CA1203808A - 4,5-dichloro-1,3-dioxolane derivatives - Google Patents

Abstract

TITLE
4,5-DICHLORO-1,3-DIOXOLANE DERIVATIVES

ABSTRACT OF THE DISCLOSURE
Novel fluorodioxoles which may have Cl or F substituents in the 4 or 5 positions and have two F or CF3 substituents in the 2 position are useful monomers for the preparation of homopolymers and copolymers with tetrafluoroethylene and terpolymers with tetrafluoroethylene and vinylidene fluoride. The homopolymers are suitable for glazing materials, while copolymers are useful, among others, for corrosion-resistant seals, gaskets, and linings.
Fluorinated 4,5-dichloro-1,3-dioxolanes are also disclosed. Such dioxolanes may be used in the manufacture of the fluorodioxoles.

Description

~2~3808 TI TJIE
NOVEL FLUORODIOXOLES AND FLUORODIOXOLE POLYMERS
BACKGROUND OF T~E I~VENTION
This invention relates to certain novel fluorodioxoles, their polymers, and processes or making the fluorodioxoles.
Various dioxolanes having the following formula 1 are known from German Patent 2,604,350 to Stanford Research Institute:
CHX - CHY
--C~ (1) F F
where each of X and Y may be F or Cl.
Dioxolanes corresponding to formula ~2), below, are reported in U.S. Patent 3,749,791 to Terrell et al.:
CHX - C~X' ~ C~ (2, CF -CF
where X is Cl or F, and X' is H, Cl, or F.
The intermediate 2,2-bis(trifluoromethyll-1,3-dioxolane is known from U.S. Patent 2,925,424 to Simmons.
Dechlorination of

2,2-bis(trifluoromethyl)-4,5-dichloro-4,5-difluoro-1,3-dioxolane to the corresponding perfluorodioxole has been reported by Resnick in U.S. Patents 3,865,845 and 3,978,030.
That perfluorodioxole has been found to form both homopolymers and copolymers (especially with tetrafluoroe,hylene) which have interesting chemical and physical properties (e.g., chemical inertness to hydrogen fluoride, optical clarity, ability to form films). It can be speculated that simpler and~or cheaper fluorodioxoles also would be capable of forming useful homopolymers and copolymers.

... .., .,- ~

~2~3~0~

S UM~ARY OF THE .I NVENTIO~
According to the present invention, there is provided a class of fluorodioxoles having the following formul.a (3):
CY = cæ
C ~ (3) R R
in which Y is hydrogen or chlorine; Z is hydrogen, fluorine, or chlorine; and R is fluorine or the trifluoromethyl group; with the proviso that when R
is trifluoromethyl, only one of Y and Z can be hydrogen or chlorine.
These fluorodioxoles are useful monomers for the preparation of homopolymers and copolymers having a wide range of potential applications. This invention also includes such polymers as well as certain novel polymers of known dioxoles. Generally, the monomers from which the novel polymers of the present invention are made can be represented by the same formula ~3) in which Y, Z and R have the same meaning as above, but the above proviso no longer applies.
DETAILED DESCRIPTIO~ OF THE I~VENTION
The Pluorodioxoles of the present inve~nt.ion can be conveniently made by ~echlorination of the corresponding 4,5-dichlorodioxolanes with magnesium in the ~resence of a catalytic amount of iodine and of a water-soluble mercury salt or metallic mercury, as shown in the following equation.
CClY - CClz C ~ Mg, I2 (3) + MgC12 , R R Hg or Hg (4) Where R, Y, and Z have the same meaning as in Formula (3), above.

~?38~8 This dechlorination reaction preferably is carried out in solution in tetrahydrofuran, For maximum production rate, an excess of magnesium is employed in this reaction, the preferred amount heing 1.1 to 8 gram-atoms of magnesium per two grarn-atoms of vicinal chlorine to be removed. However, for maximum yield ~f dioxole, less than stoichiometric amounts may be desirable to minimize side reactions.
Mercury salts suitable in this reaction include, for e~ample, mercuric chloride, acetate, and nitrate.
Metallic mercury, when used, forms in situ an amalgam with magnesium. However, an amalgam can be prepared separately in advance. The amount of mercury need not be large. For example, a weigh~ of mercuric chloride about equal to the weight of iodine, in turn equal to about 1% o~ the weight of magnesium usually is sufficient. A slightly larger amount of metallic mercury may be advisable to permit more effective agitation and thus easier amalgam formation.
Although some 4,5-dioxolanes represented by the above formula (4) are known, as discussed earlier, those represented by formula (5), below are believed to be novel:
CYCl-CFCI
`C' R R (5~
in which R is fluorine or trifluoromethyl, and Y is hydrogen or chlorine.
All the fluorodioxoles of this invention copolymerize with tetrafluoroethylene (TFE) to tough, crystalline copolymers suitable ~or use as a dielectric in electrical and electronic equipment.
In these crystalline copolymers the fluorodio~ole usually is present in an amount o~ about 12 mole percent or less. When the fluorodio~ole content ~2Q3l3V8 increases beyon~ 12 mole percent, the copolymers become amorphous. ~aturally, the 12 mole percent level is not a sharp line of demarcation, since copolymers having some crystallinity may exist ~bove 5 it, and significantly amorphous co~olymer m~y exist below it. However, one can expect that a large majority of copolymers having less than 12 mole % of a fluorodioxole (3) will be crystalline, and a large majority of those containing more than 12 mole ~ of 10 such a fluorodioxole will be amorphous. The - amorphous copolymers are tough and at moderate molecular weight soluble in various organic liquids, such as 1,1,2-trichloro-1,2,2-trifluoroethane and Fluorinert* Electronic Liquid FC-75 t3M Company) and > 15 are particularly suitable for finishes and coatings that are chemically inert and are stain and weather resistant. Fluorodioxoles (3) in which each of Y and _ Z is chlorine could not be incorporated into a copolymer with TFE at a high enough level to result ~- 20 in an amorphous copolymer. Those copolymers that were made were crystalline.
Fluorodioxoles (3) form with vin~lidene fluoride (~2) and TFE strong, plastic and elastomeric terpolvmers suitable for corrosion-resistant seals, gaskets, and linings.
-_ Finally, the fluorodioxoles corresponding to formula (3) in which Y is hydrogen and Z is hydrogen -. or fluorine form homopolymers, which are tough, ~- amorphous resins suitable for transparent glazing .
materials, especially as sight glas~es in chemically corrosive uses employing hydrogen fluoride.
In addition to the novel dioxoles of Formula

3 as defined therein, ~ioxoles in which both X and Y
are hydrogen or chlorine, and R is trifluoromethyl can be made by ~he same general techniques but are *denotes trade mark --~ 3~

not believed to be novel. Those dioxoles also form novel and valuable copolymers; the dioxoles in which X is hydrogen, and Y is hydrogen or fluorine alsQ
form homopolymers.
Broadly, this invention includes, therefore, homopolymers of the novel dioxoles of this invention as well as copolymers of the dioxoles represented by for~ula (3) in which Y is hydrogen or chlorine; Z is hydrogen, fluorine, or chlorine; and R is fluorine or trifluoromethyl with tetrafluoroethylene and terpolymers with tetrafluoroethylene and vinylidene fluoride.
This invention is now illustrated by representative examples of certain preferred embodiments thereof, wherein all parts, proportions, and percentages are by weight unless otherwise indicated. Further, unless shown otherwise, all reactions, separations, distillations, and storage were carried out in a nitrogen atmosphere.

3~?0~

TA~LE I
SUM~ARY OF PREPARATION OF DIOXOLES OF
FORMUI.A ~3) AND DIOXOLAN~S OF FORMULA (4) Example Compound Compound Substituents No. No. Y Z R
Prep. of:
lA (4a) Cl F CF3 lB (3a) Cl F CF3 lB (3b) F H CF3 lB (4b) F H CF3 lC (3a) Cl F CF3 lD (3b) F H CF3 8A (4c) H H CF3 8A (4d) Cl H CF3 8A (4e) Cl Cl CF3 8B (3c) H H CF3 8B (3d) Cl H CF3 8B ~3e) Cl Cl CF3 8C (3d) Cl H CF3 15A ~4f) Cl F . F
15B (3f) Cl F F
153 ~3g) F H F
15B (4g) F H F
16A/B (4g) F H F
17 (3g) F H F
22 (4h) H H F
22 (3h) H H F
25 (4i) Cl H F
(3i) Cl H F
28 (3j) Cl Cl F
28 (4j) Cl Cl F

,..~

TABLE II
SUMMARY OF EXAMPLES --POLYMERIZATION
Example Monomer Polymer Properties No. Compound No. Comonomer ~ol ~ Dioxole, Tm,* Tg**
2 ~3b) - 100%, Tg>300C
3 (3b) TFE 5.2%, Tm=266 ~ 320C

4 (3b) TFE 28.8%, Tg=58C
(3b) TFE 2.4%, Tm=307C
(3a) TFE 3.1%, Tm=235C
7 (3a) TFE/VF2 5.3%,14.3% TFE; Tm=131C
9 (3c) TFE 6.9%, Tm=253C
(3c) TFE 46.3%, Tg=61C
11 (3c3 TFE/VF2 7.9%, 36.4~ TFE Elast., Tm=114C
12 (3c) - ~00~
15 13 (3d) TFE 5.9%, Tm=269C
14 (3c)/(3d) TFE 8.6~ (3c)/6.2% (3d), Tg=54C
18 (3g) TFE 4.0~, Tm=274C
19 (39) - 100%
20 20 (3f) TFE 10.5%, Tg=61C
21 (3f) TFE/VF2 9~9~ t 27,7% TFE; no Tm 23 (3h) - 100 24 (3h) TF~ 7 26 (3i) TFE 6%
27 (3e) TFE 0.6%, Tm=312C
29 (3;) TFE 1.4~, Tm=3109 297C
* melt temperature (indicates that the polymer has crystallite regions) ** glass transition temperature (indicates that the polymer is amorphous) Example 1 Preparation of 2,2-bis(trifluoromethyl3-4-chloro-5-fluoro-1,3-dioxole, (3a), 2,2-bis(trifluoromethyl)-4-fluoro-1,3-di~xole, (3b~, and the corresponding dioxolanes (4a) and (4b).

, 38~3 A. 2,2-Bis~trifluoromethyl)-4,4,5-trichloro-

5-fluoro-1,3 dioxolane, (4a).
A 330 mL Hastello~ C lined shaker t~be was charged under anhydrous conditions with 100 g (0.286 mole) of 2,2-bis(trifluoromethyl)-4,4,5,5-tetrachloro-1,3-dioxolane (4e) and 8.6 9 tO.0432 mole) of antimony pentachloride; the tube was then chilled to about -50~C, and 20 9 (1 mole) of hydrogen fluoride was introduced into it. The tube was mounted in a horizontal shaker, agitated for 5 hours at 70C, then chilled in wet ice, 510wly vented, and opene~. The tube contents were dumped into wet ice. The liquid product W3S separated from the ice water, washed twice with 50 mL portions of cold water, then with 20 mL of a 10~ aqueous sodium carbonate solution. There was obtained 83.5 9 of a clear, colorless liquld product of which approximately 93% was the desired 2,2-bis(trifluoromethyl)-4,4,5-trichloro-5-fluoro-1,3-dioxolane, (4a).
The product was distilled at atmospheric pressure on a 0.76 m spinning band column; a small amount of 2,2 bis(trifluoromethyl)-4,5-dichloro-4,5-difluoro-1,3-dioxolane (about 2~ of the product) boiling at 85-86C distilled fir~t, followed by the 2,2-bis(trifluoromethyl)-4,4,5-trichloro-5-fluoro-1,3-dioxolane, b.p. 115C, which was obtained as a colorless, clear liquid in purity exceeding 99%.
Both infrared spectroscopy and Fluorine-l9 nuclear magnetic resonance spectroscopy.were consistent with this chemical structure.
The pot residue was largely starting material, approximately 5% of the total mixture from the shaker tube run.
B. ~echlorination of 2,20bis(trifluoro-methyl)-4,4,5trichloro-5-fluoro-1,3-dioxolane, (4a).
*denotes trade mark ~2Q38~

A 300 mL, 3-neck glass flask equipped with magnetic stirrer, thermometer, Vigreux column, still head to a 100 mL receiver, and dry ice trap under 1~0 kPa of nitro~en was charged with 165 mL of l-propanol, 42~6 g (0.651 mole) of zinc dust, and 1.4 g (0.0109 mole) of zinc chloride. The mixture was stirred while being heated to 98C over a 21 ~inute period; when this temperature was reached, 2,2 bis(trifluorome~hyl)-4,4,5-trichloro-5-fluoro-1,3-dioxolane, 72.0 g (0.217 mole), was introduced intothe refluxing mixture via a syrinye pump at 0.33 mL/minute. Thirty-five minutes later the head temperature fell to S9C, and distillation of the product was started. Total addition time was 127 minutes. Total distillation time was 268 minutes, during which time the head temperature decreased to a minimum of 55C. The distillate, 60 mL, contained some l~propanol which was extracted with water, leaving 47.7 9 of a clear, colorless liquid containing about 52~ of 2,2-bis(trifluoro-methyl)-4-chloro-5-fluoro-1,3-dioxole, (3a), 25% of 2,2-bis(trifluoromethyl)-4-fluoro-1,3-dioxole, (3b), and 22~ of 2,2,-bis(trifluoromethyl)-4,5-dichloro-4-fluoro-1,3-dioxolane ~4b) as a mixture of 30~ cis and 70~ trans isomers.
The crud~ reaction product was fractionated at atmospheric pressure on a 0.51 m spinning band column. 2,2-Bis(trifluoromethyl)-4-fluoro-1,3-Zioxole, (3b), b.p. 44-45C, polymerizes spontaneously at room temperature when pure. It was therefore collected in a receiver maintained at -80C
and stored in a dry ice chest. 2,2-Bis~trifluoro-methyl)-4-chloro-5 fluoro-1,3-dioxole~ (3a), distilled at 56C; this monomer did not polymerize spontaneously at room temperature. The cis/trans 3~0~3 mixture of 2,2-bis~tri-fluoromethyl)-4,5-dichloro-4-fluoro-1,3-dioxolane, (4b), distilled within the range of 8~-90C.
The IR, F-l9 and proton NMR spectra, and mass spectrometry support the above che~ical structures.
C. Alternate dechlorination of 2,2-bis(trifluoromethyl)-4,4,5-trichloro-5-fluoro-1,~-dioxolane, (4a~.
The equipment described in the above section B was charged with 80 mL of tetrahydrofuran, 10.8 g (0.444 mole) of magnesium turnings, 0.2 g of mercuric chloride, and 0.2 y of iodine and heated to 66C
(iodine color disa~pears). 2,2-Bis(trifluoro-methyl)-4,4,5-trichloro-5-fluoro-1,3-dioxolane, 33.1 g (0.1 mole), was added by means of a syrinqe pump at the rate of D~16 mL/minute over a period of 110 minutes. Distillation was started 41 minutes after the addition; the head temperature remained at 54-5SC during the re~,ainder of the addition. The distillation was stopped after 2.5 hours, and the distillate was extracted with water to remove some tetrahydro~uran. The extracted clearl colorlPss liquid was found by gas chromatography to contain ahout 95% of 2,-2-bis(trifluoromethyl)-4-chloro-5-fluoro-1,3-dioxole, (3a); the 2,2-bis(trifluoromethyl)-4-fluorool,3-dioxole, (3b), amounted to only 1%.
Do Alternate preparation of 2,2 bis(tri-fluoromethyl)-4-fluoro-1,3-dioxole, (3b).
Using the same equipment, except for a smaller, 100 mL flask, a mixture of 30 mL of tetrahydrofuran, 3.6 g of magnesium turnings, 0.~ g of mercuric chloride, and 0.1 g of iodine was heated to reflux. 2,2-Bis~trifluoromethyl)-4,5-dichloro-4-. .

~2~3808 fluoro-1,3 dioxolane, (4b), 10 g, (prepared as described in Section B, above) was then introduced into the flask at approximately 0.19 mL/minute over a 34 minute period. Distillation was started 21 minutes a~ter the addition was completed and continued until 20 mI. of cold distillate was recovered. This was extracted with ice water to remove tetrahydrofuran. The remaining product was 2,2-bis~trifluoromethyl)-4-fluoro-1,3-dioxole, (3b).
Example 2 ~ omopolymerization of 2,2-bis(tri-fluoromethyl)-4-fluoro-1,3-dioxole, (3b).
This monomer, 4 6 9, (99.88% pure by sas chromatography) was placed at 25C in a small, tightly capped vial under room lighting conditions.
Within a few hours the viscosity of the clear liquid increased to that of a light syrup, and overnight a solid, clear, colorless plug of polymer formed on the bottom of the vial.
A small sample of the monomer-polymer syrup was evaporated on a salt plate to remove the residual monomer and form a film of the homopolymerO The infrared absorbance spectrum of this film was consistent with the molecular structure of a homopolymer of 2,2-bis(trifluoromethyl~-4-fluoro-1,3-dioxole, (3b).
The plug was placed in a vacuum oven at 110-120~C to remove residual monomer, and then a sample was examined by Differential Scanning Calorimetry between room temperature and 300C.
There were no second order transitions or melting points in this region, indicating that the homopolymer was amorphous and that its Tg was above 300~C.

~2Q38~8 Example 3 Crystalline copolymer of 2,2-bis(trifluoro-methyl)-4-fluoro-1,3-dioxole, (3b~, and TFE.
A 110 mL stainless steel shaker tub~ was charged with a cold solution containing 100 g of 1,1,2-trichloro-1,2,2-trifluoroethane, 1.0 g of the dioxol~, and 0.03 q of bis(4-t-butylcyclohexYl) lperoxydicarbonate; the tube was chilled to -50C and alternately evacuated and flushed with nitro~en ~hree times. The evacuated tube was then charged with lO g of tetrafluoroethylene and agitated in a horizontal shaker. The temperature was held at 55C for two hours and then at 65C for two hours. After cooling the tube and venting, the resulting suspension of copolymer in 1,1,2-trichloro-1,2,2-trifluoroethane was recovered. The solvent was distilled off, and the polymer was dried to give ~.7 q of white, solid granules. A portion of these was pressed at 300~C
into a tough, self-supporting film. The infrared spectrum of the film showed absorbancies characteristic of a tetrafluoroethylene/2,2-bis(tri-fluoromethyl)-4-fluoro-1,3-dioxole copolymer.
Differential Scanning Calori~etry showed a major, broad, crystalline melting point at 266C; there also 25 was a minor melting point at 320C. Infrared and F-l9 NMR spectra support the copolymer structure containing 94~8 mole ~ of tetrafluoroethylene and 5.2 ~ole % of 2f 2-bis(trifluoromethyl)-4-fluoro-1,3~dioxole, (3b).
30Example 4 Amorphous copolymer of 2,2-bis(trifluoro-methyl)-4-fluoro-1,3-dioxole, t3b), and TFE.
A shaker tube was charged with 100 g of 1,1,2-trichloro-1,2,2-trifluoroethane, 0.03 g of 35 bis(4-t-butylcyclohexyl) peroxydicarbonatei 5.0 g ':, " ~2~3808 (0.022 mole) of the dioxole, and 5.0 g (0.05 mole) of TFE. Polymerization was carried out at 55~ and 65C. After separating and ~rying the product, 4.5 of a white solid polymeric product was obtained. A
5 portion of the product was pressed at 230~C into thin, tough, clear, colorless, self-supporting films. The infrared and F-l9 N~5R sPectra established the product to be a copolymer containing 71.2 mole %
of TFE and 28.8 mole ~ of the dioxole. Differential Scanning Calorimetry showed a Tg at 58C but no melting point, thereby indicating that the copolymer was amorphous.
Example S
A high melting crystalline copolymer of 2,2-bis(trifluoromethyl)-4-fluoro-1,3-dioxole, (3b) and TFE.
A shaker tube was charged with 100 g of 1,1,2-trichloro 1~2,2-trifluoroethane, 0~03 g of bis(4-t-butylcyclohexyl) peroxydicarbonate, 0.5 9 (0.0022 mole) of the dioxole, and 1~ g (0.1 mole) of TFE. Polymerization was carried out at 55 and 65C. ~fter separating and drying the product, 9.4 g of a white, solid polymer was obtained. A portion of the polymer was pressed at 330C into thin, tough, colorless, transparent, self-supporting films~ The infrared and F-l9 NMR spectra were consistent with copolymer of 97.6 mole ~ TFE and 2.4 mole ~ of 2,2-bis(trifluoromethyl)-4-fluoro-1,3-dioxole.
Differential Scanning Calorimetry showed a relatively sharp ~elting point at 307C, thus indicating the crystalline nature of the polymer.
ExamPle 6 A crystalline copolymer of 2,2-bis-(trifluoromethyl)-4-chloro-5-~luoro-1,3-dioxole, (3a), and TFR.

~Z~38[)~3 A shaker tube was charged with 100 g of 1,1,2-trichloro-1,2,2-trifluoroethane, 0.03 g of bis(4-t-butylcyclohexyl) peroxydicarbonate, 1.5 g (0.0058 mole) of the dioxole and 10 g of q'FE, and polymerization was carried out at 55 and 65C.
After separating and drying the product, 4.3 g of a white, solid polymer was obtained. A portion of the polymer was pressed at 300C to give tough, thin, colorless, clear, self-supporting films. Infrared and F-l9 NMR spectra support the structure of a copolymer containins 96.9 mole ~ of TFE and 3.1 mole % of 2,2-bis(trifluoromethyl)-4-chloro-5-fluoro-1,3-dioxole, (3a). Differential Scanning Calorimetry showed a melting point at 295C, indicating the crystalline nature of the polymer.
Example 7 A terpolymer of 2,2-bis(trifluoromethyl)-4-chloro-5-fluoro-1,3-dioxole, (3a), vinylidene fluoride, and TFE.
A shaker tube was charged with 100 g of 1,1,2-trichloro-1,2,2-trifluoroethane, 3.0 g of the dioxole, 0.03 g of bis(4-t-butylcyclohexyl~
peroxydicarbonate, 6.0 g of vinylidene fluoride, and

6.0 g of TFE. Polymerization was carried out at 55 and 65C for 4 hours under autogenous pressure.
After separating and drying the product, 3.6 g of a white, solid polymer was obtained. A portion of this polymer was pressed at 230C into thin, tough, clear, self-supporting films. Infrared and F-13 NMR ~pectra identified the polymer as a terpolymer containing 14.3 mole % of TFE, 80.4 mole % of vinylidene fluoride, and 5.3 mole % of the dioxole.
Differential Scanning Calorimetry showed a melting point at 131C, thus demonstrating the crystalline character of the polymer.

Q3~08 lS
Example 8 Preparation of 2,2-bis(trifluoromethyl)-1,3-dioxole, (3c), 2,2-bis(trifluoromethyl)-4-chloro-1,3-dioxol~, (3d), and 2,2-bis(trifluoro~
5 methyl)-4,5-dichloro-1,3-dioxole, (3e).
A. Synthesis of 2,2-bis(trifluoromethyl)-4,5-dichloro-1,3-dioxolane, (4c), 2,2-bis(tri-fluoromethyl)-4,4,5-trichloro-1,3-dioxolane, (4d), and 2,2-bis(trifluoromethyl)-4,4j5,5-tetrachloro-1,3-dioxolane, (4e).
A 300 mL, 3-neck round hottom flask equipped ~ith a magnetic stirrer, chlorine gas inlet, thermometer r and a water condense topped by a dry ice condenser communicating with a drying tower and then with a water scrubber was charged with 210 g (1.0 mole) of 2,2-bis(trifluoromethyl)-1,3-dioxolane.
After purging the system with nitrogen, chlorine was passed into the solution at such a rate as to maintain a yellow coloration of the solution. The stirred mixture was irradiated with a 275 watt General Electric sun lamp so as to maintain a reaction temperature for the most part ~n the range of 46-72C for 4.5 hours. The concentration of the starting dioxolane in the reaction mixture had dropped by then to approximately 0.1%, and the reaction was terminated. Residual chlorine and hydrogen chloride were removed with a water aspirator, leaving a colorless, clear liquid weighing 289 g and containing the di-, tri-, and tetrachloro-3~ derivatives (4c), (4d), and (4e), as confirmed byN.~R, mass spectrometry, and gas chromatographic analyses.
B. Dechlorination of the di-, tri , and tetrachlorodioxolanes obtained in step A, above.

~Q3l308 A 500 mL, 3-neck, round bottom flask equipped with a magnetic stirrer, a syringe pump inlet, a thermometer, a 15-cm still leading to a 100 mL receiver and then to a nitrogen tee and a bubbler was charged with 98.1 g (1.5 moles) of zinc dust, 3.0 9 (0.022 mole) of zinc chloride, ~nd 300 mL of n-b~tyl alcohol. A syringe pump was charged ~ith 139.5 g of the chlorinated dioxolanes from step A.
After the flask contents were brought to 115C, the chlorinated dioxolanes were pumped into the flask at 0.33 mL/minute. The addition was completed in 224 minutes. Twenty minutes after the start of the addition, distillation began at a rate of about 15-20 mL/hour. The head tempexature then was 79~-80C but during the distillation decreased to 75C and at the end was 116C; 119.8 g of product containing butyl alcohol was distilled. The produc~ distribution was about 21% o~ 2,2-bis(trifluoromethyl)-1,3-dioxole, (3c), 47% of 2,2-bis(trifluoromethyl)-4-chloro-1,3-dioxole, (3d), and 30~ of 2,2-bis(trifluoromethyl)-4,5-dichloro-1,3-dioxole, (3e). The crude product was fractionated at atmospheric pressure on a 0~76 m spinning band column to provide each dioxole as a clear, colorless liquid 2S having a ~urity of at least 99~:
2,2-bis(trifluoromethyl)-1,3-dioxole, ~3c), b.p.
67C; 2,2-bis(trifluoromethyl)4-chloro-1,3-dioxole, ~3d), b.p. 76C; and 2r2-bis(trifluoromethyl)-4,5-dichloro-1,3-dioxole, (3e)~ b~p. 85C. The infrared, F-19 and proton N~R, and mass spectrometry data for these dioxoles support their molecular - structures.
C. Alternate synthesis of 2,2-bis~trifluoro-methyl)-4-chloro-1,3-dioxole, (3d).

,~,.

~2G3808 A 100 mL, 2-neck, round-bottom glass flask equipped with magnetic stirrer, thermometer, Vigreux column, still head, and receiver was charged under a nitrogen blanket with 40 mL of di(ethylene glycol) dimethyl ether t 9 . 8 g of crude 2,2-bis(trifluoromethyl)-4,5-dichloro-1,3-dioxolane, (4c), and 6.7 g of solid potassium hydroxide. The ~lask contents were heated at 141C for 2 hours during which time the 2,2-bis(trifluoro-methyl)~4-chloro~1,3-dioxole, (3d), distilled over.
Purified by gas chromatography, the product had the same retention time and infrared spectrum as an authentic sample of 2,2-bis(trifluoromethyl)-4-chloro-1,3-dioxole, (3d).
Example 9 A crystalline copolymer of 2,2-bis(tri-fluoromethyl)-1,3-dioxole, (3c) and TFE.
A shaker tube was charged with 100 g of 1,1,2-trichloro-1,2,2-trifluoroethane, 0.03 g of bis(4-t~butylcyclohexyl) peroxydicarbonate, 1.5 g (0.0072 mole) of the dioxole, and 10 g (0.1 mole) of TFE. Polymerization was carried out at 55 and 65C. After separating and drying the product, lO.S
g of a white, solid polymer was obtained. A portion of the polymer was pressed at 300C into tough, clear, colorless, self-supporting films. Infrared and F-l9 N~R spectra established a copolymer structure of 93.1 mole ~ of TFE and 6.9 mole ~ of 2,2-bis(trifluoromethyl)-1,3~dioxole, (3c).
Differential Scanning Calorimetry showed a melting point a~ 253C, thereby establishing the crystalline character of this polymer.
Example 10 An amorphous copolymer of 2,2-bis(tri-fluoromethyl)-1,3-dioxole, (3c) and TFE.

A shaker tube was char~ed with ioo 9 of 1,1,2-trichloro-1,2,2-trifluoroethane, 4.2 g (0.02 mole) of the dioxole, 0.03 g of bis(4-t-butyl-cyclohexyl) peroxydicarbonate, and 10 g o~ TFE.
Polymerization was carried out at 55 and 65C under autogenous pressure for 4 hoursO ~fter separation and drying, a white, solid polymer, 1.4 g, was obtained. It was soluble in the trichlorotrifluoro-ethane solvent; a clear, transparent, self-supporting film was cast from this solution. Infrared and F-19 and proton N.~R spectra identified the copolymer as containing 46.3 mole ~ of the dioxole and 53.7 .mole of TFE. Differential Scanning C~lorimetry showed a Tg at 61~C and other transitions at 113C and 246C;
there was no melting poin~, and the polymer was therefore amorphous.
Exam~le 11 An elastomeric terpolymer of 2,2-bis(tri-fluoromethyl)-1,3-dioxole, ~3c), vinylidene fluoride, 20 and TFE.
A shaker tube was charged with 100 g of 1,1,2-trichloro-1-2,2,-trifluoroethane, 3.0 9 ~0.0144 mole) of the dioxole, 0.03 g of bis(4-t-butyl-cyclohexyl) peroxydicarbonate, 6~0 g ~0.094 mole~ of 25 vinylidene fluoride, and 6.0 ~ tOoO6 mole~ of TFE~
Polymerization was carried out under autogenous pressure at 55 and 65C. After separation and drying, a white, solid polymer, 6.4 ~, was obtained.
It was not soluble in the trichlorotrifluoroethane.
30 A portion of the polymer was pressed at 230~C to give thin, tough, elas~omeric, clear, self-supporting films. Infrared and F-19 NMR spectra identified the terpolymer as containing 36.4 mole ~ of TFE, 55.7 mole % of vinylidene fluoride, and 7~9 mole % of 35 dloxole. Differential Scanning Calorimetry showed a ,sv 3~

melting point at 114C, indicating the crystalline nature of the polymer.
Exam~le l2 Ho~opolymer of 2,2-bis(trifluoromethyl)-1,3-dioxole, (3c).
The dioxole, 3.0 g, which had been kept in a dry ice chest, was placed in a 10 mL closely capped, clear, glass vial and allowed to stand ~t room temDerature under laboratory ~luorescent lighting conditions. After two weeks, a portion of the liquid was placed on a salt plate and allowed to evaporate, leaving a thin, transparent, clear, colorless solid film. Infr~red analysis of this film was consistent with the homopolymer structure.
Exam~le 13 A crystalline copolymer of TFE and 2,2~bis-(trifluoromQthyl)-4-chloro-1,3-dioxole, (3d).
A shaker tube was charged with 100 g of 1,1,2-trichloro,1,2,2-trifluoroethane, 0.03 g of bis (4-t-butylcyclohexyl3 peroxydicarbonate, 1.5 g (0.00618 mole) of the dioxole, and 10 g (0.1 mole) of TFE. Polymerization was carried out under autogenous pressure at 55 and 65C. After separation and drying, a white solid polymer, 5.0 g, was obtained.
A ~ortion of the polymer was pressed at 300C into thin, tough, clear, self-supporting films. Infrared and F-l9 NMR spectra showed the copolymer to contain 94.1 mole % of TFE and 5.9 mole % of the dioxole.
Differential Scanning Calorimetry showed a melting ~oint at 269C/ thus indicating the polymer to be crystalline.
Example 14 An amorphous terpolymer of TFE with 2,2-bis-~trifluoromethyl)-1,3-dioxolQ, (3c~ and 2,2-bis(trifluoromethyl)-4-chloro 1,3-dioxole,.(3d).

lg ., --A shaker tube was charged with 100 g of 1,1,2-trichloro-1,2,2-trifluoroethane, loO g of 2,2-his(trifluoromethyl)-1,3-dioxole, (3c), 2.0 g of 2,2-bis(trifluoromethyl)-4-chloro-1,3-dioxole, (3d3 0.03 9 of bis(4-t-butylcyclohexyl) peroxydicar~onate, and 10 9 TFE. Polymerization was carried out under autogenous pressure at 55 and 65C. After separation and d~ying, 3 ~ of white, solid, polymer granules were obtained. A portion of the polymer was pressed at 300C to give thin, tough, s~lf-supportingt colorless, clear films. The infrared and F-l9 NMR spectra were consistent with a terpolymer structure consisting of 85.2 mole % of TFE, 8.6% of 2,2-bis(trifluoromethyl)-1,3-dioxole, 15 (3c~, and 6.2 mole`% of 2,2-bis(trifluoromethyl~-4-chloro-1,3-dioxole, (3d). The Differential Scanning Calorimetry analysis showed a Tg at 54C but no melting point, thereby indicating the polymer to be amorphous.
~xamPle 15 Preparation of 2,2,4-trifluoro-5~chloro-1,3-dioxole, (3f) 2,2,4-trifluoro-1,3-dioxole, (3g), and the corresponding dioxolanes (4f) and (4g)~
A. 2,2,4-trifluoro-4,5,5-trichloro-1,3-dioxolane (4f) A dry, 360 mL U~astelloyl' C lined shaker tube was charged with 81.8 g (0.33 mole) of 2,2-difluoro-4,4,5,5-tetrachloro 1~3-dioxolane, (4~, containing 9.0 g (0.03 mole1 of antimony pentachloride. The tube was cooled, alternately e~acuated and purged with nitrogen three times, and charged with 22 g (1.1 mole) of hydrogen fluoride.
The tube was agitated and warmed to 40C over a period of 1 hour~ heated under autogenous pressure for 4 hours at 40C, then cooled to 0C, 510wly .P~

~Q380l!~

vented, and opened. The contents were poured into ice; the organic phase was separated from the aqueous phase, extracted twice with distilled water and once with an aqueous 10% sodium carbonate solution; 63.3 9 of crude product was obtained which contained about 3.9% of 2,2,4,5-tetrafluoro-4,5-dichloro-1,3-dioxolane, B5.8% 2,2,4-trifluoro-4,5,5-tri-chloro-1,3-dioxolane, t4f), and 8.1% of the starting material. This product mixture was combined with those of three other similar runs and separated by distillation on a 0.76 m spinning band column;
2,2,4,5-tetrafluoro-4,5-dichloro-1,3-dioxolane boiled at 45-46C; 2,~,4-trifluoro-4,5,5-trichloro-1,3-dioxolane, (4f), at 84C; and the starting material, 2,2-difluoro-4,4,5,5-tetrachloro-1,3-dioxolane (4j), at 115C. Their purities were greater than 99%. Both infrared and F-l9 NMR
spectroscopy confirmed their structures.
B. Dechlorination of 2,2,4-trifluoro-4,5,5-trichloro-1,3-dioxolane, (4f).
A 300 mL 3-neck glass flask equipped with magnetic stirrer, thermometer, Vigreux column with a dry ice-cooled still head leading to a cold receiver, trap, a nitrogen tee, and bubbler was charged w~th 76.7 g (1.17 gram-atoms) of zinc, 2.6 g ~0.019 mole) of zinc chloride, and 175 mL of propanol The stirred mixture was heated to 94C; then 89.~ g ~0.387 mole) of 2,2,4-trifluoro-4,5,5-trichloro-1,3-dioxolane, (4f), was introduced from a syringe ~ump at a rate of Q.33 mL/minute during 172 minutes. Distillation at a rate of abo~t 15 mL/hour began 33 minutes after the start of the addition and continued for 270 minutes; 65 mL of clear, colorless distillate weighing 84.5 g and containing so~e propanol was obtained. It was redistilled through a ~ZQ3808 0.76 m spinning band column with a dry ice-cooled head. The prod~ct distribution was approximately 3.9% of 2,2,4-trifluoro-1,3-dioxole, (39), b.p. 10C;
71.7% of 2,2,4-trifluoro-5-chloro-1,3-dioxole, (3f), b.p. 25-27C; and 24.3% of 2,2,4-trifluoro-4,5-dichloro-1,3-dioxolane, (4g), b.p. 73C. The in~rared, F-l9 and proton NMR spectra of these compounds were consistent with the assigned structures.
Example 16 Alternate synthesis of 2,2,4-trifluoro-4,5-dichloro-1,3-dioxolane, (4q).
A. 4,4,5-trichloro-1,3-dioxolan-2-one.
A creased 3-neck, 300 mL, round bottom flask equipped with magnetic stirrer, gas inlet tube, thermometer, and water condenser topped by a dry ice condenser leading to a trap and scrubber was charged with 88.1 g of ethylene carbonate. The system was purged with nitrogen and then dry chlorine gas was introduced while irradiating the reaction vessel with a 275 watt General Electric*Sun Lamp; the amount of chlorine was sufficient to maintain a yellow color in the solutionO The temperature ranged from 35C
during the initial part of the chlorination and up to llS~C during the later part of the 6-hour reaction.
The reaction mixture was analy~ed by gas chromatography techniques and, when all of the 4-chloro-1,3-dioxolan-2-one had been consumed, the reaction was terminated. The product was principally 4,4,5-trichloro-1,3-dioxolan-2-one with les~er amounts of 4,5-dichloro- and 4~4,5,5-tetrachloro-derivatives. Two similar runs were made and ~he products combined~
~O ~luorination of 4,4,5-trichloro-1,3-35 dioxolan-2-one.
*denotes trade mark ~Z~38~)8 A shaker tube was charged with 113 g of crude 4,4,5-trichloro-1,3-dioxolan-2-one, 18 g of HF, and 194 g of SF4. After agitating 10 hours at 200C, the tube was cooled to 0C, and the product was mixed with ice. The organic phase was separated and neu~ralized by shaking with an aqueous potassium carbonate solution and then distilled on a 0.76 m spinning band column the ~irst fraction, 2,2,4,5-tetrafluoro-4,5-dichloro-1,3-dioxolane, b.p.
47-48C, was followed by the desired 2,2,4-trifluoro-4,5-dichloro-1,3~dioxolane, ~4g), b.~. 69-73C. Infrared and F-19 NMR spectra were consistent with this structure.
~xam~le 17 Preparation of 2,2,4-trifluoro 1,3-dioxole, (3g~, by dechlorination of 2,2,4-trifluoro-4,5-dichLoro-1,3-dloxolane, (4g).
A 100 mL, 3-neck, round bottom flask equipped with magnetic stirrer, thermometer, Vigreux still leading to a dry ice-cooled head, cold receiver and trap, was charged under a nitrogen blanket with 3~6 g of magnesium turnings, 0.2 g of mercuric chlorîde, 0.1 g of iodine, and 30 mL of tetrahydrofuran. The mixture was stirred and heated to 67C; 8.8 9 of 2,2,4-trifluoro-4,5-dichloro-1,3-dioxolane, (4g), was then added at a rate of 0.092 mL/minute. After 20 2 mL had been added the distillation began ~nd continued for 3 hours until 5 mL of distillate was obtained. The cold distillate was extracted with ice water to remove some tetrahydrofuran and there remained 4.7 g of product which was largely 2,2,4-trifluoro-1,3-dioxole, (3g), b.p. 10C.
This dioxole was purified by gas 35 chromatography; the infrared absorbance spectra, and especially the absorbance in the region of 5.fi ~m, a~
well as its subsequent polymerization substan~iated the assigned molecular structure.
ExamPle l8 A crystalline copolymer of tetrafluoro-ethylene with 2,2,4~trifluoro-1,3-dioxole, (3g~u A shaker tube was charged with 100 9 of 1,1,2-trichloro-1,2,2-tri~luoroethane, 0.8 g of the dioxole, 0.03 9 of bis~4-t-~utylcyclohexyl) peroxydicarbonate, and 10 g of TFE and heated at 55 and 65C or 4 hours. After separation of the product and drying, 4.7 ~ of a white solid polymer was obtained. A portion of this was pressed at 330C
to give thin, tough, self-supporting, colorless films. The infrared and F-~9 NMR spectra showed the copolymer composition to be 96.0 mole % TFE and 4.0 mole % dioxole. Differenti~l Scanning Calorimetry showed a crystalline melting point at 274C.
E~m~le 19 Homopolymer of 2,2,4-trifluoro-1,3-dioxole, ~3g).
A 10 mL clear, glass vial was charged with 5.7 9 of lfl,2-trichloro-1,2,2-trifluoroethane, 0.001 9 of bis(4 t-butylcyclohexyl~ peroxydi-carbonate, and G.S g of the dioxole, capped securely and allowed to stand two days on the bench ~op at about 25C exposed to the normal fluorescen~ light of the laboratory. A por~ion of the solution was then evaporated on a micro salt plate to give a ~lear, 3~ colorless, self supporting film which was identified by it~ infrared spectrum to be the dioxole homopolymer~
Example 20 An amorphous copolymer of TFE and 2~204 ~ri-fluoro-S-chloro 1,3-divxole, ~3~)c 2~

12(~38015 A shaker tube was charged with 100 g of 1,lr2-trifluoro-1,2,2-trichloroethane, 1.7 g of the dioxole, 0.03 g of bis(4-t-butylcyclohexyl) peroxy-dicarbonate, and 10 g of TFE. Polymerization was carried out at 55 and 65C under autogenous pressure for 4 hours. After separation and drying of the product, 1.8 g of a whitej solid polymer was obtained. A portion of this was pressed at 300C to give thin, tough, self-supporting, colorless clear films. The infrared and F-l9 N~R spectra of this polymer showed it to contain 10.5 mole % of the dioxole and 89.5 mole ~ of TFE. Differential Scanning Calorimetry showed a Tg of 61C; there was no melting point.
lS Example 21 An amorphous, elastomeric terpolymer of TFE, 2,2,4-trifluoro-5-chloro-1,3-dioxole, ~3f), and vinylidene fluoride.
A shaker tube was charged with 100 g of 1,1,2-trichloro-1,2,2-trifluoroethane, 2.1 ~ of the dioxole, 0.03 g of his(4-t-butylcyclohexyl~ peroxydi-carbonate, 6 g of vinylidene fluoride, and 6 9 of TFE. Polymerization was carried out at 55 and 65C
over a 4 hour period under autogenous pressure.
After separating and drying, there was obtained 2.5 g o~ white, solid polymer granules. A portion of this polymer was pressed at 200C to give thin, elastic, tough, self supporting, clear, colorless films.
~nfrared and F 19 NMR spectra showed the terpolymer to consist of 27.7 mole % of T~E, 9.~ mole % of the dioxole and 62.4 mole ~ of vinylidene fluoride.
Differential Scanning Calorimetry showed no melting point, thus indicating an amorphous polymer~

~5 :o l -~ ~203808 Example 22 Synthesis of 2,2-difluoro-1,3-dioxole, (3h).
A. 4,5-Dichloro-1,3-dioxolan-2-one A 500 mL, 3-neck round-bottom flask equipped 5 with a nitrogen purge line, magnetic stirrer, thermometer, and reflux condenser leading to a trap and drying tower was charged with 88 g of ethylene carbonate, 297 g of sulfuryl chloride, and 1.0 g of azobisisobutyronitrile. After purging the assembly 0 with nitrogen, the stirred mixture was irradiated with a Hanovia mercury vapor lamp at a temperature of 34-47C during the first 3 hours of the reaction.
During the next 7 hours, the temperature was increased from 51 to 103C. During the final 3 hours of the reaction, the temperature was held in the 95-107DC range.
After cooling to room temperature, the flask was evacuated on a water aspirator to remove small amounts of HCl. The flask contents were then flash-distilled at a pressure of abou~ 266 Pa and a pot temperature of up to 150C; 85.7 g of distillate was collected. GC analysis of the distillate showed it to contain approximately 86 3% of 4,5-dichloro-1,3-dioxolan-2-one, 8~8% of 4-chloro-1,3-dioxolan-2-one, and 3.1% of 4,4,5-trichloro-1,3-dioxolan-2-one.
B. 2,2-Difluoro-4,5-dichloro-1,3-dioxolane (4h) A 300 mL "Hastelloy" C shaker tube was charged with 136.2 g of 4,5~dichloro-1,3-dioxolan-2-one, 16.2 g of HF, and 194.4 g of SF4. The tube was then heated to 150~C and agitated for 300 hours.
After the tube was cooled to 0C, it was slowly vented and then its contents were dumped into ice.
The organic layer was separated and extracted twice ~121~3808 ` 27 with 50 mL of distilled water. The product weighed 93 . O g and contained about 69% of 2,2,4-trifluoro-5-chloro-1,3-dioxolane and abollt 7 of 2,2-difluoro-4,5-dichloro-5 1,3-dioxolane, t4h).
C. Dechlorination of 2,2-difluoro-4,5-di-chloro-1,3-dioxolane (4h) Equipment like that of Example 15B, except that a 100 mL fl~.sk was used, was charged with 7.8 g 10 of zinc dust, 0.2 9 of zinc chloride, and 40 mL of butyl alcohol. The stirreA mixture was h~ated to 114C; 6.5 ~ of crude 2,2-difluoro-4,5-dichloro-1,3-dioxolane (4h) was then added ~y a syringe pump at 0.092 mL/minute over a 52-min~te lS period. Distillation began 20 minutes after the beginning of the addition and continued for 94 minutes until 4.5 mL of distillate containing some butyl alcohol was obtained. The distillate ~as purified by ~as chromatography. The infrared 20 absorbance spectrum, especially the absorbance in the region of 6.0S ~m, was consistent with the 2,2-difluoro-1,3-dioxole structure (3h).
E~mple 23 Homopolymer of 2,2-difluoro~1,3-dioxole, (3h).
A shaker tube is charged with 3 9 of 2,2 difluoro-1,3-dioxole in 100 g of 1,1,2-trichloro-1,2,2-trifluoroethane, and 0.005 9 of bis~4-t butylcyclohexyl~ pero~ydicarbonate.
30 Polymerization is carried out at 55 and 6$C for 4 hours. After separating and drying the solid, white polymer, 0.6 g, ~ portion of it is pressed at ~50C
to give a tough, clear, transpar~nt, self supporting, t~in ~ilm, of the homopolymer, which i~ amorphous.

1~93~308 Example 24 A crystalline copolymer of tetrafluoroethylene and 2,2-difluoro-1,3-dioxole, (3h).
A shaker tube is charged with 1 9 of the dioxole in 100 9 of 1,1,2-trichloro-1,2,2-trifluoro-ethane, 0.03 g of bis(4-t-butylcyclohexyl) peroxydicarbonate, and 10 g of TFE. Polymerization is carried out ~t 55 and 65C. After separating and drying the pro~uct, 9.9 g of white, granular, solid, crystalline polymer is obtained. It contains approximately 93 mole ~ TFE and 7 mole ~ of the dioxole.
Exam~le 2~
Synthesis of 2,2-difluoro-4-chloro-1,3-dioxole, ~3i).
This synthesis is carried out in the same manner as that of Example 22, except that 106.7 g (0.5 mole) of 2,2-difl~oro-4~4,5-trichloro-1,3-dioxolane, (4i), prepared from 4,4,5-trichloro-1,3-dioxolan-2-one (Example 16A) is the starting material. Rectification of the product mix through a 0.76 m spinning band column gives 47.1 g of 2,2-difluoro-4-chloro-1,3-dioxole, t3i).
Example 26 A crystalline copolymer of TFE with 2 t 2-difluoro-4-chloro-1,3-dioxole, ~3i).
A shaker tube is charged ~ith 100 g of 1,1,2~trichloro-1,2,2-trifluoroethane containing 1 g of 2,2-d-ifluoro-4-chloro-1,3-dioxole, (3i), 0.03 g of bis(4-t-butylcyclohexyl) peroxydicarbonate, and 10 g of TFE. Polymerization is carried out at 55 and 65C. After separating and drying the product, S.2 g of a white solid gran~lar polymer is obtained. This is pressed at 300C into a tough, self-supporting, .! ' ~Z~3~
2g clear film. The polymer is crystalline and contains approximately 94 mole % TFE and 6 mole ~ of the dioxole.
Exa~ple 27 A Crystalline TFE/2,2-bis(trifluoromethyl)-4,5-dichloro-1,3-dioxole, (3e), copolymer A 110 mL ~haker tube was charged with 100 g of 1,1,2-trichloro-lr2,2-trifluoroethane, 3.0 g of the dioxole, 0.04 g bis(4-t-butylcyclohexyl) pero~ydicarbonate, 10 9 of TFE and heated 3.5 hours at 55 and 65~C under autogenous pressure. After separation and drying the product, 4.3 g of a white solid polymer was obtained. Differential thermal analysis showed a crystalline melting point at 312C;
the infrared spe~trum of a film possessed the absorbancies characteristic of the TFE/2,2-bis(trifluoromethyl)-4,5-dichloro-1,3-dioxole copolymer. By elemental analysis, the copolymer contained 0.44~ chlorine which corresponds to 0.6 2~ mole percent of dioxole.
Exa~ple 28 Synthesis of 2,2-difluoro-4,5-dichloro-1,3-dioxole, ~3i) A. Tetrachloroethylene Carbonate A 1000 mL creased flask equipped with a stirrer, thermometer and gas inlet tube, and topped by water and dry ice condensers, was charged with 352.4 9 (4 moles) of melted ethylene carbonate. The system was purged with nitrogen while ethylene carbonate was stirred and heated to 50C. After turning off the nitrogen, chlorine was introduced at a rapid rate and when the solution turned yellow, a sunlamp was l.it. The flow of chlorine and the intensity of the light were adjusted so that the solution remained yellow and the temperature did not 2~

~ l ~203808 exceed 80C during the first few hours of the chlorination. Later on, the temperature was increased to 100-120C.
The chlorination was continued until intermediates were no longer present in the product, as evidenced by periodic gas chromatographic analysis. When the product was free of the mono-, di-, and trichloro intermediates, it was distilled at a reduced pressure on a water aspirator. After the removal of chlorine and hydrogen chloride, the distillation was continued using a high vacuum pump.
B. 2,2-difluorQ-4,4,5,5-tetrachloro-1,3-dioxolane (4i) A 360 mL "Hastelloy" C shaker tube was charged with 113 g ~0.5 mole) of tetrachloroethylene carbonate, closed under nitrogen, cooled in *ry ice/acetoner evacuated, flushed with nitrogen, reevacuated and then charged with 18 g (0.9 mole) of HF and 194 g (1.8 mole) of SF4. The tube was then agitated for 10 hours at 200C. Following this, the tube ~as chilled in an ice-water bath and then slowly vented to remove the excess of SF4 and HF. The product was dumped from the tube into wet ice and allowed to stand a day. The water-product mixture was placed in a polyethylene separatory funnel, and ~he dioxolane (4;) was withdrawn into a polyethylene Erlenmeyer flask, weighed, and stirred one hour with 10 mL of a 30% K2CO3 solution in water (the pH of the aqueous phase must be alkaline). The dioxolane -(4;) was then separated and bottled. The 3 2,2-difluoro-4,4,5,5-tetrachloro-1,3-dioxolane (4j3 was dried over R2CO3 and distilled at a reduced pressure prior to use ~b.p. 126C at 101 KPa~. Fl9 NMR ~nd IR analyses supported the molecular structure.

81~ `

C~ Dechlorination of 2,2~d~fluoro~4,4,5,5-tetrachloro-1,3-di~xolane, l4j)O
~ 300 mL, 3-neck glass flask equipped with magnet$c stirrer, thermometer, Vigreux column w~h a water condenser to receiver, trap to a nitroge~ tee and bubbler was ~harged with l-propanol, 175 mL; zinc dust, 59.3 g; zinc ~hloride, 2.0 9~ After heating to reflux, the 2,2-difluoro-4,4,5,5-tetrachloro-lt3-dioxolane (4j), 74.3 9, was added by syringe pump at 0-33 mL/minute; The addition was complete in 148 minutes. Distillation was begun 40 minutes after the start of the addition and continued for 6 hours until 72 m~ of distillate was collecte~. The pro~uct was 98.7% pure desired dioxole, (3j), at 100~ conversion lS of the dioxolane; the distillate which containe~ some propan~l was redistilled through a 0.51 m spinnin~
band column to separate the dioxole, (3j), b.p.
64-65~C, at a purity of 98.6%~ A 3.66 m x oO06~ m diameter 30% Xrytox* perfluoroether (Du Pont Co.) column at 60C was used in ~he analysis. The infrared sRectrum was consistent with the structure.
~xample 29 A crystalline TFE/2,2-difluoro-4,5-dichloro-1,3-dioxole, (3i), copolymer.
A 110 mL shaker tube was charged with 100 g of 1,1,2-tr;~.hlnro-1,2,2-~r;fl.l~),ueUlane, 1.8 g of the ~;o~
0.04 g of bis~4-_-butylcyclohexyl~ peroxydi~dlL~a~e, and 10 g of tetr~fll~r~eU~lene and heated 4 hours at 60-65C. Afte~
s~d~dLion of the insoluble pLU~U1'L and dryLng, 2.4 g of a white solid polymer was obt~ined. Differential Sc~nn;n~ ~lnr;mp.try showed a major c~ystalline melting point at 310C and a ~ullor one at 297C.
F-l9 NMR analysis shohred the copolymer to onnt~;n 1.4 mole ~ of the ~;nxnl~ (3j). Both the infræed and F-l9 ~MR ~cLl~ agreed with the copolymer ~LLU~LU1~.
This application is a division of c~Pn~;n~ l;c~tion Serial No. 451 912, filed 1984 ~pril 12, which in turn is a division of c.~n-l;n~ rl;c~ n Serial No~ 427 320, filed 1983 May 03.
*denotes trade mark

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A dioxolane having the formula wherein R is a fluorine and Y is hydrogen or chlorine.