L. Politanskaya and E. Tretyakov
JournalofFluorineChemistry236(2020)109592
Acetone-d6): δ = 158.2 (s, C7), 144.6 (ddt, 1J (C3,F3) =258.8 Hz, 2J
(C3,F2) =16.3 Hz, C3, C5), 143.5 (dm, 1J (C2,F2) =251.5 Hz, 2J (C2,F3)
=16.1 Hz, C2, C6), 122.2 (t, 2J (C4,F3) ≈ 2J (C4,F5) =20.9 Hz, C4),
121.5 (t, 2J (C1,F2) ≈ 2J (C1,F6) =15.0 Hz, C1), 60.0 (s, C9), 56.0 (s, C8).
19F NMR (282 MHz, Acetone-d6): δ = –139.5 (dm, J (F2,F3) =21 Hz,
2 F, F2, F6), –143.2 (dm, J (F3,F2) =21 Hz, 2 F, F3, F5). HRMS (EI): m/z
[M]+ calcd for C9H7F4O4NS: 301.0026; found: 301.0024.
solvent in vacuo, the crude product was purified by preparative TLC.
Yellowish solid; yield: 0.68 g (73 %); Rf = 0.78 (EtOAc/hexane, 2:1,
3 times). mp 188.3 °C (dec.). IR (KBr): 3471, 3352, 3284, 3039, 2962,
1689, 1612, 1574, 1689, 1612, 1574, 1473, 1458, 1408, 1377, 1331,
1317, 1302, 1234, 1171, 1059, 1022, 977, 922, 823, 719, 638, 569, 496
cm–1. 1H NMR (300 MHz, Acetone-d6): δ = 7.68 (s, 1H, H9), 7.49 (s, 1H,
H9′), 4.97 (tm, J (H2,H3) =5.2 Hz, 2H, H2), 3.92 (tm, J (H3,H2)
=5.2 Hz, 2H, H3). 13C NMR (100 MHz, Acetone-d6): δ = 159.6 (d, C9),
144.6 (ddd, 1J (C8,F8) =251.6 Hz, 3J (C8,F6) =5.5 Hz, C8), 143.8 (ddd,
1J (C5,F5) =254.2 Hz, 2J (C5,F6) =16.1 Hz, C5), 141.2 (dt, 2J (C8a,F8)
=14.5 Hz, C8a), 141.1 (ddd, 1J (C6,F6) =247.6 Hz, 2J (C6,F5) =14.1 Hz,
C6), 121.7 (t, 2J (C7,F8) ≈ 2J (C7,F6) =22.3 Hz, C7), 119.9 (d, 2J
(C4a,F5) =16.1 Hz, C4a), 67.8 (s, C2), 52.5 (s, C3). 19F NMR (282 MHz,
Acetone-d6): δ = –135.4 (dd, J (F8,F5) =14.1 Hz, J (F8,F6) =2.6 Hz,
1 F, F8), –141.6 (dd, J (F5,F6) =23.0 Hz, J (F5,F8) =14.1 Hz, 1 F, F5),
–146.5 (dd, J (F6,F5) =23.0 Hz, J (F6,F8) =2.6 Hz, 1 F, F6). HRMS (EI):
m/z [M]+ calcd for C9H6F3O4S: 280.9964; found: 280.9976.
4.2.7.3. 2-(2,3,5,6-Tetrafluoro-4-(trifluoromethyl)phenylsulfonyl)ethanol
(13). White solid; yield: 0.85 g (71 %); mp 67.4–69.7 °C. IR (KBr):
3415, 3354, 3010, 2951, 2895, 1795, 1493, 1427, 1385, 1336, 1255,
1153, 1059, 987, 945, 847, 758, 717, 611, 507 cm–1
.
1H NMR
(400 MHz, Acetone-d6): δ = 4.09 (t, J (H9,H8) =5.4 Hz, 2H, H9), 4.05
(br. s, 1H, H10), 3.73 (t, J (H8,H9) =5.4 Hz, 2H, H8). 13C NMR
(100 MHz, Acetone-d6): δ = 144.9 (ddm, 1J (C2,F2) =258.8 Hz, 2J
(C2,F3) =15.4 Hz, C2, C6), 144.5 (ddm, 1J (C3,F3) =264 Hz, 2J (C3,F2)
=18 Hz, C3, C5), 124.8 (t, 2J (C1,F2) ≈ 2J (C1,F6) =14.2 Hz, C1), 120.6
(qm, 1J (C7,F7) =274.5 Hz, C7), 113.1 (m, C4), 59.8 (s, C9), 55.8 (s, C8).
19F NMR (282 MHz, Acetone-d6): δ = –56.0 (t, J (F7,F3) ≈ J (F7,F5)
=22.0 Hz, 3 F, F7), –135.1 (dm, J (F2,F3) =22 Hz, 2 F, F2, F6), –138.8
(m, 2 F, F3, F5). HRMS (EI): m/z [M]+ calcd for C9H5F7O3S: 325.9842;
found: 325.9844.
4.2.11. 5,6,8-Trifluoro-7-(trifluoromethyl)-4,4-dioxo-2,3-dihydrobenzo[b]
[1,4]oxathiine (17)
To the solution of 13 (0.3 g, 0.9 mmol) in MeCN (10 mL) NEt3
(1 mL) was added, and the mixture was stirred at r.t. for 72 h in closed
flack. Then the mixture was diluted with H2O (10 mL) and extracted
with EtOAc (3 × 25 mL). The combined organic layers were washed
with H2O (10 mL) and dried (MgSO4). After evaporation of the solvent
in vacuo, the crude product was recrystallized from EtOAc with hexane.
White solid; yield: 0.18 g (65 %). mp 157.4–159.2 °C. IR (KBr):
3435, 2937, 2854, 1491, 1456, 1329, 1234, 1145, 1061, 1020, 995,
4.2.8. 2-(2,3,5,6-Tetrafluorophenylsulfonyl)ethanol (14)
To the suspension of 11 (3.0 g, 10 mmol) in MeCN (15 mL) Et3N
(9 mL) was added, and the mixture was heated at reflux for 2 h with
stirring. Then, the mixture was allowed to cool down to r.t. After the
evaporation of the solvents in vacuo, the crude product was re-
crystallized from EtOAc with hexane. White solid; yield: 2.2 g (85 %);
mp 65.5–66.8 °C (63–64 °C [31]).
962, 717, 704, 569, 551, 494, 478, 422 cm–1
.
1H NMR (300 MHz,
Acetone-d6): δ = 5.04 (tm, J (H2,H3) =5.2 Hz, 2H, H2), 3.99 (tm, J
(H3,H2) =5.2 Hz, 2H, H3). 13C NMR (100 MHz, Acetone-d6): δ = 146.2
(dm, 1J (C8,F8) =261.5 Hz, 3J (C8,F9) =2.7 Hz, C8), 144.4 (ddd, 1J
(C5,F5) =254.4 Hz, 2J (C5,F6) =15.6 Hz, C5), 142.0 (dt, 2J (C8a,F8)
=13.9 Hz, C8a), 141.8 (ddm, 1J (C6,F6) =256.3 Hz, 2J (C6,F5)
=14.1 Hz, C6), 123.0 (d, 2J (C4a,F5) =15.8 Hz, C4a), 121.8 (qm, 1J
(C9,F9) =274.5 Hz, C9), 112.6 (m, C7), 68.1 (s, C2), 52.4 (s, C3). 19F
NMR (282 MHz, Acetone-d6): δ = –55.9 (t, J (F9,F6) ≈ (F9,F8)
4.2.9. 5,6,8-Trifluoro-4,4-dioxo-2,3-dihydrobenzo[b][1,4]oxathiine (15)
To the solution of 14 (2.6 g, 10 mmol) in MeCN (15 mL) NEt3 (5 mL)
was added, and the mixture was heated at reflux for 50 h with stirring.
Then, the mixture was allowed to cool down to r.t. The precipitate was
filtered, washed with H2O (15 mL) and air dried to a constant weight.
The combined filtrate was extracted with EtOAc (50 mL), washed
with H2O (20 mL) and dried (MgSO4). After evaporation of the solvent
in vacuo, the additional portion of the product was obtained and re-
crystallized from hexane with EtOAc. (Preparation of 15 from 11 is
similar to the method given above for compound 14: the reaction time
should be increased to 72 h)
=22.7 Hz, 3 F, F9), –133.2 (qdd,
J
(F8,F9) =22.9 Hz,
J
(F8,F5)
=13.6 Hz, J (F8,F6) =6.7 Hz, 1 F, F8), –140.4 (dd, J (F5,F6) =21.6 Hz, J
(F5,F8) =13.6 Hz, 1 F, F5), –146.3 (quintetd, J (F6,F5) ≈ J (F6,F9)
=22.4 Hz, J (F6,F8) =6.7 Hz, 1 F, F6). HRMS (EI): m/z [M]+ calcd for
C9H4F6O3S: 305.9780; found: 305.9782.
White solid; yield: 2.1 g (90 %); mp 203.7–205.0 °C. IR (KBr): 3061,
2954, 1643, 1495, 1331, 1319, 1306, 1252, 1196, 1136, 1051, 985,
4.2.12. N-Benzyl-6,8-difluoro-4,4-dioxo-2,3-dihydrobenzo[b][1,4]
oxathiin-5-amine (18)
922, 883, 744, 723, 694, 567, 546, 490, 469 cm–1
.
1H NMR (500 MHz,
Acetone-d6): δ = 7.63 (td, J (H7,F6) ≈ J (H7,F8) =10.4 Hz, J (H7,F5)
=7.5 Hz, 1H, H7), 4.94 (tm, J (H2,H3) =5.2 Hz, 2H, H2), 3.88 (tm, J
(H3,H2) =5.2 Hz, 2H, H3). 13C NMR (126 MHz, Acetone-d6): δ = 147.8
(ddd, 1J (C8,F8) =249.9 Hz, 3J (C8,F6) =9.1 Hz, C8), 144.0 (dm, 1J
(C6,F6) =245.2 Hz, 1J (C5,F5) =249.5 Hz, C6, C5), 141.2 (dt, 2J (C8a,F8)
=14.1 Hz, C8a), 120.2 (d, 2J (C4a,F5) =15.6 Hz, C4a), 110.6 (t, 2J
(C7,F8) ≈ 2J (C7,F6) =24.0 Hz, C7), 67.6 (s, C2), 52.6 (s, C3). 19F NMR
(282 MHz, Acetone-d6): δ = –133.2 (dd, J (F8,F5) =13.4 Hz, J (F8,H7)
To the solution of 15 (0.22 g 0.92 mmol) in DMSO (1.5 mL) phe-
nylmethanamine (0.15 g 1.40 mmol) was added under argon atmo-
sphere. The reaction mixture was heated at 100 °C for 46 h with stirring.
Then, the mixture was allowed to cool down to r.t., diluted with H2O
(20 mL) and extracted with EtOAc (3 × 15 mL). The combined organic
layers were washed with H2O (10 mL) and dried (MgSO4). After eva-
poration of the solvent in vacuo, the crude product was purified by
preparative TLC.
=10.0 Hz, 1 F, F8), –141.3 (ddd,
J
(F5,F6) =22.0 Hz,
J
(F5,F8)
Yellowish solid; yield: 0.24 g (79 %); Rf = 0.35 (EtOAc/hexane,
1:3). mp 132.8 °C (dec.). IR (KBr): 3282, 2935, 2854, 1601, 1491, 1437,
1363, 1350, 1290, 1248, 1228, 1120, 991, 976, 899, 860, 742, 704,
=13.4 Hz, J (F5,H7) =7.5 Hz, 1 F, F5), –141.5 (dd, J (F6,F5) =22.0 Hz, J
(F6,H7) =9.4 Hz, 1 F, F6). HRMS (EI): m/z [M]+ calcd for C8H5F3O3S:
237.9906; found: 237.9902. Anal. Calcd for C8H5F3O3S: C, 40.34; H,
2.12. Found: C, 40.33; H, 2.08.
567, 540, 474 cm–1
.
1H NMR (500 MHz, Acetone-d6): δ = 7.47–7.45
(m, 2H, Hm), 7.39–7.36 (m, 2H, Ho), 7.32–7.31 (m, 1H, Hp), 7.29 (dd, J
(H7,F6) =12.3 Hz, J (H7,F8) =10.4 Hz, 1H, H7), 4.49 (s, 2H, H9), 3.68
(tm, J (H2,H3) =5.5 Hz, 2H, H2), 3.46 (tm, J (H3,H2) =5.2 Hz, 2H, H3).
13C NMR (126 MHz, Acetone-d6): δ = 147.3 (dd, 1J (C8,F8) =241.2 Hz,
3J (C8,F6) =9.3 Hz, C8), 145.4 (dd, 1J (C6,F6) =238.6 Hz, 3J (C6,F8)
=11.2 Hz, C6), 140.8 (dd, 2J (C8a,F8) =16.6 Hz, C8a), 138.8 (s, C10),
133.6 (dd, 2J (C5,F6) =11.2 Hz, C5), 129.4 (s, C12), 128.8 (s, C11), 128.4
(s, C13), 120.9 (m, C4a), 109.4 (dd, 2J (C7,F8) =26.8 Hz, 2J (C7,F6)
=23.4 Hz, C7), 157.9 (d, J (C10,F6) =8.1 Hz, C10), 49.5 (s, C2), 46.1 (s,
4.2.10. 5,6,8-Trifluoro-7-carboxamide-4,4-dioxo-2,3-dihydrobenzo[b]
[1,4]oxathiine (16)
To the solution of 12 (1.0 g, 3.3 mmol) in MeCN (5 mL) NEt3
(0.5 mL) was added, and the mixture was stirred at r.t. for 520 h in
closed flack. Then the mixture was diluted with H2O (10 mL) and ex-
tracted with EtOAc (3 × 15 mL). The combined organic layers were
washed with H2O (10 mL) and dried (MgSO4). After evaporation of the
5