PERFLUOROALKYLISONITRILES
A.F.Gontar
A.N.Nesmeyanov Institute of Organoelements
Compounds RAS. 119991, Vavilova str.28, Moscow, Russia.
e-mail:
gontar@ineos.ac.ru
It has been found that the reaction of
fluoroazaalkenes (RfN=CF2) with trialkylphosphites
brings to synthesis of adducts- trialkylperfluoroalkylfluorophosphoranes
that may be used without isolation in individual form for production of
perfluoroalkylisonitriles (1-3) unavailable earlier.
Experimental
Trifluoromethylisonitrile CF3- N=C ( 1)
Trimethylphosphite (12.4 g, 0.1 mol) is placed in a four-neck flask
fitted with a thermometer, stirrer, gas supply and gas outlet pipes
connected with a cold trap cooled to -120oC. The flask is
cooled to a temperature of -40oC with a mixture of acetone-
solid carbon dioxide and perfluoro-2-azapropene (13.3g,0.1mol) let pass
at stirring. Then cooling is stopped and after the reaction mass reaches
room temperature the flask is heated on a boiling water bath to 85-90oC.
The entrapped products are fractionated in a low
temperature still. There is produced 7.5g of trifluoromethylisonitrile,
boiling temperature from -83 to -81oC. The yield is 79%.
Found,%: C, 24.93; N ,14.52; MWt 94.8
C2NF3 Calculated,%: ?, 25.26; N ,14.73;MWt 95.0
Pentafluoroethylisonitrile C2F5N=C (2)
Analogously to (1) from trimethylphosphite (12.4g, 0.1
mol) and perfluoro-2-azabut-1ene (18.3g, 0.1 mol) there is produced
pentafluoroethylisonitrile (10.6g); BP -42oC. The yield is
73.2%.
Found, %: C, 25.13, N, 9.57; MW 143.8.
C3NF5 Calculated, %: C, 24.83; N, 9.66, MW 145.0.
Heptafluoropropylisonitrile C3F7N=C (3)
Similar to (1) from trimethylphosphite (12.4g, 0.1 mol)
and perfluoroaza-2-pent-1-ene there is produced
perfluoropropylisonitrile (15.9g); BP -25 oC.The yield is
70.9%.
Found, %: C, 24.13; N, 7.29; MW 196.3
C4NF7 Calculated, %: C, 24.62; N, 7.18; MW 195
References
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