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Chemical product profile

HONGKUN / PRODUCT DIRECTORY

(2R,4R)-Ketoconazole-related tosylate (Impurity E reference identity) | CAS 134071-44-6

A stereochemically defined dichlorophenyl–imidazole dioxolane tosylate associated with ketoconazole impurity and metabolite chemistry; the (2R,4R) reference identity must be distinguished from a nonspecific cis designation when qualifying material.

CAS134071-44-6
Molecular formulaC21H20Cl2N2O5S
Molecular weight483.36 g/mol

Product overview

The (2R,4R) dioxolane combines a dichlorophenyl group, imidazole and a covalent tosylate ester. This ketoconazole-related structure is relevant to impurity E and metabolite chemistry. Specify absolute configuration alongside the cis relationship, and match stereoisomer testing and content assignment to the intended synthetic or analytical use.

Chemical identity

Chemical name
(2R,4R)-Ketoconazole-related tosylate (Impurity E reference identity)
CAS number
134071-44-6
Molecular formula
C21H20Cl2N2O5S
Molecular weight
483.36 g/mol

Application context

This (2R,4R) tosylate is relevant to ketoconazole impurity E analysis and has been used in published ketoconazole-metabolite synthesis. Analytical enquiries should specify the target stereoisomer, assigned content and chromatographic separation from its enantiomer. Synthetic enquiries should identify the covalent tosylate substrate and the isomer profile required for the planned conversion.

Chemistry and synthetic role

The tosyl group is attached through an oxygen–sulfur ester linkage; it is not a tosylate counterion. The dioxolane contains defined stereochemistry, and the imidazole/dichlorophenyl combination is a useful identity distinction from other azole-related building blocks.

Quality review

Specify absolute configuration

Specify the (2R,4R) absolute configuration alongside the cis relationship, and agree a method and acceptance limits for the enantiomeric profile.

Distinguish tosylate ester from salt

Confirm the covalent ester and evaluate the corresponding alcohol or free sulfonic-acid-related components where relevant.

Define quantitative reference requirements

For impurity quantification, request assigned content and characterization that establish suitability for the selected analytical method.

Check the antifungal route family

Identity tests should distinguish the dichlorophenyl–imidazole dioxolane from posaconazole-related difluorophenyl–triazole intermediates.

Preparing a specification

State CAS 134071-44-6 together with the (2R,4R) structure and intended analytical or synthetic use. Agree enantiomeric and diastereomeric criteria, chromatographic specificity and, for a reference material, the required content assignment.

Packaging and storage

Agree packaging, net weight and transport arrangements for the selected grade, quantity and destination. Confirm storage and handling conditions using the current SDS for the proposed material.

Documentation

Request structural and stereochemical identification, the proposed related-substance method and batch COA/SDS. For analytical-reference use, confirm whether assigned-content data and the associated traceability documentation are available from the selected source.

Procurement questions

How should cis and (2R,4R) be specified?

Cis states the relative relationship; include (2R,4R) to specify the required absolute configuration and agree the enantiomeric profile.

Which ring structure identifies this intermediate?

The stereodefined dioxolane carrying dichlorophenyl, imidazole and a covalent tosylate ester.

Is the tosylate a salt?

No. Here it is a covalent sulfonate ester.

What should a quantitative reference enquiry include?

The required stereoisomer, assigned-content basis and characterization needed for the method, with availability of supporting batch documents confirmed.

Technical sources
  1. PubChem direct CAS resolution: 134071-44-6NCBI / PubChem
  2. Ketoconazole EP Impurity E — MM0145.06LGC Standards
  3. CN119019377A: A method for preparing ketoconazole metabolitesPatent publication / Google Patents
  4. US11760750B1 — Process for preparing levoketoconazolePatent publication / Google Patents