IUPAC Name: methyl 2,2-difluoro-2-fluorosulfonylacetate
CAS: 680-15-9
Molecular Formula: C₃H₃F₃O₄S
Molecular Weight: 192.11
Molecular structure:
Boiling point:  117-118 °C(lit.)
Density:  1.509 g/mL at 25 °C(lit.)
Refractive index:  n20/D 1.351(lit.)
Flash point:  118 °F
Index of Refraction: 1.37 
Molar Refractivity: 26.97 cm³ 
Molar Volume: 118.9 cm³ 
Polarizability: 10.69 10^-24cm³ 
Surface Tension: 32 dyne/cm 
Density: 1.614 g/cm³ 
Flash Point: 44.5 °C 
Enthalpy of Vaporization: 38.68 kJ/mol 
Boiling Point: 150 °C at 760 mmHg 
Vapour Pressure: 3.93 mmHg at 25°C 

 Methyl 2,2-Difluoro-2-(fluorosulfonyl)acetate (CAS NO.680-15-9) is  commonly used as a pharmaceutical intermediate.

Safety Information of Methyl 2,2-Difluoro-2-(fluorosulfonyl)acetate (CAS NO.680-15-9):
Hazard Codes:  C,Xi
Risk Statements:  10-34 
R10:Flammable. 
R34:Causes burns.
Safety Statements:  26-36/37/39-45-16 
S26: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. 
S36/37/39:Wear suitable protective clothing, gloves and eye/face protection. 
S45:In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.) 
S16:Keep away from sources of ignition.
RIDADR:  UN 2920 8/PG 2
WGK Germany:  3
F:  10-21
Hazard Note:  Irritant
HazardClass:  3.2
PackingGroup:  III

 Methyl 2,2-Difluoro-2-(fluorosulfonyl)acetate, its CAS NO. is 680-15-9, the synonyms are Methyl fluorosulphonyl difluoro acetate ; Methyl Fluorosulfonyldifluoroacetate ; Methyl difluoro(fluorosulfonyl)acetate .