Richard Allen Nugent
Original assignee: Active Biotech Ab
Priority date: 1997-10-21
Filing date: 1998-10-20
Publication date: 1999-04-29
Also published as: AU9802198A

Abstract

The present invention provides a compound of formula (I) wherein R1, R2 and R3 are as defined herein. The compounds of the present invention are therapeutically useful in the treatment of a broad range of inflammatory disease such as, for example, hypersensitivity reactions, asthma, rheumatoid arthritis, bacterial meningitis, aspiration lung injury, inflammatory bowel disorder and related complications.

Description

ANTI INFLAMMATORY THIADIAZOLYL UREAS WHICH ACT AS LFA-1 AND MAC-1 INHIBITORS

FIELD OF THE INVENTION This invention relates to novel thiadiazole ureas, to pharmaceutical compositions containing them, and to methods of using them. The compounds of the invention are pharmaceutically active in the treatment of inflammatory diseases.

BACKGROUND OF THE INVENTION Inflammation is an integral part of a wide array of human diseases, ranging from bacterial pneumonia, in which the response is life-saving, to adult respiratory distress syndrome, in which it is life-threatening. Inflammation may result in substantial tissue damage or initiate processes leading to excessive fibrous repair, and therefore it is desirable to interrupt its progression. Today, many investigators are attempting to identify new therapeutic agents designed to directly block adhesive events involved in an array of disease processes.

LFA-1 and Mac-1, members of the β2 integrin family of adhesion molecules, are thought to play a critical role in several types of inflammatory disease processes by interacting with intercellular adhesion molecule (ICAM), which promotes the migration of the leukocyte rapidly into surrounding tissue. Support for the importance of β2 integrin in mediating inflammatory responses has been demonstrated by the evidence that transendothelial migration in vitro is markedly inhibited by monoclonal antibodies against β2 integrins or ICAM-1. C. W. Smith, Can. J. Physiol. Pharmacol., Vol. 71, pp 76-87 (1993). Furthermore, blockade of the LFA-1 complex has been shown to inhibit neutrophil influx in almost every system, including skin, peritoneum, synovium, lung, kidney, and heart. As one of the primary ligands for the β2 integrins, it would also be expected that blockade of ICAM-1 would inhibit the inflammatory response. S. M. Albelda et al., The FASEB J., Vol. 8, pp 504-512 (1994).

We now have discovered that certain novel thiadiazole ureas are LFA-1 and Mac-1 inhibitors. Molecules that inhibit LFA-1 and Mac-1 binding with ICAM-1 down regulate inappropriate leukocyte wreaking havoc on healthy tissues seen in acute and chronic inflammatory diseases. As such, these compounds of the present invention are therapeutically useful in the treatment of a broad range of inflammatory disease such as, for example, hypersensitivity reactions, asthma, rheumatoid arthritis, bacterial meningitis, aspiration lung injury, inflammatory bowel disorder and related complications. INFORMATION DISCLOSURE The following references disclose thiadiazole derivatives. International Publication No. WO 96/30370 discloses thiazole and thiadiazole derivatives useful in the treatment of thrombocytopenia. U. S. Patent 4,775,408 discloses pyridine substituted thiadiazole ureas which have herbicidal and plant growth regulatory properties.

U. S. Patent 4,576,629 discloses herbicidal thiadiazole ureas wherein the 5- position of the thiadiazole ring is hetero substituted and which exhibit enhanced selective herbicidal activity. Abstract of Japanese Patent 1160-976-A discloses 1,3,4-thiadiazole derivatives useful as antiulcer agents.

SUMMARY OF THE INVENTION The present invention presents novel compounds of formula I

N -

R -

I

H H

(0 )_n

I or pharmaceutically acceptable salts thereof wherein: R_x is a) -aryl, b) -aryl wherein aryl is substituted with one to three R₄,

0 -Q, d) -Q wherein Q is substituted with one to three R₄, e) -Het, f) -Het wherein Het is substituted with one to three R₄,

h)

_} optionally substituted with C_x_₄ alkyl or C_3.6 cycloalkyl, i) C_j.g carboalkoxy, j) -C(=O)-CH₂C0₂(C_1.4 alkyl), k) -C(=O)NH(CH₂)_/R₅,

1) C_H0 alkyl, m) C_{1 0} alkyl substituted with one to three R₆,

n) C_{1 Q} alkenyl, or o) C_{l 0} alkenyl substituted with one to three R₆; R₂ is

R₃ is a) -(CR₉R₁₀)_z(CH₂)_/-aryl, b) -(CR₉R₁₀)_/(CH₂),-aryl wherein aryl is substituted with one to three R_n, c) -(CR₉R₁₀)_Z(CH₂)_/-Q, d) -(CR₉R₁₀)_Z(CH₂) -Q wherein Q is substituted with one to three R_n, e) -(CR₉R₁₀)_/(CH₂)_/-Het, f) -(CR₉R₁₀);(CH₂) -Het wherein Het is substituted with one to three R_n, or g) -(CR₉R₁₀)_r(CH₂)_rpentafluorophenyl;

-₄ is a) halo, b) C₁ alkyl, c) C₃_₆ cycloalkyl, d) C_j.4 alkoxy, e) aryl, f) Q, g) Het, h) C₁ carboalkoxy, i) C₁ monoalkylamino, j) C₁ dialkylamino, k) amido,

1) C_x_₄ alkylthio, m) trihalomethyl, n) -(CH₂)_rO-(C₁.₄ alkyl), o) nitro, P) mercapto, q) nitrine, r) cyano, s) hydroxy. t) -NHC(=O)(C₁.₄ alkyl), or u) -NHSO₂(C_1.4 alkyl);

R₅ is a) C-i.g alkyl, b) aryl, c) Q, or d) Het;

R₆ is a) halo, b) hydroxy, c) C_λ.4 alkoxy, d) C_j.4 carboalkoxy, e) amido, f) nitro, g) trihalomethyl, h) cyano, i) mercapto, j) C_x.4 alkylthio, or k) C_j.₈ alkyl;

R₇ and R₈ are the same and different a) H, b) C_λ._e alkyl, c) C₃.₆ cycloalkyl, d) -(CH₂)_rO-C₁.₄ alkyl, e) -(CH₂)_rQ, or f) -(CH₂)_rHet;

R₉ and R₁₀ are the same and different a) H, b) C₁ alkyl, c) C₁ alkoxy, d) C₃.₆ cycloalkyl, or e) C_j.₄ carboalkoxy; R_n is a) C_j.4 alkyl, b) C₁ alkoxy, c) trihalomethyl, d) halo, e) nitro, f) cyano, g) nitrine, h) C_x.4 acyl, i) C_lΛ carboalkoxy, or j) carboxyl; aryl is monocarbocyclic, or bicarbocyclic aromatic moiety;

Q is 5- to 10-membered saturated heterocyclic moiety having one to three atoms selected from the group consisting of oxygen, nitrogen, and sulfur; Het is 5- to 10-membered unsaturated heterocyclic moiety having one to three atoms selected from the group consisting of oxygen, nitrogen, and sulfur; j is 0, 1, 2 or 3; k is 0, 1, 2, 3, 4, 5 or 6;

I is 0, 1, 2, 3, 4 or 5; n is 0, 1 or 2; and with the following provisos: a) where R₃ is a), R_x is other than c) through f); b) where R₃ is aryl substituted with cyano, R_x is other than phenyl substituted with cyano, unsubstituted pyridyl, furyl and -C(=O)-NHCH₂-pyridyl.

The compounds of the present invention are therapeutically useful in the treatment of a broad range of inflammatory disease such as, for example, hypersensitivity reactions, asthma, rheumatoid arthritis, bacterial meningitis, aspiration lung injury, inflammatory bowel disorder and related complications.

DETAILED DESCRIPTION OF THE INVENTION For the purpose of the present invention, the carbon content of various hydrocarbon containing moieties is indicated by a prefix designating the minimum and maximum number of carbon atoms in the moiety, i.e., the prefix C- defines the number of carbon atoms present from the integer "i" to the integer "j", inclusive. Thus, for example, C_x_₄ alkyl refers to alkyl of one to four carbon atoms, inclusive, or methyl, ethyl, propyl, butyl and isomeric forms thereof.

The terms "C^ alkyl", "C_M alkyl", "C^ alkyl", and "C_{1 0} alkyl" refer to an alkyl group having one to four, one to six, one to eight, or one to ten carbon atoms respectively such as, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl and their isomeric forms thereof.

The term "C_2-10 alkenyl" refers to at least one double bond alkenyl group having two to ten carbon atoms respectively such as, for example, ethenyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, heptdienyl, octenyl, octadienyl, octatrienyl, nonenyl, undecenyl, dodecenyl, and their isomeric forms thereof.

The term "C₃.₆ cycloalkyl" refers to a cycloalkyl having three to six carbon atoms such as, for example, cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl and their isomeric forms thereof.

The terms "C_x_₄ alkoxy" refers to an alkyl group having one to four carbon atoms attached to an oxygen atom of hydroxyl group such as, for example, methoxy, ethoxy, propyloxy, butyloxy and their isomeric forms thereof.

The term "C^ alkylthio" refers to an alkyl group having one to four carbon atoms attached to an thiohydroxy moiety, for example, methythio, ethyl thio, propylthio, butylthio and isomeric forms thereof.

The terms "C-^ acyl" and "C-^_g acyl" refer to a carbonyl group having an alkyl group of one to four or one to six carbon atoms respectively.

The terms "C^ carboalkoxy" and "C-^_g carboalkoxy" refer to an ester group having an alkyl group of one to four or one to six carbon atoms respectively.

The term "C-^ monoalkylamino" refers to an alkyl group having one to four carbon atoms attached to an amino moiety, for example, methylamine, ethylamine, n-propylamine, n-butylamine, and isomeric forms thereof.

The term "C-^ dialkylamino" refers to two alkyl groups having one to four carbon atoms attached to an amino moiety, for example, dimethylamine, methylethylamine, diethylamine, dipropylamine, methypropylamine, ethylpropylamine, dibutylamine, and isomeric forms thereof. The term "halo" refers to fluoro, chloro, bromo, or iodo. The term trihalomethyl refers to trifluoromethyl, trichloromethyl or tribromomethyl.

The term "aryl" refers to monocarbocyclic or bicarbocyclic aromatic moiety such as, for example phenyl, naphthyl or biphenyl. Each of these moieties may be substituted as appropriate. Aryl is preferably substituted and unsubstituted phenyl. The term "Het" refers to a 5- to 10-membered unsaturated heterocyclic moiety having one or more atoms selected from the group consisting of oxygen, nitrogen, and sulfur such as; for example, 2-pyridyl, 3-pyridyl, 4-pyridyl, 2-pyrimidinyl, 4- pyrimidinyl, 5-pyrimidinyl, 3-pyridazinyl, 4-pyridazinyl, 3-pyrazinyl, 2-quinolyl, 3- quinolyl, 1-isoquinolyl, 3-isoquinolyl, 4-isoquinolyl, 2-quinazolinyl, 4-quinazolinyl, 2- quinoxalinyl, 1-phthalazinyl, 2-imidazolyl, 4-imidazolyl, 3-isoxazolyl, 4-isoxazolyl, 5- isoxazolyl, 3-pyrazolyl, 4-pyrazolyl, 5-pyrazolyl, 2-oxazolyl, 4-oxazolyl, 5-oxazolyl, 2- thiazolyl, 4-thiazolyl, 5-thiazolyl, 3-isothiazole, 4-isothiazole, 5-isothiazole, 2-indolyl, 3-indolyl, 3-indazolyl, 2-benzoxazolyl, 2-benzothiazolyl, 2-benzimidazolyl, 2- benzofuranyl, 3-benzofuranyl, benzoisothiazole, benzoisoxazole, 2-furanyl, 3-furanyl, 2-thienyl, 3-thienyl, 2-pyrrolyl, 3-pyrrolyl, 3-isopyrrolyl, 4-isopyrrolyl, 5-isopyrrolyl, 1-indolyl, 1-indazolyl, 2-isoindolyl, 1-purinyl, 3-isothiazolyl, 4-isothiazolyl and 5- isothiazolyl, preferably pyridyl, quionlinyl, pyrrolyl, thienyl, thiazolyl, or indolyl. The term "Q" refers to a 5- to 10-membered saturated heterocyclic moiety having one to two atoms selected from the group consisting of oxygen, nitrogen, and sulfur such as, for example, piperidinyl, 2-, 3-, or 4-piperidinyl, [l,4]piperazinyl, morpholinyl, 2- or 3-morpholinyl, thiomorpholinyl, dioxolanyl, imidazolidinyl, [l,3]oxathiolanyl, [l,3]oxazolidinyl, pyrrolidinyl, butyrolactonyl, butyrolactamyl, succinimidyl, glutarimidyl, valerolactamyl, 2,5-dioxo-[l,4]-piperazinyl, pyrazolidinyl, 3-oxopyrazolidinyl, 2-oxo-imidazolidinyl, 2,4-dioxo-imidazolidinyl, 2-oxo-[l,3]- oxazolidinyl, 2,5-dioxo-[l,3]-oxazolidinyl, isoxazolidinyl, 3-oxo-isoxazolidinyl, [1,3]- thiazolidinyl, 2- or 4-oxo-[l,3]-thiazolidinyl, butyrolactamyl, succinimidyl, glutarimidyl, valerolactamyl, 2,5-dioxo-[l,4]-piperazinyl, 3-oxopyrazolidinyl, 2-oxo- imidazolidinyl, 2,4-dioxo-imidazolidinyl, 2-oxo-[l,3]-oxazolidinyl, 2,5-dioxo-[l,3]- oxazolidinyl, 3-oxo-isoxazolidinyl, 2- or 4-oxo-[l,3]-thiazolidinyl.

Within the definition of the terms "Het" and "Q", the nitrogen atom forming the hetero rings may have a protective group such as an acetyl or hydroxyacetyl group.

Certain reagents are abbreviated herein. THF refers to tetrahydrofuran, DMF refers to dimethyl formamide.

The compounds of the present invention can be converted to their salts, where appropriate, according to conventional methods. The term "pharmaceutically acceptable salts" refers to addition salts useful for administering the compounds of this invention and include hydrochloride, hydrobromide, hydroiodide, sulfate, phosphate, acetate, propionate, lactate, mesylate, maleate, malate, succinate, tartrate, citric acid, 2-hydroxyethyl sulfonate, fumarate and the like. These salts may be in hydrated form. Some of the compounds of this invention may form metal salts such as sodium, potassium, calcium and magnesium salts and these are embraced by the term "pharmaceutically acceptable salts".

Depending on substituents, the compounds of formula I of this invention may contain a chiral center and other isomeric forms and this invention embraces all possible stereoisomers and geometric forms. Typical antiinflammatory thiadiazoles ureas and amides of this invention are a N-[5-[[(3,5-Dimethoxyphenyl)methyl]thio]-l,3,4-thiadiazol-2-yl]-N'-(2- phenylethyDurea, b N-[5-[[(4-Methoxyphenyl)methyl]thio]-l,3,4-thiadiazol-2-yl]-N'-(2- phenylethyl)urea , c N-[5-[[(3,4-Dimethoxyphenyl)methyl]thio]-l,3,4-thiadiazol-2-yl]-N'-(2- phenylethyDurea, d N-[5-[[6-(l,3-Dihydro-l,3-dioxo-2H-isoindol-2-yl)hexyl]thio]-l,3,4-thiadiazol-2- yl]-N'-(2-phenylethyl)urea, e N-[5-[([l,l'-Biphenyl]-4-ylmethyl)thio]-l,3,4-thiadiazol-2-yl]-N'-(2- phenylethyl)urea, f (E)-N-[5-[(3,7-Dimethyl-2,6-octadienyl)thio]-l,3,4-thiadiazol-2-yl]-N'-(2- phenylethyDurea, g (E)-N-[5-[(3,7-Dimethyl-2,6-octadienyl)thio]-l,3,4-thiadiazol-2-yl]-N'-(3- cyanophenyl)urea, h (E)-N-[5-[(3,7-Dimethyl-2,6-octadienyl)thio]-l,3,4-thiadiazol-2-yl]-N'-[l-(2- naphthalenyDethyl] urea, i N-(2-Phenylethyl)-N'-[5-[(phenylmethyl)thio]-l,3,4-thiadiazol-2-yl]urea, j Methyl [ [5- [ [ [(2-phenylethyl)amino] carbonyl] amino] - 1 ,3 ,4-thiadiazol-2- yl]thio] acetate, k Methyl [[5-[[[(3-cyanophenyl)amino]carbonyl]amino]-l,3,4-thiadiazol-2- yl]thio] acetate, 1 t-Butyl [[5- [ [ [(3-cyanophenyl)amino] carbonyl] amino] -l,3,4-thiadiazol-2- yl] thio] acetate, m Methyl 3-[[[5-[[[(3-cyanophenyl)amino]carbonyl]amino]-l,3,4-thiadiazol-2- yl]thio]methyl]benzoate, n Methyl 3-[[[5-[[[(2-trifluoromethylphenyl)amino]carbonyl]amino]-l,3,4- thiadiazol-2-yl]thio]methyl]benzoate, o Methyl 3-[[[5-[[[(3-trifluoromethylphenyl)amino]carbonyl]amino]-l,3,4- thiadiazol-2-yl] thio] methyl] benzoate, p Methyl 3-[[[5-[[[(4-trifluoromethylphenyl)amino]carbonyl]amino]-l,3,4- thiadiazol-2-yl] thio] methyl] benzoate, q 2- [ [5- [ [ [(3-Cyanophenyl)amino] carbonyl] amino] -1,3, 4-thiadiazol-2-yl] thio] -N- octylacetamide , r N-(3-Cyanophenyl)-N'-[5-[(2-fluoro-4-nitrophenyl)thio]-l,3,4-thiadiazol-2- yl]urea, s N-[5-[(Cyanomethyl)thio]-l,3,4-thiadiazol-2-yl]-N'-(3-cyanophenyl)urea, t N-(3-Cyanophenyl)-N'-[5-[[2-(l,3-dihydro-l,3-dioxo-2H-isoindol-2-yl)ethyl]thio]- l,3,4-thiadiazol-2-yl]urea, u N-(3-Cyanophenyl)-N'-[5-[(2-quinolinylmethyl)thio]-l,3,4-thiadiazol-2-yl]urea, v Methyl 4- [ [5- [ [ [(3-cyanophenyl)amino] carbonyl] amino] - 1 ,3 ,4-thiadiazol-2- yl]thio]-3-oxobutanoate, w N-(3-cyanophenyl)-N'-[5-[(3-pyridinylmethyl)thio]-l,3,4-thiadiazol-2-yl]urea, x N-[5-[(5-Cyanopentyl)thio]-l,3,4-thiadiazol-2-yl]-N'-(3-cyanophenyl)urea, y N-[5-[[(4-Chloro-2-nitrophenyl)methyl]thio]-l,3,4-thiadiazol-2-yl]-N'-(3- cyanophenyl)urea, z N-(3-Cyanophenyl)-N'-[5-(2-propenylthio)-l,3,4-thiadiazol-2-yl]urea, aa N-(3-Cyanophenyl)-N'-[5-(2-propynylthio)-l,3,4-thiadiazol-2-yl]urea, bb N-(3-cyanophenyl)-N'-t5-(octylthio)-l,3,4-thiadiazol-2-yl]urea, cc Methyl 3- [ [ [5- [ [ [(3-cyanophenyl)amino] carbonyl] amino] - 1 ,3 ,4-thiadiazol-2- yl] thio] methyl] benzoate , dd Methyl 3-[[[5-[[[(2-phenylethyl)amino]carbonyl]amino]-l,3,4-thiadiazol-2- yl] thio] methyl] benzoate, ee N-[5-[(3-Pyridinylmethyl)thio]-l,3,4-thiadiazol-2-yl]-N'-[3-

(trifluoromethyl)phenyl] urea, ff N- [5- [(4-Pyridinylmethyl)thio] -1 ,3 ,4-thiadiazol-2-yl] -N'- [3- (trifluoromethyl)phenyl]urea, gg N-(3-Fluorophenyl)-N'-[5-[(2-pyridinylmethyl)thio]-l,3,4-thiadiazol-2-yl]urea, hh N-(3-Fluorophenyl)-N'-[5-[(3-pyridinylmethyl)thio]-l,3,4-thiadiazol-2-yl]urea, ii N-(3-Fluorophenyl)-N'-[5-[(4-pyridinylmethyl)thio]-l,3,4-thiadiazol-2-yl]urea, jj 2- [ [5- [ [ [(3-Cyanophenyl)amino] carbonyl] amino] - 1 ,3 ,4-thiadiazol-2-yl] thio] -N-(2- methoxyethyDacetamide, kk 2- [ [5- [ [ [(3-Cyanophenyl)amino] carbonyl] amino] - 1 ,3 ,4-thiadiazol-2-yl] thio] -N-(2- pyridinylmethyl)acetamide, 11 2- [ [5- [ [[(3-Cyanophenyl)amino] carbonyl] amino] -l,3,4-thiadiazol-2-yl] thio]-N-(4- pyridinylmethyl)acetamide, mm N-(2-Phenylethyl)-N'-[5[(3-pyridinylmethyl)thio]-l,3,4-thiadiazol-2-yl]urea, nn N-(2-Phenylethyl)-N'-[5[(2-pyridinylmethyl)thio]-l,3,4-thiadiazol-2-yl]urea, oo (E)-N-(3-Acetylphenyl)-N'-[5-[(3,7-dimethyl-2,6-octadienyl)thio]-l,3,4- thiadiazol-2-yl] urea, pp 2- [ [5- [ [ [(3-Cyanophenyl)amino] carbonyl] amino] - 1 ,3 ,4-thiadiazol-2-yl] thio] -N- phenylacetamide , qq N-(3-Fluorophenyl)-N'-[5-[(2-quinolinylmethyl)thio]-l,3,4-thiadiazol-2-yl]urea, rr N-[5-[(2-Quinolinylmethyl)thio]-l,3,4-thiadiazol-2-yl]-N'-[3-

(trifluoromethyl)phenyl] urea, ss 2- [ [5- [ [ [(3-Cyanophenyl)amino] carbonyl] amino] - 1 ,3 ,4-thiadiazol-2-yl] thio] -N-2- propenylacetamide, tt 2- [ [5- [ [ [(3-Cyanophenyl)amino] carbonyl] amino] - 1 ,3 ,4-thiadiazol-2-yl] thio] -N-

(phenylmethyl)acetamide, uu 1 , 1-Dimethylethyl 5- [ [ [5- [ [ [ [3-(trifluoromethyl)phenyl] amino] carbonyl] amino] -

1 ,3 ,4-thiadiazol-2-yl] thio] methyl] -2-thiophenecarboxylate, w N-(3-Cyanophenyl)-N'-[5-[[(l-cyclohexyl-lH-tetrazol-5-yl)methyl]thio]-l,3,4- thiadiazol-2-yl]urea, ww 1, 1-Dimethylethyl 3-[[[5-[[[(3-fluorophenyl)amino]carbonyl]amino]-l,3,4- thiadiazol-2-yl]thio]methyl]benzoate, xx 1 , 1-Dimethylethyl 3- [ [ [5- [ [ [(3-cyanophenyl)amino] carbonyl] amino] -1,3,4- thiadiazol-2-yl]thio]methyl]benzoate, yy N-(3-Cyanophenyl)-N'-[5-[[l-(3-methylfuro[2,3-c]pyridin-5-yl)ethyl]thio]-l,3,4- thiadiazol-2-yl] urea, zz N-(3-Cyanophenyl)-N'-[5-[[[4-(l-methylethyl)-2-pyridinyl]methyl]thio]-l,3,4- thiadiazol-2-yl] urea, aaa N-(3-Fluorophenyl)-N'-[5-[(l-phenylpropyl)thio]-l,3,4-thiadiazol-2-yl]urea, bbb N-(3-Fluorophenyl)-N'-[5-[(3-furanylmethyl)thio]-l,3,4-thiadiazol-2-yl]urea, ccc N- [ [ [5- [(2-Quinolinylmethyl)thio] - l,3,4-thiadiazol-2-yl] amino] carbonyl] -L- phenylalanine ethyl ester, ddd N- [5- [(2-Pyridinylmethyl)thio] - 1 ,3,4-thiadiazol-2-yl] -N'- [3-

(trifluoromethyl)phenyl] urea, eee N-[5-[(3-Pyridinylmethyl)thio]-l,3,4-thiadiazol-2-yl]-N'-[3-

(trifluoromethyl)phenyl] urea, fff N- [5- [(4-Pyridinylmethyl)thio] -l,3,4-thiadiazol-2-yl] -N'- [3-

(trifluoromethyl)phenyl] urea, ggg N-(3-Chlorophenyl)-N'-[5-[(3-pyridinylmethyl)thio]-l,3,4-thiadiazol-2-yl]urea, hhh N-(3,5-Dichlorophenyl)-N'-[5-[(3-pyridinylmethyl)thio]-l,3,4-thiadiazol-2- yl]urea, iii N-(3-Cyanophenyl)-N'-[5-[[l-[5-(l-methylethyl)-3-pyridinyl]ethyl]thio]-l,3,4- thiadiazol-2-yl] urea, jjj N-(3-Fluorophenyl)-N'-[5-[[(5-phenyl-3-pyridinyl)methyl]thio]-l,3,4-thiadiazol-

2-yl]urea, kkk N-(3-Fluorophenyl)-N'-[5-[[l-(phenylmethyl)propyl]thio]-l,3,4-thiadiazol-2- yl]urea, 111 N-[5-[(Cyclopropylphenylmethyl)thio]-l,3,4-thiadiazol-2-yl]-N'-(3- fluorophenyl)urea, mmm N-(3-Fluorophenyl)-N'-[5-[[l-(3-pyridinyl)propyl]thio]-l,3,4-thiadiazol-2- yl]urea, nnn N-(3-Fluorophenyl)-N'-[5-[(l-phenylbutyl)thio]-l,3,4-thiadiazol-2-yl]urea, ooo N-(3-Fluorophenyl)-N'-[5-[[l-(2-pyridinyl)propyl]thio]-l,3,4-thiadiazol-2- yl]urea, ppp N-(3-Fluorophenyl)-N'-[5-[[l-(4-pyridinyl)propyl]thio]-l,3,4-thiadiazol-2- yl]urea, qqq N-(3-Fluorophenyl)-N'- [5- [ [ [5-(3-thienyl)-3-pyridinyl] methyl] thio] -1,3,4- thiadiazol-2-yl] urea, rrr Ethyl 3-[[[[5-[(l-phenylpropyl)thio]-l,3,4-thiadiazol-2- yl] amino] carbonyl]amino]benzoate, sss 3-[[[[5-[(l-Phenylpropyl)thio]-l,3,4-thiadiazol-2- yl] amino] carbonyl] amino] benzoic acid, ttt N-(3-Chlorophenyl)-N'-[5-[(2-quinolinylmethyl)thio]-l,3,4-thiadiazol-2-yl]urea, uuu Ethyl 3- [ [ [ [5- [(2-quinolinylmethyl)thio] - 1 ,3 ,4-thiadiazol-2- yl] amino] carbonyl] amino] benzoate, vw N-[5-[(2-Quinolinylmethyl)thio]-l,3,4-thiadiazol-2-yl]-3,5- bis(trifluoromethyl)benzamide, www N-[5-[[l-[3-(Acetylamino)phenyl]ethyl]thio]-l,3,4-thiadiazol-2-yl]-3,4- dichlorobenzamide, xxx N- [3- [1- [ [5- [ [ [(3-Fluorophenyl)amino] carbonyl] amino] - l,3,4-thiadiazol-2- yl] thio] ethyl] phenyl] methanesulfonamide, yyy N-[5-[[l-(3-Azidophenyl)ethyl]thio]-l,3,4-thiadiazol-2-yl]-N'-(3- fluorophenyDurea, zzz N-[5-[[l-(3-Azidophenyl)ethyl]thio]-l,3,4-thiadiazol-2-yl]-3,4- dichlorobenzamide, aaaa 3-Azido-4-chloro-N-[5-t(l-phenylpropyl)thio]-l,3,4-thiadiazol-2-yl]benzamide, bbbb 3-Azido-6-chloro-N-[5-[(l-phenylpropyl)thio]-l,3,4-thiadiazol-2-yl]benzamide, cccc 2,6-Difluoro-N-[5-[[l-(3-pyridinyl)propyl]thio]-l,3,4-thiadiazol-2-yl]benzamide, dddd N-(3-Fluorophenyl)-N'-[5-[[l-(4-fluorophenyl)ethyl]thio]-l,3,4-thiadiazol-2- yl]urea, and eeee N-(3-Azido-4-fluorophenyl)-N'-[5-[[l-(3-pyridinyl)propyl]thio]-l,3,4-thiadiazol- 2-yl]urea.

The compounds of formula I are generally prepared by coupling an alkylating agent A

R' - halo (A) with commercially available 5-amino-l,2,5-thiadiazole-2-thiol in the presence of appropriate base such as, for example, triethylamine or sodium hydride. R' is

R_x-R₂- radical as defined previously and halo is fluoro, chloro, bromo or iodo. The alkylating agents A are either commercially available or can be prepared from the corresponding alcohols with an activating agents such as methanesulfonyl chloride or thionyl chloride. The coupling results in the formation of the intermediate B:

N-N

RX ^R2^ .Λ„ -_tIMH, (B)

in the presence of an appropriate solvent such as, for example, THF, EtOAc, DMF, CH₃C1 or CH₃CN at room or slightly elevated temperature.

Particularly useful starting compounds in the preparation of compounds of formula I of the present invention is a compound of formula D:

wherein R₄ is as defined previously, R" is R₇ or R₈ are as defined previously, the ring E is aryl, Q or Het as defined previously. All these starting compounds are either commercially available or can be easily prepared according to the methods well known in the art. Some of the starting compounds preparations are illustrated in Examples as described hereinafter.

To provide compounds of formula I of the present invention, the intermediate

B is converted to the corresponding thiadiazoles ureas by addition of isocyanate, R₃-N=C=O, in an appropriate solvent such as THF. The methods of these reactions are well known to those skilled in the art. When desirable, the sulfur atom of the side chain can be oxidized by an appropriate oxidizer using the methods well known to those skilled in the art in an early synthetic step or at the end of synthetic sequence to the corresponding sulfones and sulfoxides, respectively. The pharmaceutical compositions of this invention may be prepared by combining the compounds of formula I of this invention with a solid or liquid pharmaceutically acceptable carrier, and optionally, with pharmaceutically acceptable adjuvants and excipients employing standard and conventional techniques. Solid form compositions include powders, tablets, dispersible granules, capsules and suppositories. A solid carrier can be at least one substance which may also function as a diluent, flavoring agent, solubilizer, lubricant, suspending agent, binder, tablet disintegrating agent, and encapsulating agent. Inert solid carriers include magnesium carbonate, magnesium stearate, talc, sugar, lactose, pectin, dextrin, starch, gelatin, cellulosic materials, low melting wax, cocoa butter, and the like. Liquid form compositions include solutions, suspensions and emulsions. For example, there may be provided solutions of the compounds of this invention dissolved in water, water-propylene glycol, and water-polyethylene glycol systems, optionally containing conventional coloring agents, flavoring agents, stabilizers and thickening agents. The pharmaceutical composition is provided by employing conventional techniques. Preferably the composition is in unit dosage form containing an effective amount of the active component, that is, the compounds of formula I according to this invention.

The quantity of active component, that is, the compounds of formula I according to this invention, in the pharmaceutical composition and unit dosage form thereof may be varied or adjusted widely depending upon the particular application method, the potency of the particular compound and the desired concentration. Generally, the quantity of active component will range between 0.5% to 90% by weight of the composition. In therapeutic use for treating inflammatory complications in humans and other animals that have been diagnosed with inflammatory disease, the compounds or pharmaceutical compositions thereof will be administered orally, parenterally, aerosol, and/or topically at a dosage to obtain and maintain a concentration, that is, an amount, or blood-level of active component in the animal undergoing treatment which will be antiinflammatory effective. Generally, such antiinflammatory effective amount of dosage of active component will be in the range of about 0.1 to about 200 gfkg, more preferably about 3.0 to about 50 mg/kg of body weight/day. It is to be understood that the dosages may vary depending upon the requirements of the patient, the severity of the inflammatory complication being treated, and the particular compounds being used. Also, it is to be understood that the initial dosage administered may be increased beyond the above upper level in order to rapidly achieve the desired blood-level or the initial dosage may be smaller than the optimum and the daily dosage may be progressively increased during the course of treatment depending on the particular situation. If desired, the daily dose may also be divided into multiple doses for administration, e.g., two to four times per day. These compounds are useful for the treatment of inflammatory complications in humans and other warm blooded animals by either parenteral, oral, aerosol, or topical administration. In general, the preferred form of administration is orally. Pharmaceutical compositions for parenteral administration will generally contain a pharmaceutically acceptable amount of the compounds according to formula I as a soluble salt (acid addition salt or base salt) dissolved in a pharmaceutically acceptable liquid carrier such as, for example, water-for-injection and a suitably buffered isotonic solution having a pH of about 3.5 - 6. Suitable buffering agents include, for example, trisodium orthophosphate, sodium bicarbonate, sodium citrate, N-methylglucamine, L(+)-lysine and L(+)-arginine, to name a few. The compounds according to formula I generally will be dissolved in the carrier in an amount sufficient to provide a pharmaceutically acceptable injectable concentration in the range of about 1 mg/ml to about 400 mg/ml. The resulting liquid pharmaceutical composition will be administered so as to obtain the above mentioned antiinflammatory effective amount of dosage. The compounds of formula I according to this invention are advantageously administered orally in solid and liquid dosage forms.

The compounds of this invention are useful antiinflammatory agents, effective against a broad range of inflammatory disease states in which neutrophils wreak havoc on healthy tissues. Therefore, they are therapeutically useful in the treatment of chronic or acute inflammatory disease such as, for example, hypersensitivity reactions, asthma, rheumatoid arthritis, bacterial meningitis, aspiration lung injury, inflammatory bowel disorder and related complications. Humans or animals suffered with such complications are readily diagnosed by a physician or veterinarian of ordinary skill. The compounds and their preparations of the present invention will be better understood in connection with the following examples, which are intended as an illustration of and not a limitation upon the scope of the invention.

I. Preparation of intermediate Compound B.

Method A: 5-Amino-l,3,4-thiadiazole-2-thiol (1 equiv.) is partially dissolved in CH₃CN.

Triethylamine (2-3 equiv.) is added, followed by the alkyl chloride. The chloride is either commercially available, or generated from the alcohol with thionyl chloride (2 equiv.) in chloroform. The excess thionyl chloride is removed under reduced pressure, and the neat alkyl chloride was then added to the thiadiazole in CH₃CN. The reaction is stirred at 25-65 °C overnight. The CH₃CN is removed in vacuo, and the residual oil is partitioned between CHC1₃ and H₂O. After the layers are separated, the aqueous phase is extracted with CHC1₃. The combined organics are washed with brine, dried over MgSO₄, and concentrated to crude material. Product is purified by either recrystallization or flash chromatography. Method B:

The mesylate of the appropriate alcohol is prepared in situ. The alcohol (1 equiv.) is dissolved in THF, and triethylamine (2 equiv.) is added. The reaction is cooled to 0 °C, and methanesulfonyl chloride (1.1 equiv.) is added. The reaction is allowed to warm to room temperature. After 1 hour, 5-amino-l,3,4-thiadiazole-2- thiol (1 equiv.) is added. The reaction is stirred overnight. The reaction is diluted with EtOAc and H₂O. After separation, the aqueous phase is extracted with EtOAc. The combined organics are washed with brine, dried over MgSO₄, and concentrated to crude material. Product is purified by flash chromatography or recrystallization. Method C: 5-Amino-l,3,4-thiadiazole-2-thiol (1 equiv.) is dissolved in DMF and cooled to

0 °C. Sodium hydride (1.1 equiv) is added, and the reaction is stirred at 0 °C until all the solids are dissolved (1-2 hours). The alkyl chloride is generated from the alcohol (1 equiv.) with thionyl chloride (2 equiv.) in chloroform. The excess thionyl chloride is removed in vacuo. The alkyl chloride is added to the sodium anion of the thiadiazole. The reaction is allowed to warm to room temperature and stirred for 5- 12 hours. The reaction is quenched and then diluted with H₂O. The aqueous solution is extracted with EtOAc, and the combined organics are washed with brine. After drying over MgSO₄, solvent is removed in vacuo to yield crude material. The product is purified by flash chromatography or recrystallization. Method D:

The appropriate alcohol (1 equiv.) and triethylamine (1.1 equiv.) is dissolved in THF and cooled to 0 °C. Methanesulfonyl chloride (1.1 equiv.) is then added, and the reaction is stirred at room temperature for 1 hour. The reaction is diluted with EtOAc and H₂O, and the layers are separated. The organic phase is washed with brine and dried over MgSO₄. The solvent is removed in vacuo, yielding pale yellow oil. The mesylate is added neat to the sodium anion of the thiadiazole. The thiadiazole is deprotonated by added sodium hydride (1.1 equiv.) to a 0 °C solution of 5-amino-l,3,4-thiadiazole-2-thiol (1 equiv.) dissolved in DMF. The reaction is allowed to warm to room temperature and stirred overnight. The reaction is quenched and diluted with H₂O. The aqueous phase is extracted with EtOAc, and the combined organics are washed with brine. After drying over MgSO₄, the solvent is removed in vacuo yielding crude material. The product is isolated by flash chromatography or recrystallization. II. Preparation of Thiadiazoles Ureas. Method E: To a solution (or slurry) of alkylated thiadiazole (1 equiv.) in THF is added the desired isocyanate (1.1 equiv.). The reaction is stirred at room temperature for 5-12 hours. The solvent is removed in vacuo. The product is purified by flash chromatography or recrystallization.

EXAMPLE 1 Preparation of N-(3-fluorophenyl)-N'-[5[(2- pyridinylmethyl)thio]-l,3,4-thiadiazol-2-yl]urea.

Step 1 Preparation of 5-[(2-pyridinylmethyl)thio]-l,3,4-thiadiazol-2-amine. Following the general procedure outlined in Method A and making non- critical variations but starting with 2-picolyl chloride HC1 and 2-amino-5-mercapto- 1,3,4-thiadiazole, the title compound is obtained as a solid, mp 147-9 °C. 1H NMR (DMSO) 6 4.37, 7.26, 7.40, 7.74, 8.48. IR (mull) 3307, 3265, 3087, 3016, 2435, 2322, 2257, 2155, 20, 68, 1650, 1499, 1431, 1405, 1051, 671, cm ¹.

Anal. Calcd for C₈H₈N₄S₂ : C, 42.84; H, 3.60; N, 24.98. Found: C, 42.66; H, 3.69; N, 24.90. Step 2 Preparation of N-(3-fluorophenyl)-N'-[5[(2-pyridinylmethyl)thio]-l,3,4- thiadiazol-2-yl] urea. Following the general procedure outlined in Method E and making non- critical variations but starting with the product of Step 1, Example 1, the title compound is obtained as a solid, mp 202-204 °C.

1H NMR (DMSO) δ 4.54, 6.80-6.89, 7.16-7.20, 7.28-7.34, 7.42-7.49, 7.74-7.81, 8.50- 8.54, 9.29, 11.21.

¹³C NMR (DMSO) δ 105.4, 105.7, 109.2, 109.5, 114.6, 122.6, 123.1, 130.3, 130.5, 137.0, 149.1, 156.1, 160.6, 163.8. IR (mull) 3368, 1959, 1924, 1709, 1614, 1604, 1568, 1554, 1495, 1481, 1444, 1430, 1403, 1315, 1226, cm P

Anal. Calcd for C₁₅H₁₂FN₅OS₂: C, 49.85; H, 3.35; N, 19.38. Found: C, 49.76; H, 3.49; N, 19.22.

EXAMPLE 2 Preparation of N-(3-fluorophenyl)-N'- [5 [(3-pyridinylmethyl)thio] l,3,4-thiadiazol-2-yl]urea.

Step 1 Preparation of 5-[(4-pyridinylmethyl)thio]-l,3,4-thiadiazol-2-amine.

Following the general procedure outlined in Method A and making non- critical variations but starting with 3-picolyl chloride HCl and 2-amino-5-mercapto- 1,3,4-thiadiazole, the title compound is obtained as a solid, mp 152-3 °C. *H NMR (DMSO) δ 4.30, 7.33, 7.74, 8.43, 8.48.

IR (mull) 3271, 3099, 2499, 2319, 2279, 2202, 2068, 1641, 1510, 1480, 1432, 1416, 1138, 1028, 712, cm^"1.

Anal. Calcd for C₈H₈N₄S₂: C, 42.84; H, 3.60; N, 24.98; S, 28.59. Found: C, 42.43; H, 3.64; N, 24.75.

Step 2 Preparation of N-(3-fluorophenyl)-N'-[5[(3-pyridinylmethyl)thio]-l,3,4- thiadiazol-2-yl]urea. Following the general procedure outlined in Method E and making non- critical variations but starting with the product of Step 1, Example 2 and 3- fluorophenyl isocyanate, the title compound is obtained as a solid, mp 173-175 °C. ^XH NMR (CH₃OH) δ 4.49, 6.78-6.84, 7.14-7.17, 7.28-7.35, 7.43-7.47, 7.95-7.98, 8.45, 8.58.

¹³C NMR (DMSO) δ 34.5, 105.3, 105.7, 109.2, 109.5, 130.4, 130.5, 133.1, 136.7, 148.3, 149.6, 160.6, 163.8. IR (mull) 3374, 1957, 1928, 1711, 1618, 1608, 1597, 1553, 1548, 1485, 1439, 1401, 1277, 1227, 1215, cm^'1.

Anal. Calcd for C₁₅H₁₂FN₅OS₂: C, 49.85; H, 3.35. Found: C, 49.69; H, 3.47; N, 19.25.

EXAMPLE 3 Preparation of N-(3-fluorophenyl)-N'- [5 [(4-pyridinylmethyl)thio] ■ l,3,4-thiadiazol-2-yl]urea.

Step 1 Preparation of 5-[(3-pyτidinylmethyl)thio]-l,3,4-thiadiazol-2-amine.

Following the general procedure outlined in Method A and making non- critical variations but starting with 4-picolyl chloride HCl and 2-amino-5-mercapto-

1,3,4-thiadiazole, the title compound is obtained as a solid, mp 183-4 °C.

1H NMR (DMSO) δ 4.28, 7.31, 7.48.

IR (mull) 3310, 3110, 2499, 2362, 2150, 2044, 1944, 1638, 1606, 1527, 1514, 1415,

1070, 1049, 1024, cm^"1. Anal. Calcd for C₈H₈N₄S₂: C, 42.84; H, 3.60; N, 24.98.

Found: C, 42.80; H, 3.74; N, 24.77.

Step 2 Preparation of N-(3-fluorophenyl)-N'-[5[(4-pyridinylmethyl)thio]-l,3,4- thiadiazol-2-yl]urea. Following the general procedure outlined in Method E and making non- critical variations but starting with the product of Step 1, Example 3 and 3- fluorophenyl isocyanate, the title compound is obtained as a solid, mp 178-179 °C.

1H NMR (DMSO) δ 4.46, 6.82-6.91, 7.18, 7.28-7.33, 7.39-7.45, 8.50-8.52.

¹³C NMR (DMSO) δ 36.0, 105.4, 105.7, 109.3, 109.5, 114.6, 123.8, 130.4, 130.5, 140.0,

140.1, 146.3, 149.5, 160.6, 163.8. IR (mull) 3384, 3369, 1944, 1726, 1618, 1601, 1557, 1495, 1430, 1408, 1317, 1305, 1219, 1205, 1152, cm^"1.

Anal. Calcd for C₁₅H₁₂FN₅OS₂: C, 49.85; H, 3.35; N, 19.38.

Found: C, 49.69; H, 3.41; N, 19.21.

EXAMPLE 4 Preparation of N-(3-chlorophenyl)-N'- [5 [(3- pyridinylmethyl)thio]-l,3,4-thiadiazol-2-yl]urea.

Following the general procedure outlined in Method E and making non- critical variations but starting with the product of Step 1, Example 2 and 3- chlorophenyl isocyanate, the title compound is obtained as a solid, mp 192-193 °C. 1H NMR (DMSO) δ 4.46, 7.07-7.09, 7.31-7.37, 7.66, 7.79-7.82, 8.45, 8.55, 9.25, 11.12. ¹³C NMR (DMSO) δ 34.6, 116.7, 117.3, 117.6, 118.2, 121.6, 123.5, 130.3, 133.1, 136.4, 140.9, 148.5, 149.8, 152.1. IR (mull) 1987, 1917, 1709, 1608, 1600, 1577, 1562, 1490, 1408, 1401, 1300, 1246, 1225, 1211, 1059, cm^"1.

Anal. Calcd for C₁₅H₁₂ClN₅OS₂: C, 47.68; H, 3.20; N, 18.53. Found: C, 47.40; H, 3.29; N, 18.29.

EXAMPLE 5 Preparation of N-[5-[(3-pyridinylmethyl)thio]-l,3,4-thiadiazol-2- yl]- N'-[3-(trifluoromethyl)phenyl]urea

Following the general procedure outlined in Method E and making non- critical variations but starting with the product of Step 1, Example 2 and α,α,α- trifluoro-m-tolyl isocyanate, the title compound is obtained as a solid. mp 177-179 °C.

^XH NMR (DMSO) δ 4.47, 7.33-7.36, 7.53, 7.65, 7.81, 7.96, 8.45, 8.56, 9.52, 11.56. ¹³C NMR (DMSO) δ 34.6, 114.7, 114.8, 119.2, 119.5, 122.5, 123.5, 125.8, 129.3, 129.7, 130.0, 133.0, 136.5, 129.3, 148.5, 149.7. IR (mull) 3374, 2237, 1991, 1952, 1715, 1598, 1559, 1443, 1402, 1344, 1321, 1206, 1179, 1171, 1119.

Anal. Calcd for C₁₆H₁₂F₃N₅OS₂: C, 46.71; H, 2.94; N, 17.02. Found: C, 46.34; H, 3.08; N, 16.71.

EXAMPLE 6 Preparation of N-(2-phenylethyl)-N'-[5[(2-pyridinylmethyl)thio]- l,3,4-thiadiazol-2-yl]urea.

Following the general procedure outlined in Method E and making non- critical variations but starting with the product of Step 1, Example 2 and phenethyl isocyanate, the title compound is obtained as a solid, mp 146-148 °C.

1H NMR (DMSO) δ 2.73, 3.34, 4.42, 6.61, 7.19-7.36, 7.76-7.79, 8.44, 8.53, 10.91. ¹³C NMR (DMSO) δ 34.7, 35.3, 40.9, 123.5, 126.1, 128.3, 128.6, 133.1, 136.4, 138.9, 148.5, 149.8, 153.2, 161.2. IR (mull) 3410, 3027, 2813, 1987, 1955, 1918, 1699, 1593, 1532, 1408, 1315, 1248, 752, 718, 706, cm^"1.

Anal. Calcd for C₁₇H₁₇N₅OS₂: C, 54.97; H, 4.61; N, 18.85. Found: C, 54.43; H, 4.52; N, 18.76.

EXAMPLE 7 Preparation of N-(3-fluorophenyl)-N'-[5-[(2- quinolinylmethyl)thio]-l,3,4-thiadiazol-2-yl]urea.

Step 1 Preparation of 5-amino-2[2-quinolinylmethyl]thio-l,3,4- thiodiazole. Following the general procedure outlined in Method A and making non- critical variations, the title compound is prepared from 2-chloromethylquinoline HCl and 2-amino-5-mercapto-l,3,4-thiadiazole as a solid, mp 177-8 °C. ^XH NMR (DMSO) δ 4.56, 7.26, 7.60, 7.73, 7.95, 8.32.

IR (mull) 3258, 3070, 3059, 2328, 2164, 2071, 1969, 1955, 1657, 1508, 1501, 1396, 1131, 834, 763, cm^"1. Step 2 Preparation of N-(3-fluorophenyl)-N'-[5-[(2-quinolinylmethyl)thio]-l,3,4- thiadiazol-2-yl] urea. Following the general procedure outlined in Method E and making non- critical variations but starting with the product of Step 1, Example 7 and 3- fluorophenyl isocyanate, the title compound is obtained as a solid, mp 212-214 °C. 1H NMR (DMSO) δ 4.74, 6.84-6.87, 7.17-7.19, 7.31-7.33, 7.41-7.44, 7.58, 7.64, 7.74, 8.35.

¹³C NMR (DMSO) δ 105.4, 105.7, 109.5, 114.6, 121.1, 126.5, 126.7, 127.8, 128.3, 129.8, 130.4, 130.5, 136.9, 146.9, 156.9, 160.6, 163.8.

IR (mull) 3373, 1945, 1930, 1716, 1614, 1599, 1561, 1497, 1426, 1409, 1313, 1301, 1216, 1204, 778, cm^"1.

Anal. Calcd for C₁₉H₁₄FN₅OS₂: C, 56.19; H, 4.24; N, 16.38. Found: C, 55.25; H, 3.59; N, 16.63.

EXAMPLE 8 Preparation of l,l-Dimethylethyl-3-[[[5-[[[(3- fluorophenyl)amino] -carbonyl] amino] -l,3,4-thiadiazol-2- yl] thio] methyl] benzoate .

Step 1 Preparation of 1,1-dimethylethyl 3-[[(5-amino-l,3,4-thiadiazole-2- yl] methyl] benzoate . A solution of 3-(chloromethyl)benzoyl chloride (5.3 mmol, 0.75 ml) in THF (10 ml) at 0 °C. t-BuOK (5.8 mmol, 5.8 ml) is added. After three hours, the reaction is quenched with H₂0 and diluted with EtOAc. The aqueous phase is extracted with

EtOAc (2x), and the combined organics are washed with brine. After drying over

MgSO4 , the solvent is removed in vacuo. The resulting oil is dissolved in CH₃CN

(15 ml). 5-Amino-l,3,4-thiadiazole-2-thiol (5.3 mmol, 0.71 g) and triethylamine (5.8 mmol, 0.81 ml) are added to the reaction, which is stirred overnight. The solvent is removed in vacuo, and the title compound is recrystallized from CH₃OH as a solid. mp 163-165 °C.

1H NMR (DMSO) δ 1.52, 4.34, 7.29, 7.42, 7.55, 7.77, 7.85.

¹³C NMR (DMSO) δ 27.7, 37.8, 80.7, 127.9, 128.6, 129.3, 131.4, 133.3, 137.8, 148.8, 164.6, 169.9.

IR (mull) 3298, 3107, 2398, 2334, 1982, 1921, 1710, 1504, 1310, 1292, 1167, 1110,

1077, 765, 699, cm^"1.

Step 2 Preparation of l,l-Dimethylethyl-3-[[[5-[[[(3-fluorophenyl)amino]- carbonyl] amino] - 1 , 3 ,4-thiadiazol-2-yl] thio] methyl] benzoate. Following the general procedure outlined in Method E and making non- critical variations but starting with the product of Step 1, Example 8 and 3- fluorophenyl isocyanate, the title compound is obtained as a solid, mp 177-178 °C.

1H NMR (DMSO) δ 1.51, 4.50, 6.82-6.89, 7.16-7.19, 7.28-7.33, 7.41-7.46, 7.62, 7.78,

7.89. ¹³C NMR (DMSO) δ 27.6, 37.1, 80.7, 105.3, 105.7, 109.2, 109.5, 114.6, 128.0, 128.7,

129.3, 130.3, 130.7, 131.4, 133.3, 137.6, 160.6, 136.8, 164.5.

IR (mull) 3373, 2422, 1947, 1905, 1712, 1612, 1605, 1546, 1442, 1414, 1307, 1299,

1278, 1219, 1207, cm^"1.

Anal. Calcd for C₂₁H₂₁FN₄O₃S₂: C, 54.77; H, 4.60; N, 12.16. Found: C, 54.96; H, 4.50; N, 12.05.

EXAMPLE 9 Preparation of N-(3-Fluorophenyl)-N'-[5-[[5-phenyl-3- pyridinyl)methyl]thio]-l,3,4-thiadiazole-2-yl]urea.

Step 1 Preparation of 5-Bromo-3-pyridine methanol.

Triethylamine (78 mmol, 10.8 ml) is added to a slurry of 5-bromonicotinic acid (74 mmol, 15.0 g) in toluene (400 ml), and all solids are dissolved. Ethyl chloroformate (78 mmol, 7.4 ml) is added, and the reaction is stirred at room temperature for one hour. The salts are removed by filtration, and the solvent is removed in vacuo, yielding yellow oil. The oil is dissolved in THF (200 ml) and this solution is added dropwise to a slurry of LAH (78 mmol, 2.93 g) in THF (100 ml) cooled to -78 °C. The reaction is stirred at -78 °C for one hour, and then quenched sequentially with 3 ml H₂0, 3 ml 15% NaOH, and 9 ml H₂O. The resulting salts are removed by filtration and are rinsed with EtOAc. The filtrate is dried over MgSO₄ and concentrated to orange oil. The title compound is obtained as an oil and purified by flash chromatography (5% CH₃OH/CH₂Cl₂). ^XH NMR (CDC1₃) δ 2.74, 4.72, 7.89, 8.45, 8.55.

Step 2 Preparation of 5-bromo-3-pyridine methanol tetrahydropyran ether.

The product of Step 1, Example 9 is dissolved in CH₂C1₂ (250 ml) and cooled to 0 °C. Dihydropyran (182 mmol, 16 ml) and pTsOH (0.1 g) is added. The reaction is heated to reflux for 5 hours. After cooling to room temperature, the reaction is diluted with EtOAc (500 ml) and an aqueous solution (100 ml brine, 100 ml sat. NaHC0₃, and 100 ml H₂O). The organic phase is washed with sat. NaHCO₃ and brine. It is dried over MgSO₄ and concentrated to give the title compound as orange oil. The product is purified by flash chromatography (2% CH₃OH/CH₂Cl₂). 1H NMR (CDCI₃) δ 1.57-1.85, 3.53-3.57, 3.82-3.88, 4.48, 4.70, 4.77, 7.85, 8.49, 8.58. Step 3 Preparation of 5-Phenyl-3-pyridinemethanol.

To a slurry of the product of Step 2, Example 9 (6.0 mmol, 1.67 g) and Pd(PPh₃)₂Cl₂ (0.03 mmol, 0.02 g) in toluene (12 ml) is added 6 ml 2M aq. Na₂CO₃. Next, phenyl boronic acid (7.2 mmol, 0.93 g) in CH₃OH (4 ml) is added. The reaction is heated to 70 °C for 3 hours. After cooling to room temperature, the reaction is diluted with CH₂C1₂ and 2 M Na₂CO₃. The layers are separated, and the organic phase is dried over MgSO₄. After filtering through silica gel to remove metal salts, the solvent is removed in vacuo leaving a yellow oil. It is dissolved in CH₃OH (20 ml), and pTsOH (0.1 g) is added. The reaction is stirred overnight at room temperature, and then overnight at 60 °C. The solvent is removed in vacuo, the residual oil is dissolved in CHC1₃. The organic solution is washed with NaHCO₃ and brine, and dried over MgSO₄. It is concentrated to give the title compound as oil. The product is isolated by flash chromatography (60%EtOAc/hex). which crystallized on standing, mp 65-67 °C. ^XH NMR (CDCI₃) δ 4.71, 5.98, 7.25-7.42, 7.87, 8.41, 8.50.

¹³C NMR (DMSO) δ 62.1, 127.0, 128.3, 128.4, 129.1, 134.2, 134.3, 136.7, 136.9, 145.5.

Step 4 Preparation of N-(3-Fluorophenyl)-N'-[5-[[5-phenyl-3- pyridinyl)methyl]thio]-l,3,4-thiadiazole-2-yl]urea. Following the general procedure outlined in Method E and making non- critical variations but starting with the product of Step 3, Example 9 and 3- fluorophenyl isocyanate, the title compound is obtained as a solid.

EXAMPLE 10 Preparation of N-(3-Fluorophenyl)-N'-[5-[[[5-(3-thienyl)-3- pyridinyl]methyl]thio] l,3,4-thiadiazol-2-yl]urea.

Step 1 Preparation of 5-(3-thienyl)-3-pyridine methanol.

Following the general procedure outlined in Steps 1-3, Example 9 and making non-critical variations but starting with the product of step 2, Example 9 and 3-thiophene boronic acid, the title compound is obtained as a solid. The product is purified by flash chromatography (60% EtOAc hex), which crystallized on standing.

¹³C NMR (CD₃OD) δ 62.5, 123.2, 126.8, 128.3, 130.0, 133.2, 134.1, 139.3, 146.5, 147.1 Step 2 Preparation of 5-[[[5-(3-thienyl)-3-pyridinyl]methyl]thio]-l,3,4 thiadiazol-2-amine.

Following the general procedure outlined in Method A and making non- critical variations but starting with the product of Step 1, Example 10, the title compound is obtained as a solid. The product is recrystallized from CH₃OHZEtOAc. mp 183-185 °C. 1H NMR (DMSO) δ 4.33, 7.35, 7.57-7.59, 7.68-7.71, 7.98-7.99, 8.05, 8.40, 8.84. ¹³C NMR (DMSO) δ 35.4, 122.3, 125.8, 127.7, 130.3, 133.3, 133.5, 137.7, 146.0, 148.2, 148.4, 170.1.

Step 3 Preparation of N-(3-fluorophenyl)-N'-[5-[[[5-(3-thienyl)-3- pyridinyl] methyl] thio] 1 ,3 ,4-thiadiazol-2-yl] urea. Following the general procedure outlined in Method E and making non- critical variations but starting with the product of Step 2, Example 10 and 3- fluorophenyl isocyanate, the title compound is obtained as a solid. The product is recrystallized from CH₃OH. mp 221-223 °C.

^XH NMR (DMSO) δ 4.50, 6.84-6.87, 7.17-7.20, 7.28-7.33, 7.41-7.45, 7.58-7.60, 7.68- 7.71, 8.00-8.01, 8.11-8.13, 8.47, 8.85. ¹³C NMR (DMSO) d 34.6, 105.2, 105.7, 109.2, 109.5, 114.6, 122.4, 125.8, 127.7, 130.3, 133.0, 133.6, 137.6, 146.1, 148.2, 160.6, 163.8.

IR (mull) 3375, 1726, 1601, 1560, 1495, 1432, 1401, 1316, 1206, 1173, 848, 783, 735, 653, 644, cm^"1.

Anal. Calcd for C₁₉H₁₄FN₅OS₃: C, 51.45; H, 3.18; N, 15.79. Found: C, 51.39; H, 3.34; N, 15.48.

EXAMPLE 11 Preparation of N-[3-fluorohenyl)-N'-[5-[(l-phenylpropyl)thio]- l,3,4-thiadiazol-2-yl]urea.

Step 1 Preparation of 5-[(l-phenylpropyl)thio]-l,3,4-thiadiazol-2-amine. Following the general procedure outlined in Method B and making non- critical variations but starting with 1-phenylpropyl alcohol and 2-amino-5-mercapto- 1,3,4-thiadiazole, the title compound is obtained as a solid. The crude product is purified by flash chromatography (5% CH₃OH/CH₂Cl₂). mp 113-114 °C. 1H NMR (CDC1₃) δ 0.94, 1.97-2.15, 4.40, 5.30, 7.25-7.31. ¹³C NMR (DMSO) δ 11.8, 28.5, 54.9, 127.5, 127.7, 128.4, 140.5, 148.0, 170.4.

Step 2 Preparation of N-[3-Fluorohenyl)-N'-[5-[(l-phenylpropyl)thio]-l,3,4- thiadiazol-2-yl] urea. Following the general procedure outlined in Method E and making non- critical variations but starting with the product of Step 1, Example 11 and 3- fluorophenyl isocyanate, the title compound is obtained as a solid. The crude product is recrystallized from CH₃OH/EtOAc. mp 165-167 °C. 1H NMR (DMSO) δ 0.85, 1.92-2.07, 4.56, 6.82-6.87, 7.16-7.44, 9.25, 11.15. ¹³C NMR (DMSO) δ 11.8, 28.8, 54.5, 105.3, 105.7, 114.6, 127.6, 127.7, 128.5, 130.4, 130.5, 140.1, 140.3, 160.6, 163.8, 170.9, 183.9, 223.3. IR (mull) 1952, 1917, 1710, 1607, 1551, 1493, 1438, 1411, 1309, 1295, 1280, 1206, 722, 699, 678, cm^"1. Anal. Calcd for C₁₈H₁₇FN₄OS₂: C, 55.65; H, 4.41; N, 14.42. Found: C, 55.55; H, 4.51; N, 14.21.

EXAMPLE 12 Preparation of N-[5-[(cyclopropylphenylmethyl)thio]-l,3,4- thiadiazole-2-yl]urea.

Step 1 Preparation of 5-[(cyclopropylphenylmethyl)thio]-l,3,4-thiadiazol-2- amine. Following the general procedure outlined in Method D and making non- critical variations but starting with α-cyclopropyl benzyl alcohol and 2-amino-5- mercapto-l,3,4-thiadiazole, the title compound is obtained as a solid, mp 148-150

°C.

1H NMR (DMSO) δ 2.51-2.57, 3.19, 6.22-6.31, 6.45, 7.19-7.38.

¹³C NMR (DMSO) d 33.46, 33.8, 125.8, 127.1, 127.7, 128.2, 128.5, 131.2, 136.8, 149.9, 169.4.

Step 2 Preparation of Preparation of N-[5-[(cyclopropylphenylmethyl)thio]- l,3,4-thiadiazole-2-yl]urea. Following the general procedure outlined in Method E and making non- critical variations but starting with the product of Step 1, Example 12 and 3- fluorophenyl isocyanate, the title compound is obtained as a solid. The crude product is isolated by flash chromatography (5% CH₃OH/CH₂Cl₂) and recrystallized from CH₃OH. mp 186-187 °C.

1H NMR (DMSO) δ 2.60, 3.34-3.36, 6.23-6.33, 6.47, 6.83-7.03, 7.19-7.22, 7.26-7.38,

7.45, 9.24, 11.11. ¹³C NMR (DMSO) δ 32.4, 33.1, 105.3, 105.7, 109.2, 109.5, 114.6, 125.9, 127.2, 127.7,

128.5, 130.4, 130.5, 131.3, 136.7, 160.6, 136.8, 184.2.

IR (mull) 3381, 1996, 1950, 1721, 1608, 1558, 1497, 1445, 1406, 1326, 1315, 1281,

1222, 1210, 737, cm^"1.

Anal. Calcd for C₁₉H₁₇FN₄OS₂: C, 56.98; H, 4.28; N, 13.99. Found: C, 56.92; H, 4.25; N, 13.94. EXAMPLE 13 Preparation of N-(3-fluorophenyl)-N'- [5- [ [1-

(phenylmethyl)propyl]thio]-l,3,4-thiadiazol-2-yl]urea

Step 1 Preparation of 5-[[l-(phenylmethyl)propyl]thio-l,3,4-thiadiazole-2- amine.

Following the general procedure outlined in Method D and making non- critical variations but starting with l-phenyl-2-butanol and 2-amino-5-mercapto- 1,3,4-thiadiazole, the title compound is obtained as a solid. The crude product is isolated by flash chromatography (5% CH₃OH/CH₂Cl₂), which is slowly crystallized. mp 81-83 °C.

^XH NMR (CD3OD) δ 1.03, 1.51-1.75, 2.88-2.98, 3.47-3.52, 7.18-7.28, 7.95.

¹³C NMR (CD3OD) δ 26.2, 30.6, 35.7, 53.0, 126.3, 128.1, 129.1, 138.6, 148.1, 162.2,

170.1.

Step 2 Preparation of N-(3-fluorophenyl)-N'-[5-[[l-(phenylmethyl)propyl]thio]- l,3,4-thiadiazol-2-yl]urea.

Following the general procedure outlined in Method E and making non- critical variations but starting with the product of Step 1, Example 13 and 3- fluorophenyl isocyanate, the title compound is obtained as a solid. The crude product is recrystallized from EtOAc. mp 128-130 °C. 1H NMR (DMSO) δ 0.99, 1.51-1.73, 2.95, 3.68-3.73, 6.83-6.90, 7.18-7.37, 7.45, 9.30, 11.12.

¹³C NMR (DMSO) δ 10.9, 26.3, 52.8, 105.3, 105.7, 109.2, 109.5, 114.6, 114.6, 126.4, 128.2, 129.1, 130.4, 130.5, 128.5, 160.6, 163.8. IR (mull) 3377, 2418, 2242, 1958, 1725, 1616, 1587, 1544, 1487, 1428, 1311, 1277, 1209, 861, 709, cm^"1.

Anal. Calcd for C₁₉H₁₉FN₄OS₂: C, 56.70; H, 4.76; N, 13.92. Found: C, 56.78; H, 4.78; N, 13.86.

EXAMPLE 14 Preparation of N-(3-Fluorophenyl)-N'- [5- [( l-phenylbutyl)thio] - l,3,4-thiadiazol-2-yl]urea.

Step 1 Preparation of 5-[(l-phenylbutyl)thio]-l,3,4-thiadiazol-2-amine.

Following the general procedure outlined in Method D and making non- critical variations but starting with 1-phenyl-l-butanol and 2-amino-5-mercapto- 1,3,4-thiadiazole, the title compound is obtained as a solid. The crude product is purified by flash chromatography (5% CH₃OH/CH₂Cl₂). mp 108-110 °C. 1H NMR (DMSO) δ 0.82, 1.16-1.30, 1.85-1.93, 4.41, 7.22-7.31. ¹³C NMR (DMSO) δ 13.3, 20.0, 37.4, 53.1, 127.4, 127.7, 128.4, 140.7, 148.0, 170.4. Step 2 Preparation of N-(3-Fluorophenyl)-N'-[5-[(l-phenylbutyl)thio]-l,3,4- thiadiazol-2-yl] urea. Following the general procedure outlined in Method D and making non- critical variations but starting with the product of Step 1, Example 14 and 3- fluorophenyl isocyanate , the title compound is obtained as a solid. The crude product is recrystallized from EtOAc/hex. mp 166-168 °C. ^XH NMR (DMSO) δ 0.84, 1.15-1.28, 1.93-1.98, 4.63, 6.83-6.88, 7.18-7.44. ¹³C NMR (DMSO) δ 13.3, 20.1, 37.6, 52.7, 105.3, 105.7, 109.2, 109.5, 114.6, 127.6, 127.0, 128.5, 130.4, 130.5, 140.6, 160.6, 163.8.

IR (mull) 2315, 1954, 1912, 1712, 1620, 1610, 1563, 1495, 1440, 1414, 1309, 1298, 1280, 1209, 698, cm^"1. Anal. Calcd for C₁₉H₁₉FN₄OS₂: C, 56.70; H, 4.76; N, 13.92. Found: C, 56.87; H, 4.85; N, 13.86.

EXAMPLE 15 Preparation of N-(3-fluorophenyl)-N'-[5[[l-(2- pyridinyl)propyl]thio]-l,3,4-thiadiazole-2-yl]urea.

Step 1 Preparation of α-Ethyl-2-pvridinemethanol.

2-Pyridinecarboxaldehyde (40 mmol, 3.8 ml) is dissolved in THF (200 ml) and cooled to 0 °C. Ethyl magnesium bromide (48 mmol, 48 ml) is added via addition funnel over 20 minutes. The reaction is stirred for 3.5 hours at 0 °C, and then quenched with H₂O. It is diluted Et₂O, and the layers are separated. The aqueous phase is extracted with Et₂O (2x), and the combined ethereal layers are washed with brim and dried over MgSO₄. It is concentrated to provide the title compound as oil. ^XH NMR (CDC1₃) δ 0.94, 1.67-1.92, 4.69, 7.16-7.23, 7.64-7.70, 8.53-8.56. Step 2 Preparation of 5-[[l-(2-pyridinyl)propyl]thio]-l,3,4-thiadiazol-2-amine.

Following the general procedure outlined in Method C and making non- critical variations but starting with the product of Step 1, Example 15, the title compound is obtained. The crude product is purified by flash chromatography (5% CH₃OH/CH₂Cl₂), which crystallized on standing. The pale brown solid was treated with decolorizing carbon and recrystallized from CH₃OH/EtOAc. mp 110-112 °C. ^XH NMR (DMSO) δ 0.83, 1.94-2.10, 4.46, 7.24-7.38, 7.71-7.77, 8.50-8.52. ¹³C NMR (DMSO) δ 11.6, 27.6, 56.1, 122.5, 122.7, 136.7, 148.1, 149.1, 159.2, 170.4. Step 3 Preparation of N-(3-fluorophenyl)-N'-[5[[l-(2-pyridinyl)propyl]thio]- l,3,4-thiadiazole-2-yl]urea. Following the general procedure outlined in Method E and making non- critical variations but starting with the product of Step 2, Example 15 and 3- fluorophenyl isocyanate, the title compound is obtained. The crude product is recrystallized (2x) from EtOAc as solid, mp 173-175 °C.

1H NMR (DMSO) δ 0.85, 2.04-2.11, 4.70, 6.83-6.88, 7.18, 7.26-7.26, 7.41-7.44, 7.73- 7.79, 8.52, 9.25, 11.10.

¹³C NMR (DMSO) δ 11.5, 28.0, 55.6, 105.3, 105.7, 109.2, 109.5, 114.6, 122.7, 122.7, 130.4, 130.5, 136.8, 149.2, 158.9, 160.6, 163.8. IR (mull) 2413, 2016, 1980, 1903, 1705, 1615, 1559, 1545, 1485, 1438, 1405, 1298, 1277, 1207, 1199, cm^"1.

Anal. Calcd for C₁₇H₁₆FN₅OS₂: C, 52.43; H, 4.14; N, 17.98. Found: C, 52.51; H, 4.10; N, 17.72.

EXAMPLE 16 Preparation of N-(3-fluorophenyl)-N'- [5 [[l-(3- pyridinyl)propyl]thio]-l,3,4-thiadiazole-2-yl]urea.

Step 1 Preparation of α-Ethyl-3-pyridinemethanol.

Following the procedure outlined in Steps 1, Example 15 and making non- critical variations but starting with 3-pyridinecarboxaldehyde, the title compound is obtained. The crude product is purified by flash chromatography. 1H NMR (CDC1₃) δ 0.94, 1.72-1.90, 2.17, 4.66, 7.28-7.30, 7.68-7.72, 8.51, 8.55.

Step 2 Preparation of 5-[[l-(3-pyridinyl)propyl]thio]-l,3,4-thiadiazol-2-amine.

Following the general procedure outlined in Method A and making non- critical variations but starting with the product of Step 1, Example 16, the title compound is obtained. The crude product is purified by flash chromatography (5% CH₃OH/CH₂Cl₂).

1H NMR (DMSO) δ 0.18, 1.21-1.34, 3.62, 6.57-6.61, 7.01-7.04, 7.56-7.61. ¹³C NMR (DMSO) d 11.8, 27.9, 52.2, 123.5, 135.0, 136.5, 147.1, 148.6, 149.1, 170.5 Step 3 Preparation of N-(3-fluorophenyl)-N'-[5[[l-(3-pyridinyl)propyl]thio]- l,3,4-thiadiazole-2-yl]urea. Following the general procedure outlined in Method E and making non- critical variations but starting with the product of Step 2, Example 16 and 3- fluorophenyl isocyanate, the title compound is obtained. The crude product is purified by flash chromatography (5% CH₃OH/CH₂Cl₂), which crystallized on standing. The solid is recrystallized from EtOAc/hex. mp 157-159 °C. 1H NMR (DMSO) δ 0.89, 1.97-2.09, 4.63, 6.83-6.88, 7.17, 7.28-7.44, 7.78-7.81, 8.44, 8.52, 9.28, 11.22.

¹³C NMR (DMSO) δ 11.8, 28.1, 51.8, 105.4, 105.7109, 3, 109.5, 114.6, 123.6, 130.4, 130.5, 135.0, 136.3, 140.0, 140.1, 148.7, 149.1, 160.6, 163.7. IR (mull) 1956, 1924, 1707, 1616, 1591, 1548, 1488, 1433, 1424, 1302, 1281, 1218, 1199, 806, 770, cm^"1.

Anal. Calcd for C₁₇H₁₆FN₅OS₂: C, 52.43; H, 4.14; N, 17.98. Found: C, 52.60; H, 4.31; N, 17.81.

EXAMPLE 17 Preparation of N-(3-fluorophenyl)-N'- [5 [[l-(4- P5rridinyl)propyl]thio]-l,3,4-thiadiazole-2-yl]urea.

Step 1 Preparation of α-Ethyl-4-pyridinemethanol.

Following the procedure outlined in Steps 1, Example 15 and making non- critical variations but starting with 4-pyridinecarboxaldehyde, the title compound is obtained. The crude product is purified by flash chromatography (50% EtOAc/hex to EtOAc).

1H NMR (CDC1₃) δ 0.97, 1.72-1.82, 4.64, 4.75, 7.27-7.30, 8.52-8.55.

Step 2 Preparation of 5-[[l-(4-pyridinyl)propyl]thio]-l,3,4-thiadiazol-2-amine.

Following the general procedure outlined in Method C and making non- critical variations but starting with the product of Step 2, Example 17 and 3- fluorophenyl isocyanate, the title compound is obtained. The crude product is purified by flash chromatography (5% CH₃OH/CH₂Cl₂).

Step 3 Preparation of N-(3-fluorophenyl)-N'-[5[[l-(4-pyridinyl)propyl]thio]- l,3,4-thiadiazole-2-yl]urea. Following the general procedure outlined in Method E and making non- critical variations but starting with the product of Step 2, Example 17 and 3- fluorophenyl isocyanate, the title compound is obtained. The crude product is crystallized from EtOAc as a solid, mp 168-170 °C.

1H NMR (DMSO) δ 0.89, 1.94-2.05, 4.60, 6.83-6.89, 7.18, 7.29-7.44, 8.49-8.51, 10.35,

11.20. ¹³C NMR (DMSO) δ 12.4, 29.56, 55.5, 107.2, 107.6, 110.9, 111.2, 124.8, 125.8, 131.3,

131.5, 150.4, 125.9, 157.7, 162.9, 166.1.

IR (mull) 1937, 1708, 1699, 1624, 1614, 1606, 1574, 1532, 1497, 1489, 1433, 1423,

1309, 1282, 1226, cm^"1.

Anal. Calcd for C₁₇H₁₆FN₅OS₂: C, 52.43; H, 4.14; N, 17.98. Found: C, 52.10; H, 4.07; N, 18.16.

INHIBITION OF β₂ INTEGRIN LIGAND BINDING ASSAYS The compounds may be tested in one of several biological assays to determine the concentration of compound which is required to have a given pharmacological effect.

To identify inhibitors of β₂ integrin ligand binding function, two primary and two secondary assays are performed. The assays are established to identify compounds which inhibit the interaction of either LFA-1 or Mac-1 with immobilized ICAM-1. The interaction of the β₂ integrins with ICAM-1 plays as important role in a number of adhesive events during normal immune and inflammatory responses including antigen presentation to T cells, T cell mediated cyto toxicity, and the firm attachment and extravasation of circulating leukocytes into the surrounding tissue. Both the primary LFA-1 and Mac-1 adhesion assays are performed using the well- known scintillation proximity assay (SPA) bead technology which is discussed in further in Cook, N.D. et. al. Pharmaceutical Manufacturing International (1992) pp. 49-53, "SPA: A revolutionary new technique for drug screening". Bosworth, N. and Towers, P. Nature (1989) 341:167-168, "Scintillation proximity assay". Undefriend, S., Gerber, L. and Nelson, N. Analytical Biochemistry (1987) 161: 494-500 "Scintillation Proximity Assay, a sensitive and continuous isotopic method for monitoring ligand-receptor and antigen-antibody interactions". Briefly, the assay relies upon three major components: a radiolabeled CHO cell that has been transfected with the heterodimeric either LFA-1 or Mac-1 molecule and is functionally expressed on the cell surface; a secreted soluble form of intercellular adhesion molecule produced from a transfected CHO cell line and which has subsequently been biotinylated; and streptavidin SPA beads to monitor the interaction of these two components. The SPA technology is utilized because it obviates the need for a wash step(s), allowing low affinity interactions to remain undisturbed.

Stable CHO cells expressing either LFA-1 or Mac-1 were established. Cells were grown in modified Dulbecco's media and labeled overnight in a leucine deficient media in the presence of ³H-leucine (10 mCi/10⁶ cells for LFA-1 and 50 mCi/10⁶ cells for Mac-1). After labeling, cells (1 x 10⁴ LFA-1 and 5 x 10⁴ for Mac-1) were activated with phorbol ester (100 nM for LFA-1 and 500 nM for Mac-1) and allowed to react with streptavidin SPA beads previously coated with biotinylated soluble ICAM-1 dispensed into 96 well plates. To inhibit adhesion to ICAM-1 coated SPA beads, 4X stock of compound, blocking antibodies or buffer control were added to the wells immediately prior to the addition of cells. Following incubation for 8 hours, adhesion was quantitated in the wells using a scintillation counter.

For further analysis of compounds that inhibit LFA-1 interactions, a secondary adhesion assay using .JY and human soluble ICAM-1 was established. JY cells, a human lymphoblastoid cell line, constitutively expresses LFA-1. Microtiter wells were coated with soluble ICAM-1 diluted in 0.1 1M NaCO₃ buffer (pH 8.0) overnight at 4°C. The remaining binding sites on the plastic were blocked with phosphate buffered saline (PBS) containing 1 mM Ca²⁺/Mg²⁺ and 1% human serum albumin (PBS/HSA) for 1 hour at 37°C. JY cells were harvested by centrifugation and fluorescently labeled with 2'7'-bis-(carboxyethyl)-5(6)-carboxy-fluorescein. JY cells were then washed once in PBS/HSA, and stimulated with phorbol 12-myristate 13-acetate (PMA; 50 ng/ml) for 5 minutes. The microtiter plates was washed once with PBS containing 1 mM Ca²⁺/Mg ⁺ and 0.5% Tween-20 and then immediately washed with PBS/HSA. A 80 mL aliquot of cells (1 x 10⁵) was plated in triplicate on the microtiter wells. To inhibit adhesion to ICAM-1 coated wells, a 20 ml aliquot of 5X stock of compound, blocking antibodies or buffer control were added to the wells immediately prior to the addition of cells to the wells. Following incubation for 30 minutes at 37°C, the plates were washed with PBS/HSA. Fluorescence was quantitated in the wells using a Pandex fluorescence concentration analyzer. For further analysis of compounds that inhibit Mac-1 interactions, a secondary adhesion assay using human neutrophils and human soluble ICAM-1 was established. Human neutrophils were used because of the limited availability of cultured cell lines expressing Mac-1. Mac-1 expressed on stimulated neutrophils play a major role in the adherence of neutrophils to endothelial cells and transendothelial migration via its interaction with ICAM-1. Microtiter wells were coated with soluble ICAM-1 diluted in 0.1 mM NaCO₃ buffer (pH 8.0) overnight at 4°C. The remaining binding sites on the plastic were blocked with PBS containing 1 mM Ca²⁺/Mg²⁺ and 1% fetal calf serum (PBS/FCS) at room temperature for 30 minutes. Neutrophils were purified from the peripheral blood of healthy adult individuals by dextran sedimentation and centrifugation on a Ficoll-Hypaque solution. Neutrophils were then fluorescently labeled with 2'7'-bis-(carboxyethyD- 5(6)-carboxy-fluorescein. The cells were then washed in PBS/FCS and subjected to hypotonic lysis. To each well, 30 ml of PBS/FCS, 10 ml 10X stock of compound or blocking antibody, 10 ml f-Met-Leu-Phe (10^"7M), and 50 ml of cells (2 X 10⁶ cells/ml) was plated in triplicate. Following incubation for 30 minutes at 37°C, the plates were washed with PBS. Fluorescence was quantitated in the wells using a Pandex fluorescence concentration analyzer.

The inhibition results are given in Table 1. LFA/SPA and Mac-1/SPA refer to LFA-1 and Mac-1 adhesion assays are performed using the SPA technology; JY/ICAM refers to a secondary adhesion assay, inhibition of LFA-1 interactions, using JY and human soluble ICAM-1. PMN/ICAM refers to a secondary adhesion assay, inhibition of Mac-1 interactions, using human neutrophils and human soluble ICAM-1. TABLE 1

Claims

We claim:

1. A compound of a formula I

^ _{N '} ^N X' , optionally substituted with C_x.₄ alkyl or C₃.₆ cycloalkyl,

ΓÇó //

N -N i) C-_J.6 carboalkoxy, j) -C(=O)-CH₂CO₂(C_1.4 alkyl), k) -C(=O)NH(CH₂) R₅,

1) C_{1 0} alkyl, m) C_1.10 alkyl substituted with one to three R₆,

n) C_t__1Q alkenyl, or o) C_{1 0} alkenyl substituted with one to three R₆;

R₂ is

R₃ is a) -(CR₉R₁₀),(CH₂)_/-aryl, b) -(CR₉R₁₀)_;(CH₂)_;-aryl wherein aryl is substituted with one to three R_n, c) -(CRgR_jo^CH^-Q, d) -(CR₉R₁₀)_Z(CH₂)-Q wherein Q is substituted with one to three R_n, e) -(CR₉R₁₀)_/(CH₂)_/Het, f) -(CR₉R₁₀);(CH₂)_/-Het wherein Het is substituted with one to three R_n, or g) -(CR₉R₁₀)_r(CH₂)_rpentafluorophenyl;

R₄ is a) halo, b) C_1-4 alkyl, c) C_3.6 cycloalkyl, d) C_1╬¢ alkoxy, e) aryl, f) Q, g) Het, h) C_1.4 carboalkoxy, i) C_x_₄ monoalkylamino, j) C_j.4 dialkylamino, k) amido,

1) C_x.4 alkylthio, m) trihalomethyl, n) -(CH₂)_rO-(C_1.4 alkyl), o) nitro,

P) mercapto, q) nitrine, r) cyano, s) hydroxy, t) -NHC(=O)(C₁.₄ alkyl), or u) -NHSO₂(C_1.4 alkyl);

R₅ is a) C^_g alkyl, b) aryl, c) Q, or d) Het;

R₆ is a) halo, b) hydroxy, c) C-^₄ alkoxy, d) C₁.₄ carboalkoxy, e) amido, f) nitro, g) trihalomethyl, h) cyano, i) mercapto, j) C_j.₄ alkylthio, or k) C ₈ alkyl;

R₇ and R₈ are the same and different and are a) H, b) Ci.₆ alkyl, c) C₃.₆ cycloalkyl, d) -(CH₂)_rO-C_1.4 alkyl, e) -(CH₂)_rQ, or f) -(CH₂)_rHet;

R₉ and R₁₀ are the same and different and are a) H, b) C_x.4 alkyl, c) C_j.4 alkoxy, d) C₃.₆ cycloalkyl, or e) C-_j^ carboalkoxy; R_n is a) C_x.4 alkyl, b) C_j.4 alkoxy, c) trihalomethyl, d) halo, e) nitro, f) cyano, g) nitrine, h) C_j.4 acyl, i) C_j.₄ carboalkoxy, or j) carboxyl; aryl is monocarbocyclic, or bicarbocyclic aromatic moiety;

Q is 5- to 10-membered saturated heterocyclic moiety having one to three atoms selected from the group consisting of oxygen, nitrogen, and sulfur;

Het is 5- to 10-membered unsaturated heterocyclic moiety having one to three atoms selected from the group consisting of oxygen, nitrogen, and sulfur; j is 0, 1, 2 or 3; k is 0, 1, 2, 3, 4, 5 or 6; I is 0, 1, 2, 3, 4 or 5; n is 0, 1 or 2; and with the following provisos: a) where R₃ is a), R_x is other than c) through f); b) where R₃ is aryl substituted with cyano, R_x is other than phenyl substituted with cyano, unsubstituted pyridyl, furyl and -C(-=O)-NHCH₂-pyridyl.

2. A compound of claim 1 which is a N-[5-[[(3,5-Dimethoxyphenyl)methyl]thio]-l,3,4-thiadiazol-2-yl]-N'-(2- phenylethyDurea, b N-[5-[[(4-Methoxyphenyl)methyl]thio]-l,3,4-thiadiazol-2-yl]-N'-(2- phenylethyl)urea, c N-[5-[[(3,4-Dimethoxyphenyl)methyl]thio]-l,3,4-thiadiazol-2-yl]-N'-(2- phenylethyl)urea, d N- [5- [ [6-( 1 ,3-Dihydro- 1 ,3-dioxo-2H-isoindol-2-yl)hexyl] thio] - 1 ,3 ,4-thiadiazol-2- yl]-N'-(2-phenylethyl)urea, e N-[5-[([l,l'-Biphenyl]-4-ylmethyl)thio]-l,3,4-thiadiazol-2-yl]-N'-(2- phenylethyl)urea, f (E)-N-[5-[(3,7-Dimethyl-2,6-octadienyl)thio]-l,3,4-thiadiazol-2-yl]-N'-(2- phenylethyl)urea, g (E)-N-[5-[(3,7-Dimethyl-2,6-octadienyl)thio]-l,3,4-thiadiazol-2-yl]-N'-(3- cyanophenyl)urea, h (E)-N-[5-[(3,7-Dimethyl-2,6-octadienyl)thio]-l,3,4-thiadiazol-2-yl]-N'-[l-(2- naphthalenyl)ethyl] urea, i N-(2-Phenylethyl)-N'-[5-[(phenylmethyl)thio]-l,3,4-thiadiazol-2-yl]urea, j Methyl [[5-[[[(2-phenylethyl)amino]carbonyl]amino]-l,3,4-thiadiazol-2- yl] thio] acetate, k Methyl [[5-[[[(3-cyanophenyl)amino]carbonyl]amino]-l,3,4-thiadiazol-2- yl] thio] acetate, 1 t-Butyl [ [5- [ [ [(3-cyanophenyl)amino] carbonyl] amino] - 1 ,3,4-thiadiazol-2- yl] thio] acetate, m Methyl 3- [[ [5- [[ [(3-cyanophenyl)amino] carbonyl] amino] -l,3,4-thiadiazol-2- yl] thio] methyl] benzoate, n Methyl 3- [ [ [5- [ [ [( 2-trifluoromethylphenyl)amino] carbonyl] amino] -1,3,4- thiadiazol-2-yl] thio] methyl] benzoate, o Methyl 3- [ [ [5- [ [ [(3-trifluoromethylphenyl)amino] carbonyl] amino] - 1,3,4- thiadiazol-2-yl] thio] methyl] benzoate, p Methyl 3- [ [ [5- [ [ [(4-trifluoromethylphenyl)amino] carbonyl] amino] -1,3,4- thiadiazol-2-yl] thio] methyl] benzoate, q 2-[[5-[[[(3-Cyanophenyl)amino]carbonyl]amino]-l,3,4-thiadiazol-2-yl]thio]-N- octylacetamide , r N-(3-Cyanophenyl)-N'-[5-[(2-fluoro-4-nitrophenyl)thio]-l,3,4-thiadiazol-2- yl]urea, s N-[5-[(Cyanomethyl)thio]-l,3,4-thiadiazol-2-yl]-N'-(3-cyanophenyl)urea, t N-(3-Cyanophenyl)-N'- [5- [ [2-( l,3-dihydro-l,3-dioxo-2H-isoindol-2-yl)ethyl] thio] - l,3,4-thiadiazol-2-yl]urea, u N-(3-Cyanophenyl)-N'-[5-[(2-quinolinylmethyl)thio]-l,3,4-thiadiazol-2-yl]urea, v Methyl 4- [ [5- [ [ [(3-cyanophenyl)amino] carbonyl] amino] - 1 ,3 ,4-thiadiazol-2- yl]thio]-3-oxobutanoate, w N-(3-cyanophenyl)-N'-[5-[(3-pyridinylmethyl)thio]-l,3,4-thiadiazol-2-yl]urea, x N-[5-[(5-Cyanopentyl)thio]-l,3,4-thiadiazol-2-yl]-N'-(3-cyanophenyl)urea, y N-[5-[[(4-Chloro-2-nitrophenyl)methyl]thio]-l,3,4-thiadiazol-2-yl]-N'-(3- cyanophenyl)urea, z N-(3-Cyanophenyl)-N'-[5-(2-propenylthio)-l,3,4-thiadiazol-2-yl]urea, aa N-(3-Cyanophenyl)-N'-[5-(2-propynylthio)-l,3,4-thiadiazol-2-yl]urea, bb N-(3-cyanophenyl)-N'-[5-(octylthio)-l,3,4-thiadiazol-2-yl]urea, cc Methyl 3-[[[5-[[[(3-cyanophenyl)amino]carbonyl]amino]-l,3,4-thiadiazol-2- yl] thio] methyl] benzoate, dd Methyl 3- [ [ [5- [ [ [(2-phenylethyl)amino] carbonyl] amino] - 1,3 ,4-thiadiazol-2- yl]thio]methyl]benzoate, ee N-[5-[(3-Pyridinylmethyl)thio]-l,3,4-thiadiazol-2-yl]-N'-[3- (trifluoromethyl)phenyl]urea, ff N-[5-[(4-Pyridinylmethyl)thio]-l,3,4-thiadiazol-2-yl]-N'-[3-

(trifluoromethyl)phenyl] urea, gg N-(3-Fluorophenyl)-N'-[5-[(2-pyridinylmethyl)thio]-l,3,4-thiadiazol-2-yl]urea, hh N-(3-Fluorophenyl)-N'-[5-[(3-pyridinylmethyl)thio]-l,3,4-thiadiazol-2-yl]urea, ii N-(3-Fluorophenyl)-N'-[5-[(4-pyridinylmethyl)thio]-l,3,4-thiadiazol-2-yl]urea, jj 2- [ [5- [ [ [(3-Cyanophenyl)amino] carbonyl] amino] - 1 ,3,4-thiadiazol-2-yl] thio] -N-(2- methoxyethyDacetamide, kk 2-[[5-[[[(3-Cyanophenyl)amino]carbonyl]amino]-l,3,4-thiadiazol-2-yl]thio]-N-(2- pyridinylmethyDacetamide, 11 2- [ [5- [ [ [(3-Cyanophenyl)amino] carbonyl] amino] - 1 , 3 ,4-thiadiazol-2-yl] thio] -N-(4- pyridinylmethyDacetamide, mm N-(2-Phenylethyl)-N'-[5[(3-pyridinylmethyl)thio]-l,3,4-thiadiazol-2-yl]urea, nn N-(2-Phenylethyl)-N'-[5[(2-pyridinylmethyl)thio]-l,3,4-thiadiazol-2-yl]urea, oo (E)-N-(3-Acetylphenyl)-N'-[5-[(3,7-dimethyl-2,6-octadienyl)thio]-l,3,4- thiadiazol-2-yl] urea, pp 2- [ [5- [ [ [(3-Cyanophenyl)amino] carbonyl] amino] - 1 ,3 ,4-thiadiazol-2-yl] thio] -N- phenylacetamide, qq N-(3-Fluorophenyl)-N'-[5-[(2-quinolinylmethyl)thio]-l,3,4-thiadiazol-2-yl]urea, rr N-[5-[(2-Quinolinylmethyl)thio]-l,3,4-thiadiazol-2-yl]-N'-[3-

(trifluoromethyl)phenyl]urea, ss 2-[[5-[[[(3-Cyanophenyl)amino]carbonyl]amino]-l,3,4-thiadiazol-2-yl]thio]-N-2- propenylacetamide , tt 2- [ [5- [ [ [(3-Cyanophenyl)amino] carbonyl] amino] - 1,3 ,4-thiadiazol-2-yl] thio] -N-

(phenylmethyl)acetamide, uu 1 , 1-Dimethylethyl 5- [ [ [5- [ [ [ [3-(trifluoromethyl)phenyl] amino] carbonyl] amino] - l,3,4-thiadiazol-2-yl]thio]methyl]-2-thiophenecarboxylate, w N-(3-Cyanophenyl)-N'- [5- [ [( 1-cyclohexyl- lH-tetrazol-5-yl)methyl] thio] -1,3,4- thiadiazol-2-yl] urea, ww 1 , 1-Dimethylethyl 3- [ [ [5- [ [ [(3-fluorophenyl)amino] carbonyl] amino] -1,3,4- thiadiazol-2-yl] thio] methyl] benzoate, xx 1, 1-Dimethylethyl 3-[[[5-[[[(3-cyanophenyl)amino]carbonyl]amino]-l,3,4- thiadiazol-2-yl] thio] methyl] benzoate, yy N-(3-Cyanophenyl)-N'-[5-[[l-(3-methylfuro[2,3-c]pyridin-5-yl)ethyl]thio]-l,3,4- thiadiazol-2-yl] urea, zz N-(3-Cyanophenyl)-N'-[5-[[[4-(l-methylethyl)-2-pyridinyl]methyl]thio]-l,3,4- thiadiazol-2-yl]urea, aaa N-(3-Fluorophenyl)-N'-[5-[(l-phenylpropyl)thio]-l,3,4-thiadiazol-2-yl]urea, bbb N-(3-Fluorophenyl)-N'-[5-[(3-furanylmethyl)thio]-l,3,4-thiadiazol-2-yl]urea, ccc N- [ [ [5- [(2-Quinolinylmethyl)thio] - 1 ,3,4-thiadiazol-2-yl] amino] carbonyl] -L- phenylalanine ethyl ester, ddd N-[5-[(2-Pyridinylmethyl)thio]-l,3,4-thiadiazol-2-yl]-N'-t3-

(trifluoromethyl)phenyl] urea, fff N-[5-[(4-Pyridinylmethyl)thio]-l,3,4-thiadiazol-2-yl]-N'-[3-

2-yl]urea, kkk N-(3-Fluorophenyl)-N'-[5-[[l-(phenylmethyl)propyl]thio]-l,3,4-thiadiazol-2- yl]urea, 111 N-[5-[(Cyclopropylphenylmethyl)thio]-l,3,4-thiadiazol-2-yl]-N'-(3- fluorophenyl)urea, mmm N-(3-Fluorophenyl)-N'-[5-[[l-(3-pyridinyl)propyl]thio]-l,3,4-thiadiazol-2- yl]urea, nnn N-(3-Fluorophenyl)-N'-[5-[(l-phenylbutyl)thio]-l,3,4-thiadiazol-2-yl]urea, ooo N-(3-Fluorophenyl)-N'-[5-[[l-(2-pyridinyl)propyl]thio]-l,3,4-thiadiazol-2- yl]urea, ppp N-(3-Fluorophenyl)-N'-[5-[[l-(4-pyridinyl)propyl]thio]-l,3,4-thiadiazol-2- yl]urea, qqq N-(3-Fluorophenyl)-N'-[5-[[[5-(3-thienyl)-3-pyridinyl]methyl]thio]-l,3,4- thiadiazol-2-yl] urea, rrr Ethyl 3-[[[[5-[(l-phenylpropyl)thio]-l,3,4-thiadiazol-2- yl] amino] carbonyl] amino] benzoate , sss 3- [ [ [ [5- [( l-Phenylpropyl)thio] - l,3,4-thiadiazol-2- yl] amino] carbonyl] amino] benzoic acid, ttt N-(3-Chlorophenyl)-N'-[5-[(2-quinolinylmethyl)thio]-l,3,4-thiadiazol-2-yl]urea, uuu Ethyl 3-[[[[5-[(2-quinolinylmethyl)thio]-l,3,4-thiadiazol-2- yl] amino] carbonyl] amino] benzoate , wv N-[5-[(2-Quinolinylmethyl)thio]-l,3,4-thiadiazol-2-yl]-3,5- bis(trifluoromethyl)benzamide, www N- [5- [ [1- [3-(Acetylamino)phenyl] ethyl] thio] -l,3,4-thiadiazol-2-yl] -3,4- dichlorobenzamide, xxx N-[3-[l-[[5-[[[(3-Fluorophenyl)amino]carbonyl]amino]-l,3,4-thiadiazol-2- yl] thio] ethyl] phenyl] methanesulfonamide, yyy N-[5-[[l-(3-Azidophenyl)ethyl]thio]-l,3,4-thiadiazol-2-yl]-N'-(3- fluorophenyl)urea, zzz N-[5-[[l-(3-Azidophenyl)ethyl]thio]-l,3,4-thiadiazol-2-yl]-3,4- dichlorobenzamide, aaaa 3-Azido-4-chloro-N-[5-[(l-phenylpropyl)thio]-l,3,4-thiadiazol-2-yl]benzamide, bbbb 3-Azido-6-chloro-N-[5-[(l-phenylpropyl)thio]-l,3,4-thiadiazol-2-yl]benzamide, cccc 2,6-Difluoro-N-[5-[[l-(3-pyridinyl)propyl]thio]-l,3,4-thiadiazol-2-yl]benzamide, dddd N-(3-Fluorophenyl)-N'-[5-[[l-(4-fluorophenyl)ethyl]thio]-l,3,4-thiadiazol-2- yl]urea, or eeee N-(3-Azido-4-fluorophenyl)-N'-[5-[[l-(3-pyridinyl)propyl]thio]-l,3,4-thiadiazol-

2-yl]urea.

3. A method of inhibiting LFA-1 and Mac-1 which comprises administering to a patient in need thereof an effective amount of a compound of claim 1.

4. A method of treating a patient suffering from inflammatory diseases which comprises administering to a patient in need thereof an effective amount of a compound of claim 1.

5. A method of claim 4 wherein the inflammatory diseases are hypersensitivity reactions, asthma, rheumatoid arthritis, bacterial meningitis, aspiration lung injury, inflammatory bowel disorder and related complications.

6. A pharmaceutical composition which comprises an effective amount of the compound of claim 1 and a pharmaceutically acceptable carrier.