US 12,168,656 B1
Process for making (e)-7-(4-((5-((2-chlorobenzylidene)amino)-2-thioxo-1,3,4-thiadiazol-3(2H)-yl)methyl)piperazin-1-yl)-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid
Hany Mohamed Abd El-Lateef Ahmed, Al-Ahsa (SA); Mai Mostafa Khalaf Ali, Al-Ahsa (SA); Antar Ahmed Abdelhamid Ahmed, Sohag (EG); and Amer A. Amer, Sohag (EG)
Assigned to KING FAISAL UNIVERSITY, Al-Ahsa (SA)
Filed by KING FAISAL UNIVERSITY, Al-Ahsa (SA)
Filed on Feb. 6, 2024, as Appl. No. 18/434,620.
Application 18/434,620 is a division of application No. 18/369,782, filed on Sep. 18, 2023, granted, now 11,958,848.
Int. Cl. C07D 241/04 (2006.01); A61P 29/00 (2006.01); C07D 417/12 (2006.01)
CPC C07D 417/12 (2013.01) [A61P 29/00 (2018.01)] 8 Claims
 
1. A process for making (E)-7-(4-((5-((2-chlorobenzylidene)amino)-2-thioxo-1,3,4-thiadiazol-3(2H)-yl)methyl)piperazin-1-yl)-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid having the formula IV:

OG Complex Work Unit Chemistry
wherein the process comprises the following steps:
(1) stirring a solution of (E)-5-((2-chlorobenzylidene)amino)-1,3,4-thiadiazole-2(3H)-thione having the formula I:

OG Complex Work Unit Chemistry
and formaldehyde having the formula II:

OG Complex Work Unit Chemistry
in ethanol, to obtain a first reaction mixture;
(2) adding ciprofloxacin hydrochloride having the formula III:

OG Complex Work Unit Chemistry
and triethylamine to the first reaction mixture formed in step (1) above, to obtain a second reaction mixture;
(3) heating the second reaction mixture formed in step (2) above to reflux while stirring;
(4) cooling the reaction mixture formed in step (3) above to room temperature; and
(5) filtering the reaction mixture formed in step (4) above, to obtain a precipitate of (E)-7-(4-((5-((2-chlorobenzylidene)amino)-2-thioxo-1,3,4-thiadiazol-3(2H)-yl)methyl)piperazin-1-yl)-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid having the formula IV:

OG Complex Work Unit Chemistry