Dental Materials With Light-Induced Reversible Coloring

Abstract

The invention relates to a radically polymerizable dental material having photochromic properties, which contains at least one compound of formula (I) and optionally radically polymerizable monomers, an initiator for radical polymerization and other components.

Claims

1. A radically polymerizable dental material, characterized in that it contains at least one compound of Formula (I), ##STR00015## in which the variables have the following meanings: X, Y independently of each other are O, S, Se, CH.sub.2, NR.sup.11 or CR.sup.12R.sup.13, wherein R.sup.11 to R.sup.13 independently of each other in each case are a branched or unbranched C.sub.1-C.sub.16 alkyl radical, aryl or CH.sub.2-aryl; R.sup.1, R.sup.2 independently of each other in each case are a branched or unbranched C.sub.1-C.sub.3 alkyl radical, wherein these alkyl radicals can be substituted by one or more fluorine atoms; R.sup.5; R.sup.6 independently of each other in each case are halogen, CN, COOH, COOR.sup.4, CH.sub.2OH, CONH.sub.2, CH.sub.2NH.sub.2, wherein R.sup.4 is a C.sub.1-C.sub.6 alkyl radical, aryl or alkyl-aryl, or R.sup.5 and R.sup.6 together form a (CH.sub.2).sub.n, C(O)OC(O) or C(O)NR.sup.3C(O) group, wherein n is 3 or 4 and R.sup.3 is H, a C.sub.1-C.sub.6 alkyl radical, aryl or alkyl-aryl and wherein in the (CH.sub.2).sub.n group one or more or all of H atoms can be replaced by F; R.sup.7-10 independently of each other in each case are H, a C.sub.1-C.sub.12 alkyl radical, which can be interrupted by O, OC(O)NH or phenylene, or an aromatic C.sub.6-C.sub.10 hydrocarbon radical, wherein these radicals in each case can carry a radically polymerizable group, or R.sup.7 and R.sup.8 and/or R.sup.9 and R.sup.10, together with the C atoms to which they are bonded, form a benzene ring, which can be unsubstituted or which can carry 1 to 4 substituents, which are selected from halogen, CN, CO-aryl, COCH.sub.2-aryl, COO-aryl, COOCH.sub.2-aryl, branched or unbranched C.sub.1-C.sub.16 alkyl radicals, O-alkyl, CO-alkyl and COO-alkyl, wherein alkyl in each case stands for a branched or unbranched C.sub.1-C.sub.16 alkyl radical and wherein all alkyl radicals can be substituted by one or more fluorine atoms.

2. The dental material according to claim 1, in which the variables of Formula I have the following meanings: X, Y independently of each other are O, S or NR.sup.11, wherein R.sup.11 is a branched or unbranched C.sub.1-C.sub.6 alkyl radical; R.sup.1, R.sup.2 independently of each other in each case are a C.sub.1-C.sub.2 alkyl radical, wherein these alkyl radicals can be substituted by one or more fluorine atoms; R.sup.5; R.sup.6 together form a (CH.sub.2).sub.n group, wherein n is 3 or 4 and wherein in the (CH.sub.2).sub.n group one, or more, or all H atoms can be replaced by F; R.sup.7-10 independently of each other in each case are H or a C.sub.1-C.sub.6 alkyl radical, which can be interrupted by O or OC(O)NH, wherein one or more H atoms can be substituted by fluorine atoms and wherein 1 or 2 of the radicals R.sup.7-10 carry a radically polymerizable group, or a (meth)acrylate group.

3. The dental material according to claim 2, in which the variables of Formula I have the following meanings: X, Y in each case are S; R.sup.1, R.sup.2 in each case are methyl; R.sup.5; R.sup.6 together form a (CH.sub.2).sub.n group, wherein n is 3 and wherein all H atoms are replaced by F; R.sup.7, R.sup.9 independently of each other in each case are H or a C.sub.1-C.sub.3 alkyl radical; R.sup.8, R.sup.10 independently of each other in each case are a C.sub.1-C.sub.6 alkyl radical, which can be interrupted by O or OC(O)NH and which carries a terminal radically polymerizable group, or a methacrylate group.

4. The dental material according to claim 1, wherein R.sup.7 and R.sup.8 stand for a group with Formula Ia and R.sup.9 and R.sup.10 stand for a group with Formula Ib ##STR00016## and, together with Formula I, form Formula (II): ##STR00017## in which R.sup.a, R.sup.b, R.sup.c, R.sup.d and R.sup.a, R.sup.b, R.sup.c, R.sup.d independently of each other in each case have the following meanings: H, halogen, CN, a branched or unbranched C.sub.1-C.sub.16 alkyl radical, O-alkyl, CO-alkyl, COO-alkyl, wherein alkyl in each case stands for a branched or unbranched C.sub.1-C.sub.16 alkyl radical and wherein all alkyl radicals can be substituted by one or more fluorine atoms, CO-aryl, COCH.sub.2-aryl, COO-aryl, COOCH.sub.2-aryl; wherein the radicals R.sup.a, R.sup.b, R.sup.c, R.sup.d or R.sup.a, R.sup.b, R.sup.c, R.sup.d can be linked to each other, forming one or more non-aromatic or aromatic rings or annulated aromatic ring systems, which have 2 to 5 rings, wherein the rings or ring systems can be substituted or unsubstituted.

5. The dental material according to claim 4, wherein the variables have the following meanings, which can be chosen independently of each other: X, Y independently of each other in each case are 0, NR.sup.11, wherein R.sup.11 is a branched or unbranched C.sub.1-C.sub.16 alkyl radical, N-aryl or NCH.sub.2-aryl; R.sup.1, R.sup.2 independently of each other in each case are a branched or unbranched C.sub.1-C.sub.6 alkyl radical, wherein the alkyl radicals can be substituted by one or more fluorine atoms; R.sup.5, R.sup.6 independently of each other in each case are halogen, CN, COOH, COOR.sup.4, wherein R.sup.4 is H, alkyl, aryl, alkyl-aryl, CH.sub.2OH, CONH.sub.2 or CH.sub.2NH.sub.2, or R.sup.5 and R.sup.6 together form a C(O)OC(O), C(O)NR.sup.3C(O) or (CH.sub.2).sub.n group, wherein n is 3 or 4 and one or more or all H atoms can be replaced by F and wherein R.sup.3 is H or a C.sub.1-C.sub.6 alkyl radical, aryl or alkyl-aryl; R.sup.a, R.sup.b, R.sup.c, R.sup.d and R.sup.a, R.sup.b, R.sup.c, R.sup.d independently of each other are H, halogen, a branched or unbranched C.sub.1-C.sub.16 alkyl radical, O-alkyl, COO-alkyl, wherein alkyl in each case stands for a branched or unbranched C.sub.1-C.sub.16 alkyl radical and wherein all alkyl radicals can be substituted by one or more fluorine atoms, CO-aryl, COCH.sub.2-aryl, COO-aryl, COOCH.sub.2-aryl; wherein the radicals R.sup.a, R.sup.b, R.sup.c, R.sup.d or the radicals R.sup.a, R.sup.b, R.sup.c, R.sup.d can be linked to each other, forming one or more aromatic rings, or an annulated aromatic ring system with 2 to 3 rings, wherein the rings or ring systems can be substituted or are unsubstituted.

6. The dental material according to claim 4, wherein the variables have the following meanings: X, Y independently of each other in each case are O, NR.sup.11, wherein R.sup.11 is a branched or unbranched C.sub.1-C.sub.16 alkyl radical; R.sup.1, R.sup.2 independently of each other in each case are a methyl group, which can be substituted by one or more fluorine atoms; R.sup.5, R.sup.6 independently of each other in each case are COOH, CH.sub.2OH, CONH.sub.2, CH.sub.2NH.sub.2 or R.sup.5 and R.sup.6 together form a C(O)OC(O) or (CH.sub.2).sub.n group, wherein n is 3 or 4 and one or more, or all H atoms can be replaced by F, or R.sup.5 and R.sup.6 together form a (CF.sub.2).sub.3 group; R.sup.a, R.sup.b, R.sup.c, R.sup.d and R.sup.a, R.sup.b, R.sup.c, R.sup.d independently of each other are H, halogen, a branched or unbranched C.sub.1-C.sub.16 alkyl radical, O-alkyl, wherein alkyl stands for a branched or unbranched C.sub.1-C.sub.16 alkyl radical and wherein all alkyl radicals can be substituted by one or more fluorine atoms, wherein the radicals R.sup.a, R.sup.b, R.sup.c, R.sup.d or the radicals R.sup.a, R.sup.b, R.sup.c, R.sup.d can be linked to each other, forming one or more aromatic rings, which are not substituted.

7. The dental material according to claim 1 which additionally contains at least one radically polymerizable monomer, or a mono- or polyfunctional (meth)acrylic acid derivative, and at least one initiator or photoinitiator for the radical polymerization.

8. The dental material according to claim 1, which additionally contains at least one particulate filler.

9. The Dental material according to claim 1, which contains a) 0.0001 to 5.0 wt.-% of at least one compound of general formula I, b) 0.01 to 10 wt.-% of at least one initiator, and optionally c) 0 to 80 wt.-% other monomer(s), and optionally d) 0 to 80 wt.-% filler(s), and optionally e) 0 to 70 wt.-% solvent, in each case relative to the total mass of the dental material.

10. The dental material according to claim 9 for use as dental cement or dental filling composite, which contains a) 0.0001 to 5.0 wt.-% of at least one compound of general formula I, b) 0.01 to 10 wt.-% of at least one initiator, c) 0 to 50 wt.-% other monomer(s), d) 10 to 80 wt.-% filler(s).

11. The dental material according to claim 9 for use as dental adhesive or coating material, which contains a) 0.0001 to 5.0 wt.-% of at least one compound of general formula I, b) 0.01 to 10 wt.-% of at least one initiator, c) 0 to 80 wt.-% other monomer(s), d) 0 to 20 wt.-% filler(s), e) 0 to 70 wt.-% solvents.

12. The dental material according to claim 1 for intraoral use to restore damaged teeth.

13. The dental material according to claim 12 for therapeutic use as dental cement, dental filling composite, dental adhesive or veneering material.

14. A photochromic dental material comprising a compound of Formula I, as defined in claim 1.

15. The dental material according to claim 3, which additionally comprises at least one mono- or polyfunctional methacrylate and at least one photoinitiator.

16. The dental material according to claim 9, which contains a) 0.001 to 3.0 wt.-% of at least one compound of general formula I, b) 0.1 to 3.0 wt.-% of at least one initiator, and optionally c) 0 to 60 wt.-% other monomer(s), and optionally d) 0 to 80 wt.-% filler(s), and optionally e) 0 to 70 wt.-% solvent, in each case relative to the total mass of the dental material.

17. The dental material according to claim 9, which contains a) 0.01 to 1.0 wt.-% of at least one compound of general formula I, b) 0.1 to 3.0 wt.-% of at least one initiator, and optionally c) 5 to 50 wt.-% other monomer(s), and optionally d) 0 to 80 wt.-% filler(s), and optionally e) 0 to 70 wt.-% solvent, in each case relative to the total mass of the dental material. 10.

18. The dental material according to claim 10 for use as dental cement or dental filling composite, which contains a) 0 0.001 to 3.0 wt.-% of at least one compound of general formula I, b) 0.1 to 3.0 wt.-% of at least one initiator, c) 0 to 40 wt.-% other monomer(s), d) 20 to 80 wt.-% filler(s).

19. The dental material according to claim 10 for use as dental cement or dental filling composite, which contains a) 0.01 to 1.0 wt.-% of at least one compound of general formula I, b) 0.1 to 3.0 wt.-% of at least one initiator, c) 5 to 40 wt.-% other monomer(s), d) 30 to 80 wt.-% filler(s).

20. The dental material according to claim 11 for use as dental adhesive or coating material, which contains a) 0.001 to 3.0 wt.-% of at least one compound of general formula I, b) 0.1 to 3.0 wt.-% of at least one initiator, c) 5 to 60 wt.-% other monomer(s), d) 0 to 20 wt.-% filler(s), e) 0 to 60 wt.-% solvents, wherein the solvents comprise water and/or ethanol.

21. The dental material according to claim 11 for use as dental adhesive or coating material, which contains a) 0.01 to 1.0 wt.-% of at least one compound of general formula I, b) 0.1 to 3.0 wt.-% of at least one initiator, c) 5 to 50 wt.-% other monomer(s), d) 0 to 20 wt.-% filler(s), e) 0 to 50 wt.-% solvents, wherein the solvents comprise water and/or ethanol.

Description

EMBODIMENT EXAMPLES

Example 1

[0103] Methacrylate Resin and Fissure Sealant Based on a Photochromic Additive

[0104] The following compositions (proportions in wt.-%) were prepared in a mixing bowl (resin) or with a three roll mill (Table 1):

TABLE-US-00001 TABLE 1 Composition of the materials [wt. - %] Component Resin Fissure sealant Bis-GMA 19.90 11.98 UDMA 39.44 23.74 TEGDMA.sup.1) 39.66 23.54 CQ.sup.2) 0.10 0.06 EDMAB.sup.3) 0.40 0.24 B2287.sup.4) 0.50 0.50 Aerosil Ox-50.sup.5) 15.64 HDK 2000.sup.6) 4.00 Glass filler.sup.7) 20.30 .sup.1)Triethylene glycol dimethacrylate .sup.2)Camphorquinone .sup.3)p-Dimethylamino-benzoic acid ethyl ester .sup.4)Photochromic additive: 1,2-bis[2-methylbenzo-[b]thiophen-3-yl]-3,3,4,4,5,5-hexafluoro- 1-cyclopentene (TCI Europe): [00008].sup.5)Silanized pyrogenic silicic acid (Degussa) with a specific surface area (BET) of approx. 50 m.sup.2/g .sup.6)Pyrogenic silicic acid (Wacker) with a specific surface area (BET) of approx. 200 m.sup.2/g .sup.7)Silanized glass ionomer filler G018-090 (Schott) with a particle diameter d.sub.50 of 3 m

[0105] Round test pieces (diameter 10 mm, height: 1 mm) were prepared from the compositions and hardened for 21 minute with a dental light source (Spectramat, Ivoclar Vivadent AG). Colourless (resin) or white (fissure sealant) test pieces which discoloured to pink when irradiated (2 s) with an LED (.sub.1=385 nm) resulted. It was possible to decolour the test pieces again rapidly by irradiation (2 s) with an LED (.sub.2=470 nm). The alternate discolouration and decolouration were able to be repeated at least 20 without restrictions.

Example 2

Synthesis of the Polymerizable Photochromic Compound 3,3,4,4,5,5-hexafluoro-1,2-bis(5-methacryloyloxymethyl-2-methyl-3-thienyl)cyclopent-1-ene

1.SUP.st .Stage: 4-Bromo-5-methylthiophene-2-carboxaldehyde

[0106] ##STR00009##

[0107] A solution of bromine (19.18 g; 0.12 mol) in acetic acid (50 ml) was added dropwise to a solution of 5-methyl-2-thiophenecarboxaldehyde (12.62 g; 97.9 mmol) in acetic acid (80 ml) under exclusion of light. The temperature was kept below 30 C. by cooling in a water bath. The reaction mixture was stirred for 72 h at RT and then carefully poured into saturated aqueous Na.sub.2CO.sub.3 solution (500 ml). After the gas evolution had abated, diethyl ether (400 ml) was added and the phases were separated. The aqueous phase was extracted with diethyl ether (2100 ml). The combined organic phases were washed with saturated aqueous NaHCO.sub.3 solution (150 ml), dried over Na.sub.2SO.sub.4, filtered and concentrated on a rotary evaporator. The crude product was purified by means of column chromatography (SiO.sub.2, n-hexane/ethyl acetate 9:1; R.sub.f=0.47). 14.67 g (71.5 mmol; 73%) of a yellowish solid was obtained.

[0108] .sup.1H-NMR (CDCl.sub.3, 400 MHz): =2.48 (s, 3H; CH.sub.3), 7.59 (s, 1H, CH), 9.77 (s, 1H, CHO).

[0109] .sup.13C-NMR (CDCl.sub.3, 100.6 MHz): =15.9 (CH.sub.3), 111.2 (C), 138.7 (CH), 140.1 (C), 145.8 (C), 181.6 (CO).

2.SUP.nd .Stage: 4-Bromo-2-hydroxymethyl-5-methylthiophene

[0110] ##STR00010##

[0111] Sodium borohydride (5.36 g; 0.142 mol) was added to a solution of 4-bromo-5-methylthiophene-2-carboxaldehyde (24.20 g; 0.118 mol) in ethanol (250 ml) at 0 C. The reaction mixture was stirred for 1 h at 0 C. and for 2 h at ambient temperature. Then saturated aqueous NH.sub.4Cl solution (100 ml), water (200 ml) and ethyl acetate (300 ml) were added and the phases were separated. The aqueous phase was extracted with ethyl acetate (100 ml). The combined organic phases were washed with saturated aqueous NaHCO.sub.3 solution (100 ml) and saturated aqueous NaCl solution (100 ml), dried over Na.sub.2SO.sub.4, filtered and concentrated on a rotary evaporator. The crude product was purified by means of column chromatography (SiO.sub.2, n-hexane/ethyl acetate 4:1; R.sub.f=0.35). 17.72 g (73%) of a yellowish liquid was obtained.

[0112] .sup.1H-NMR (CDCl.sub.3, 400 MHz): =2.35 (s, 3H; CH.sub.3), 3.15 (t, 1H; J=4.4 Hz; OH), 4.60 (d, 2H; J=4.4 Hz; CH), 6.74 (s, 1H; CH).

[0113] .sup.13C-NMR (CDCl.sub.3, 100.6 MHz): =14.7 (CH.sub.3), 59.4 (CH.sub.2OH), 108.2 (C), 127.7 (CH), 134.2 (C), 140.8 (C).

3.SUP.rd .Stage: (4-Bromo-5-methyl-thiophen-2-ylmethoxy)-tert.-butyldimethylsilane

[0114] ##STR00011##

[0115] Imidazole (6.36 g; 93.5 mmol) was added to a solution of 4-bromo-2-hydroxymethyl-5-methylthiophene (17.60 g; 85.0 mmol) and tert.-butyldimethylchlorosilane (14.09 g; 93.5 mmol) in anhydrous dichloromethane (100 ml) and the suspension was stirred at RT. After 2 h, the reaction mixture was washed with diluted hydrochloric acid (IN; 100 ml), dried over Na.sub.2SO.sub.4, filtered and concentrated on a rotary evaporator. The crude product was dissolved in n-hexane (50 ml) and filtered over silica gel (SiO.sub.2, n-hexane). The filtrate was concentrated on a rotary evaporator and the residue was dried under fine vacuum. 25.84 g (95%) of a colourless oil was obtained.

[0116] .sup.1H-NMR (CDCl.sub.3, 400 MHz): =0.11 (s, 6H; SiCH.sub.3), 0.93 (s, 9H; CCH.sub.3), 2.36 (s, 3H; CH.sub.3), 4.75 (s, 2H; OCH.sub.2), 6.70 (s, 1H; CH).

[0117] .sup.13C-NMR (CDCl.sub.3, 100.6 MHz): =5.3 (CH.sub.3), 14.7 (CH.sub.3), 18.3 (C), 25.8 (CH.sub.3), 60.5 (CH.sub.2), 107.9 (C), 126.0 (CH), 133.1 (C), 142.2 (C).

[0118] .sup.29Si-NMR (CDCl.sub.3, 79.5 MHz): =21.6.

4.SUP.th .Stage: 3,3,4,4,5,5-Hexafluoro-1,2-bis((tert.-butyldimethvl-silyl)oxymethyl-2-methyl-3-thienyl)cyclopent-1-ene

[0119] ##STR00012##

[0120] A solution of (4-bromo-5-methyl-thiophen-2-ylmethoxy)-tert.-butyldimethylsilane (25.74 g; 80.0 mmol) in anhydrous tetrahydrofuran (100 ml) under argon was cooled to 75 C. n-Butyllithium (2.5M in n-hexane; 32.6 ml; 82.0 mmol) was added dropwise and the yellow solution was stirred for 2 h at 75 C. Octafluorocyclopentene (8.48 g; 40.0 mmol) was added and the reaction mixture was stirred overnight in a thawing cold bath. After 20 h, water (100 ml) and ethyl acetate (300 ml) were added to the reaction mixture and the phases were separated. The organic phase was washed with water (2100 ml). The combined aqueous phases were re-extracted with ethyl acetate (100 ml). The combined organic phases were washed with saturated aqueous NaCl solution (100 ml), dried over Na.sub.2SO.sub.4, filtered and concentrated on a rotary evaporator. The crude product was purified by means of column chromatography (SiO.sub.2, n-hexane/ethyl acetate 20:1; R.sub.f=0.63). 19.46 g (74%) of a brownish liquid was obtained.

[0121] .sup.1H-NMR (CDCl.sub.3, 400 MHz): =0.11 (s, 12H; SiCH.sub.3), 0.94 (s, 18H; CCH.sub.3), 1.88 (s, 6H; CH.sub.3), 4.80 (s, 4H; OCH.sub.2), 6.87 (s, 2H; CH).

[0122] .sup.13C-NMR (CDCl.sub.3, 100.6 MHz): =5.3 (CH.sub.3), 14.4 (CH.sub.3), 18.3 (C), 25.8 (CH.sub.3), 60.6 (CH.sub.2), 111.1 (m; CF.sub.2), 113.7 (m; CF.sub.2), 116.2 (m; CF.sub.2), 118.8 (m; CF.sub.2), 123.1 (CH), 124.3 (C), 135.8 (m, CCF), 141.1 (C), 143.5 (C).

[0123] .sup.19F-NMR (CDCl.sub.3, 376.5 MHz): =131.9 (2F), 110.0 (4F).

[0124] .sup.29Si-NMR (CDCl.sub.3, 79.5 MHz): =21.7.

5.SUP.th .Stage: 3,3,4,4,5,5-hexafluoro-1,2-bis(5-hydroxymethyl-2-methyl-3-thienyl)cyclopent-1-ene

[0125] ##STR00013##

[0126] Tetrabutyl ammonium fluoride (75% in water; 25.00 g; 66.9 mmol) was added dropwise to a solution of 3,3,4,4,5,5-hexafluoro-1,2-bis[(tert.-butyldimethylsilyl)oxymethyl-2-methyl-3-thienyl)cyclopent-1-ene (19.20 g; 29.2 mmol) in tetrahydrofuran (100 ml). The reaction solution was stirred for 4 h at RT, then saturated aqueous NH.sub.4Cl solution (100 ml) and ethyl acetate (100 ml) were added and the phases were separated. The organic phase was washed with water (2100 ml) and saturated aqueous NaCl solution (100 ml), dried over Na.sub.2SO.sub.4, filtered and concentrated on a rotary evaporator. The crude product was purified by means of column chromatography (SiO.sub.2, n-hexane/ethyl acetate 1:1; R.sub.f=0.38). 4.35 g (10.2 mmol; 35%) of a colourless solid was obtained.

[0127] 1H-NMR (CDCl.sub.3, 400 MHz): =1.87 (s, 6H; CH.sub.3), 4.26 (s, 2H; OH), 4.68 (s, 4H; OCH.sub.2), 6.91 (s, 2H; CH).

[0128] .sup.13C-NMR (CDCl.sub.3, 100.6 MHz): =14.3 (CH.sub.3), 59.1 (CH.sub.2), 110.8 (m; CF.sub.2), 113.4 (m; CF.sub.2), 116.0 (m; CF.sub.2), 118.5 (m; CF.sub.2), 124.0 (CH), 135.7 (m, CCF.sub.2), 141.4 (C), 143.1 (C).

[0129] .sup.19F-NMR (CDCl.sub.3, 376.5 MHz): =131.9 (2F), 110.0 (4F).

6.SUP.h .Stage: 3,3,4,4,5,5-Hexafluoro-1,2-bis(5-methacryloyloxymethyl-2-methyl-3-thienyl)cyclopent-1-ene

[0130] ##STR00014##

[0131] A solution of methacrylic anhydride (3.21 g; 20.8 mmol) in dichloromethane (20 ml) was added dropwise to a solution of 3,3,4,4,5,5-hexafluoro-1,2-bis(5-hydroxymethyl-2-methyl-3-thienyl)cyclopent-1-ene (4.25 g; 9.9 mmol), triethylamine (2.21 g; 21.8 mmol) and N,N-dimethylaminopyridine (0.24 g; 2.0 mmol) in anhydrous dichloromethane (80 ml) at 5 C. The reaction mixture was stirred for 3 h at 5 C. and then at ambient temperature. After 20 h, the solution was washed with water (3100 ml) and saturated aqueous NaCl solution (100 ml), dried over Na.sub.2SO.sub.4, filtered and concentrated on a rotary evaporator. The crude product was purified by means of column chromatography (SiO.sub.2, n-hexane/ethyl acetate 9:1; R.sub.f=0.40). 4.68 g (8.3 mmol; 84%) of a colourless solid was obtained (m.p.: 58 C.).

[0132] .sup.1H-NMR (CDCl.sub.3, 400 MHz): =1.86 (s, 6H; CH.sub.3), 1.95 (m, 6H; CH.sub.3), 5.24 (s, 4H; OCH.sub.2), 5.61 (m, 2H; CH), 6.14 (m, 2H; CH); 7.05 (s, 2H; CH).

[0133] .sup.13C-NMR (CDCl.sub.3, 100.6 MHz): =14.2 (CH.sub.3), 18.2 (CH.sub.3), 60.5 (CH.sub.2), 110.9 (m; CF.sub.2), 113.4 (m; CF.sub.2), 116.0 (m; CF.sub.2), 118.5 (m; CF.sub.2), 124.3 (C), 126.3 (CH.sub.2), 127.5 (CH), 135.8 (C), 136.1 (m, CCF.sub.2), 136.4 (C), 143.2 (C), 166.9 (CO).

[0134] .sup.19F-NMR (CDCl.sub.3, 376.5 MHz): =131.9 (2F), 110.2 (4F). IR (neat): 2958 (w), 1716 (s), 1637 (m), 1561 (w), 1441 (m), 1404 (w), 1380 (w), 1337 (m), 1316 (m), 1273 (s), 1191 (m), 1136 (vs), 1109 (vs), 1046 (s), 1011 (m), 984 (vs), 942 (s), 898 (m), 856 (m), 813 (s), 740 (m), 709 (w), 656 (m), 635 (w) cm.sup.1.

[0135] Analysis calculated for C.sub.25H.sub.22F.sub.6O.sub.4S.sub.2: C, 53.19; H, 3.93; S, 11.36.

[0136] Found: C, 53.20; H, 3.76; S, 11.10.