1. A process for preparing moxifloxacin hydrochloride of formula (I): comprising the following steps: (a) forming a salt of moxifloxacin base of formula (II): with a sulfonic acid of formula (III): R-SO3H (III) wherein R represents a linear or branched alkyl C1-C12, or represents aryl, to form a compound of formula (IV) :( b) optional purification of moxifloxacin hydrochloride in the formula (I) .2 compound of formula (IV), (c) converting a compound of formula (IV). A method according to claim 1, wherein when the formula R-SO3H (III) represents naphthalenedisulfonic acid, it is used in step (a) in the molar ratio 1: 2 relative to the base moxifloxacin formula (II) .3. A method according to claim 1, wherein R is selected from C1-C4 alkyl, phenyl and tolila.4. A method according to any one of claims. 1-3, wherein step (a) is carried out in an alcohol C1-S4.5. A method according to claim 4, wherein the alcohol is a izopropanol.6. A method according to claim 1, wherein step (c) comprises the steps of: (c1) converting the compound of formula (IV) in moxifloxacin base of formula (II), (c2) forming a salt of moxifloxacin base of formula (II) with hydrochloric acid to form hydrochloride moxifloxacin formula (I) .7. A compound of formula (IV): wherein R represents a linear or branched C1-C12 alkyl, or represents aril.8. A compound according to claim 7, wherein R is selected from C1-C4 alkyl, phenyl and tolila.9. A process for preparing a compound of formula (IV): wherein R represents a linear or branched alkyl C1 -C12, or is aryl, comprising forming a salt from the base moxifloxacin formula (II): with a sulfonic acid of formula (III): R-SO3H (III ) wherein R has the same meaning as given in 1.10.1. Способ получения гидрохлорида моксифлоксацина формулы (I):включающий следующие стадии:(а) образования соли основания моксифлоксацина формулы (II):с сульфоновой кислотой формулы (III):R-SO3H(III)в которой R представляет собой линейный или разветвленный алкил С1-С12, или представляе
