Peramivir Isoxazoline Intermediate

About This Product

This intermediate is methyl (3aR,4R,6S,6aS)-4-[(tert-butoxycarbonyl)amino]-3-(pentan-3-yl)-3a,5,6,6a-tetrahydro-4H-cyclopenta[d]isoxazole-6-carboxylate, formula C18H30N2O5, molecular weight 354.4 and CAS number 229613-93-8. It is an off-white to white crystalline solid melting at 65 to 70 °C. It is sometimes listed under the name of its cyclopentene precursor, so identity should be confirmed by CAS number. Peramivir, an intravenous neuraminidase inhibitor used against influenza, is built on a cyclopentane ring carrying four contiguous substituents, and this compound is where that ring's stereochemistry is set. It is made by 1,3-dipolar cycloaddition of the nitrile oxide derived from 2-ethylbutanal oxime to the Boc-protected aminocyclopentene ester, a reaction that fuses an isoxazoline onto the ring and installs the pentan-3-yl group that the drug retains. Subsequent reductive opening of the isoxazoline unmasks the amino and hydroxyl functions from which the acetamido and guanidino groups are elaborated. Because the cycloaddition can approach either face of the ring, the unwanted diastereoisomer is the critical impurity, held here to 0.1 percent, with a specific rotation of +61° to +63° confirming the single enantiomeric series. It is used as a key intermediate in peramivir manufacture and in the synthesis of related cyclopentane neuraminidase inhibitors for antiviral research. Bio Green Chem supplies this intermediate at 98 percent minimum to specification on appearance, identification, melting point, specific rotation, water, loss on drying, residue on ignition, heavy metals, diastereoisomer and impurities, packed in fibre drums or bags. Regulatory documentation for pharmaceutical use is confirmed at enquiry.