Methane → HCID 131724646, compound

Participants

Reaction Conditions

Reaction Steps

To a suspension of (R,S)-7-(3-aminomethyl-4-syn-methoxyiminopyrrolidin-1-yl)-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylic acid (20.00 g, 51.4 mmol) in isopropanol (120 ml) and water (60 ml) was added methanesulfonic acid (3.300 ml, 50.9 mmol) at 38-40° C. The resultant dark brown solution was stirred for 15 min after which time charcoal (6.00 g of Darco G-60) was added. The suspension was stirred at 38-40° C. for 4 h then filtered. The filtrate was allows to cool to 30° C. and seed crystals of (R,S)-7-(3-aminomethyl-4-syn-methoxyiminopyrrolidin-1-yl)-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylic acid methanesulfonate sesquihydrate (15 mg) added. A precipitate began to form within 15 min. The suspension was allowed to cool to 20-23° C. over 90 min and was stirred for 36 h. The slurry was cooled to 0-5° C. for 60 min then filtered and washed with isopropanol (50 ml and 44 ml). The product was sucked dry for 30 min and then further dried at 50-55° C. under vacuum. The dried product was exposed to the atmosphere for 18 h to give the methanesulfonate sesquihydrate 21.29 g (85%), purity>99.5% by HPLC.

Provenance & Evidence