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Chemical product profile

HONGKUN / PRODUCT DIRECTORY

1-Bromo-2-butyne | CAS 3355-28-0

A four-carbon alkynylating building block that introduces the but-2-yn-1-yl group, including the N7 side chain in published linagliptin intermediate chemistry.

CAS3355-28-0
Molecular formulaC4H5Br
Molecular weight132.99 g/mol

Product overview

The bromomethyl end of 1-bromo-2-butyne provides a substitution site beside an internal alkyne. Its four-carbon chain distinguishes it from propargyl bromide, which contains a terminal alkyne and one fewer carbon. This distinction is critical when a route requires a specific alkynyl side chain. In medicinal-chemistry intermediates, incorporation of the correct fragment depends on reagent identity as well as chemical assay. A purchase specification should identify the neat or solution form, define the assay basis and address related brominated compounds that could produce alternative alkylated products.

Chemical identity

Chemical name
1-Bromo-2-butyne
CAS number
3355-28-0
Molecular formula
C4H5Br
Molecular weight
132.99 g/mol

Application context

Published linagliptin routes use 1-bromo-2-butyne to introduce a but-2-yn-1-yl group onto a xanthine intermediate. This step establishes the unsaturated N7 side chain before further elaboration of the heterocycle. The material is therefore a side-chain reagent rather than the xanthine nucleus or the final active ingredient. Route qualification should consider how structurally related alkylating impurities might be transferred into downstream intermediates. A resolved chromatographic profile and clear reagent-content calculation provide more useful information than bromine content alone.

Chemistry and synthetic role

The structure BrCH2–C≡C–CH3 combines a primary bromide with an internal carbon–carbon triple bond.

Quality review

Distinguish the C4 alkynyl fragment

Confirm connectivity by an appropriate identity test; propargyl bromide is a different reagent.

Resolve related bromides

Review organic impurities capable of introducing alternative side chains.

Define reagent concentration

Specify neat material or solution, solvent identity and assay basis.

Preparing a specification

Include CAS, but-2-yn-1-yl identity, reagent assay, solvent or neat form, water criteria and limits for reactive related bromides.

Packaging and storage

Packaging and net weight are agreed for the selected grade, order quantity and destination. Check the actual supplier SDS and label for storage and transport requirements.

Documentation

Request a batch COA, SDS and the analytical methods for the acceptance criteria below. Confirm which supporting chromatograms and identity data are available from the selected manufacturer.

Procurement questions

Can propargyl bromide replace this material?

It introduces a different carbon chain and terminal alkyne, so it is not an identity-equivalent substitute.

Why request a chromatographic impurity profile?

Reactive bromide impurities may carry through as different alkylated intermediates.

Does a GC area percentage establish the dose?

Not by itself if solvent, water or response factors are not accounted for.

Technical sources
  1. PubChem CID 2756862NCBI / PubChem
  2. 1-Bromo-2-butyneTCI
  3. Process for the preparation of linagliptinPatent publication