Fluorinated compounds and process for preparing them

Abstract: By reacting 3,3,4,4-tetrafluoro-2-(trifluoromethyl)-1,2-­ oxazetidine (I) with a Lewis acid, in particular SbF₅ or AsF₅, the fluorinated compounds (II), (III) and (IV) are obtained:

Description: The present invention relates to new fluorinated compounds and to a process for preparing them. More particularly, it relates to three fluorinated compounds obtainable by reacting 3,3,4,4-tetrafluoro-2-(trifluoromethyl)-1,2-oxazetidine: with a Lewis acid. The above oxazetidine of formula (I) is a known compound, described by D.A. Barr et al. in J. Chem. Soc. 1955, 1881. It has now, surprisingly, been found that said compound reacts with Lewis acids, thereby generating three fluorinated compounds. An object of the present invention is to provide the above fluorinated compounds. Another object is to provide a process for preparing them. The first object is achieved by the compounds of the following three formulae: 3,3,5-trifluoro-2,5-di(trifluoromethyl)-4-(1,1,2,2,2-pentafluoroethoxy)-1,2,4-oxadiazolidine; 2,2,4,4,6,6-hexafluoro-1,3,5-tris(1,1,2,2,2-pentafluoroethoxy)-1,3,5-triazine; (CF₃)₂N-O-CF₂CF₃ (IV) N,N-bis(trifluoromethyl)-N-(1,1,2,2,2-pentafluoroethoxy)amine. The compound of formula (II), which is a liquid at atmospheric pressure with a boiling point of 75°C is, for example, useful as lubricant, heat transfer medium and test fluid for electronic components. The compound of formula (III), a solid compound with a melting point of 60 to 61°C is, for example, useful as lubricant. The compound for formula (IV), a low-boiling liquid with a boiling point of 27°C may, for example, be used as test fluid for electronic components and as heat transfer medium. The above compounds are formed simultaneously in the process according to the present invention. This process is characterized in that 3,3,4,4-tetrafluoro-2-(trifluoromethyl)-1,2-oxazetidine of formula (I) is reacted with a Lewis acid. The reaction is usually carried out at a temperature of from about 0 to about 100°C, and preferably of from about 10 to about 40°C. As Lewis acid fluorinated Lewis acids, in particular SbF₅ and AsF₅, are preferably used. The molar ratio of the Lewis acid (for instance SbF₅) to oxazetidine (I) generally ranges from 0.1 to 2.0 and preferably from 0.9 to 1.1. The reaction can be carried out batchwise inside an autoclave under the autogenous pressure of the system. The reaction time generally ranges from 1 minute up to 24 hours. At the end of the reaction the reaction mixture is preferably treated with a neutralizing agent in order to neutralize the Lewis acid (for example, SbF₅). A particularly suitable neutralizing agent is NaF. The molar ratio of neutralizing agent to Lewis acid (for example, NaF to SbF₅) usually is within the range of from about 1 to about 50 and preferably of from 5 to 15. The following example is given in order to illustrate the present invention. EXAMPLE Inside a 20 ml tubular reactor of Teflon (R) FEP, equipped with a valve, the following compounds were condensed, in the order given, at the temperature of liquid nitrogen (-196°C): 2.88 g (13.3 mmol) of SbF₅; and 2.90 g (14.6 mmol) of oxazetidine (I). Said oxazetidine had been prepared by reacting CF₃-N=O with CF₂=CF₂ (D.A. Barr et al., J. Chem. Soc. 1955, 1881). The reactor then was kept at 20°C for 12 hours. To the crude reaction mixture, cooled down to -196°C and kept under an anhydrous nitrogen atmosphere, 5.60 g 133 mmol) of fine NaF powder were added. Thereafter, the reactor was kept at 20°C for a further 24 hours and was repeatedly shaken in order to achieve a good solid-liquid contact. The reaction products were recovered by transfering them under low pressure (10⁻³ torr) from the reactor into a cold trap (temperature -196°C). This step required 24 hours, whereupon the mixture of the reaction products was distilled under a pressure of 10⁻³ torr. The vapours emerging from the distillation flask were passed through four cold traps maintained at temperatures of -50°C, -85°C, -110°C and -196°C, respectively. Inside the trap at -50°C, 145 mg of compound of formula (III) were collected (molar yield 5% relative to oxazetidine (I)). Said compound of formula (III) was characterized by the following spectra: Mass spectrum: chemical ionization (CI) CI gas = CH₄ m/z, 598 (MH⁺) 578 (MH-HF⁺) Infrared spectrum: main absorption bands (cm⁻¹) 1391 (d) 1332 (d) 1289 (f) 1242 (f) 1180 (m) 1089 (f) 946 (m) ¹⁹F-N.M.R. spectrum: (internal reference: CFCl₃; solvent: CDCl₃; temperature = 50°C). A = -84.7 ppm B = -93.0 ppm C = -84.7 ppm. Inside the trap at -85°C, 1.37 g of compound of formula (II) were collected (molar yield 47% relative to oxazetidine (I)). Said compound was characterized by the following spectra: Mass spectrum: chemical ionization (CI) CI gas = CH₄ m/z, 399 (MH⁺) 379 (MH-HF⁺). Infrared spectrum: main absorption bands (cm⁻¹) 1362 (d) 1315 (m) 1282 (m) 1246(f) 1225 (f) 1179 (m) 1120 (m) 1098 (f) 942 (d). ¹⁹F-N.M.R. spectrum: (internal reference: CFCl₃; solvent: CDCl₃) A = -111.6 ppm B = - 82.3 ppm C = - 66.7 ppm D = - 78.7 ppm; -83.1 ppm (AB system) E = - 90.1 ppm; -95.2 ppm (AB system) F = - 84.7 ppm. Inside the trap at -110°C, 0.42 g of compound of formula (IV) were collected (molar yield 10% relative to oxazetidine (I)). Said compound was characterized by the following spectra: Mass spectrum: chemical ionization (CI) CI gas = CH₄ m/z, 288 (MH⁺) 287 (M⁺) 258 (M-F⁺). Infrared spectrum: main absorption bands (cm⁻¹) 1361 (d) 1319 (f) 1272 (f) 1240 (f) 1218 (f) 1183 (f) 1095 (f) 1035 (d) 970 (m) 713 (m). ¹⁹F-N.M.R. spectrum: (internal reference: CFCl₃; solvent; CDCl₃) A = -67.9 ppm B = -94.3 ppm C = -85.0 ppm. The trap at -196°C contained 0.25 g of oxazetidine of formula (I).

Claims: Process for the simultaneous preparation of 3,3,5-trifluoro-2,5-di(trifluoromethyl)-4-(1,1,2,2,2-penta-fluoroethoxy)-1,2,4-oxadiazolidine of formula (II): 2,2,4,4,6,6-hexafluoro-1,3,5-tris(1,1,2,2,2-pentafluoroethoxy)-1,3,5-triazine of formula (III): and N,N-bis(trifluoromethyl)-N-(1,1,2,2,2-pentafluoroethoxy)-amine of formula (IV): (CF₃)₂N-O-CF₂CF₃ (IV) characterized in that 3,3,4,4-tetrafluoro-2-(trifluoromethyl)-1,2-oxazetidine of formula (I): is reacted with a Lewis acid. Process according to claim 1, characterized in that the reaction is carried out at a temperature of from 0°C to 100°C. Process according to claim 1 or 2, characterized in that the Lewis acid is a fluorinated compound. Process according to any one of claims 1 to 3, characterized in that the Lewis acid is selected from SbF₅, AsF₅ and mixtures thereof. Process according to claim 4, characterized in that the Lewis acid is SbF₅. Compound of formula (II) obtainable by the process of claim 1, i.e., 3,3,5-trifluoro-2,5-di(trifluoromethyl)-4-(1,1,2,2,2-penta-fluoroethoxy)-1,2,4-oxadiazolidine. Compound of formula (III) obtainable by the process of claim 1, i.e., 2,2,4,4,6,6-hexafluoro-1,3,5-tris(1,1,2,2,2-pentafluoroethoxy)-1,3,5-triazine. Compound of formula (IV) obtainable by the process of claim 1, i.e., N,N-bis(trifluoromethyl)-N-(1,1,2,2,2-pentafluoroethoxy)amine. Use of the compounds according to any one of claims 6 and 7 as lubricants. Use of the compounds according to any one of claims 6 and 8 as heat transfer media or test fluids for electronic compounds.

Inventors: DESMARTEAU DARRYL D, MALACRIDA ALESSANDRO, DESMARTEAU, DARRYL D., MALACRIDA, ALESSANDRO
Applicants: AUSIMONT SPA, AUSIMONT S.P.A.
Application year: 1989
Main classification: C07D271
IPC codes: C07D273, C07D271, C07D251, C09K5, C10M105, C07C239