Pharmaceutical Intermediate 5-Bromo-1-Pentene CAS 1119-51-3 Low Dihalide Liquid

When 5-bromo-1-pentene goes into an API route, the impurity that causes trouble is not the isomer, it is the dihalide. A 1,5-dibromopentane type impurity alkylates twice, so it drags two molecules of your substrate into a dimer that is hard to separate and shows up as an unknown in the final drug substance. Holding that impurity at 0.1% or below is the whole point of this grade.

We also document the rest of the profile the way a process chemist needs it: alcohol, isomeric bromides, water, and a chromatogram with the peaks labelled. Nothing exotic, just enough for a vendor qualification file and an impurity discussion at the start of a project rather than three months in.

• Dihalide under 0.1%: no dimer impurity from double alkylation, which is the usual reason a batch fails at the end
• Assay 99.5% minimum: predictable equivalents, so the charge calculation does not need a purity correction
• Alcohol under 0.2%: no competing leaving group and no extra base demand
• Water 0.05% maximum: usable in anhydrous and moisture sensitive steps
• Labelled chromatogram with the COA: the impurity picture is visible up front, not discovered in a prequalification review
• Batch records available: manufacturing description and retention sample for a vendor audit

Used to install a pentenyl chain on heterocycles and amines in API routes, particularly where the terminal alkene is kept for a later ring closing metathesis or hydroboration step.

Run the alkylation in a polar aprotic solvent with a mild base to keep the alkene out of side reactions, and add the bromide slowly to avoid a local excess that favours double alkylation. If you need the free alcohol removed further, a short plug of silica is usually enough.

1 kg amber glass, 5 kg lined can, 25 kg plastic drum. Nitrogen padded, labelled with batch, assay, dihalide content and date, with the chromatogram reference on the label.

Store below 25 degrees C, sealed, in the dark. Flammable liquid, handle with earthing and away from ignition sources. Air freight for 1 to 5 kg, sea for drums.

COA with assay, dihalide, isomer and alcohol content, water, residue on evaporation, colour, refractive index and the labelled chromatogram. A 100 g retention sample is held for 18 months.

We can supply a manufacturing description and an impurity summary for your vendor qualification file, and support a customer audit at our plant with reasonable notice.