Compositions and methods for inhibition of the JAK pathway

1. A method of inhibiting an activity of a JAK kinase, comprising contacting the JAK kinase with an amount of a compound effective to inhibit an activity of the JAK kinase wherein the compound is a compound of formula IA:

or therapeutically acceptable salt thereof,

wherein:

q is 0, 1, 2 or 3;

p is 1;

R is hydrogen;

X is fluoro;

Y is a covalent bond and;

alk is a covalent bond;

R 1 is —C(O)NR 4 R 5 ;

each R 2 independently is selected from the group consisting of alkyl, substituted alkyl, alkoxy, substituted alkoxy, amino, substituted amino, aryl, substituted aryl, aryloxy, substituted aryloxy, cycloalkyl, substituted cycloalkyl, heteroaryl, substituted heteroaryl, heteroaryloxy, substituted heteroaryloxy, heterocyclic, substituted heterocyclic, heterocyclyloxy, substituted heterocyclyloxy, carboxyl, carboxyl ester, alkynyl, substituted alkynyl, hydroxyl, acyl, oxo, halo, acylamino, aminocarbonyl, and cyano;

R 3 is 4-(1-methylpiperazin-4-yl); and

R 4 and R 5 independently are selected from the group consisting of hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, alkoxy, cycloalkyl, substituted cycloalkyl, and acyl; or

R 4 and R 5 together with the nitrogen atom bound thereto, form a heterocyclic or substituted heterocyclic.

2. The method of claim 1 , wherein each R 2 independently is selected from the group consisting of alkyl, substituted alkyl, alkoxy, substituted alkoxy, heteroaryl, substituted heteroaryl, heterocyclic, substituted heterocyclic, halo, and cyano.

3. A method of inhibiting an activity of a JAK kinase, comprising contacting in vitro a JAK3 kinase with an amount of a compound effective to inhibit an activity of the JAK kinase wherein the compound is a compound of formula IA:

or therapeutically acceptable salt thereof,

wherein:

q is 0, 1, 2 or 3;

p is 1;

R is hydrogen;

X is fluoro;

Y is a covalent bond and;

alk is a covalent bond;

R 1 is —C(O)NR 4 R 5 ;

each R 2 independently is selected from the group consisting of alkyl, substituted alkyl, alkoxy, substituted alkoxy, amino, substituted amino, aryl, substituted aryl, aryloxy, substituted aryloxy, cycloalkyl, substituted cycloalkyl, heteroaryl, substituted heteroaryl, heteroaryloxy, substituted heteroaryloxy, heterocyclic, substituted heterocyclic, heterocyclyloxy, substituted heterocyclyloxy, carboxyl, carboxyl ester, alkynyl, substituted alkynyl, hydroxyl, acyl, oxo, halo, acylamino, aminocarbonyl, and cyano;

R 3 is 4-(1-methylpiperazin-4-yl); and

R 4 and R 5 independently are selected from the group consisting of hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, alkoxy, cycloalkyl, substituted cycloalkyl, and acyl; or

R 4 and R 5 together with the nitrogen atom bound thereto, form a heterocyclic or substituted heterocyclic.

4. A method of inhibiting a signal transduction cascade in which JAK3 kinase plays a role, comprising contacting a cell expressing a receptor involved in such a signaling cascade with a compound wherein the compound is a compound of formula IA:

or therapeutically acceptable salt thereof,

wherein:

q is 0, 1, 2 or 3;

p is 1;

R is hydrogen;

X is fluoro;

Y is a covalent bond and;

alk is a covalent bond;

R 1 is —C(O)NR 4 R 5 ;

each R 2 independently is selected from the group consisting of alkyl, substituted alkyl, alkoxy, substituted alkoxy, amino, substituted amino, aryl, substituted aryl, aryloxy, substituted aryloxy, cycloalkyl, substituted cycloalkyl, heteroaryl, substituted heteroaryl, heteroaryloxy, substituted heteroaryloxy, heterocyclic, substituted heterocyclic, heterocyclyloxy, substituted heterocyclyloxy, carboxyl, carboxyl ester, alkynyl, substituted alkynyl, hydroxyl, acyl, oxo, halo, acylamino, aminocarbonyl, and cyano;

R 3 is 4-(1-methylpiperazin-4-yl); and

R 4 and R 5 independently are selected from the group consisting of hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, alkoxy, cycloalkyl, substituted cycloalkyl, and acyl; or

R 4 and R 5 together with the nitrogen atom bound thereto, form a heterocyclic or substituted heterocyclic.

5. A method of inhibiting an activity of a JAK kinase, comprising contacting the JAK kinase with an amount of a compound effective to inhibit the activity of the JAK kinase wherein the compound is selected from the group consisting of:

5-Bromo-N4-(3-chloro-4-methoxyphenyl)-N2-[3-(N-methylaminocarbonylmethyleneoxy)phenyl]-2,4-pyrimidinediamine;

N4-(3-Chloro-4-methoxyphenyl)-5-fluoro-N2-[4-((1-methyl-1H-pyrazol-3-yl)aminocarbonyl)phenyl ]-2,4-pyrimidinediamine;

N4-(3-Chloro-4-methoxyphenyl)-N2-[4-((1-ethyl-1H-pyrazol-5-yl)aminocarbonyl)phenyl]-5-fluoro-2,4-pyrimidinediamine;

N4-(3-Chloro-4-methoxyphenyl)-5-fluoro-N2[4-((1-methyl-1H-pyrazol-5-yl)aminocarbonyl)phenyl]-2,4-pyrimidinediamine;

N2-(3-Aminocarbonothioylphenyl)-5-fluoro-N4-[4-(2-propynyloxy)phenyl]-2,4-pyrimidinediamine;

N2-(3-Aminocarbonylphenyl)-5-fluoro-N4-[4-(2-propynyloxy)phenyl]-2,4-pyrimidinediamine;

N2-(4-Aminocarbonothioylphenyl)-5-fluoro-N4-[4-(2-propynyloxy)phenyl]-2,4-pyrimidinediamine;

N2-(4-Aminocarbonylphenyl)-5-fluoro-N4-[4-(2-propynyloxy)phenyl]-2,4-pyrimidinediamine;

N2-(4-Aminocarbonylphenyl)-5-fluoro-N4-[4-((3-methyl -1,2,4-oxadiazol-5-yl)methyleneoxy)phenyl]-2,4-pyrimidinediamine Hydrogen Chloride Salt;

N2-(4-Aminocarbonyl-3-chlorophenyl)-5-fluoro-N4-[3-methyl-4-(4-methylpiperazin-1-yl)phenyl]-2,4-pyrimidinediamine;

N2-(4-Aminocarbonylphenyl)-5-fluoro-N4-[3-(oxazol-2-yl)phenyl]-2,4-pyrimidinediamine;

N2-(4-Aminocarbonyl-3-chlorophenyl)-5-fluoro-N4-[3-(oxazol-2-yl)phenyl]-2,4-pyrimidinediamine;

N2-(4-Aminocarbonylphenyl)-5-fluoro-N4-methyl-N4[3-methyl-1,2,4-oxadiazol-5-yl)methyleneoxy)phenyl]-2,4-pyrimidinediamine;

N2-(4-Aminocarbonyl-3-chlorophenyl)-5-fluoro-N4-methyl-N4-[4-((3-methyl-1,2,4-oxadiazol -5-yl)methyleneoxy)phenyl]-2,4-pyrimidinediamine;

N2-(3-Cyanophenyl)-5-fluoro-N4-methyl-N4-[4-((3-methyl-1,2,4-oxadiazol-5-yl)methyleneoxy)phenyl]-2,4-pyrimidinediamine;

N4-(3-Chloro-4-methoxyphenyl)-N2-(3-cyanophenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-(4-Aminocarbonylmethoxyphenyl)-N2-(3-cyanophenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-(4-Aminocarbonylmethoxyphenyl)-N2-(3-aminocarbonylphenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-(4-Aminocarbonylmethoxyphenyl)-N2-(4-cyanophenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-(4-Aminocarbonylmethoxyphenyl)-N2-(4-aminocarbonylphenyl)-5-fluoro-2,4-pyrimidinediamine;

5-Fluoro-N4-[4-((1-methylethoxy)carbonylmethoxy)phenyl]-N2-[4-((4-methylpiperazin-1-yl)carbonyl)phenyl]-2,4-pyrimidinediamine;

N2-(4-Aminocarbonylphenyl)-N4-(4-cyanomethoxyphenyl)-5-fluoro-2,4-pyrimidinediamine;

N2-(3-Aminocarbonylphenyl)-N4-(4-cyanomethoxyphenyl)-5-fluoro-2,4-pyrimidinediamine;

N2-(4-Cyanolphenyl)-N4-(4-cyanomethoxyphenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-(4-Cyanomethoxyphenyl)-N2-(3-cyanophenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-(4-Cyanomethoxyphenyl)-5-fluoro-N2[((4-methylpiperazin-1-yl)carbonyl)phenyl]-2,4-pyrimidinediamine;

N4-(3-Aminocarbonylmethoxyphenyl)-N2-(4-aminocarbonylphenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-(3-Aminocarbonylmethoxyphenyl)-N2-(3-aminocarbonylphenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-(3-Aminocarbonylmethoxyphenyl)-N2-(4-cyanophenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-(3-Aminocarbonylmethoxyphenyl)-N2-(3-cyanophenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-(4-Aminocarbonylmethoxyphenyl)-5-fluoro-N2-[4-((4-methylpiperazin-1-yl)carbonyl)phenyl]-2,4-pyrimidinediamine;

N4-(4-Aminocarbonylmethoxyphenyl)-5-fluoro-N2-[3((4-methylpiperazin-1-yl)carbonyl)phenyl]-2,4-pyrimidinediamine;

N2-[3-Aminocarbonyl-4-(4-methylpiperazin-1-yl)phenyl]-N4-(4-aminocarbonylmethoxyphenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-(4-Aminocarbonylmethoxyphenyl)-5-fluoro-N2-[3-methylaminocarbonyl-4-(4-methylpiperazin-1-yl)phenyl]-2,4-pyrimidinediamine;

N4-(4-Cyanomethoxyphenyl)-5-fluoro-N2-[3-((4-methylpiperazin-1-ylcarbonyl)phenyl]-2,4-pyrimidinediamine;

N4-(4-Cyanomethoxyphenyl)-N2-[3-cyano-4-(4-methylpiperazin-1-yl)phenyl]-5-fluoro-2,4-pyrimidinediamine;

N2-[3-Aminocarbonyl-4-(4-methylpiperazin-1-yl)phenyl]-N4-(4-cyanomethoxyphenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-(4-Cyanomethoxyphenyl)-5-fluoro-N2-[3-methylaminocarbonyl-4-(4-methylpiperazin-1-yl)phenyl]-2,4-pyrimidinediamine;

N2-(4-Aminocarbonylphenyl)-N4-(3-cyanomethoxyphenyl)-5-fluoro-2,4-pyrimidinediamine;

N2-(3-Aminocarbonylphenyl)-N4-(3-cyanomethoxyphenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-(3-Cyanomethoxyphenyl)-N2-(4-cyanophenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-(3-Cyanomethoxyphenyl)-N2-(3-cyanophenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-(3-Aminocarbonylmethoxyphenyl)-5-fluoro-N2-[4-((4-methylpiperazin-1-yl)carbonyl)phenyl]-2,4-pyrimidinediamine;

N4-(3-Aminocarbonylmethoxyphenyl)-5-fluoro-N2-[4((4-methylpiperazin-1-yl)carbonyl)phenyl]-2,4-pyrimidinediamine;

N4-(3-Aminocarbonylmethoxyphenyl)-N2-[3-aminocarbonyl-4-(4-methylpiperazin-1-yl)phenyl]-5-fluoro-2,4-pyrimidinediamine;

N4-(3-Aminocarbonylmethoxyphenyl)-5-fluoro-N2-[3-methylaminocarbonyl-4-(4-methylpiperazin-1-yl)phenyl]-2,4-pyrimidinediamine;

N4-(3-Cyanomethoxyphenyl)-5-fluoro-N2-[4-((4-methylpiperazin-1-yl)carbonyl)phenyl]-2,4-pyrimidinediamine;

N4-(3-Cyanomethoxyphenyl)-5-fluoro-N2-[4-((4-methylpiperazin-1-yl)carbonyl)phenyl]-2,4-pyrimidinediamine;

N4-(3-Cyanomethoxyphenyl)-5-fluoro-N2[3-methylaminocarbonyl-4-(4-methylpiperazin-1-yl)phenyl]-2,4-pyrimidinediamine;

N2-(4-Aminocarbonylphenyl)-5-fluoro-N4-[4((5-methyl-1,2,4-oxadiazol-3-yl)methoxy)phenyl]-2,4-pyrimidinediamine;

N2-(3-Aminocarbonylphenyl)-5-fluoro-N4-[4-((5-methyl-1,2,4-oxadiazol-3-yl)methoxy)phenyl]-2,4-pyrimidinediamine;

N2-(4-Cyanophenyl)-5-fluoro-N4-[4-((5-methyl-1,2,4-oxadiazol-3-yl)methoxy)phenyl]-2,4-pyrimidinediamine;

N2-(3-Cyanophenyl)-5-fluoro-N4-[4-((5-methyl-1,2,4-oxadiazol-3-yl)methoxy)phenyl]-2,4-pyrimidinediamine;

5-Fluoro-N4-[4-((5-methyl-1,2,4-oxadiazol-3-yl)methoxy)phenyl]-N2-[4((4-methylpiperazin-1-yl)carbonyl)phenyl]-2,4-pyrimidinediamine;

5-Fluoro-N4-[4-((5-methyl-1,2,4-oxadiazol-3-yl)methoxy)phenyl]-N2-[4((4-methylpiperazin-1-yl)carbonyl)phenyl]-2,4-pyrimidinediamine;

N2-[3-Aminocarbonyl-4-(4-methylpiperazin-1-yl)phenyl]-5-fluoro-N4-[4((5-methyl-1,2,4-oxadiazol-3-yl)methoxy)phenyl]-2,4-pyrimidinediamine;

5-Fluoro-N2-[3-methylaminocarbonyl-4-(4-methylpiperazin-1-yl)phenyl]-N4-[4-((5-methyl-1,2,4-oxadiazol-3-yl)methoxy)phenyl]-2,4-pyrimidinediamine;

N4-(4-Cyanomethoxyphenyl)-N2-(4-cyanomethylphenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-(3-Aminocarbonylmethoxyphenyl)-N2-(4-cyanomethylphenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-(3-Cyanomethoxyphenyl)-N2-(4-cyanomethylphenyl)-5-fluoro-2,4-pyrimidinediamine;

N2-(4-Aminocarbonylphenyl)-N4-(4-cyanomethylphenyl)-5-fluoro-2,4-pyrimidinediamine;

N2-(3-Aminocarbonylphenyl)-N4-(4-cyanomethylphenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-(4-Cyanomethylphenyl)-N2-(4-cyanophenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-(4-Cyanomethylphenyl)-N2-(3-cyanophenyl)-5-fluoro-2,4-pyrimidinediamine;

N2,N4-Bis(4-cyanomethylphenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-(4-Cyanomethylphenyl)-5-fluoro-N2-[4-((4-methylpiperazin-1-yl)carbonyl)phenyl]-2,4-pyrimidinediamine;

N4-(4-Cyanomethylphenyl)-5-fluoro-N2-[4-((4-methylpiperazin-1-yl)carbonyl)phenyl]-2,4-pyrimidinediamine;

N2-[3-Aminocarbonyl -4-(4-methylpiperazin-1-yl)phenyl]-N4-(4-cyanomethylphenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-(4-Cyanomethylphenyl)-5-fluoro-N2-[3-methylaminocarbonyl-4-(4-methylpiperazin-1-yl)phenyl]-2,4-pyrimidinediamine;

N4-(4-Aminocarbonylmethoxyphenyl)-N2-(4-cyanomethylphenyl)-5-fluoro-2,4-pyrimidinediamine;

N2-(4-Cyanomethylphenyl)-5-fluoro-N4-[4-((5-methyl-1,2,4-oxadiazol-3-yl)methoxy)phenyl]-2,4-pyrimidinediamine;

N4-[4-(1-Cyanoethoxy)phenyl]-N2-(4-cyanomethylphenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-[4-(1-Cyanoethoxy)phenyl]-N2-(4-cyanophenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-[4-(1-Cyanoethoxy)phenyl]-N2-(3-cyanophenyl)-5-fluoro-2,4-pyrimidinediamine;

N2-(4-Aminocarbonylphenyl)-N4-[4-(1-cyanoethoxy)phenyl]-5-fluoro-2,4-pyrimidinediamine;

N2-(3-Aminocarbonylphenyl)-N4-[4-(1-cyanoethoxy)phenyl]-5-fluoro-2,4-pyrimidinediamine;

N4-[4-(1-Cyano-1-methylethoxy)phenyl]-N2-(4-cyanomethylphenyl)-5-fluoro-2,4-pyrimidinediamine;

N2-(4-Aminocarbonylphenyl)-N4-[4-(1-cyano-1-methylethoxy)phenyl]-5-fluoro-2,4-pyrimidinediamine;

N2-(3-Aminocarbonylphenyl)-N4-[4-(1-cyano-1-methylethoxy)phenyl]-5-fluoro-2,4-pyrimidinediamine;

N4-(4-Cyanomethoxy-3-methylphenyl)-N2-(4-cyanomethylphenyl)-5-fluoro-2,4-pyrimidinediamine;

N2-(4-Aminocarbonylphenyl)-N4-(4-cyanomethoxy-3-methylphenyl)-5-fluoro-2,4-pyrimidinediamine;

N2-(3-Aminocarbonylphenyl)-N4-(4-cyanomethoxy-3-methylphenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-(4-Cyanomethoxy-3,5-dimethylphenyl)-N2-(4-cyanomethylphenyl)-5-fluoro-2,4-pyrimidinediamine;

N2-(4-Aminocarbonylphenyl)-N4-(4-cyanomethoxy-3,5-dimethylphenyl)-5-fluoro-2,4-pyrimidinediamine;

N2-(3-Aminocarbonylphenyl)-N4-(4-cyanomethoxy-3,5-dimethylphenyl)-5-fluoro-2,4-pyrimidinediamine;

N2-(4-Aminocarbonylphenyl)-N4-[4-(1-cyanoethoxy)-3-methylphenyl]-5-fluoro-2,4-pyrimidinediamine;

N2-(3-Aminocarbonylphenyl)-N4-[4-(1-cyanoethoxy)-3-methylphenyl]-5-fluoro-2,4-pyrimidinediamine;

N4-[4-(1-Cyanoethoxy)-3-methylphenyl]-N2-(4-cyanomethylphenyl)-5-fluoro-2,4-pyrimidinediamine;

N2-(4-Aminocarbonylphenyl)-N4-[4-(1-cyanoethoxy)-3,5-dimethylphenyl]-5-fluoro-2,4-pyrimidinediamine;

N2-(3-Aminocarbonylphenyl)-N4-[4-(1-cyanoethoxy)-3,5-dimethylphenyl]-5-fluoro-2,4-pyrimidinediamine;

N4-[4-(1-Cyanoethoxy)-3,5-dimethylphenyl]-N2-(4-cyanomethylphenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-(4-(1-Cyanoethoxy)-3,5-dimethylphenyl]-5-fluoro-N2[4-((4-methylpiperazin-1-yl)carbonyl)phenyl]-2,4-pyrimidinediamine;

N2-(3-Aminocarbonylphenyl)-N4-(3-chloro-4-cyanomethoxyphenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-(3-Chloro-4-cyanomethoxyphenyl)-N2-(4-cyanomethylphenyl)-5-fluoro-2,4-pyrimidinediamine;

N2-(4-Aminocarbonylphenyl)-N4-(4-cyanomethoxy-3-fluorophenyl)-5-fluoro-2,4-pyrimidinediamine;

N2-(3-Aminocarbonylphenyl)-N4-(4-cyanomethoxy-3-fluorophenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-(4-Cyanomethoxy-3-fluorophenyl)-N2-(4-cyanomethylphenyl)-5-fluoro-2,4-pyrimidinediamine;

N2-(4-Chloro-3-cyano-5-ethylphenyl)-N4-(4-cyanomethoxyphenyl)-5-fluoro-2,4-pyrimidinediamine;

N2-(4-Chloro-3-cyano-5-ethylphenyl)-N4-(3-cyanomethoxyphenyl)-5-fluoro-2,4-pyrimidinediamine;

N2-(4-Chloro-3-cyano-5-ethylphenyl)-N4-(4-cyanomethylphenyl)-5-fluoro-2,4-pyrimidinediamine;

N2,N4-Bis(3-chloro-4-cyanomethoxyphenyl)-5-fluoro-2,4-pyrimidinediamine;

N2-(4-Chloro-3-cyano-5-ethylphenyl)-N4-(3-chloro-4-cyanomethoxyphenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-(3-Cyanomethoxy-4,5-dimethoxyphenyl)-5-fluoro-N2-[3-(N-methylaminocarbonylmethyleneoxy)phenyl]-2,4-pyrimidinediamine;

N2-(4-Cyanomethylphenyl)-5-fluoro-N4-[4((3-methyl-1,2,4-oxadiazol-5-yl)methoxy)phenyl]-2,4-pyrimidinediamine;

N2-(3-Cyanolphenyl)-5-fluoro-N4-[4-((3-methyl-1,2,4-oxadiazol-5-yl)methoxy)phenyl]-2,4-pyrimidinediamine;

N2-(3-Cyanophenyl)-5-fluoro-N4-[4-((3-methyl-1,2,4-oxadiazol-5-yl)methyl)phenyl]-2,4-pyrimidinediamine;

N2-(4-Cyanomethylphenyl)-5-fluoro-N4-[4-((3-methyl-1,2,4-oxadiazol-5-yl)methyl)phenyl]-2,4-pyrimidinediamine;

N2-(3-Cyanophenyl)-5-fluoro-N4-[4-(3-(3-methyl-1,2,4-oxadiazol-5-yl)propyl)phenyl]-2,4-pyrimidinediamine;

N2-(4-Cyanomethylphenyl)-5-fluoro-N4-[2-methyl -4-((3-methyl-1,2,4-oxadiazol-5-yl)methoxy)phenyl]-2,4-pyrimidinediamine;

N2-(3-Cyanophenyl)-5-fluoro-N4-[2-methyl-4-((3-methyl-1,2,4-oxadiazol-5-yl)methoxy)phenyl]-2,4-pyrimidinediamine;

N4-(3-Chloro-4-fluorophenyl)-N2-(4-cyanomethylphenyl)-5-fluoro-2,4-pyrimidinediamine;

N4-(3-Cyano-4-fluorophenyl)-N2-(4-cyanomethylphenyl)-5-fluoro-2,4-pyrimidinediamine;

N2-(4-Cyanomethylphenyl)-N4-(3-cyano-4-methylphenyl)-5-fluoro-2,4-pyrimidinediamine;

N2-(4-Cyanomethylphenyl)-5-fluoro-N4-[4-(2-(3-methyl-1,2,4-oxadiazol-5-yl)ethyl)phenyl]-2,4-pyrimidinediamine;

5-Fluoro-N4-[4-(2-(3-methyl-1,2,4-oxadiazol-5-yl)ethyl)phenyl]-N2-[4-(2-cyanoethyl)phenyl]-2,4-pyrimidinediamine;

N2-(4-Cyanomethylphenyl)-5-fluoro-N4-(5-methoxycarbonylthiophen-2-yl)-2,4-pyrimidinediamine;

N2-(3-Aminocarbonylphenyl)-5-fluoro-N4-(5-methoxycarbonylthiophen-2-yl)-2,4-pyrimidinediamine;

N2,N4-Bis[4-(2-cyanoethyl)phenyl]-5-fluoro-2,4-pyrimidinediamine;

N2-[4-(2-(N,N-Diethylamino)ethylaminocarbonyl)phenyl]-5-fluoro-N4-[3-(3-methyl-1,2,4-oxadiazol-5-yl)methyleneoxyphenyl]-2,4-pyrimidinediamine;

N2-(4-Cyanophenyl)-5-fluoro-N4-[3-((3-methyl-1,2,4-oxadiazol-5-yl)methyleneoxy)phenyl]-2,4-pyrimidinediamine;

N2-[4-(2-(N,N-Diethylamino)ethylaminocarbonyl)phenyl]-5-fluoro-N4-[4-((5-methylisoxazol-3-yl)methyleneoxy)phenyl]-2,4-pyrimidinediamine;

N2-(3-Aminocarbonylphenyl)-5-fluoro-N4-[3-((3-methyl-1,2,4-oxadiazol-5-yl)methyleneoxy)phenyl]-2,4-pyrimidinediamine;

N2-(4-Cyanomethylphenyl)-5-fluoro-N4-[3-((3-methyl-1,2,4-oxadiazol-5-yl)methyleneoxy)phenyl]-2,4-pyrimidinediamine;

N2-(4-Cyanomethylphenyl)-5-fluoro-N4-[4-((5-methylisoxazol-3-yl)methyleneoxy)phenyl]-2,4-pyrimidinediamine;

N2-(4-Cyanomethylphenyl)-5-fluoro-N4-[4-(4-pyridinylmethyl)phenyl]-2,4-pyrimidinediamine;

5-Fluoro-N2-[3-(N-methylaminocarbonylmethyleneoxy)phenyl]-N4-[4-(4-pyridinylmethyl)phenyl]-2,4-pyrimidinediamine;

N2-(3-Aminocarbonylphenyl)-5-fluoro-N4-[4-(2-pyridinylmethyleneoxy)phenyl]-2,4-pyrimidinediamine;

N2-(3-Aminocarbonylphenyl)-5-methyl-N4-[4-(2-pyridinylmethyleneoxy)phenyl]-2,4-pyrimidinediamine; and

N2-[4-(2-(N,N-Diethylamino)ethylaminocarbonyl)phenyl)-5-fluoro-N4-[4-(2-pyridinylmethyleneoxy)phenyl]-2,4-pyrimidinediamine.

6. A method of inhibiting an activity of a JAK kinase, comprising contacting the JAK kinase with an amount of a compound effective to inhibit the activity of the JAK kinase wherein the compound is N2-[3-Aminocarbonyl-4-(4-methylpiperazin-1-yl)phenyl]-N4-(3-cyanomethoxyphenyl)-5-fluoro-2,4-pyrimidinediamine.