Sildenafil Impurity 38 CAS 319491-68-4

Purity 97%+In StockPharmacopoeial Impurity Standards
CAS No.319491-68-4
Molecular FormulaC18H23N5O4S
Molecular Weight405.47 g/mol
CategoryPharmacopoeial Impurity Standards / EP Impurities
AvailabilityIn Stock

Chemical Structure

Sildenafil Impurity 38 CAS 319491-68-4 chemical structure

Description

Compared with other compounds in its class, the molecular weight of 405.47 g/mol gives Sildenafil Impurity 38 distinctive chromatographic separation conditions and mass-spectrometry parameter settings.

CATO supplies Sildenafil Impurity 38 (CAS 319491-68-4), a pharmacopoeial impurity reference standard (molecular formula C18H23N5O4S, MW 405.47 g/mol) used for the identification and quantification of trace impurities in APIs.

The molecular framework of Sildenafil Impurity 38 (C18H23N5O4S) is characterized by a flavonoid core, an amide group, a sulfone group, a hydroxyl group, an ether linkage. In reversed-phase chromatography, its retention is governed primarily by the protonation state of its nitrogen-containing groups, which provides a practical basis for HPLC-UV/DAD or LC-MS method development. Nitrogen-containing functional groups confer excellent ionization efficiency in positive-ion electrospray (ESI) mode, making the compound well suited to LC-MS/MS analysis.

Recommended for quantitative analysis by HPLC, GC, LC-MS/MS, or GC-MS as an external calibration standard; it can also be used for spiked-recovery experiments, LOD/LOQ determination, and LC-MS/MS multiple-reaction-monitoring (MRM) calibration.

The assigned purity is verified by mass-balance and quantitative NMR (qNMR) approaches, with the expanded uncertainty reported at a 95% confidence level (k=2). Batch homogeneity and stability are independently assessed for every lot.

Physical & Chemical Properties

Molecular FormulaC18H23N5O4S
Molecular Weight405.47 g/mol
Purity97%+
StorageStore in a cool place (≤25°C), protect from light, keep sealed and dry
Solubility (reference)Soluble in DMSO, DMF, methanol
StabilityMay oxidize slowly on prolonged air exposure; Light-sensitive; avoid direct strong light; Hygroscopic; reseal immediately after opening
Degree of Unsaturation (DBE)10.0
UV AbsorptionUV-absorbing
Structural FeaturesAromatic ring present
CAS Registry Year (est.)2025
Nitrogen Atoms5
Sulfur Atoms1

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