An efficient synthesis of florfenicol

A novel no‐carrier‐added submicromolar scale radiosynthesis of [S‐methyl‐14C]‐florfenicol

“…In the literature, several approaches for the synthesis of florfenicol have been reported . But none of the reported procedures could be adopted as such because our requirement was for the [ S ‐methyl‐ 14 C]‐florfenicol.…”

“…It is found to be active against bovine respiratory disease associated with Mannheimia haemolytica , Pasteurella multocida , Histophilus sumni , and Mycoplasma bovis in beef and non‐lactating dairy cattle. Florfenicol is of interest as a veterinary product for use against diseases such as bovine mastitis and bovine shipping fever and for use in aqua culture . Florfenicol is marketed as Nuflor Gold injection, Aquaflor® and Resflor® (Merck and Co., Inc., USA).…”

“…Florfenicol is of interest as a veterinary product for use against diseases such as bovine mastitis and bovine shipping fever and for use in aqua culture. 4 Florfenicol is marketed as Nuflor Gold injection, Aquaflor W and Resflor W (Merck and Co., Inc., USA). [S-methyl-14 C]-Florfenicol is used as a radiotracer for ADME, PK and ecotoxic studies.…”

Enantioselective addition of methyllithium to a prochiral imine—the substrate in the Pomeranz–Fritsch–Bobbitt synthesis of tetrahydroisoquinoline derivatives mediated by chiral monooxazolines

“…Enantiomerically pure oxazoline ligands 14-24, listed in Table 1, have been prepared by the reaction of (+)-thiomicamine 6 with the appropriate nitrile according to the known procedure, 19 via the 4-hydroxymethyl precursors 7-11 or esters 12, 13. Oxazoline 9 with the methyl substituent at C-2 has been prepared by the orthoester method.…”

“…The addition product, amine 3, which is a key substrate in the enantioselective Pomeranz-Fritsch-Bobbitt synthesis of tetrahydroisoquinoline derivatives, has been obtained in high yield (up to 92%) and with enantiomeric excess reaching 76%, when ligands 16 or 28, with methyl substituents, were applied to control this process. 19 General procedure. To a suspension of (1S,2S)-(+)-thiomicamine 6 (4.26 g, 20 mmol) and potassium carbonate (0.43 g) in a mixture of ethylene glycol (6.4 mL) and glycerol (3.5 mL) was added excess nitrile (30-50 mmol).…”