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Impurities & Reference Standards

API Impurities

Source 1942 api impurities for research, QC and production, documented with COA and SDS.

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Reference Standard

4-Chlorobutyraldehyde diethyl acetal chemical structure

4-Chlorobutyraldehyde diethyl acetal

CAS: 6139-83-9
Formula: C₈H₁₇ClO₂
MW: 180.67 g/mol

VQ-039002

Reference Standard

4-Chlorobutyraldehyde Dimethyl Acetal chemical structure

4-Chlorobutyraldehyde Dimethyl Acetal

CAS: 29882-07-3
Formula: C₆H₁₃ClO₂
MW: 152.62 g/mol

VQ-039058

Reference Standard

4-Chlorobutyrophenone chemical structure

4-Chlorobutyrophenone

CAS: 939-52-6
Formula: C₁₀H₁₁ClO
MW: 182.64 g/mol

VQ-037572

Reference Standard

4-Chloronicotinic acid chemical structure

4-Chloronicotinic acid

CAS: 10177-29-4
Formula: C₆H₄ClNO₂
MW: 157.55 g/mol

VQ-032765

Reference Standard

4-Chlorophenothiazine chemical structure

4-Chlorophenothiazine

CAS: 7369-69-9
Formula: C₁₂H₈ClNS
MW: 233.72 g/mol

VQ-023560

Reference Standard

4-Chlorophenyl Phenyl Sulfone chemical structure

4-Chlorophenyl Phenyl Sulfone

CAS: 80-00-2
Formula: C₁₂H₉ClO₂S
MW: 252.72 g/mol

VQ-025188

Reference Standard

4-Chlorophenyl-2-pyridinylmethanol chemical structure

4-Chlorophenyl-2-pyridinylmethanol

CAS: 27652-89-7
Formula: C₁₂H₁₀ClNO
MW: 219.66 g/mol

VQ-022006

Reference Standard

4-Chlorophenylbiguanide chemical structure

4-Chlorophenylbiguanide

CAS: 5304-59-6
Formula: C₈H₁₀ClN₅
MW: 211.65 g/mol

VQ-027648

Reference Standard

4-Chloropyridine-3-sulfonyl chloride chemical structure

4-Chloropyridine-3-sulfonyl chloride

CAS: 33263-44-4
Formula: C₅H₃Cl₂NO₂S
MW: 212.05 g/mol

VQ-041087

Reference Standard

4-Chloroquinazoline-6,7-diol chemical structure

4-Chloroquinazoline-6,7-diol

CAS: 1145671-36-8
Formula: C₈H₅ClN₂O₂
MW: 196.59 g/mol

VQ-030895

Reference Standard

4-Chlorothiophene-2-carboxylic Acid chemical structure

4-Chlorothiophene-2-carboxylic Acid

CAS: 59614-95-8
Formula: C₅H₃ClO₂S
MW: 162.59 g/mol

VQ-032426

Reference Standard

4-Chlorotrityl chloride chemical structure

4-Chlorotrityl chloride

CAS: 27023-37-6
Formula: C₁₉H₁₄Cl₂
MW: 313.2 g/mol

VQ-025068

Reference Standard

4-Cyano-4'-methylbiphenyl chemical structure

4-Cyano-4'-methylbiphenyl

CAS: 50670-50-3
Formula: C₁₄H₁₁N
MW: 193.24 g/mol

VQ-039613

Reference Standard

4-Cyanoindanone chemical structure

4-Cyanoindanone

CAS: 60899-34-5
Formula: C₁₀H₇NO
MW: 157.17 g/mol

VQ-041289

Reference Standard

4-Cyclohexylbutan-2-amine chemical structure

4-Cyclohexylbutan-2-amine

CAS: 791752-94-8
Formula: C₁₀H₂₁N
MW: 155.28 g/mol

VQ-039532

Reference Standard

4-Cyclopropyl-2-fluorobenzoic acid chemical structure

4-Cyclopropyl-2-fluorobenzoic acid

CAS: 1247927-81-6
Formula: C₁₀H₉FO₂
MW: 180.17 g/mol

VQ-033495

Reference Standard

4-Cyclopropyl-2-fluorobenzonitrile chemical structure

4-Cyclopropyl-2-fluorobenzonitrile

CAS: 1394068-31-5
Formula: C₁₀H₈FN
MW: 161.18 g/mol

VQ-033494

Reference Standard

4-Defluoro-2-fluoro Haloperidol Decanoate chemical structure

4-Defluoro-2-fluoro Haloperidol Decanoate

CAS: 1798004-21-3
Formula: C₃₁H₄₂FNO₃
MW: 495.7 g/mol

VQ-037574

Reference Standard

4-Dehydroxy-4-dimethylhydroxysilyl Entecavir chemical structure

4-Dehydroxy-4-dimethylhydroxysilyl Entecavir

CAS: 870614-82-7
Formula: C₁₄H₂₁N₅O₃Si
MW: 335.43 g/mol

VQ-022542

Reference Standard

4-Deschloro-2-chloro Sibutramine Hydrochloride chemical structure

4-Deschloro-2-chloro Sibutramine Hydrochloride

CAS: 2724727-26-6
Formula: C₁₇H₂₇Cl₂N
MW: 316.3 g/mol

VQ-033836

Reference Standard

4-Descyano 4-Bromo Citadiol chemical structure

4-Descyano 4-Bromo Citadiol

CAS: 488148-10-3
Formula: C₁₉H₂₃BrFNO₂
MW: 396.3 g/mol

VQ-045272

Reference Standard

4-Desdimethylamine 4-Oxo Omadacycline chemical structure

4-Desdimethylamine 4-Oxo Omadacycline

CAS: 885112-31-2
Formula: C₂₇H₃₃N₃O₈
MW: 527.6 g/mol

VQ-027014

Reference Standard

4-Desethylamino 4-oxobrinzolamide chemical structure

4-Desethylamino 4-oxobrinzolamide

CAS: 154127-41-0
Formula: C₁₀H₁₄N₂O₆S₃
MW: 354.4 g/mol

VQ-021886

Reference Standard

4-Desfluoro-6-fluoro Dolutegravir Impurity chemical structure

4-Desfluoro-6-fluoro Dolutegravir Impurity

CAS: 2244161-72-4
Formula: C₂₀H₁₉F₂N₃O₅
MW: 419.4 g/mol

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