Isopropanol → Levofloxacin

Participants

Reaction Conditions

Reaction Steps

5 g (17.8 mmole) of (S)-(−)-9,10-difluoro-3-methyl-7-oxo-2,3-dihydro-7H-pyrido [1,2,3-de][1,4]benzoxazine-6-carboxylic acid was put in suspension in 2.5 mL of DMSO and 4.2 mL (37.9 mmole) of N-methyl piperazine. The reaction mixture was heated to 120° C. and the suspension became soluble. After 2.5 h the reaction was completed. The mixture was then cooled to 70° C. and isopropanol (25 mL) was then added at this temperature. The reaction mixture was slurried for 1 h at ambient temperature, filtered, and dried overnight to obtain 5.86 g (91.3%) of levofloxacin.

Provenance & Evidence