tofacitinib and its Impurities
Tofacitinib is used to treat psoriatic arthritis and moderate-to-severe forms of rheumatoid arthritis. It is sold under the brand Xeljanz. Reference standards of Tofacitinib API,and its pharmacopeial, non pharmacopeial impurities, and stable isotopes are listed below.


3-((3R,4R)-3-((6-Aminopyrimidin-4-yl)(methyl)amino)-4-methylpiperidin-1-yl)-3-oxopropanenitrile
3-((3R,4R)-3-((6-Aminopyrimidin-4-yl)(methyl)amino)-4-methylpiperidin-1-yl)-3-oxopropanenitrile
Catalogue No.:PA 73 0061001
CAS :
1640971-60-3
Molecular Formula : C14H20N6O
Molecular Weight : 288.36

![N-Methyl-N-[(3R,4R)-4-methyl-3-piperidinyl]-7H-Pyr PA 73 0061002](https://www.pharmaffiliates.com/pimages/PA730061002.jpg)
N-Methyl-N-[(3R,4R)-4-methyl-3-piperidinyl]-7H-Pyrrolo[2,3-d]pyrimidin-4-amine Hydrochloride
N-Methyl-N-[(3R,4R)-4-methyl-3-piperidinyl]-7H-Pyrrolo[2,3-d]pyrimidin-4-amine Hydrochloride
Catalogue No.:PA 73 0061002
CAS :
1260590-51-9
Molecular Formula : C13H20ClN5
Molecular Weight : 281.79

![(3R,4R)-4-Methyl-3-(methyl(7H-pyrrolo[2,3-d]pyrimi PA 73 0061004](https://www.pharmaffiliates.com/pimages/PA730061004.jpg)
(3R,4R)-4-Methyl-3-(methyl(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidine-1-carbaldehyde
(3R,4R)-4-Methyl-3-(methyl(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidine-1-carbaldehyde
Catalogue No.:PA 73 0061004
CAS :
2227199-28-0
Molecular Formula : C14H19N5O
Molecular Weight : 273.34

![3-(4-methyl-3-(methyl(7H-pyrrolo[2,3-d]pyrimidin-4 PA 73 0061005](https://www.pharmaffiliates.com/pimages/PA730061005.jpg)
3-(4-methyl-3-(methyl(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)-3,6-dihydropyridin-1(2H)-yl)-3-oxopropanenitrile
3-(4-methyl-3-(methyl(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)-3,6-dihydropyridin-1(2H)-yl)-3-oxopropanenitrile
Catalogue No.:PA 73 0061005
CAS :
2504210-31-3
Molecular Formula : C16H18N6O
Molecular Weight : 310.36


N1-methyl-N1-((3R,4R)-4-methyl-1-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)piperidin-3-yl)malonamide
N1-methyl-N1-((3R,4R)-4-methyl-1-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)piperidin-3-yl)malonamide
Catalogue No.:PA 73 0061009
CAS :
2504210-30-2
Molecular Formula : C16H22N6O2
Molecular Weight : 330.39


2-cyano-N-methyl-N-((3R,4R)-4-methyl-1-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)piperidin-3-yl)acetamide
2-cyano-N-methyl-N-((3R,4R)-4-methyl-1-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)piperidin-3-yl)acetamide
Catalogue No.:PA 73 0061010
CAS :
1092578-43-2
Molecular Formula : C16H20N6O
Molecular Weight : 312.38


1,3-bis((3R,4R)-4-methyl-3-(methyl(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidin-1-yl)propane-1,3-dione
1,3-bis((3R,4R)-4-methyl-3-(methyl(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidin-1-yl)propane-1,3-dione
Catalogue No.:PA 73 0061012
CAS :
2504210-41-5
Molecular Formula : C29H38N10O2
Molecular Weight : 558.69


N2,N4-bis((3R,4R)-1-benzyl-4-methylpiperidin-3-yl)-N2,N4-dimethyl-7H-pyrrolo[2,3-d]pyrimidine-2,4-diamine
N2,N4-bis((3R,4R)-1-benzyl-4-methylpiperidin-3-yl)-N2,N4-dimethyl-7H-pyrrolo[2,3-d]pyrimidine-2,4-diamine
Catalogue No.:PA 73 0061013
CAS :
2459302-78-2
Molecular Formula : C34H45N7
Molecular Weight : 551.78


N-((3S,4R)-1-benzyl-4-methylpiperidin-3-yl)-N-methyl-7-tosyl-7H-pyrrolo[2,3-d]pyrimidin-4-amine
N-((3S,4R)-1-benzyl-4-methylpiperidin-3-yl)-N-methyl-7-tosyl-7H-pyrrolo[2,3-d]pyrimidin-4-amine
Catalogue No.:PA 73 0061018
CAS :
2056104-91-5
Molecular Formula : C27H31N5O2S
Molecular Weight : 489.64


N-((3R,4S)-1-benzyl-4-methylpiperidin-3-yl)-N-methyl-7-tosyl-7H-pyrrolo[2,3-d]pyrimidin-4-amine
N-((3R,4S)-1-benzyl-4-methylpiperidin-3-yl)-N-methyl-7-tosyl-7H-pyrrolo[2,3-d]pyrimidin-4-amine
Catalogue No.:PA 73 0061019
CAS :
1092578-44-3
Molecular Formula : C27H31N5O2S
Molecular Weight : 489.22


3-((3R,4R)-4-methyl-3-(methyl(7-tosyl-7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidin-1-yl)-3-oxopropanenitrile
3-((3R,4R)-4-methyl-3-(methyl(7-tosyl-7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidin-1-yl)-3-oxopropanenitrile
Catalogue No.:PA 73 0061020
CAS :
2259288-22-5
Molecular Formula : C23H26N6O3S
Molecular Weight : 466.56


3-(4-(((3R,4R)-1-(2-cyanoacetyl)-4-methylpiperidin-3-yl)(methyl)amino)-5,6-dihydro-7H-pyrrolo[2,3-d]pyrimidin-7-yl)-3-oxopropanenitrile
3-(4-(((3R,4R)-1-(2-cyanoacetyl)-4-methylpiperidin-3-yl)(methyl)amino)-5,6-dihydro-7H-pyrrolo[2,3-d]pyrimidin-7-yl)-3-oxopropanenitrile
Catalogue No.:PA 73 0061021
CAS :
2459302-82-8
Molecular Formula : C19H23N7O2
Molecular Weight : 381.44


N-((3R,4R)-1-benzyl-4-methylpiperidin-3-yl)-N-methyl-7-(p-tolylsulfinyl)-7H-pyrrolo[2,3-d]pyrimidin-4-amine
N-((3R,4R)-1-benzyl-4-methylpiperidin-3-yl)-N-methyl-7-(p-tolylsulfinyl)-7H-pyrrolo[2,3-d]pyrimidin-4-amine
Catalogue No.:PA 73 0061022
CAS :
2504210-33-5
Molecular Formula : C27H31N5OS
Molecular Weight : 473.64


3-((3R,4R)-4-methyl-3-(methyl(6-oxo-6,7-dihydro-5H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidin-1-yl)-3-oxopropanenitrile
3-((3R,4R)-4-methyl-3-(methyl(6-oxo-6,7-dihydro-5H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidin-1-yl)-3-oxopropanenitrile
Catalogue No.:PA 73 0061025
CAS :
1640971-51-2
Molecular Formula : C16H20N6O2
Molecular Weight : 328.38

![3-((3R,4R)-3-((7H-pyrrolo[2,3-d]pyrimidin-4-yl)ami PA 73 0061016](https://www.pharmaffiliates.com/pimages/PA730061016.jpg)
3-((3R,4R)-3-((7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)-4-methylpiperidin-1-yl)-3-oxopropanenitrile
3-((3R,4R)-3-((7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)-4-methylpiperidin-1-yl)-3-oxopropanenitrile
Catalogue No.:PA 73 0061016
CAS :
1527525-58-1
Molecular Formula : C15H18N6O
Molecular Weight : 298.35


(Z)-2-((3R,4R)-3-((1H-indol-4-yl)(methyl)amino)-4-methylpiperidine-1-carbonyl)-3-amino-5-((3R,4R)-4-methyl-3-(methyl(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidin-1-yl)-5-oxopent-2-enenitrile
(Z)-2-((3R,4R)-3-((1H-indol-4-yl)(methyl)amino)-4-methylpiperidine-1-carbonyl)-3-amino-5-((3R,4R)-4-methyl-3-(methyl(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidin-1-yl)-5-oxopent-2-enenitrile
Catalogue No.:PA 73 0061015
CAS :
2382711-65-9
Molecular Formula : C34H42N10O2
Molecular Weight : 622.78


3-Imino-5-((3R,4R)-4-methyl-3-(methyl(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidin-1-yl)-2-((3R,4R)-4-methyl-3-(methyl(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidine-1-carbonyl)-5-oxopentanenitrile
3-Imino-5-((3R,4R)-4-methyl-3-(methyl(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidin-1-yl)-2-((3R,4R)-4-methyl-3-(methyl(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidine-1-carbonyl)-5-oxopentanenitrile
Catalogue No.:PA 73 0061028
CAS :
2102040-00-4
Molecular Formula : C32H40N12O2
Molecular Weight : 624.75

![3-((3R,4S)-4-Methyl-3-(methyl(7H-pyrrolo[2,3-d]pyr PA 73 0061030](https://www.pharmaffiliates.com/pimages/PA730061030.jpg)
3-((3R,4S)-4-Methyl-3-(methyl(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidin-1-yl)-3-oxopropanenitrile 2-hydroxypropane-1,2,3-tricarboxylate
3-((3R,4S)-4-Methyl-3-(methyl(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidin-1-yl)-3-oxopropanenitrile 2-hydroxypropane-1,2,3-tricarboxylate
Catalogue No.:PA 73 0061030
CAS :
2174011-53-9
Molecular Formula : C22H28N6O8
Molecular Weight : 504.5


3-((3R,4R)-4-Methyl-3-(methyl(7-nitroso-7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidin-1-yl)-3-oxopropanenitrile
3-((3R,4R)-4-Methyl-3-(methyl(7-nitroso-7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidin-1-yl)-3-oxopropanenitrile
Catalogue No.:PA 73 0061032
CAS :
NA
Molecular Formula : C16H19N7O2
Molecular Weight : 341.38


1-((4R)-4-Methyl-3-(methyl(7-nitroso-7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidin-1-yl)propan-1-one
1-((4R)-4-Methyl-3-(methyl(7-nitroso-7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidin-1-yl)propan-1-one
Catalogue No.:PA 73 0061037
CAS :
NA
Molecular Formula : C16H22N6O2
Molecular Weight : 330.39


N-((3R,4R)-1-(2-Cyanoacetyl)-4-methylpiperidin-3-yl)-N-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)nitrous Amide
N-((3R,4R)-1-(2-Cyanoacetyl)-4-methylpiperidin-3-yl)-N-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)nitrous Amide
Catalogue No.:PA 73 0061039
CAS :
NA
Molecular Formula : C15H17N7O2
Molecular Weight : 327.35

![3-((3R,4R)-4-Methyl-3-(methyl(7H-pyrrolo[2,3-d]pyr PA STI 089598](https://www.pharmaffiliates.com/pimages/PASTI089598.jpg)
3-((3R,4R)-4-Methyl-3-(methyl(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidin-1-yl)-3-oxopropanenitrile-1,2,3-13C3-15N
3-((3R,4R)-4-Methyl-3-(methyl(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidin-1-yl)-3-oxopropanenitrile-1,2,3-13C3-15N
Catalogue No.:PA STI 089598
CAS :
2256762-71-5
Molecular Formula : C1313C3H20N515NO
Molecular Weight : 316.35


3-(4-Methyl-3-(methyl(6-oxo-6,7-dihydro-5H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidin-1-yl)-3-oxopropanenitrile
3-(4-Methyl-3-(methyl(6-oxo-6,7-dihydro-5H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidin-1-yl)-3-oxopropanenitrile
Catalogue No.:PA 73 0061042
CAS :
1269823-96-2
Molecular Formula : C16H20N6O2
Molecular Weight : 328.38


3-((3R,4R)-4-Methyl-3-(methyl(7-methyl-7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidin-1-yl)-3-oxopropanenitrile
3-((3R,4R)-4-Methyl-3-(methyl(7-methyl-7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidin-1-yl)-3-oxopropanenitrile
Catalogue No.:PA 73 0061043
CAS :
NA
Molecular Formula : C17H22N6O
Molecular Weight : 326.40


Ethyl (E)-3-amino-2-cyano-5-((3R,4R)-4-methyl-3-(methyl(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidin-1-yl)-5-oxopent-2-enoate
Ethyl (E)-3-amino-2-cyano-5-((3R,4R)-4-methyl-3-(methyl(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidin-1-yl)-5-oxopent-2-enoate
Catalogue No.:PA 73 0061044
CAS :
2459302-85-1
Molecular Formula : C21H27N7O3
Molecular Weight : 425.49


Butyl 3-amino-2-cyano-5-((3R,4R)-4-methyl-3-(methyl(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidin-1-yl)-5-oxopent-2-enoate
Butyl 3-amino-2-cyano-5-((3R,4R)-4-methyl-3-(methyl(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidin-1-yl)-5-oxopent-2-enoate
Catalogue No.:PA 73 0061048
CAS :
2716897-36-6
Molecular Formula : C23H31N7O3
Molecular Weight : 453.55