.

9. 10.

T. I. Filyakova, A. Ya. Zapevalov, and I. P. Kolenko, et al., Izv. Akad. Nauk SSSR, Ser. Khim., No. 8, 1878 (1979). V. M. Rogovik, S. D. Chepik, N. I. Delyagina, et al., Izv. Akad. Nauk SSSR, Ser. Khim., No. 9, 2063 (1990). V. M. Rogovik, N. I. Delyagina, E. I. Mysov, et al., Izv. Akad. Nauk SSSR, Ser. Khim., No. 9, 2057 (1990).

FLUOROALIPHATIC ESTERS OF FLUOROSULFONIC ACID. 2. REACTION OF BIS(FLUOROSULFATO)PERFLUOROALKANES WITH CESIUM FLUORIDE UDC 542.92:547.412.92+546. 865"161:547.446.6"161

V. M. Rogovik, N. I. Delyagina, E. I. Mysov, V. F. Cherstkov, S. R. Sterlin, and L. S. German

2,3-Bis(fluorosulfato)perfluoroalkanes split under the action of CsF in the absence of solvents, giving a mixture of e~-fluorosulfatoperfluoro ketones, perfluoroalkene sulfates, and perfluoro a-diketones. The occurrence of these reactions in solutions results mainly in the formation o/oxides of the corresponding fluoroolefins or products o/ their conversions. The reactions carried out are the first examples of nucleophilic substitution at a secondary carbon atom in a perfluorinated saturated chain. Perfluorinated ketones and alkanoyl fluorides are known to add alkali metal fluorides with the formation of the alkoxides of perfluoro alcohols, which have found extensive application in syntheses [1]. We found that fluoroaliphatic esters of fluorosulfonic acid in the presence of stoichiometric quantities of K F or CsF are convenient sources of perfluoroalkoxides of these metals. For example, the reaction of a,oJ-bis(fluorosulfato)perfluoroalkanes Ia-c with Me,SO 4 in DMF in the presence of 2 moles of CsF gives dimethoxyperfluoroalkanes IVa-c. Diether IVa can be synthesized with practically the same yield on the basis of fluorosulfatodifluoroacetyl fluoride II, and diether IVc can be obtained from perfluoroadipyl difluoride acid III. CsF

F SO2OCF~(CF2--CF2)nCF2OSO2F - - - 2-S O , F , (I a - - c ) FSO2OCF2COF (ii) FOCCF~CF2COF (hi)

CsF

--80,F CsF

I

----~[~s(~CF2(CFr--CF2)nCF2(~s]

Me,S04 MeOCF~(CFz--CF2)nCFsOMe

(IV a - - c ) n = 0 (a), 1 (b), 2 (e).

It might be expected that the analogous reaction of 2,3-bis(fluorosulfato)-4-trifluoromethylperfluoropentane V will give dimethyl ether VII, which is a derivative of a-diketone VI; the decomposition of V under the action of CsF with the formation of VI was previously demonstrated in [2]. However, it turned out that the only product of the reaction of V with Me2SO4/CsF is monomethyl ether VIII, which is a derivative of perfluoroethyl isopropyl ketone, whose formation from bis(fluorosulfate) V is possible only when an FSO 3 group is replaced by a fluorine atom.

(CFs)2CF--CF--CF--CFa

CsF

OSOzF

FS020

(v)

Me~S04,

A. N. Nesmeyanov Institute of Organometallic Compounds, Academy of Sciences of the USSR, Moscow. Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2057-2063, September, 1990. Original article submitted July 7, 1989. 1870

0568-5230/90/3909-1870512.50 9

Plenum Publishing Corporation

0 --*

0

CsF [ ( C F ~ ) . , C F - - C - - C - - C F z ] ~ - - (CF3),,CF--CF--CF--CF., (VI)

(VII)

OMe

OMc

---~ ((;F:,)~CF--(:F--CF.,--(:F~ }

(~Mc (VIII)

The nucleophilic replacement of an unactivated fluorosulfato group was not previously observed in perfluorinated compounds. As it turned out, in the absence of a solvent, bis(fluorosulfate) V is split under the action of catalytic amounts of CsF with the formation of a mixture of ~-keto fluorosulfate IX, c~-ketone VI, and cyclic sulfate X as a minor impurity. Similar compounds were also obtained as a result of the decomposition of unbranched bis(fluorosulfate) XI; however, in that case, the principal sulfur-containing product is cyclic sulfate XII.

FSOzO

OSOzF

(7), (m

00SOzF

(~x), (x~z;

----

RF- F~FF'F-~F31 ~ O\ /13 50Z

(x), (m)

FSOZO

0

(zz~), ( x ~

t

(

RF-~- ~F-f'Fa 0 05DzF

R~- C-C-CF31t , 0 0

(~z), (xz~)

(zz), (x~)

~r = i-hF, (7), (zz), (rr), (x),(xz~), (zeza), (zero)

Rr = qF7 (zz), (m),(~), (rex), (z~),(zer~),(zzr4

The e - k e t o fluorosulfates obtained as a result of the decomposition of V and XI are represented only by the isomers in which the carbonyl group is located closer to the middle of the molecule (compounds IX and XIV). Selectivity of the nucleophilic attack of the fluoride ion at the fluorosulfato group in position 3 of the original bis(fluorosulfates) is unlikely. Apparently, mixtures of isomeric c~-keto sulfates IX and XVa and of XIV and XVb form initially. In the presence of CsF, they give an equilibrium mixture of the alkoxides of c~-fluorosulfatoperfluoro alcohols X V I a - d , in which the equilibrium is shifted toward alkoxide XVIa or X V I b due to the steric factors (when a bulky perfluoroisopropyl group is present in the molecule, this difference is especially pronounced). The subsequent intramolecular perfluorosulfonation of more stable alkoxides XVIa and X V I b displaces the equilibrium in favor of alkoxides XVIc and XVId, whose lower stability is ultimately also responsible for the exclusive formation of a - k e t o fluorosulfates IX and XIV, and the nucleophilic replacement of the fluorine atom in the FSO s results in the cyclization of X V I a - d to sulfates X and XII. In the presence of CsF, the latter, in turn, form an equilibrium mixture with the corresponding e - k e t o fluorosulfates, in which the relative content of the components is also determined by steric factors.

1871

Confirmation of the proposed scheme is provided by the formation of a mixture of IX and X of identifical composition both from cyclic sulfate X and from a mixture of a - k e t o fluorosulfates IX and XVa under the action of CsF. The reaction of bis(fluorosulfate) XVII, which contains fluorosulfato groups at secondary and tertiary carbon atoms, with CsF gives a mixture of practically equal amounts of c~-keto sulfate XVIII and cyclic sulfate XIX. The latter is also clearly obtained as a result of the cyclization of X V I I I under the action of CsF, as is confirmed by the formation of a mixture of identical composition when X V I I I is reacted with CsF.

(CFa)2C--CFCzF~ [C~F]__(CFa)~-C--CC2F~ [csrl

I

~

FSO..O OSO2F

(XVII) -

[ (c~,)c

CFc~F~ ]

I

I il FS020 0 (XVIII)

,

" (CF=)=C

s

CFC#,

o'

o~s.o~"-~

\

~)

/

'

S02 (XIX)

The reaction of bis(fluorosuifates) with CsF in solutions has a fundamentally different character. In this case, the principal products are oxides of the corresponding fluoroolefins or products of their further conversions. It is obvious that here, too, the alkoxides of c~-fluorosulfatoperfluoro alcohols also appear as intermediates and that in a medium of a solvating solvent they attack the a - c a r b o n atom and undergo cyclization with the elimination of an FSO 3" anion. The usual splitting for fluoroaliphatic fluorosulfates in the presence of alkali metal fluorides with the formation of carbonyl compounds is realized to an insignificant extent and is observed mainly when solvents with lower dielectric constants are employed. For example, the reaction of V with CsF (in a V:CsF mole ratio equal to 1:1) in diglyme gives a mixture of 4trifluoromethyl-2,3-epoxyperfluoropentane X X I (24%) and ~-diketone VI (58%). In DMF the same reaction results in the formation of a mixture of X X I (69%) and ~-keto fluorosulfate IX (30%). A higher yield of X X I (84%) is obtained when equimolar amounts of IX and CsF are reacted in DMF. At the same time, the analogous reaction in diglyme results in the predominant formation of the a - d i k e t o n e (60%); the yield of oxide X X I is then equal to only 23%.

(~)

-

(~)

(CFo)zCF~C-- CF--CFa m ,

'

so ivent

('CF~)zCF-CF-GF-GF~ \/ 0

(~)

csv (V) - -

'

DMF

~ (XXI)+(IX) 69% 3t %

Diglyme

CsF . ( [X) - -

DMF

(XXI) 84 %

Diglyme

(xx~) + (v~) 24% 58%

, ( x x ; ) + (vJ) 23% ~u%

The recovery of a - o x i d e X X I also makes it possible to explain the formation of methyl perfluoroisohexyl ether VIII in the reaction of V with M%SO 4 in the presence of an excess of CsF: intermediately obtained oxide XXI isomerizes to ketone XXII, which is methylated under the action of Me2SO4/CsF. In the absence of MezSO 4, ketone XXII, whose formation still could not be detected, mainly undergoes haloform splitting, as is evidenced by the recovery of perfluoropropionic acid X X I I I after the decomposition of the reaction mass by water.

1872

[F-]

CsF (V)

~ [XXl]

~

(CFa)2CF--C--C2F s ~

(XX[l)

C2FsCOF + [CFaCF----CF2]

0

(XX) ~Lo

t

, MeaSOdCsF !

Co.FsCO01[ (xxiil)

(viii)

The general character of the intramolecular nucleophilic substitution in the a-fluorosulfatoperfluoro ketones or their precursors in the presence of F- is confirmed by the synthesis of 2,3-epoxyperfluorohexane X X I V from a mixture of a - k e t o fluorosulfate XIV and cyclic sulfate XII according to the scheme

CsP

(xiJ) + (xlv) DN'

> CaFrCF--CF--CF \ /

3

O

(xxlv)

as well as 2 - t r i f l u o r o m e t h y l - 2 , 3 - e p o x y p e r f l u o r o p e n t a n e X X V I from bis(fluorosulfate) XVII. In the latter case, the yield of oxide X X V I and its isomerization product, viz., ketone XXII, is low due to the low stability of intermediately formed c~-keto fluorosulfate X V I I I in the presence of F-, whose haloform decomposition gives hexafluoroacetone and perfluoropropionyl fluoride XX. The attempts to suppress this process by binding the O" anion X X V with Me2SO 4 were unsuccessful. The reaction of XVII with Me2SO4/CsF in DMF at 0~ gives a mixture of methyl perfluoropropyl ether X X V I I and methyl perfluoroisopropyl ether XXVIII, and the formation of insignificant quantities of ether VIII and diether X X X in addition to XXVII, XXVIII, and 2 - m e t h y l - 2 - t r i f l u o r o m e t h y l p e r f l u o r o p e n t a n e X X I X was observed only in the analogous reaction at 20~

,.~M<,m,/CSF j

(z~'~/"

]

,i ~ .~

l/ LLSrJ

'l

I

f

[cscF:cr~]+(zz) i [r.sF]

r.,3P.rC(tr3)2r.Hs

EXPERIMENTAL The N M R spectra were recorded on a Perkin--Elmer R-32 spectrometer (90 MHz for 1H and 84.6 MHz for 19F) and a Bruker WP-200 SY spectrometer (200 MHz for 1H and 188.3 MHz for 19F). The chemical shifts are given in parts per million relative to the external references TMS and CF3COOH. The IR spectra were recorded on a U R - 2 0 instrument. The mass spectra were recorded on a VGMS 70-70e spectrometer with an ionizing voltage of 70 eV; m / z and the proposed assignment followed by the intensity in percent in parentheses are presented. 1,2-Dimethoxytetrafluoroethane (IVa). A mixture of 19 g of dry CsF and 30 ml of absolute DMF was given a dropwise addition of 13 g of bis(fluorosulfate) Ia with stirring (0~ and then an addition of 13 g of (CH3)2SO4. The mixture obtained was stirred at 10~ for 4 h, and the reaction products were distilled at 20~ (5 mm Hg). Fractionation of the distillate gave 4.7 g (66%) of ether IVa, bp 95-97"C. Found: C, 29.05; H, 3.57; F, 46.75%. Calculated for C4HsF1402: C, 28.39; H, 3.70; F, 46.94%. 19F N M R spectrum: 16.6 s (CF2). 1H N M R spectrum: 3.5 s (CH3). The reaction of 9 g of fluorosulfato acid fluoride II and 20 g of CsF in 20 ml of DMF with 20 g of (CH3)2504 (15~ 3 h) was carried out in a similar manner; ether IVa was obtained with an 80% yield.

1873

1,4-Dimethoxyoctafluorobutane (IVb). A mixture of 15.5 g of dry CsF, 35 ml of absolute of DMF was given a dropwise addition of 14 g of bis(fluorosulfate) Ib with stirring (0~ and then 13 g of (CHs)2SO 4 were gradually added. The mixture was stirred at 20~ for 2 h and poured into HCI (1:5), and the organic layer was separated, washed with water, and dried by MgSO 4. Distillation gave 10.8 g (82%) of ether IVb, bp 134~ Found: C, 27.26; H, 2.23%. Calculated for C6H6FaO: C, 27.48; H, 2.29%. 19F NMR spectrum: 12 t (CF20); 49.5 t (CF2); JCF2_CF2O = 3.8 Hz. 1,6-Dimethoxydodecafluorohexane (IVc). The reaction of 4 g of bis(fluorosuifate) Ic and 6 g of CsF in 15 ml of absolute tetraglyme with 3 g of (CHs)2SO 4 was carried out in analogy to the synthesis of IVb. This gave 2 g (69%) of ether IVc, bp 165-167"C. Found: C, 26.38; H, 1.66; F, 62.96%. Calculated for CaH6FlzO2: C, 26.52; H, 1.66; F, 62.98%. 19NMR: 11.8 m (CF~O); 45.5 m (CF2)2; 58.6 m (CF2) 2. Ether IVc was obtained with a 75% yield in a similar manner from 18 g of CsF, 30 ml of tetraglyme, 13 g (CHa)2SO4, and 15 g of acid fluoride III. Reaction of 4-Trifluoromethyl-2,3-bis(fluorosulfato)perfluoropentane (V) with (CHs)2SO4/CsF. A mixture of 25 g of dry CsF, 50 ml of absolute DMF, 25 g of (CHa)2SO 4 was given a dropwise addition of 20 g of bis(fluorosulfate) V with stirring (7~ the mixture obtained was stirred for 4 h (20~ and the reaction products were distilled at 20~ (50 mm Hg). Subsequent redistillation gave 10.1 g (72%) of ether VIII, bp 98-100~ Found: C, 24.29; H, 1.03; F, 69.71%. Calculated for CTHaFlzO: C, 24.00; H, 0.85; F, 70.07%. 19F NMR spectrum: --4.8; --2.8 (CFa)2C; 4.8 (CHz); 45.3 (CF2); 57.6 (CFO); 107 (CF); broadened signals with a 6:3:2:1:1 intensity ratio. 1H NMR spectrum: 3.6 s (CHs). Reaction of 4-Trifluoromethyl-2,3-bis(fluorosulfato)perfluoropentane (V) with CsF. A mixture of 20 g of bis(fluorosulfate) V and 1.1 g of dry CsF was stirred at 20~ for 8 h, and the reaction mixture was filtered out. This gave 13.2 g of a mixture containing the following (GLC): 16.5% diketone VI [2], 77.5% keto fluorosulfate IX, 0.5% cyclic sulfate X [3], and 5.4% bis(fluorosulfate) V. The reaction mixture was washed with .water and dried by MgSO 4. Distillation gave 10.1 g (63.5%) of keto fluorosuifate IX, bp 108-1090C (GLC, 19F NMR) [4]. Reaction of 2,2-Bis(fluorosulfato)perfluorohexane (XI) with CsF. A mixture of 14.6 g of bis(fluorosulfate) XI and 0.5 g of dry CsF was stirred for 20 rain (30~ and the reaction products were distilled o f f in a vacuum into a trap (--78~ This gave 9.7 g of mixture containing the following (GLC, 19F NMR): 19.7% diketone XIII [2], 20.6% keto fluorosulfate XIV [4], and 59.7% cyclic sulfate XII. Subsequent distillation gave 1.6 g of diketone XIII with bp 25~ (102 mm Hg) and 7.2 g of a fraction with bp 60-62~ (102 mm Hg) containing (GLC) 23.6% keto fluorosulfate XIV and 76.4% cyclic sulfate XII. Found: C, 18.34; F, 57.87%. Calculated for C6F1204S: C, 18.19; F, 57.56%. IR spectrum of keto fluorosulfate XIV (~,, cm-1): 1490 (S=O), 1785 (C=O). IR spectrum of cyclic sulfate XII (v, cm-1): 1475 (S=O). 19F NMR spectrum of XII: CFa~--CFzZ--CF~'4--CF~--CF6--CFa7 i I O () \/ 1.8 m (FT); 4.6 m (FI); 47 m, 48.5 m (F s, F6); 49.3 m (F~); A B quartet with a center at 43.8, A6 = 4 (F3,4), and JAB = 320 Hz.

Reaction of 4-Trifluoromethylperfluoropent-2-ene Sulfate (X) with CsF. A 2.2-g portion of cyclic sulfate X was given an addition of 0.1 g of dry CsF with stirring, and the mixture obtained was stirred for 20 min and then filtered. This gave 1.1 g of a mixture containing (GLC, 19F NMR) 87.8% keto fluorosuifate IX, 11.6% of diketone VI, and 0.6% of cyclic sulfate X. Reaction of a- Fluorosuifatotetrafluoroethyl Heptafluoroisopropyl Ketone (IX) and ~Fiuorosuifatooctafluoroisobutyl Trifluoromethyi Ketone (XVa) with CsF. A catalytic quantity of dry CsF and a mixture of keto fluorosulfates IX and XVa in a 3:2 ratio were placed in an NMR ampul, and the mixture obtained was held at 20~ for 30 min and treated with concentrated H2SO4. The organic layer contains (GLC, 19F NMR) 91% keto fluorosulfate IX, 5.7% cyclic sulfate X, and 3.3% diketone VI. Reaction of 2-Trifluoromethyl-2,3,-bis(fluorosulfato)perfluoropentane (XVII) with CsF. A mixture of 2 g of dry CsF andl2 g of bis(fluorosulfate) XVII was stirred at 20~ for 1.5 h and poured into water and the organic layer was separated and dried with MgSO 4. Distillation gave 7.5 g of a fraction with bp 112-113~ containing (GLC) 47% keto fluorosulfate XVIII [5] and 53% cyclic sulfate XIX. mF NMR spectrum of XIX: --7.1 m (CFa/~C), --5.9 m _( F >C), 4.1 m (CFz), 38.2 m (CF), AB quartet with a center at 46.2 (CH2), JAB = 300 and JCFs--CF = 16 Hz. Mass spectrum of

1874

XIX: 377 [M - F] + (t.1), 277 [M - C2Fs] + (2.6); 169 [CsFT] + (9.4), 147 [C3FsO] + (30.8), 119 [CzFs] + (19.6), 97 [CzF30] + (23.8), 83 [SO2F] + (8), 69 [CFs] + (100), 64 [SO2] + (3.9), 48 [SO] + (2.7), 47 [COF] + (4.1). Reaction of 4-Trifluoromethyi-2,3-bis(fluorosulfato)perfluoropentane (V) with CsF in Aprotic Solvents. A mixture of 3 g of dry CsF and I0 ml of absolute diglyme was given a dropwise addition (5~ of I0 g of bis(fluorosulfate) V with stirring. The reaction mixture was stirred for 1 h at 5~ and the lower layer was separated. This gave 1.5 g (24%) of oxide X X I (GLC, 19F NMR) [6]; the upper layer was poured into water, and the organic layer was separated and distilled over concentrated HzSO 4. This gave 3.5 g (58%) of diketone VI, bp 52~ (GLC, 19NMR)

[2]. T h e reaction of 10 g of bis(fluorosulfate) V with 3 g of CsF in 15 ml of DMF (5~ was carried out in a similar manner, and distillation of the reaction mass at 20~ (10 mm Hg) gave 6.5 g of a mixture containing 69% oxide XXI and 31% keto fluorosulfate IX (GLC, 19F NMR). A mixture of 25 g of dry CsF and 50 ml of absolute DMF at 5~ was gradually given an addition of 20 g of bis(fluorosulfate) V with stirring, then the reaction mixture was stirred at 20~ for 4 h, and distillation of the reaction mixture at 80~ (80 mm Hg) gave 2 g (16%) of ketone XXII (GLC, 19F NMR) [6]. The reaction mass was poured into HCI (1:5), extracted by three 30-ml portions of ether, washed with water, and dried with MgSO 4. The residue remaining after the ether was driven o f f was distilled over concentrated H2SO 4, and 5 g (76%) of acid X X I I I with bp 95-99~ (19F N M R ) were obtained. Reaction of ~-Fiuorosulfatotetrafluoroethyl Heptafluoroisopropyl Ketone (IX) with CsF. The reaction of 7 g of keto fluorosulfate IX with 2.7 g of CsF in 15 ml of DMF was carried out in analogy to the preceding experiment. The lower layer was separated from the reaction mass, and its subsequent distillation gave 4.7 g (84%) of oxide XXI, bp 48~ (GLC, 19F NMR). Reaction of c~-Finorosnlfatotetrafinoroethyl Heptafluoropropyl Ketone (XIV) and P e r f l u o r o - 2 - h e x e n e Sulfate ( X I I ) with CsF with DMF. The reaction of 5.8 g of a mixture of keto fluorosulfate XIV and cyclic sulfate XII with 2.2 g of CsF in 10 ml of DMF was carried out under the conditions of the experiment with V. The mixture was stirred for 1 h at 200C, and the lower layer was separated. Subsequent distillation gave 3.1 g (67%) of oxide XXIV, bp 50-52"C (19F N M R ) [7]. Reaction of 2-Trifluoromethyi-2,3-bis(fluorosulfato)perfluoropentane (XVII) with CsF in DMF. A mixture of 7 g of dry CsF and 30 ml of absolute DMF was given a dropwise addition of I0 g of bis(fluorosulfate) XVII with stirring (5~ The mixture obtained was stirred for 1 h at 10~ and distillation at 20~ (10 mm Hg) gave 0.3 g of oxide X X V I (GLC, 19F N M R ) [6]. The residue was poured into HC! (1:5), extracted by three 40-ml portions of ether, washed with water, and dried with MgSO 4. Distillation gave 1.5 g of ketone X X I I with bp 50~ (GLC, 19F NMR) [6] and 6 g of a fraction with bp 93-105~ containing (19F N M R ) (CF3)zC(OH)2 and CFzCFzCOOH in a 1:1 ratio. Reaction of 2-Trifluoromethyi-2,3-bis(fluorosulfato)perfluoropentane (XVII) with ( C H s ) ~ O 4 / C s F in DMF. A mixture of 25 g of dry CsF and 35 ml of absolute D M F was given a dropwise addition of 20 g of bis(fluorosulfate) XVII with stirring (5~ and then 22.6 g of (CHs)2SO 4 were gradually added. The mixture was stirred at 20~ for 3 h, and 10 g were driven o f f at 30~ mm Hg. Subsequent distillation gave 7.5 g (47%) of a mixture of ethers XXVII and X X V I I I with bp 33-35~ (GLC, 19F N M R ) [8], 1.5 g of a fraction with bp 80-130~ containing (GLC) 37% 2methyl-2-trifluoromethylperfluoropentane (XXIX), 45% ether VIII, and 18% diether XXX. Mass spectrum of XXIX: 315 [M - - F] + (10.2), 295 [M - - HFz] + (4.2), 227 [M - - CFs] + (13.8), 215 [M - - C~Fs] + (29.1), 207 [M - - CzHFs] + (1.I), 195 [M - - C2HFe] + (8.4), 177 [M - - C~FT] + (8.1), 169 [CsF7] + (13.7), 163 [M - - C3H2FT] + (3.5), 145 [M - - C3HFs] + (8.1), 127 [M - - CzFg]+ (44.9), 119 [C2F5] + (10.7), 100 [C2F4] + (5.4), 95 [CsHzF3] + (3.8), 77 [C3H3F2] + (16.9), 69 [CF3] + (100). Mass spectrum of XXX: 331 [M - - OCHz] + (3.1), 313 [M - - CzH6F] + (1.2), 297 [C6FllO] + (8.7), 281 [C~FlI] + (3.2), 247 [C5F90] + (2.9), 231 [C5F9] + (2.5), 197 [C4F70] + (4.6), 185 [C3F70] + (5.8), 181 [C4H3F60] + (100), 147 [CzFsO] + (40.5), 131 [C3Fs] + (29.6), 97 [C9F30] + (21.9), 69 [CF3] + (73). L I T E R A T U R E CITED 1.

2. .

J. A. Joung, J. Org. Chem., 42, 4055 (1977). M. A. Kurykin, L. S. German, Yu. N. Studnev, and A. V. Fokin, Izv. Akad. Nauk SSSR, Ser.-Khim., No. 7, 1679 (1980). V. M. Rogovik, Ya. I. Koval'skii, N. I. Delyagina, et al., Izv. Akad. Nauk SSSR, Ser. Khim., No. 9, 2048 (1990).

1875

4.

5. 6. 7. .

T. I. Filyakova, A. Ya. Zapevalov, I. P. Kolenko, et al., Izv. Akad. Nauk SSSR, Ser. Khim., No. 8, 1878 (1979). V. M. Rogovik, S. D. Chepik, N. I. Delyagina, et al., Izv. Akad. Nauk SSSR, Ser. Khim., No. 9, 2063 (1990). A. Ya. Zapevalov, T. I. Filyakova, and I. P. Kolenko, Izv. Akad. Nauk SSSR, Ser. Khim., No. 12, 2812 (1979). I. P, Kolenko, T. I. Filyakova, A. Ya. Zapevaiov, and 1~. P. Lur'e, Izv. Akad. Nauk SSSR, Ser. Khim., No. 1 I, 2509 (1979). USA Patent 3,962,460; Chem. Abstr., 85, 142632 (1976).

FLUOROALIPHATIC ESTERS OF FLUOROSULFONIC ACID. 3. DECOMPOSITION OF POLY(FLUOROSULFATO)PERFLUOROALKANES UNDER T H E ACTION OF ANTIMONY PENTAFLUORIDE

UDC 542.91:547.446.5+546.224:546.34"131

V. M. Rogovik, S. D. Chepik, N. I. Delyagina, E. I. Mysov, V. F. Cherstkov, S. R. Sterlin, and L. S. German

Vicinal bis(fluorosulfato)perfluoroalkanes containing FSO 3 groups in the middle of a fluorocarbon chain eliminate one or two molecules of sulfuryl fluoride under the action of SbF s, forming a mixture o f isomeric a-fluorosulfato ketones and a-diketones.

1-Fluorosulfatoperfluoroalkanes react with SbF s at 50-80"C to form perfluoroalkanoyl fluorides and SO2F~. [1]. It has been shown in the present work that vicinal bis(fluorosulfato)perfluoroalkanes Ia and Ib, which contain FSO 3 groups in the middle of a fluorocarbon chain, also eliminate SO2F z in the presence of SbFs, but under considerably more severe conditions, i.e., at 135-140~ In the case of 2,3-bis(fluorosulfato)perfluorohexane Ia, the elimination of either one or two molecules of SOzF 2 with the formation of a mixture of isomeric a-fluorosulfato ketones IIa and Ilia and c~-diketones IVa takes place under the action of SbF s, and cyclic sulfate V forms as a minor component. When bis(fluorosulfate) Ib is treated with SbFs, it is also converted into the corresponding a-fluorosulfato ketones lib and Illb and a-diketone IVb, but the formation of a cyclic sulfate, i.e., an analog of V, is not observed in this case. FFCF--CFCFa~

,---I j

FSO20 OSO..F

I

l III,,CF_CFCF3 l +

I

i

j

SOlO OS02FJ

[S],F,]

I

FS020 OSO2F

I+

i

--L

I (Ia, b)

I

!

t)

I

o

\ St/)2 (V)

I

FSO~.O

OSO2FJ

0 o oo I/ II II tlFCCFCFa'{- IIpCFCCFa -[Sl,Fd - - - IIFCCCF,~ OSO~F FSO~O (II a,b) (1II a, b) II~, = n_CzF7 (a); i-C3F7(b).

(1Va,b)

A. N. Nesmeyanov Institute of Organometallic Compounds, Academy of Sciences of the USSR, Moscow. Translated from lzvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2063-2065, September, t990. Original article submitted July 7, 1989. 1876

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