Pharmaceutical Intermediate 1-Bromo-5-Fluoropentane CAS 407-97-6 Low Dihalide

In an API route the impurity that hurts is the dihalide. It alkylates twice, dragging two substrate molecules into a dimer that is hard to separate and usually shows up late, as an unknown peak in the drug substance. Holding 1,5-dibromopentane type material at 0.1% or below is the whole reason this grade exists.

We also write the rest of the profile the way a process chemist reads it: difluoro, alcohol, water, and a chromatogram with the peaks labelled. Nothing exotic, just enough for a vendor qualification file and a sensible conversation at project kick-off instead of three months in.

• Dihalide under 0.1%: no dimer from double alkylation, which is the usual reason a late batch fails
• Assay 98.5% minimum: charge calculations do not need a purity correction
• Free alcohol under 0.3%: no competing leaving group and no extra base demand
• Water 0.05% maximum: usable in anhydrous steps without a separate drying operation
• Labelled chromatogram with the COA: impurity picture visible before the drum is opened
• Manufacturing description available: supports a vendor audit and a regulatory filing

Installing a 5-fluoropentyl chain on a heterocycle or an amine in an API route, particularly where the fluorine is there to block metabolism at that position and the chain has to be clean at both ends.

Run the alkylation in a polar aprotic solvent with a mild base, and add the halide slowly to avoid a local excess that favours double alkylation. A short silica plug removes residual alcohol if the specification is tight.

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 and dark, away from ignition sources. Air freight for 1 to 5 kg, sea freight for drums.

COA with assay, dihalide, difluoro and alcohol levels, water, residue, colour, density and the labelled chromatogram. A 100 g retention sample is held for 18 months.

Manufacturing description and impurity summary can be supplied for your vendor qualification file. Audits at our plant can be arranged with reasonable notice.