Sci Pharm. 2009; 77: 67–77.
Isolation and Characterization of an Impurity Obtained During the Synthesis of the Antibiotic Drug Sparfloxacin
Nirmala MUNIGELA * 1, Moses BABU J. 1, Anjaneyulu YERRAMILLI 3, Peddy VISHWESHWAR 1, Ganesh YADDANAPUDI SESHA SIVA 2, Narayana Murthy VALAVALA 2
1 Department of Analytical Research, Discovery Research, Dr. Reddy’s Laboratories, Miyapur, Hyderabad 500 049, India.
2 Process R&D, Custom pharmaceutical synthesis-II, Dr. Reddy’s Laboratories Ltd., Jeedimetla, Hyderabad, India.
3 Jawaharlal Nehru Technological University, Kukatpally, Hyderabad-500072, India.
* Corresponding author. E-mail: nirmalam@drreddys.com (N. Munigela).
Abstract
During the synthesis of Sparfloxacin, a fluoroquinolone antibiotic drug, an unknown impurity (SF5-IMP) was identified in the fifth stage of the synthetic process. The impurity has been isolated from the mother liquor of intermediate SF5. The mother liquor was concentrated to dryness added dichloromethane and stirred for 1 h and filtered to generate SF5-IMP and the molecular structure was elucidated as 7-amino-1-cyclopropyl-5,6,8-trifluoro-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid by 19F NMR and single crystal X-ray diffraction studies. The structural features of SF5-IMP and SF5 have been discussed here.
Keywords
Sparfloxacin • 1H NMR • 19F NMR • Single crystal X-ray diffraction
Received December 31st, 2008 | Accepted February 4th, 2009 | Published Online February 5th, 2009
