4-(4-Carboxyphenoxy)-3-(chlorosulfonyl)benzoic Acid (2). Yield 6.92 g (92%), light-yellow powder,
mp 227-228°С (decomp.). IR spectrum, , cm-1: 1698 (CO), 1594 (C–C Ar), 1504 (C–C Ar), 1491 (C–C Ar),
1421, 1374 (SO2Cl), 1262 (Ar–O–Ar), 1163. 1H NMR spectrum, δ, ppm (J, Hz): 6.94 (1Н, d, J = 8.0, Н-5); 6.97
(2Н, d, J = 8.5, Н-2',6'); 7.87 (1Н, dd, J = 8.0, J = 2.5, Н-6); 7.90 (2Н, d, J = 8.5, Н-3',5'); 8.38 (1Н, d, J = 2.5,
13
Н-2). C NMR spectrum, δ, ppm: 118.4; 120.7; 125.3; 125.8; 130.6; 131.4; 132.0; 139.3; 156.1; 160.9; 166.5;
166.8. Mass spectrum, m/z (Irel, %): 337 [M-H]- (100) (sulfonic acid). Found, %: С 47.20; Н 2.51; S 9.02.
C14H9ClO7S. Calculated, %: С 47.14; Н 2.54; S 8.99.
4,4'-Oxybis[3-(chlorosulfonyl)benzoic Acid] (3). Yield 7.94 g (90%), light-yellow powder, mp 230-231°С
(decomp.). IR spectrum, , cm-1: 1703 (CO), 1593 (C–C Ar), 1490 (C–C Ar), 1400, 1372 (SO2Cl), 1261 (Ar–O–Ar),
1181. 1H NMR spectrum, δ, ppm (J, Hz): 6.94 (2Н, d, J = 8.5, Н-5,5'); 7.83 (2Н, dd, J = 8.5, J = 2.5, Н-6,6');
8.39 (2Н, d, J = 2.5 Н-2,2'). 13C NMR spectrum, δ, ppm: 123.0; 125.9; 130.5; 132.7; 138.9; 159.1; 167.1. Mass
spectrum, m/z (Irel, %): 419 [M+H]+ (100) (sulfonic acid). Found, %: С 36.88; Н 1.75; S 14.12. C14H8Cl2O9S2.
Calculated, %: С 36.94; Н 1.77; S 14.09.
4-(Chlorosulfonyl)-10,10-dioxo-10λ6-phenoxathiin-2,8-dicarboxylic Acid (4). Yield 7.54 g (93%),
white powder, mp 268-269°С (decomp.). IR spectrum, , cm-1: 1722 (CO), 1592 (C–C Ar), 1375 (SO2Cl), 1327
1
(SO2), 1216 (Ar–O–Ar), 1165. H NMR spectrum, δ, ppm (J, Hz): 7.68 (1Н, d, J = 9.0, Н-6); 8.37 (1Н, dd,
13
J = 9.0, J = 2.0, Н-7); 8.44 (1Н, d, J = 2.0), 8.48 (1Н, d, J = 2.0) and 8.65 (1Н, d, J = 2.0, Н-1,3,9). C NMR
spectrum, δ, ppm: 121.0; 124.7; 125.0; 125.2; 125.8; 127.8; 129.1; 134.2; 136.5; 139.0; 151.0; 154.2; 165.4;
165.6. Mass spectrum, m/z (Irel, %): 399 [M-H]- (100) (sulfonic acid). Found, %: С 39.94; Н 1.72; S 15.02.
C14H7ClO9S2. Calculated, %: С 40.15; Н 1.68; S 15.31.
Sodium 2,8-Dicarboxy-10,10-dioxo-10λ6-phenoxathiin-4-sulfonate (5). A 50-ml flask was equipped
with magnetic stirrer and a reflux condenser and charged with acid 1 (2 g, 7.78 mmol) and oleum with 20% SO3
(20 ml). The reaction mixture was stirred for 3.5 h at 120°С, then poured on ice, and the solution was saturated
with NaCl. The white precipitate that formed was filtered off, washed twice with ice water (2×10 ml), and dried
in desiccator over CaCl2. Yield 1.15 g (35%), white crystals, mp >310°С (decomp.). IR spectrum, , cm-1: 1736
1
(CO), 1596 (C–C Ar), 1386, 1304 (SO2), 1269, 1232, 1209 (Ar–O–Ar), 1178, 1102, 1042 (SO3Na). H NMR
spectrum, δ, ppm (J, Hz): 7.68 (1Н, d, J = 9.0, Н-6); 8.37 (1Н, dd, J = 9.0, J = 2.0, Н-7); 8.44 (1Н, d, J = 2.0),
8.48 (1Н, d, J = 2.0) and 8.65 (1Н, d, J = 2.0, Н-1,3,9). Mass spectrum, m/z (Irel, %): 399 [M-H]- (100) (sulfonic
acid). Found, %: С 40.01; Н 2.05; S 15.11. C14H7NaO10S2. Calculated, %: С 39.82; Н 1.67; S 15.18.
4-(Chlorosulfonyl)-10,10-dioxo-10λ6-phenoxathiin-2,8-dicarbonyl Dichloride. DMF (2 drops) was
added to a suspension of acid 4 (1 g, 2.4 mmol) in SOСl2 (30 ml), the reaction mixture was refluxed in a flask
with reflux condenser for 1.5 h until full dissolution of acid 4. The excess of SOCl2 was then removed by
distillation, the solid residue was washed with hexane (2×10 ml) and dried under vacuum. Yield 0.58 g (53%),
1
white powder, mp 225-228°С. IR spectrum, , cm-1: 1758 (CO), 1319 (SO2), 1214 (Ar–O–Ar), 1170. H NMR
spectrum, δ, ppm (J, Hz): 7.67 (1Н, d, J = 9.0, Н-6); 8.37 (1Н, dd, J = 9.0, J = 2.5, Н-7); 8.44 (1Н, d, J = 2.5),
8.48 (1Н, d, J = 2.5) and 8.64 (1Н, d, J = 2.5, Н-1,3,9).
4-[(Diethylamino)sulfonyl]-10,10-dioxo-N2,N2,N8,N8-tetraethyl-10λ6-phenoxathiin-2,8-dicarboxamide (6).
Diethylamine (2 ml, 19.34 mmol) was added to a solution of 4-(chlorosulfonyl)-10,10-dioxo-10λ6-phenoxathiin-
2,8-dicarbonyl dichloride (0.4 g, 0.88 mmol) in THF (15 ml). The reaction mixture was stirred at room
temperature for 2 h, then diluted with Н2О (30 ml). The precipitate that formed was filtered off, washed with
water (2×15 ml), and dried in desiccator over CaCl2. Yield 0.25 g (51%), white needle-shaped crystals,
mp 192-193°С. IR spectrum, , cm-1: 1632 (CO), 1429 (C–C Ar), 1395 (SO2Cl), 1305 (SO2), 1273 (Ar–O–Ar),
1
1149. H NMR spectrum, δ, ppm (J, Hz): 1.10 (12Н, t, J = 7.0, 2CON(CH2CH3)2); 1.16-1.20 (6Н, m,
SO2N(CH2CH3)2); 3.20 (4Н, br. s, SO2N(CH2CH3)2); 3.44 (8Н, q, J = 7.0, 2CON(CH2CH3)2); 7.75 (1Н, d,
J = 9.0, Н-6); 7.87 (1Н, dd, J = 9.0, J = 2.0, Н-7); 8.10 (1Н, d, J = 2.0), 8.18 (1Н, d, J = 2.0) and 8.35 (1Н, d,
J = 2.0, Н-1,3,9). Found, %: С 55.14; Н 6.25; N 7.50; S 11.28. C26H35N3O7S2. Calculated, %: С 55.20; Н 6.24;
N 7.43; S 11.34.
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