Synthesis of trifluoroacetonitrile (cyanotrifluoromethane)

Preparation of trifluoroacetonitrile

Trifluoroacetonitrile is prepared by dehydrating the trifluoroacetamide with phosphorus pentoxide.

Preparation of trifluoroacetonitrile (cyanotrifluoromethane)

Preparation of trifluoroacetonitrile (cyanotrifluoromethane)

For the preparation of trifluoroacetonitrile the following glass apparatus was used.  The first 500 ml distillation flask was connected to the second 500 ml flask, which was fashioned as a trap and cooled with crushed ice. Two dry ice traps, fashioned from 50 ml test tubes, were connected in series and served as receivers. Tygon tubing was used for all flexible connections. All glassware was oven dried and assembled hot. A cotton filled drying tube was attached at the exit of the dry ice tube bank to permit venting during cooling and was replaced with a freshly dried tube for the dehydration. In the preparation, ice was packed around the trap and the receivers were cooled in a Dewar flask containing dry ice and acetone. Using the above described setup, 25 g (or 0.219 mole) of trifluoroacetamide and 25 g (or 0.178 mole) of phosphorus pentoxide were introduced into the first 500 ml flask and mixed by shaking. Approximately 10 g of phosphorus pentoxide was added to a top layer. The dehydrating flask was heated gently heated. All portions of the flask above the heating source were insulated with glass wool. The contents of the flask soon became a frothy plastic mass. Heating was continued until apparent gas evolution ceased. By using insulation and a high mantle temperature, sublimation of trifluoroacetamide and subsequent plugging of the dehydrating exit tube was avoided. The trifluoroacetonitrile was collected in the dry ice-cooled receivers and purified by distillation collecting fraction with boiling point 63° C.

A study of the synthesis of 2-triflouromethyl pyrimidines, by J. King, 28-29, 1961





InChI Key


Canonical SMILES


Depositor-Supplied Synonyms

Trifluoroacetonitrile, Cyanotrifluoromethane, Acetonitrile, trifluoro-, 353-85-5, 2,2,2-trifluoroacetonitrile, trifluoro(1-14c)acetonitrile, trifluoro(2-14c)acetonitrile, Acetonitrile, 2,2,2-trifluoro-, SFFUEHODRAXXIA-UHFFFAOYSA-N, trifluoroaceto-nitrile, CF3CN, AC1Q28DE, AC1Q28DF, AC1Q4I1I, 544078_ALDRICH, AC1L285N, Acetonitrile,2,2,2-trifluoro-, CTK4H4448, MolPort-001-777-199, EINECS 206-542-6, AR-1I2805, AR-1L7356, AR-1L7357, PC7190, ZINC05019026, AKOS005258524, AN-44488, DB-048791, TR-031619, FT-0632020, X-4505, I14-2453

Removed Synonyms

CID67710, 36443-68-2, 7465-86-3, 74660-84-7

Share This

Leave a Reply

Your email address will not be published. Required fields are marked *