title: Semi-continuous multi-step synthesis of lamivudine.
abstract: We report the first continuous flow synthesis of lamivudine, an antiretroviral drug used in the treatment of HIV/AIDS and hepatitis B. The key intermediate (5-acetoxy oxathiolane) was prepared by an integrated two step continuous flow process from l-menthyl glyoxalate hydrate in a single solvent, in 95% overall conversion. For the crucial glycosidation reaction, using pyridinium triflate as the novel catalyst, an improved conversion of 95% was obtained. The overall isolated yield of the desired isomer of lamivudine (40%) was improved in the flow synthesis compared to the batch process.
authors.affiliation: Nelson Mandela Metropolitan University, University Way, Port Elizabeth, 6031, South Africa. Paul.Watts@nmmu.ac.za.
authors.forename: Devender
authors.initials: D
authors.lastname: Mandala
authors.forename: Sravanthi
authors.initials: S
authors.lastname: Chada
authors.forename: Paul
authors.initials: P
authors.lastname: Watts
mesh_terms: D001894:Borohydrides / Q000737:chemistry; D060326:Chemistry Techniques, Synthetic; D006031:Glycosylation; D019259:Lamivudine / Q000138:chemical synthesis* / Q000737:chemistry*; D013876:Thiophenes / Q000737:chemistry
chemical_list: D001894:Borohydrides; D013876:Thiophenes; C013177:1,3-oxathiolane; D019259:Lamivudine; C025364:sodium borohydride