Quinolone carboxylic acids, derivatives thereof, and methods of making and using same
A process of preparing a quinolone carboxylic acid or its derivatives having Formula I, Ia, or IV, as shown herein, comprises using a starting quinolone that already has one or more desired substituents at one or more particular positions on the quinolone ring and preserving the orientation of such substituents throughout the synthesis. The present process comprises fewer steps than prior-art processes. The present process also can include a simple separation of a desired enantiomer of the quinolone carboxylic acid or its derivatives from the enantiomeric mixture. Pharmaceutical compositions comprising fluoroquinolones prepared by the present process can be used effectively against a variety of microbial pathogens.
1. A process of preparing a fluoroquinolone enantiomer having Formula IV or salts thereof, the method comprising:
(a) contacting a first compound having Formula II with a third compound having Formula V to produce a fourth compound having Formula VI, wherein the fluoroquinolone having Formula IV, the first compound, the third compound, and the fourth compound are represented by
wherein R 1 is selected from the group consisting of hydrogen, unsubstituted lower alkyl groups, substituted lower alkyl groups, cycloalkyl groups, unsubstituted C 5 -C 24 aryl groups, substituted C 5 -C 24 aryl groups, unsubstituted C 5 -C 24 heteroaryl groups, substituted C 5 -C 24 heteroaryl groups, and groups that can be hydrolyzed in living bodies; R 3 is selected from the group consisting of hydrogen, unsubstituted lower alkyl groups, substituted lower alkyl groups, cycloalkyl groups, unsubstituted lower alkoxy groups, substituted lower alkoxy groups, unsubstituted C 5 -C 24 aryl groups, substituted C 5 -C 24 aryl groups, unsubstituted C 5 -C 24 heteroaryl groups, substituted C 5 -C 24 heteroaryl groups, unsubstituted C 5 -C 24 aryloxy groups, substituted C 5 -C 24 aryloxy groups, unsubstituted C 5 -C 24 heteroaryloxy groups, substituted C 5 -C 24 heteroaryloxy groups, and groups that can be hydrolyzed in living bodies; X is selected from the group consisting of halogen atoms; Y is CH 2 ; Z is selected from the group consisting of oxygen and two hydrogen atoms; and R 5 comprises a protected amino group having a formula or —NR 6 , wherein R 6 comprises a protecting group that is capable of leaving the protected amino group —NR 6 ; and
(b) contacting the fourth compound with a sufficient amount of a catalyst and at a condition sufficient to effect a cleavage of the protecting group R 6 from the —NR 6 group, to produce a fluoroquinolone having Formula IV;
wherein the orientation of R 2 is preserved throughout the process.
2. The process of claim 1 , wherein R 1 is selected from the group consisting of hydrogen, C 1 -C 5 substituted and unsubstituted alkyl groups, C 3 -C 10 cycloalkyl groups, C 6 -C 14 substituted and unsubstituted aryl groups, C 6 -C 14 substituted and unsubstituted heteroaryl groups, and groups that can be hydrolyzed in living bodies; R 3 is selected from the group consisting of hydrogen, C 1 -C 5 substituted and unsubstituted alkyl groups, C 3 -C 10 cycloalkyl groups, C 1 -C 5 substituted and unsubstituted alkoxy groups, C 5 -C 14 substituted and unsubstituted aryl groups, C 5 -C 14 substituted and unsubstituted heteroaryl groups, and C 5 -C 14 substituted and unsubstituted aryloxy groups; R 6 is selected from the group consisting of nitrophenylalkylidene, t-Boc, and Fmoc; and X is selected from the group consisting of Cl, F, and Br.
3. The process of claim 1 , wherein R 1 is selected from the group consisting of hydrogen, C 1 -C 5 substituted and unsubstituted alkyl groups and groups that can be hydrolyzed in living bodies; R 3 is selected from the group consisting of C 3 -C 10 cycloalkyl groups; R 6 comprises a nitrophenylalkylidene group; X is selected from the group consisting of Cl and F; Y comprises CH 2 ; and Z comprises two hydrogen atoms.
4. The process of claim 1 , wherein the catalyst is selected from the group consisting of acids and bases.
5. The process of claim 3 , wherein the step of contacting is carried out at a temperature in a range from about room temperature to about 100° C.
6. The process of claim 3 , wherein the catalyst is hydrochloric acid.
7. The process of claim 1 , wherein the process further comprises recovering the enantiomer is carried out by recrystallization.
8. A process for preparing a fluoroquinolone carboxylic acid enantiomer having Formula Ia or salts thereof, the process comprising:
(a) contacting a compound having Formula IIa with a compound having Formula VIIa at a temperature in the range from about room temperature to about 100° C. for a time from about 10 minutes to about 7 days, to produce a compound having Formula VIa, wherein the fluoroquinolone having Formula Ia and the compounds having Formulae IIa, VIa, and VIIa are represent by
(b) contacting the compound having Formula VIa with an amount of HCl equal to about 0.1 to about 5 moles per mole of the compound having Formula VIIa at a temperature in the range from about room temperature to about 100° C., in a presence of methanol to produce the fluoroquinolone carboxylic acid having Formula Ia; and
(c) recovering the fluoroquinolone carboxylic acid enantiomer having Formula Ia;
wherein the orientation of the amino group is presented throughout the process.
9. The process of claim 8 , wherein the step of recovering the fluoroquinolone carboxylic acid enantiomer is carried out by recrystallization.