Remdesivir and its Impurities
Remdesivir is a broad-spectrum antiviral medication developed by the biopharmaceutical company Gilead Sciences. As of 2020, remdesivir is being tested as a specific treatment for COVID-19, and has been authorized for emergency use in the U.S. and approved for use in Japan for people with severe symptoms. Reference standards of Remdesivir API,and its pharmacopeial, non pharmacopeial impurities, and stable isotopes are listed below.

![(2S,3R,4S,5R)-2-(4-Aminopyrrolo[2,1-f][1,2,4]triaz PA 18 1081000](https://www.pharmaffiliates.com/pimages/PA181081000.jpg)
(2S,3R,4S,5R)-2-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-3,4-dihydroxy-5-(hydroxymethyl)tetrahydrofuran-2-carbonitrile
(2S,3R,4S,5R)-2-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-3,4-dihydroxy-5-(hydroxymethyl)tetrahydrofuran-2-carbonitrile
Catalogue No.:PA 18 1081000
CAS :
1355049-95-4
Molecular Formula : C12H13N5O4
Molecular Weight : 291.27

![(2R,3R,4S,5R)-2-(4-Aminopyrrolo[2,1-f][1,2,4]triaz PA 18 1081001](https://www.pharmaffiliates.com/pimages/PA181081001.jpg)
(2R,3R,4S,5R)-2-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-((benzyloxy)methyl)-3,4-dihydroxytetrahydrofuran-2-carbonitrile
(2R,3R,4S,5R)-2-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-((benzyloxy)methyl)-3,4-dihydroxytetrahydrofuran-2-carbonitrile
Catalogue No.:PA 18 1081001
CAS :
NA
Molecular Formula : C19H19N5O4
Molecular Weight : 381.39


2-Ethylbutyl ((R)-(((3aR,4R,6R,6aR)-6-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-6-cyano-2,2-dimethyltetrahydrofuro[3,4-d][1,3]dioxol-4-yl)methoxy)(phenoxy)phosphoryl)-L-alaninate
2-Ethylbutyl ((R)-(((3aR,4R,6R,6aR)-6-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-6-cyano-2,2-dimethyltetrahydrofuro[3,4-d][1,3]dioxol-4-yl)methoxy)(phenoxy)phosphoryl)-L-alaninate
Catalogue No.:PA 18 1081009
CAS :
2614984-92-6
Molecular Formula : C30H39N6O8P
Molecular Weight : 642.65


2-Ethylbutyl ((S)-(((2R,3S,4R,5S)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)-L-alaninate
2-Ethylbutyl ((S)-(((2R,3S,4R,5S)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)-L-alaninate
Catalogue No.:PA 18 1081010
CAS :
NA
Molecular Formula : C27H35N6O8P
Molecular Weight : 602.58


2-Ethylbutyl ((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)-D-alaninate
2-Ethylbutyl ((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)-D-alaninate
Catalogue No.:PA 18 1081011
CAS :
2093124-26-4
Molecular Formula : C27H35N6O8P
Molecular Weight : 602.58


2-Ethylbutyl ((R)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)-L-alaninate
2-Ethylbutyl ((R)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)-L-alaninate
Catalogue No.:PA 18 1081012
CAS :
1911578-75-0
Molecular Formula : C27H35N6O8P
Molecular Weight : 602.58

![((S)-(((2R,3S,4R,5R)-5-(4-Aminopyrrolo[2,1-f][1,2, PA 18 1081014](https://www.pharmaffiliates.com/pimages/PA181081014.jpg)
((S)-(((2R,3S,4R,5R)-5-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)-L-alanine
((S)-(((2R,3S,4R,5R)-5-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)-L-alanine
Catalogue No.:PA 18 1081014
CAS :
NA
Molecular Formula : C21H23N6O8P
Molecular Weight : 518.42

![((2R,3S,4R,5R)-5-(4-Aminopyrrolo[2,1-f][1,2,4]tria PA 18 1081016](https://www.pharmaffiliates.com/pimages/PA181081016.jpg)
((2R,3S,4R,5R)-5-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methyl phenyl hydrogen (R)-phosphate
((2R,3S,4R,5R)-5-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methyl phenyl hydrogen (R)-phosphate
Catalogue No.:PA 18 1081016
CAS :
NA
Molecular Formula : C18H18N5O7P
Molecular Weight : 447.34

![(3aR,4R,6R,6aR)-4-(4-Aminopyrrolo[2,1-f][1,2,4]tri PA 18 1081021](https://www.pharmaffiliates.com/pimages/PA181081021.jpg)
(3aR,4R,6R,6aR)-4-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-6-(hydroxymethyl)-2,2-dimethyltetrahydrofuro[3,4-d][1,3]dioxole-4-carbonitrile
(3aR,4R,6R,6aR)-4-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-6-(hydroxymethyl)-2,2-dimethyltetrahydrofuro[3,4-d][1,3]dioxole-4-carbonitrile
Catalogue No.:PA 18 1081021
CAS :
1191237-80-5
Molecular Formula : C15H17N5O4
Molecular Weight : 331.33

![(2R,3R,4S,5R)-2-(4-Aminopyrrolo[2,1-f][1,2,4]triaz PA 18 1081022](https://www.pharmaffiliates.com/pimages/PA181081022.jpg)
(2R,3R,4S,5R)-2-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-3,4-dihydroxy-5-(hydroxymethyl)tetrahydrofuran-2-carbonitrile
(2R,3R,4S,5R)-2-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-3,4-dihydroxy-5-(hydroxymethyl)tetrahydrofuran-2-carbonitrile
Catalogue No.:PA 18 1081022
CAS :
1191237-69-0
Molecular Formula : C12H13N5O4
Molecular Weight : 291.27

![(2R,3R,4R,5R)-2-(4-Aminopyrrolo[2,1-f][1,2,4]triaz PA 18 1081023](https://www.pharmaffiliates.com/pimages/PA181081023.jpg)
(2R,3R,4R,5R)-2-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-3,4-bis(benzyloxy)-5-((benzyloxy)methyl)tetrahydrofuran-2-carbonitrile
(2R,3R,4R,5R)-2-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-3,4-bis(benzyloxy)-5-((benzyloxy)methyl)tetrahydrofuran-2-carbonitrile
Catalogue No.:PA 18 1081023
CAS :
1355357-49-1
Molecular Formula : C33H31N5O4
Molecular Weight : 561.64

![(2S,3R,4R,5R)-2-(4-Aminopyrrolo[2,1-f][1,2,4]triaz PA 18 1081024](https://www.pharmaffiliates.com/pimages/PA181081024.jpg)
(2S,3R,4R,5R)-2-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-3,4-bis(benzyloxy)-5-((benzyloxy)methyl)tetrahydrofuran-2-ol
(2S,3R,4R,5R)-2-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-3,4-bis(benzyloxy)-5-((benzyloxy)methyl)tetrahydrofuran-2-ol
Catalogue No.:PA 18 1081024
CAS :
1911578-73-8
Molecular Formula : C32H32N4O5
Molecular Weight : 552.63

![(((2R,3S,4R,5R)-5-(4-Aminopyrrolo[2,1-f][1,2,4]tri PA 18 1081025](https://www.pharmaffiliates.com/pimages/PA181081025.jpg)
(((2R,3S,4R,5R)-5-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methyl)triphosphoric Acid
(((2R,3S,4R,5R)-5-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methyl)triphosphoric Acid
Catalogue No.:PA 18 1081025
CAS :
1355149-45-9
Molecular Formula : C12H16N5O13P3
Molecular Weight : 531.2

![(2S,3R,4R,5R)-2-(4-Aminopyrrolo[2,1-f][1,2,4]triaz PA 18 1081028](https://www.pharmaffiliates.com/pimages/PA181081028.jpg)
(2S,3R,4R,5R)-2-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-3,4-bis(benzyloxy)-5-((benzyloxy)methyl)tetrahydrofuran-2-carbonitrile
(2S,3R,4R,5R)-2-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-3,4-bis(benzyloxy)-5-((benzyloxy)methyl)tetrahydrofuran-2-carbonitrile
Catalogue No.:PA 18 1081028
CAS :
1369903-46-7
Molecular Formula : C33H31N5O4
Molecular Weight : 561.64


Butyl ((S)-(((2R,3S,4R,5S)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)-L-alaninate
Butyl ((S)-(((2R,3S,4R,5S)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)-L-alaninate
Catalogue No.:PA 18 1081030
CAS :
NA
Molecular Formula : C25H31N6O8P
Molecular Weight : 574.53


Butyl (2S)-2-{[(S)-{[(2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl]methoxy}(phenoxy)phosphoryl]amino}propanoate
Butyl (2S)-2-{[(S)-{[(2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl]methoxy}(phenoxy)phosphoryl]amino}propanoate
Catalogue No.:PA 18 1081031
CAS :
2601424-37-5
Molecular Formula : C25H31N6O8P
Molecular Weight : 574.53


2-Ethylbutyl ((S)-(((3aR,4R,6R,6aR)-6-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-6-cyano-2,2-dimethyltetrahydrofuro[3,4-d][1,3]dioxol-4-yl)methoxy)(phenoxy)phosphoryl)-L-alaninate
2-Ethylbutyl ((S)-(((3aR,4R,6R,6aR)-6-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-6-cyano-2,2-dimethyltetrahydrofuro[3,4-d][1,3]dioxol-4-yl)methoxy)(phenoxy)phosphoryl)-L-alaninate
Catalogue No.:PA 18 1081032
CAS :
1884576-18-4
Molecular Formula : C30H39N6O8P
Molecular Weight : 642.65

![((2R,3S,4R,5R)-5-(4-Aminopyrrolo[2,1-f][1,2,4]tria PA 18 1081033](https://www.pharmaffiliates.com/pimages/PA181081033.jpg)
((2R,3S,4R,5R)-5-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methyl phenyl hydrogen phosphate
((2R,3S,4R,5R)-5-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methyl phenyl hydrogen phosphate
Catalogue No.:PA 18 1081033
CAS :
2607871-93-0
Molecular Formula : C18H18N5O7P
Molecular Weight : 447.34


2-Ethylbutyl ((((3aR,4R,6S,6aR)-6-(4-aminopyrrolo[1,2-a][1,3,5]triazin-7-yl)-6-cyano-2,2-dimethyltetrahydrofuro[3,4-d][1,3]dioxol-4-yl)methoxy)(phenoxy)phosphoryl)-L-alaninate
2-Ethylbutyl ((((3aR,4R,6S,6aR)-6-(4-aminopyrrolo[1,2-a][1,3,5]triazin-7-yl)-6-cyano-2,2-dimethyltetrahydrofuro[3,4-d][1,3]dioxol-4-yl)methoxy)(phenoxy)phosphoryl)-L-alaninate
Catalogue No.:PA 18 1081038
CAS :
NA
Molecular Formula : C30H39N6O8P
Molecular Weight : 642.65

![(3R,4R,5R)-2-(4-Aminopyrrolo[2,1-f][1,2,4]triazin- PA 18 1081044](https://www.pharmaffiliates.com/pimages/PA181081044.jpg)
(3R,4R,5R)-2-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-3,4-bis(benzyloxy)-5-((benzyloxy)methyl)tetrahydrofuran-2-carbonitrile
(3R,4R,5R)-2-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-3,4-bis(benzyloxy)-5-((benzyloxy)methyl)tetrahydrofuran-2-carbonitrile
Catalogue No.:PA 18 1081044
CAS :
1191237-68-9
Molecular Formula : C33H31N5O4
Molecular Weight : 561.64

![((((2R,3S,4R,5R)-5-(4-Aminopyrrolo[2,1-f][1,2,4]tr PA 18 1081048](https://www.pharmaffiliates.com/pimages/PA181081048.jpg)
((((2R,3S,4R,5R)-5-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(hydroxy)phosphoryl)-L-alanine
((((2R,3S,4R,5R)-5-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(hydroxy)phosphoryl)-L-alanine
Catalogue No.:PA 18 1081048
CAS :
1911579-04-8
Molecular Formula : C15H19N6O8P
Molecular Weight : 442.32


Butyl ((R)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)-L-alaninate
Butyl ((R)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)-L-alaninate
Catalogue No.:PA 18 1081049
CAS :
NA
Molecular Formula : C25H31N6O8P
Molecular Weight : 574.53


2-Ethylbutyl ((R)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)-D-alaninate
2-Ethylbutyl ((R)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)-D-alaninate
Catalogue No.:PA 18 1081050
CAS :
2096990-00-8
Molecular Formula : C27H35N6O8P
Molecular Weight : 602.58