Chemical identity

Promethazine EP Impurity B / Isopromethazine

CAS 303-14-0 · C17H20N2S

01Identity

Identifiers and names for this exact compound. Empty fields are left unassigned.

Lazychem IDLC-26103
PubChem CID110669
NamePromethazine EP Impurity B / Isopromethazine
CAS RN303-14-0
Molecular formulaC17H20N2S
Molecular weight284.42 g/mol
IUPAC name(2RS)-N,N-Dimethyl-2-(10H-phenothiazin-10-yl)propan-1-amine
InChIKeyCGNHCKZJGQDWBG-UHFFFAOYSA-N

02Structure identifiers

2D structurePubChem CID 110669
Two-dimensional chemical structure of Promethazine EP Impurity B / Isopromethazine, CAS 303-14-0
Two-dimensional structure for the PubChem identity linked to this record. Confirm the identifiers before analytical use.

The parsed structure contains 3 rings, includes aromatic atoms, includes aliphatic carbon. These statements are calculated from the published structure string.

Defined stereocentres0
Unassigned stereocentres1
Ring count3
Secondary amines0
Tertiary amines2
N-methyl amine sites2
SMILESCC(CN(C)C)N1C2=CC=CC=C2SC3=CC=CC=C31
InChINot listed
Formula from structureC17H20N2S
Molecular weight from structure284.42 g/mol

03Stereochemistry

The published structure contains 0 defined and 1 unassigned tetrahedral stereocentre. The exact wedge and dash depiction is shown above.

Defined centres0Structure assigned
Unassigned centres1Structure unspecified
Assignment statusUnassignedExact published identity
Tetrahedral upper bound≤ 2Before symmetry reduction

Published same-connectivity configurations

1 record

These records have the same connectivity, molecular formula and protonation layer, but a different complete InChIKey stereochemical layer. Only separately structure-linked records are shown.

No additional structure-linked configuration with the same connectivity is currently present in the LazyChem dataset.

Scope: The mathematical 2^n value is only an upper bound. Symmetry and other stereogenic elements can change the number of distinct stereoisomers. A hypothetical configuration is not published as a compound record without a verified structure identity.

04Possible N-nitroso structures

Shown for structural screening only. These candidates are not confirmed impurities, formation predictions or analytical findings.

Matched amine site1 candidate
Chemical structure of Promethazine EP Impurity B / Isopromethazine with the matched amine site highlighted in amber
Amber identifies the screened atom and adjacent bonds.
Possible structure candidateUnverified identity
First calculated possible N-nitroso structure derived from Promethazine EP Impurity B / Isopromethazine, with the new N-nitroso group highlighted in amber
The new N-N=O atoms and bonds are highlighted. No CAS number or compound name is assigned by this calculation.
Candidate 1Possible N-nitroso structural candidate
Calculated formula
C16H17N3OS
Candidate SMILES
CC(CN(C)N=O)N1c2ccccc2Sc2ccccc21

Interpretation: A structural alert alone does not establish that a nitrosamine forms. Evaluate nitrite sources, amine reagents, pH, temperature, process sequence, purge and analytical evidence.

05India status for this compound

These results apply only to this exact compound name and CAS number. Confirm the current official instruments before making a regulatory decision.

NDPS / RCSNO EXACT MATCH FOUNDCAS 303-14-0 has no exact match in the reviewed published schedule.
SCOMETNO EXACT REVIEWED CAS MATCHCAS 303-14-0 has no exact match in the reviewed SCOMET list.
Review date2026-08-01Recheck the current official instruments for the material, concentration, activity and date in question.

06Names and relationships

Associated parent compound

Promethazine

View API and impurity family

Other names

  • Promethazine EP Impurity B
  • Isopromethazine
  • N,N,β-Trimethyl-10H-phenothiazine-10-ethanamine
  • Phenothiazine, 10-[2-(dimethylamino)-1-methylethyl]
  • 10-(2-Dimethylaminoisopropyl)phenothiazine
  • Isomethazine
  • Isophenergan
  • N-[2-(Dimethylamino)-1-methylethyl]phenothiazine
  • Prothiazin
  • Isopromethazine (IP)
  • N,N-Dimethyl-2-(10H-phenothiazin-10-yl)propan-1-amine
  • Promethazine Related Compound B (USP-HCl)

Related records from the same parent family

07Documented history

Dated discovery, occurrence, use and issue claims are published only when a suitable primary or government source is available.

No dated history available

No verified discovery, first report, occurrence, use or issue event is currently available for this identity.

08Sources