Fluoroꢀcontaining thiols and thioacyl halides
Russ.Chem.Bull., Int.Ed., Vol. 55, No. 7, July, 2006
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stirred for 4 h and poured into ice water. The product was
extracted with CH2Cl2 and washed with 20% NaOH, 10% HCl,
and water. The organic layer was separated, dried over
Na2SO4, and fractionated. This procedure was used to obtain
1,1,2,2ꢀtetrafluoroethyl 2,2,2ꢀtrifluoroethyl sulfide (20),
1,1,2,2ꢀtetrafluoroethyl 2,2,3,3ꢀtetrafluoropropyl sulfide (21),
2ꢀchloroꢀ1,1,2ꢀtrifluoroethyl 2,2,3,3ꢀtetrafluoropropyl sulfide
(22), and 1,1,2,2ꢀtetrafluoroethyl 2,2,3,3,4,4,5,5ꢀoctafluoroꢀ
pentyl sulfide (23).
2,2,2ꢀTrifluoroethyl 1,1,2,2,3,3,3ꢀheptafluoropropyl sulfide
(24). Sodium formate (1.36 g, 20 mmol) was added to a stirred
mixture of thiol 1 (2.0 g, 17 mmol), perfluoropropyl iodide
(5.1 g, 17 mmol), sodium sulfite (2.2 g, 17 mmol), DMF (17 mL),
and water (5.6 mL). The mixture was stirred at 20 °C for 12 h
and poured into water (100 mL). The product was extracted
with tetrachloroethane, washed with 10% HCl and water, dried
over Na2SO4, and fractionated. 19F NMR, δ: –46.35, –10.24
(both m, 2 F each, CF2); –2.27 (m, 3 F, CF3); 10.93 (t, 3 F,
CF3, J = 8 Hz).
2ꢀ(2,2,3,3ꢀTetrafluoropropylthio)ꢀ1Hꢀisoindoleꢀ1,3(2H )ꢀ
dione (35) was obtained analogously.
4ꢀMethylꢀ2ꢀ(2,2,3,3ꢀtetrafluoropropylthio)phenol (36).
A mixture of sulfenyl chloride 28 (1.0 g, 5.4 mmol) and pꢀcresol
(0.6 g, 5.4 mmol) was stirred at room temperature until HCl
ceased to evolve (24 h) and fractionated.
OꢀMethyl 2,2,3,3ꢀtetrafluoropropanethioate (37). Thioacyl
chloride 16 (1.8 g, 10 mmol) was added at room temperature to
stirred anhydrous methanol (5 mL). The reaction mixture was
stirred for 1 h and washed with water. The product was extracted
with ether and the organic layer was separated, dried over
Na2SO4, and fractionated.
3ꢀChloroꢀ3ꢀ(1,1,2,2ꢀtetrafluoroethyl)ꢀ2ꢀthiabiꢀ
cyclo[2.2.2]octꢀ5ꢀene (38). Thioacyl chloride 16 (1.8 g,
10 mmol) was added at –78 °C to a stirred solution of cyclohexaꢀ
1,3ꢀdiene (1.0 g, 12.5 mmol) in CH2Cl2 (10 mL). The reaction
mixture was stirred for 1 h, warmed to room temperature, kept
for 12 h, and fractionated. 19F NMR, δ: –56.5 (m, 2 F, CF2H);
–39.4 (m, 2 F, CF2).
An analogous procedure was used to obtain compounds 25
and 26 from thiol 2 and perfluoroethyl iodide or perfluoropropyl
iodide, respectively.
1,1,2,2,2ꢀPentafluoroethyl 2,2,3,3ꢀtetrafluoropropyl sulfide
(25). 19F NMR, δ: –58.51 (m, 2 F, CF2H); –40.37 (m, 2 F,
CF2CH2); –15.41 (m, 2 F, CF2S); –6.47 (m, 3 F, CF3).
1,1,2,2,3,3,3ꢀHeptafluoropropyl 2,2,3,3ꢀtetrafluoropropyl
sulfide (26). 19F NMR, δ: –59.01 (m, 2 F, CF2H); –48.05 (m,
2 F, CF2CF3);–38.25 (m, 2 F, CF2CH2); –12.17 (m, 2 F,
CF2S); –4.25 (m, 3 F, CF3).
2,2,2ꢀTrifluoroethanesulfenyl chloride (27) (see Ref. 6). Dry
gaseous chlorine (1.42 g, 20 mmol) was slowly bubbled at 15 °C
through a solution of thiol 1 (1.16 g, 10 mmol) in tetrachloroetꢀ
hane (5 mL). The reaction mixture was kept for 1 h and fracꢀ
tionated. 19F NMR, δ: 11.2 (t, CF3, J = 6 Hz).
16ꢀChloroꢀ16ꢀ(1,1,2,2ꢀtetrafluoroethyl)ꢀ15ꢀthiatetraꢀ
cyclo[6.6.2.0.2,7.09,14]hexadecaꢀ2,4,6,9,11,13ꢀhexaene (39).
Thioacyl chloride 16 (1.8 g, 10 mmol) was added at room temꢀ
perature to a stirred solution of anthracene (1.8 g, 10 mmol) in
dry toluene (25 mL). The reaction mixture was kept for 12 h and
concentrated in vacuo. The residue was recrystallized from
hexane.
3,4ꢀDimethylꢀ6ꢀ(1,1,2,2ꢀtetrafluoroethyl)ꢀ2Hꢀthiopyran
(40). Thioacyl chloride 16 (1.8 g, 10 mmol) in CH2Cl2 (5 mL)
was added dropwise at –78 °C to a stirred solution of 2,3ꢀdiꢀ
methylbutadiene (0.98 g, 12 mmol) in CH2Cl2 (10 mL). The
reaction mixture was warmed to room temperature (evolution of
HCl was observed), refluxed until HCl ceased to evolve (8 h),
and fractionated.
An analogous procedure was used to obtain 2,2,3,3ꢀtetraꢀ
fluoropropanesulfenyl chloride (28) (with CH2Cl2 as a solvent)
and 1,1,1,3,3,3ꢀhexafluoropropaneꢀ2ꢀsulfenyl chloride (29) from
thiols 2 and 5, respectively.
Bis(2,2,2ꢀtrifluoroethyl) disulfide (30).18 Dry chlorine (0.71 g,
10 mmol) was bubbled at room temperature through a solution
of thiol 1 (1.16 g, 10 mmol) in CH2Cl2 (5 mL). The mixture was
fractionated. 19F NMR, δ: 11.5 (t, CF3, J = 9 Hz).
Bis(2,2,3,3ꢀtetrafluoropropyl) disulfide (31) was obtained
analogously. 19F NMR (DMSOꢀd6), δ: –60.5 (m, 2 F, CF2H);
–39.2 (m, 2 F, CF2).
1ꢀPhenylꢀ2ꢀ(2,2,3,3ꢀtetrafluoropropylthio)ethanꢀ1ꢀone (32).
Sulfenyl chloride 28 (1.0 g, 5.4 mmol) was added dropwise at
room temperature to a solution of acetophenone (0.65 g,
5.4 mmol) in CCl4 (3 mL). The reaction mixture was stirred
until HCl ceased to evolve (20 h) and fractionated.
2ꢀ(1,1,1,3,3,3ꢀHexafluoropropanꢀ2ꢀylthio)indanꢀ1ꢀone (33).
A mixture of sulfenyl chloride 29 (1.0 g, 4.5 mmol) and indanꢀ1ꢀ
one (0.6 g, 4.5 mmol) was kept for 24 h and recrystallized from
hexane.
2ꢀ(2,2,2ꢀTrifluoroethylthio)ꢀ1Hꢀisoindoleꢀ1,3(2H )ꢀdione
(34). A solution of sulfenyl chloride 27 (1.5 g, 10 mmol) in
benzene (2.5 mL) was added at 20 °C to a suspension of potasꢀ
sium phthalimide (1.5 g, 8 mmol) in benzene (2.5 mL). The
reaction mixture was stirred for 1 h and concentrated in vacuo.
The residue was recrystallized from benzene—light petroꢀ
leum (1 : 2).
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