Skip to product details

Chemical product profile

HONGKUN / PRODUCT DIRECTORY

Ertapenem side-chain intermediate (PNZ-protected) | CAS 202467-69-4

A (2S,4S) mercaptopyrrolidine side-chain partner in published ertapenem synthesis, combining a reactive thiol, a carboxyphenyl amide and PNZ protection on the ring nitrogen for subsequent carbapenem assembly.

CAS202467-69-4
Molecular formulaC20H19N3O7S

Product overview

The thiol and protected pyrrolidine nitrogen give this ertapenem side-chain intermediate a distinct qualification profile. CAS 202467-69-4 refers to the (2S,4S) compound with a free benzoic acid group, an amide linkage and a para-nitrobenzyloxycarbonyl protecting group, often abbreviated PNZ. It does not contain the carbapenem nucleus itself. In published route chemistry, these features allow the side-chain fragment to be introduced through sulfur while its nitrogen remains protected. Procurement should therefore specify more than the shorthand 'ertapenem side chain': the free-thiol state, acid form, protecting group and both stereocentres define the required substance. A proposed batch needs assessment against the buyer's chosen coupling stage and related-substance method before its suitability can be established.

Chemical identity

Chemical name
3-((2S,4S)-4-Mercapto-1-(((4-nitrobenzyl)oxy)carbonyl)pyrrolidine-2-carboxamido)benzoic acid
CAS number
202467-69-4
Molecular formula
C20H19N3O7S

Application context

This PNZ-protected side chain is used in published ertapenem assembly with an activated carbapenem nucleus. Its free thiol forms the sulfur connection and supplies the 2S,4S pyrrolidine with its carboxyphenyl amide. The ring nitrogen remains protected and the benzoic acid is unesterified. Match these features to the coupling step and define controls for stereochemistry, free-thiol content and related protected or oxidized components.

Chemistry and synthetic role

Two stereocentres define the pyrrolidine fragment. The free thiol provides the sulfur coupling functionality; PNZ protects the ring nitrogen, while the benzoic acid remains unesterified. Each feature differentiates this CAS from related protected or salt forms.

Quality review

Verify the 2S,4S fragment

Agree stereochemical identification and controls for relevant pyrrolidine diastereomers.

Review free thiol versus oxidation products

Agree a method that distinguishes the free thiol from relevant disulfide-related species, selecting reportable components according to the actual route and batch profile.

Match protection and acid form

Confirm N-PNZ protection and free benzoic acid rather than a deprotected, esterified or salt analogue.

Preparing a specification

Include the full (2S,4S) structure, free thiol, N-PNZ group and free-acid form in the RFQ. Define assay, stereochemical criteria and a route-specific related-substance panel; request the method used for thiol-related impurities.

Packaging and storage

Confirm packaging format, net weight and transport arrangements for the selected grade, quantity and destination. Agree storage and handling conditions using the actual supplied material’s SDS and label.

Documentation

Request COA, SDS, proposed specification and structural confirmation. Confirm whether stereochemical chromatograms and a method addressing thiol/disulfide-related species are available from the selected manufacturer.

Procurement questions

Which functional group is protected by PNZ?

PNZ protects the pyrrolidine ring nitrogen. The thiol remains free for the sulfur-linking step, and the benzoic acid is unesterified.

Can a sodium salt replace this material?

Only after route review; this CAS identifies the free-acid form.

Why assess thiol-related impurities?

The sulfur group is the coupling functionality. Its chemical state should be established for the intended step.

Technical sources
  1. PubChem CID 15409260: properties and CAS synonymsNCBI / NLM / NIH
  2. 3-((2S,4S)-4-Mercapto… )benzoic acid,202467-69-4Ambeed
  3. EP2388261A2 — Improved process for preparation of carbapenem…European patent publication, Google Patents