A. Garimalla and M. Harmata
Tetrahedron 84 (2021) 131991
found: 388.0775.
4.3.9. 2-(2-Bromophenyl)-7-fluorobenzo [c][1,2]thiazine 2-oxide
(11a)
Purified by column chromatography (SiO2) using 30% ethyl ac-
etate/hexanes, yellow sticky liquid, Rf ¼ 0.4 (30% ethyl acetate/
hexanes), 28% yield; IR (CHCl3) 3072, 3035, 2928, 1605, 1539,
1496, 1286, 1215, 1041, 907, 884, 784, 727, 676, 569, cm-1; 1H NMR
4.3.5. 6-(Benzyloxy)-2-(2-chlorophenyl) benzo[c][1,2]thiazine 2-
oxide (9c)
Purified by column chromatography (SiO2) using 30% ethyl ac-
etate/hexanes; pale yellow oil; 50% yield; IR (CHCl3) 3067, 2925,
1652, 1590, 1472, 1215, 1170, 1023, 990, 829, 749, 668 593 cm-1; 1H
(500 MHz, CDCl3)
d
8.41 (dd, J ¼ 7.0, 1.0 Hz, 1H), 7.76 (d, J ¼ 8.0 Hz,
1H), 7.74 (d, J ¼ 10.0 Hz,1H), 7.59 (t, J ¼ 7.5 Hz,1H), 7.48 (t, J ¼ 7.5 Hz,
1H), 7.34 (dd, J ¼ 6.5, 2.5 Hz, 1H), 6.93 (dt, J ¼ 10.5, 2.0 Hz, 1H), 6.76
(dt, J ¼ 8.0, 2.0 Hz, 1H), 6.28 (d, J ¼ 10.0 Hz, 1H); 13C NMR (125 MHz,
NMR (500 MHz, CDCl3)
d
8.33 (d, J ¼ 8.0 Hz, 1H), 7.69 (d, J ¼ 10.0 Hz,
1H), 7.53e7.50 (m, 3H), 7.44e7.38 (m, 2H), 7.40 (t, J ¼ 7.5 Hz, 2H),
7.20e7.19 (m, 1H), 6.90 (d, J ¼ 2 Hz, 1H), 6.37 (d, J ¼ 10 Hz, 1H), 5.07
CDCl3)
d
166.3 (d, J ¼ 250 Hz), 147.6 (d, J ¼ 13.75 Hz), 141.2, 138.7,
(s, 2H) 13C NMR (125 MHz, CDCl3)
d 152.4, 140.9, 140.0, 138.0, 137.0,
135.9, 134.6, 131.8 (d, J ¼ 11.25 Hz), 130.8, 129.1, 128.7, 127.7, 124.7,
113.2, 109.7 (d, J ¼ 22.5 Hz), 109.1 (d, J ¼ 23.75 Hz), 105.8 (d,
J ¼ 2.5 Hz); HRMS calculated for (C14H9BrFNOS)Naþ: 359.9564,
found: 359.9474.
135.7, 134.5, 132.2, 130.5, 128.6, 128.0, 127.5, 125.0, 125.1, 122.2,
116.0, 112.6, 107.5, 70.7; HRMS calculated for (C21H16ClNO2S)Naþ:
404.0482, found: 404.0490.
4.3.6. 2-(2-Bromophenyl)-8-methoxybenzo [c][1,2]thiazine 2-oxide
(10a)
4.3.10. 7-Fluoro-2-(2-fluorophenyl) benzo[c] [1,2]thiazine 2-oxide
(11b)
Purified by column chromatography (SiO2) using 30% ethyl ac-
etate/hexanes; pale yellow solid; 40% yield; mp 173e175 ꢀC; IR
(CHCl3) 3057, 2992, 2937, 2836, 1601, 1599, 1429, 1372, 1175, 1080,
Purified by column chromatography (SiO2) using 30% ethyl ac-
etate/hexanes, sticky liquid, Rf ¼ 0.4 (30% ethyl acetate/hexanes);
45% yield; IR (CHCl3) 3040, 2918, 1607, 1520, 1450, 1286, 1047, 998,
997, 807, 720, 668 cmꢂ1 1H NMR (500 MHz, CDCl3)
; d 8.44 (dt,
890, 784, 727, 626 cmꢂ1 1H NMR (500 MHz, CDCl3)
; d 8.04 (dt,
J ¼ 7.5, 1.5 Hz, 1H), 7.77 (d, J ¼ 10.0 Hz, 1H), 7.70 (d, J ¼ 8.0 Hz, 1H),
7.53 (t, J ¼ 7.5 Hz, 1H), 7.42 (dt, J ¼ 7.5, 6.0 Hz, 1H), 7.02e6.97 (m,
3H), 6.31 (d, J ¼ 10.0 Hz,1H). 3.92 (s, 3H); 13C NMR (125 MHz, CDCl3)
J ¼ 8.0, 1.5 Hz, 1H), 7.68 (d, J ¼ 10.0 Hz, 1H), 7.64e7.63 (m, 1H), 7.36
(t, J ¼ 8.0 Hz, 1H), 7.35 (m, 1H), 7.19 (t, J ¼ 9.0 Hz, 1H), 6.93 (dd,
J ¼ 11.0, 2.5 Hz, 1H), 6.77 (dt, J ¼ 8.0, 2.5 Hz, 1H), 6.46 (d, J ¼ 10.0 Hz,
1H); 13C NMR (125 MHz, CDCl3)
d
166.3 (d, J ¼ 250 Hz), 160.6 (d,
d
151.9, 141.6, 138.9, 135.8, 135.6, 134.3, 131.0, 127.3, 125.2, 121.7,
119.6, 116.7, 112.5, 107.0, 56.1; HRMS calculated for (C15H12BrNO2S)
J ¼ 255 Hz), 147.2 (d, J ¼ 13.75 Hz), 140.1, 136.2 (d, J ¼ 8.75 Hz), 131.7
(d, J ¼ 11.25 Hz),129.4 (d, J ¼ 12.5 Hz),124.4 (d, J ¼ 3.75 Hz),117.6 (d,
J ¼ 21.25 Hz), 113.01 (d, J ¼ 1.25 Hz), 109.6 (d, J ¼ 22.5 Hz), 109.1 (d,
J ¼ 23.75 Hz), 107.6; HRMS calculated for (C14H9F2NOS)Naþ:
300.0265, found: 300.0270.
Naþ: 371.9664, found: 371.9662.
4.3.7. 2-(2-Fluorophenyl)-8-methoxybenzo [c][1,2]thiazine 2-oxide
(10b)
Purified by column chromatography (SiO2) using 30% ethyl ac-
etate/hexanes; pale yellow solid recrystallized from ethyl acetate/
hexane, 65% yield; mp 168e170 ꢀC; IR (CHCl3) 3064, 2986, 2937,
2837, 1599, 1547, 1472, 1289, 1257, 1000, 997, 828, 720, 682,
4.3.11. 2-(2-Chlorophenyl)-7-fluorobenzo [c][1,2]thiazine 2-oxide
(11c)
Purified by column chromatography (SiO2) using 30% ethyl ac-
etate/hexanes; sticky liquid; Rf ¼ 0.4 (30% ethyl acetate/hexanes);
42% yield; IR (CHCl3) 3040, 2908, 1616, 1512, 1450, 1215, 1170 1046,
593 cmꢂ1; 1H NMR (500 MHz, CDCl3)
d
8.09 (dt, J ¼ 7.5, 1.5 Hz, 1H),
7.72 (d, J ¼ 10.0 Hz, 1H), 7.60e7.59 (m, 2H), 7.35 (t, J ¼ 7.5 Hz, 1H),
978, 854, 727, 684 646 cmꢂ1 1H NMR (500 MHz, CDCl3)
; d 8.32 (d,
7.16 (dt, J ¼ 9.5, 8.5 Hz, 1H), 7.01e6.97 (m, 3H), 6.50 (d, J ¼ 10 Hz,
1H). 3.94 (s, 3H) 13C NMR (125 MHz, CDCl3)
d 161.0, (d,
J ¼ 6.0, 1.5 Hz, 1H), 7.72 (d, J ¼ 10.0 Hz, 1H), 7.54e7.53 (m, 3H), 7.35
(dd, J ¼ 6.5, 2.0 Hz, 1H), 6.93 (dd, J ¼ 11.0, 2.5 Hz, 1H), 6.76 (dt,
J ¼ 2.5, 0.5 Hz, 1H), 6.39 (d, J ¼ 10.0 Hz, 1H); 13C NMR (125 MHz,
J ¼ 256.25 Hz), 151.9, 140.5, 136.1 (d, J ¼ 8.75 Hz), 135.5, 135.9 (d,
J ¼ 7.5 Hz),129.9,129.5 (d, J ¼ 11.25 Hz),124.17 (d, J ¼ 3.75 Hz),121.7,
119.7, 117.5 (d, J ¼ 20 Hz), 116.6, 112.6, 109.0, 56.1; HRMS calculated
for (C15H12FNO2S)Naþ: 312.0464, found: 312.0463.
CDCl3)
d
166.3 (d, J ¼ 250 Hz), 147.5 (d, J ¼ 13.75 Hz), 141.0, 137.7,
135.7, 134.7, 132.3, 131.8 (d, J ¼ 11.25 Hz), 130.4, 127.1, 113.0, 109.6 (d,
J ¼ 22.5 Hz), 109.0 (d, J ¼ 23.75 Hz), 106.2 (d, J ¼ 2.5 Hz); HRMS
calculated for (C14H9ClFNOS)Naþ: 315.9969, found: 315.9976.
4.3.7.1. Crystal structure of compound 10b. C14H12FNO2S,
M ¼ 289.32; a block crystal (0.55 ꢁ 0.14 ꢁ 0.10 mm), T ¼ 173 (2) K,
4.4. Typical procedure for the coupling reaction of 2-bromophenyl
sulfoximine 4a with 5 (procedure B)
l
¼ 0.71073 Å, trigonal, space group: P21/n, a ¼ 30.100 (13) Å,
b ¼ 30.100 (13) Å, c ¼ 7.609 (3)Å, V ¼ 5970 (4) A^3, 22 369 total
reflections, 3049 unique, R int ¼ 0.0279 R1 ¼ 0.0255(I > 2s),
wR2 ¼ 0.0628, Flack parameter: 0.00 (5).
2-Bromobenzaldehyde 5 (0.164 g, 0.89 mmol), sulfoximine 4a
(0.25 g, 1.06 mmol), Pd(OAc)2 (0.0100 g, 0.0443 mmol), Cs2CO3
(0.405 g, 1.24 mmol), BINAP (0.0415 g, 0.0667 mmol) were added
together in a sealed tube with toluene (8.9 mL, 0.1 M) inside a glove
bag filled with nitrogen and capped. The mixture was degassed by
bubbling with argon for 15 min with stirring at rt and heated to
110 ꢀC for 48 h. After cooling to rt, the reaction mixture was diluted
in dichloromethane and filtered through a plug of Celite. After
concentrated in vacuo, the brownish semisolid was purified by
flash chromatography (SiO2) with 20e30% ethyl acetate/hexanes to
afford 0.113 g of 7a (37%) as pale yellow solid, 0.016 g of 6a (7%),
0.018 g of 8a (6%) and 0.07 g of 4a (28%) were recovered.
4.3.8. 2-(2-Chlorophenyl)-8-methoxybenzo [c][1,2]thiazine 2-oxide
(10c)
Purified by column chromatography (SiO2) using 30% ethyl ac-
etate/hexanes; pale yellow solid recrystallized from ethyl acetate/
hexane; 60% yield; mp 185e187 ꢀC; IR (CHCl3) 3057, 2992, 2937,
2836, 1601, 1599, 1429, 1372, 1215, 1170, 1080, 997, 807, 720,
668 cmꢂ1; 1H NMR (500 MHz, CDCl3)
d
8.44 (dt, J ¼ 7.5, 1.5 Hz, 1H),
7.77 (d, J ¼ 10 Hz, 1H), 7.70 (d, J ¼ 8.0 Hz, 1H), 7.53 (t, J ¼ 7.5 Hz, 1H),
7.42 (dt, J ¼ 7.5, 6.0 Hz, 1H), 7.02e6.97 (m, 3H), 6.31 (d, J ¼ 10.0 Hz,
1H). 3.92 (s, 3H) 13C NMR (125 MHz, CDCl3)
d 151.9, 141.6, 138.9,
135.8, 135.6, 134.3, 131.0, 127.3, 125.2, 121.7, 119.6, 116.7, 112.5, 107.0,
56.1; HRMS calculated for (C15H12ClNO2S)Naþ: 328.0169, found:
328.0172.
4.4.1. 2-(((2-Bromophenyl) (methyl) (oxo)-l6-sulfaneylidene)
amino)benzaldehyde (6a)
Purified by column chromatography (SiO2) using 30% ethyl
5