Systematic Name: 9,10-Difluoro-3-methyl-7-oxo-2,3-dihydro-7H-[1,4]oxazino[2,3,4-ij]quinoline-6-carboxylic acid     
Synonyms of (±)-9,10-difluoro-3-methyl-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylic acid (CAS NO.82419-35-0): Oxygen-fluorine acid ; 9,10-difluoro-2,3-dihydro-3-methyl-7-oxo-7h-pyrido[1,2,3-de]-1,4-benzoxazine-6-carboxyllic acid
CAS NO: 82419-35-0
Molecular Formula: C₁₃H₉F₂NO₄
Molecular Weight: 281.21
Molecular Structure:
H bond acceptors:  5 
H bond donors:  1 
Freely Rotating Bonds:  1 
Polar Surface Area:  55.84 Å² 
ndex of Refraction:  1.635 
Molar Refractivity:  62.34 cm³ 
Molar Volume:  173.9 cm³ 
Surface Tension:  64 dyne/cm 
Density:  1.61 g/cm³ 
Flash Point:  231.5 °C 
Melting Point: 320-322 °C(lit.) 
Enthalpy of Vaporization:  75.83 kJ/mol 
Boiling Point:  459.2 °C at 760 mmHg 
Vapour Pressure:  3.14E-09 mmHg at 25°C
Melting Point: 320-322 °C(lit.) 
Appearance: Grey-Yellow Powder.
Product Categories: OFLOXACIN INTERMIDATE;Various Intermediates;Intermediates;Intermediates & Fine Chemicals;Pharmaceuticals;Benzoxazines;Building Blocks;Heterocyclic Building Blocks  
InChI: InChI=1/C13H9F2NO4/c1-5-4-20-12-9(15)8(14)2-6-10(12)16(5)3-7(11(6)17)13(18)19/h2-3,5H,4H2,1H3,(H,18,19)
InChIKey: NVKWWNNJFKZNJO-UHFFFAOYAE 
Std. InChI: InChI=1S/C13H9F2NO4/c1-5-4-20-12-9(15)8(14)2-6-10(12)16(5)3-7(11(6)17)13(18)19/h2-3,5H,4H2,1H3,(H,18,19)
Std. InChIKey: NVKWWNNJFKZNJO-UHFFFAOYSA-N

 (±)-9,10-difluoro-3-methyl-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylic acid (CAS NO.82419-35-0) is used as ofloxacin intermediate.

Hazard Codes: Xi
Risk Statements: 36/37/38
R36/37/38: (±)-9,10-difluoro-3-methyl-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylic acid (CAS NO.82419-35-0) is irritating to eyes, respiratory system and skin.
Safety Statements: 26-36
S26: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. 
S36: Wear suitable protective clothing.
WGK Germany: 3