Abstract: The invention provides a process for the production of a compound of formula (I): wherein P1 and P2, which may be the same or different, are amino protecting groups, which comprises protection of a compound of formula (II) in solution phase continuous operation mode. This confers advantages over batch mode operation. The process is usually conducted in reaction equipment adapted for use in continuous processing mode, for example comprising one or more static mixers or a plug flow reactor. Preferably, the plug flow reactor comprises a jacketed tubular reactor fitted inside with internal mixing elements which continually split and remix the reaction streams promoting mass and heat transfer, whereby a uniform plug flow profile with turbulent fluid flow is achieved. The invention also provides a process for production of the antibacterial compound gemifloxacin or a pharmaceutically acceptable salt and/or hydrate thereof, comprising converting a compound of formula (I).

Abstract: The invention relates to a process for the crystallisation of a chemical substance, and more particularly a substance to be used as a pharmaceutically active agent.