J. Mizukado et al. / Journal of Fluorine Chemistry 127 (2006) 400–404
403
+
3. Conclusion
CF2); MS: m/z, 311 (M+ÀF), 211 (CF3CF2CH2OCHFOCH2 ),
182, 181 (CF3CF2CH2OCHF+), 133 (CF3CF2CH2 ), 113, 83,
+
+
69 (CF3 ), 64, 51, 49, 45, 29.
The reactions of aliphatic fluoro-alcohols with CHClF2
proceeded at atmospheric pressure in ethereal solvents such as
1,4-dioxane, diglyme and THF, and afforded difluoromethy-
lated ether accompanied by acetal and orthoformate. Addition
of water in the solvents was effective to improve the selectivity
of the difluoromethylated ether. It was considered that the effect
of adding water was derived from the promotion of the
protonation of the anion intermediate. The results of the
reactions with various alcohols showed that the acidity of the
alcohol had an effect on the reaction.
4.5. Tris(2,2,3,3,3-pentafluoropropoxy)methane (5)
1H NMR: d 4.07 (6H, t, J = 13.1 Hz, CH2), 5.53 (1H, s, CH);
19F NMR: d À84.2 (9F, s, CF3), À124.2 (6F, t, J = 13.1 Hz,
CF2); HRMS calcd. for C10H6F15O3, 459.0077; found,
459.0038; MS: m/z, 459 (M+ÀH), 311 ((CF3CF2CH2O)2CH+),
+
+
179, 159, 133 (CF3CF2CH2 ), 113, 111, 83, 69 (CF3 ), 64, 51.
4.6. 2,2,3,3-Tetrafluoro-1-difluoromethoxypropane (3b)
[7,14]
4. Experimental
4.1. General
1H NMR: d 4.22 (2H, t, J = 12.3 Hz, CH2), 5.92 (2H, t of t,
J = 53.0 Hz, 4.2 Hz, CHF2CF2), 6.32 (1H, t, J = 72.2 Hz,
CHF2O); 19F NMR: d À86.3 (2F, d, J = 72.2 Hz, CHF2O),
À124.9 (2F, t, J = 12.3 Hz, CF2), À138.7 (2F, d, J = 53.0 Hz,
All of the reagents were used without further purification.
1H- (300 MHz) and 19F NMR (282 MHz) were measured with
JEOL ECA-300S using TMS and CFCl3 as internal standards
and CDCl3 as a solvent. MS (EI, 70 eV) spectra were measured
using the Shimazu GCMS-QP2010 system equipped with GC-
2010. HRMS (EI, 70 eV) spectra were measured using Hitachi
M-80B.
+
CHF2CF2); MS: m/z, 163 (M+ÀF), 115 (CHF2CF2CH2 ), 95,
+
83, 82, 81 (CHF2CH2 ), 65, 51 (CHF2 ), 33, 31, 29.
+
4.7. 1,1-Difluoro-2-difluoromethoxyethane (3c)
1H NMR: d 4.04 (2H, t of d, J = 13.1 Hz, 4.1 Hz, CH2), 5.93
(1H, t of t, J = 55.0 Hz, 4.1 Hz, CHF2CH2), 6.30 (1H, t,
J = 72.6 Hz, CHF2O); 19F NMR: d À86.1 (2F, d, J = 72.6 Hz,
CHF2O), À126.1 (2F, d of t, J = 55.0 Hz, 13.1 Hz, CHF2CH2);
4.2. A typical experimental procedure for the reaction of
CHClF2 with alcohol (Table 1, Entry 1)
+
+
+
2,2,3,3,3-Pentafluoropropanol (40 mmol), sodium hydro-
xide (200 mmol) and 1,4-dioxane (60 ml) were placed into a
100 ml flask equipped with a cooled condenser, a thermo-
couple and a gas inlet bubbler tube (Kinoshita glass-filter G-
4, 5–10 mm). After the solution was heated at 50 8C,
chlorodifluoromethane was introduced at 10 ml/min for about
2.5 h (total: 60 mmol), and the reactor was kept at 50 8C for
1 h. After cooling, the mixture was poured into 200 ml cooled
water, and the products were extracted with chloroform.
Benzotrifluoride (7.0 mmol) was added to the extraction as an
internal standard, and the structure and the ratio of the
products were determined by GC–MS, 1H NMR and 19F
NMR spectra.
MS: 81 (CHF2OCH2 ), 65 (CHF2CH2 ), 51 (CHF2 ), 45, 31,
29.
4.8. 1,1,1-Trifluoro-3-difluoromethoxypropane (3d)
1H NMR: d 2.49 (2H, q of t, J = 10.3 Hz, 6.5 Hz, CF3CH2),
4.09 (2H, t, J = 6.5 Hz, CH2O), 6.23 (1H, t, J = 73.3 Hz,
CHF2); 19F NMR: d À65.7 (3F, t, J = 10.3 Hz, CF3), À86.3 (2F,
d, J = 73.3 Hz, CHF2); HRMS calcd. for C4H4F5O, 163.0182;
found, 163.0180; MS: m/z, 115, 97 (CF3CH2CH2+), 95, 81
+
+
+
(CHF2OCH2 ), 77, 69 (CF3 ), 65, 64, 51 (CHF2 ), 49, 47, 45,
33, 31, 29, 27.
4.9. Difluoromethoxypropane (3e)
4.3. 1,1,1,2,2-Pentafluoro-3-difluoromethoxypropane (3a)
1H NMR: d 0.96 (3H, t, J = 7.4 Hz, CH3), 1.67 (2H, q of t,
J = 7.4 Hz, 6.6 Hz, CH3CH2), 3.80 (2H, t, J = 6.6 Hz, CH2O),
6.19 (1H, t, J = 75.3 Hz, CHF2); 19F NMR: d À84.2 (d,
1H NMR: d 4.27 (2H, t, J = 12.7 Hz, CH2), 6.33 (1H, t,
J = 71.1 Hz, CHF2); 19F NMR: d À84.3 (3F, s, CF3), À87.2 (2F,
d, J = 71.1 Hz, CHF2), À124.5 (2F, t, J = 12.7 Hz, CF2). MS:
J = 75.3 Hz);MS:110(M+), 109(M+ÀH), 81(CHF2OCH2 ), 63,
+
m/z, 181 (M+ÀF), 133 (CF3CF2CH2 ), 81 (CHF2OCH2 ), 69
51 (CHF2 ), 43 (CH3CH2CH2 ), 42, 41, 31, 29 (CH3CH2 ), 27.
+
+
+
+
+
+
(CF3 ), 51 (CHF2 ).
+
4.10. 1,1,1-Trifluoro-2-difluoromethoxypropane (3f)
4.4. Bis(2,2,3,3,3-pentafluoropropoxy)fluoromethane (4)
1H NMR: d 1.47 (3H, d, J = 6.6 Hz, CH3), 4.59 (1H, q of q,
This compound is new, but could not be isolated because it
was decomposed during distillation.
1H NMR: d 4.19 (4H, t of d, J = 12.6 Hz, 6.6 Hz, CH2), 6.02
(1H, d, J = 75.3 Hz, CHF); 19F NMR: d À84.2 (6F, s, CF3),
À95.2 (1F, d, J = 75.3 Hz, CHF), À124.3 (4F, t, J = 12.6 Hz,
J = 6.6 Hz, 6.6 Hz, =CH-), 6.32 (1H, t, J = 72.6 Hz, CHF2); 19
F
NMR: d À79.8 (3F, d of m, J = 6.6 Hz, CF3), À84.3 (2F, d of m,
J = 72.6 Hz, CHF2); HRMS calcd. for C4H4F5O, 163.0182;
found, 163.0157; MS: 149 (M+ÀCH3), 97 (CF3CHCH3 ), 95
+
(M+ÀCF3), 79, 77, 69 (CF3 ), 51 (CHF2 ), 49, 47, 45, 43, 29, 27.
+
+