1-Methyl-4-nitro-3-propyl-1H-pyrazole-5-carboxamide
- CAS
- 139756-01-7
- Formula
- C8H12N4O3
- MW
- 212.21 g/mol
ZX-026924
Impurity reference standards
Sildenafil impurity standards
This page brings together 36 Sildenafil related compounds that analytical teams use to identify, quantify and control impurities in the active ingredient and the finished dosage form. The range includes 6 pharmacopoeial impurities, 3 isotope-labelled standards and 5 metabolites or hydroxylated analogues.
36reference materials
6pharmacopoeial
3isotope labelled
5metabolites
Every standard comes with a certificate of analysis. Structure confirmation data, typically NMR, MS and chromatographic purity, is available on request. They are bought for system suitability, peak identification, quantitation against limits and the impurity justification sections of regulatory submissions.
By impurity type
Pharmacopoeial6EP, USP, BP or JP named impurities
Isotope labelled3Deuterated, 13C or 15N internal standards
Metabolites5Hydroxy, desmethyl and conjugated forms
Counts are based on product names. One compound can fall into more than one type.
All Sildenafil reference materials
1–36 of 36 standards
1-Methyl-4-nitro-3-propyl-1H-pyrazole-5-carboxylic acid
- CAS
- 139756-00-6
- Formula
- C8H11N3O4
- MW
- 213.19 g/mol
ZX-022768
4-[[2-Ethoxy-5-[(4-methyl-1-piperazinyl)- sulfonyl]benzoyl]amino]-1-methyl-3-propyl- 1H-pyrazole-5-carboxamide
- CAS
- 200575-15-1
- Formula
- C22H32N6O5S
- MW
- 492.6 g/mol
ZX-026926
4-Amino-1-methyl-3-propyl-1H-pyrazole-5-carboxamide Hydrochloride
- CAS
- 247584-10-7
- Formula
- C8H15ClN4O
- MW
- 218.68 g/mol
ZX-032468
5-(2-Ethoxyphenyl)-1-methyl-3-n-propyl-1,6-dihydro- 7H-pyrazolo[4,3-d]pyrimidin-7-one
- CAS
- 139756-21-1
- Formula
- C17H20N4O2
- MW
- 312.37 g/mol
ZX-022769
5-(2-Ethoxyphenyl)-2-methyl-3-propyl-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one
- CAS
- 501120-40-7
- Formula
- C17H20N4O2
- MW
- 312.37 g/mol
ZX-042498
5-(5-Carboxy-2-ethoxyphenyl)-1-methyl-3-n-propyl-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one
- CAS
- 147676-78-6
- Formula
- C18H20N4O4
- MW
- 356.4 g/mol
ZX-026927
Ethyl 4-ethoxy-3-(1-methyl-7-oxo-3-propyl-6,7-dihydro-1H-pyrazolo[4,3-d]pyrimidin-5-yl)benzenesulfonate
- CAS
- 1971915-89-5
- Formula
- C19H24N4O5S
- MW
- 420.5 g/mol
ZX-026929
Questions
Sildenafil impurities, answered
What Sildenafil reference materials are available?
The catalogue currently lists 36 compounds for Sildenafil, including 6 pharmacopoeial impurities, 3 isotope-labelled standards and 5 metabolites or hydroxylated analogues. Each product page shows the CAS number where one is assigned, the structure, formula and molecular weight.
What documents come with a Sildenafil impurity standard?
A certificate of analysis travels with every lot. On request we share the characterisation set, usually 1H-NMR, mass spectrum, HPLC purity and IR, and for some materials TGA or water content. Ask for the data before ordering if your QA team needs to review it.
Can Zemixal make a Sildenafil impurity that is not listed?
Often yes. Send the structure, name or CAS number with the quantity you need and our sourcing team checks custom synthesis options, usually from 10 mg up to gram scale, with a quoted lead time.
Are isotope-labelled Sildenafil standards available?
Yes. 3 stable-isotope labelled compounds are listed, suitable as internal standards for LC-MS bioanalysis and trace impurity quantitation.