S. Ito et al. / Tetrahedron 59 (2003) 4651–4659
4657
4.1.4. N-Sulfinyl-1,3-bis(ethoxycarbonyl)-6-azulenyl-
amine (2). The same procedure used for the prepartion of
1 was adopted. The reaction of 8 (115 mg, 0.400 mmol)
with thionyl chloride (267 mg, 2.24 mmol) in dry benzene
(20 ml) for 1 d afforded 2 (128 mg, 96%): brown crystals;
mp 108.5–1108C; MS (70 eV) m/z (relative intensity) 333
(Mþ, 100%) and 288 (Mþ2OEt, 53); IR (KBr disk) nmax
1678 (CvO), 1651 (CvO), 1431, 1387, 1204, 1171, and
1048 cm21; UV–vis (CH2Cl2) lmax 257 (log 1 4.39), 270 sh
(4.28), 311 sh (4.32), 315 sh (4.32), 340 (4.45), 372 sh
(4.20), 399 (3.93), 417 sh (3.81), and 553 (2.69) nm. HRMS
calcd for C16H15NO5S, 333.0665; found 333.0666. Anal.
Calcd for C16H15NO5S: C, 57.65; H, 4.54; N, 4.20; S, 9.62.
Found: C, 57.84; H, 4.73; N, 4.23; S, 9.37.
3.80 (d, J¼16.0 Hz, 1H, H-3), 3.77 (d, J¼16.1 Hz, 1H,
H-6), 3.33 (d, J¼16.1 Hz, 1H, H-6), 1.88 (s, 6H, 4-Me and
5-Me), and 1.45 (t, J¼7.2 Hz, 6H, 10,30-COOEt); 13C NMR
(100 MHz, CDCl3) d¼165.0 (s, 10,30-COOEt), 156.7 (C-60),
141.3 (C-200), 140.6 (C-30a,80a), 138.1 (C-40,80), 124.3 (C-5),
122.6 (C-5 ,70), 116.9 (C-10,30), 115.4 (C-4), 60.0 (t, 10,30-
COOEt), 55.1 (C-6), 46.5 (C-3), 19.6 (5-Me), 17.4 (4-Me),
and 14.5 (q, 10,30-COOEt). Anal. Calcd for C22H25NO5S: C,
63.60; H, 6.06; N, 3.37; S, 7.72. Found: C, 63.86; H, 6.31;
N, 3.32; S, 7.81.
4.1.7. Ethyl 4-[1,3-bis(ethoxycarbonyl)-2-azulenyl-
amino]-2,3-dimethyl-2-butene-1-sulfinate (15). To a solu-
tion of 13 (86 mg, 0.21 mmol) in CHCl3 (10 ml) and ethanol
(5 ml) was added two drops of conc HCl. The color of the
solution immediately changed from red to orange. The
reaction mixture was poured into water. The organic layer
was separated, dried over MgSO4, and concentrated under
reduced pressure. The residue was purified by column
chromatography on silica gel with ethyl acetate to afford 15
(94 mg, 98%): yellow crystals; mp 50.5–528C; MS (70 eV)
m/z (relative intensity) 461 (Mþ, 3%), 368 (Mþ2SO2Et,
100), 367 (Mþ2HSO2Et, 54), and 276 (Mþ2SO2Et–2OEt,
82); IR (KBr disk) nmax 3028 (m, NH), 1684 (CvO), 1653
4.1.5. 2-[1,3-Bis(ethoxycarbonyl)-2-azulenyl]-4,5-
dimethyl-6H-2,3-dihydro-1,2-thiazine 1-oxide (13). A
teflon vessel (9.1 ml) was filled with
1 (507 mg,
1.52 mmol), 12 (626 mg, 7.62 mmol), and CH2Cl2. The
mixture was left at 10 kbar (408C) for 3 d. After the solvent
was removed under reduced pressure, the residue was
purified by column chromatography on silica gel with 5%
ethyl acetate/CH2Cl2 and 70% ethyl acetate/CH2Cl2 to
afford 5 (110 mg, 25%) and 13 (414 mg, 66%): orange
needles; mp 126–1288C; MS (70 eV) m/z (relative inten-
sity) 415 (Mþ, 7%), 367 (Mþ2SO, 40), and 333
(Mþ2C6H10, 100); IR (KBr disk) nmax 1700 (CvO),
1673 (CvO), 1460, 1433, 1196, and 1086 cm21; UV–vis
(CH2Cl2) lmax 271 (log 1 4.27), 305 sh (4.42), 323 (4.51),
(CvO), 1638 (CvO), 1559, 1524, 1163, and 1132 cm21
;
UV–vis (CH2Cl2) lmax 255 (log 1 4.35), 285 (4.33), 320 sh
(4.68), 329 (4.75), 380 sh (3.96), 414 (4.04), and 456 sh
(3.38) nm; 1H NMR (600 MHz, CDCl3) d¼8.90 (br, 2H, H-
40,800), 08.21 (br s, 1H, 4-NH), 7.48 (dd, J¼10.1, 9.9 Hz, 2H,
H-5 ,7 ), 7.39 (t, J¼9.8 Hz, 1H, H-60), 4.45 (q, J¼7.2 Hz,
4H, 10,30-COOEt), 4.13 (dq, J¼10.1, 7.1 Hz, 1H, 1-SO2Et),
4.10 (d, J¼14.2 Hz, 1H, H-4), 4.06 (dq, J¼10.1, 7.1 Hz, 1H,
1-SO2Et), 4.05 (d, J¼14.2 Hz, 1H, H-4), 3.70 (d,
J¼13.2 Hz, 1H, H-1), 3.60 (d, J¼13.2 Hz, 1H, H-1), 1.87
(s, 3H, 2-Me), 1.81 (s, 3H, 3-Me), 1.46 (t, J¼7.2 Hz, 6H,
10,30-COOEt), and 1.32 (t, J¼7.1 Hz, 3H, 1-SO2Et); 13C
NMR (150 MHz, CDCl3) d¼166.7 (br s, 10,30-COOEt),
160.5 (C-200), 145.0 (br, C-30a,800a), 134.1 (C-3), 132.5 (C-60),
131.7 0(C-5 ,70), 130.4 (br, C-4 ,80), 122.3 (C-2), 0101.8 (br,
C-10,3 ), 65.0 (t, 1-SO2Et), 63.1 (C-1), 60.2 (t, 10,3 -COOEt),
50.4 (C-4), 20.7 (2-Me), 17.7 (3-Me), 15.9 (q, 1-SO2Et), and
14.6 (q, 10,30-COOEt). Anal. Calcd for C24H31NO6S: C,
62.45; H, 6.77; N, 3.03; S, 6.95. Found: C, 62.29; H, 6.60;
N, 3.15; S, 6.85.
1
362 sh (3.81), 391 sh (3.64), and 505 (2.65) nm; H NMR
(400 MHz, CDCl3) d¼9.27 (dd, J¼10.7, 1.1 Hz, 2H, H-
40,80), 7.82 (tt, J¼9.7, 1.1 Hz, 1H, H-60), 7.65 (dd, J¼10.7,
9.7 Hz, 2H, H-50,70), 4.540(d, J¼16.3 Hz, 1H, H-3), 4.47 (dq,
J¼10.8, 7.1 Hz, 2H, 1 ,30-COOEt), 4.44 (dq, J¼10.8,
7.1 Hz, 2H, 10,30-COOEt), 3.98 (d, J¼15.7 Hz, 1H, H-6),
3.68 (d, J¼16.3 Hz, 1H, H-3), 3.15 (d, J¼15.7 Hz, 1H,
H-6), 1.87 (s, 3H, 05-Me), 1.79 (s, 3H, 4-Me), and 1.43 (t,
J¼7.1 Hz, 6H, 100,3 -COOEt); 13C NMR (100 MHz, CDCl3)
d¼165.2 (s, 10,3 -COOEt), 0154.0 (C-20), 0141.3 (C-30a,80a),
138.9 (C-60), 137.3 (C-400,80), 130.3 (C-5 ,70), 124.4 (C-5),
115.6 (C-4), 112.9 (C-1 ,3 ), 60.8 (t, 10,30-COOEt), 54.5
(C-6), 48.8 (C-3), 20.1 (5-Me), 17.1 (4-Me), and 14.4 (q,
10,30-COOEt). Anal. Calcd for C22H25NO5S: C, 63.60; H,
6.06; N, 3.37; S, 7.72. Found: C, 63.56; H, 6.15; N, 3.32; S,
7.51.
4.1.8. Ethyl 4-[1,3-bis(ethoxycarbonyl)-6-azulenyl-
amino]-2,3-dimethyl-2-butene-1-sulfinate (16). The
same procedure used for the preparation of 15 was adopted.
The reaction of 14 (312 mg, 0.752 mmol) with 8 drops of
conc HCl in CHCl3 (30 ml) and ethanol (15 ml) afforded 16
(288 mg, 83%) and 17 (24 mg, 9%).
4.1.6. 6-[1,3-Bis(ethoxycarbonyl)-6-azulenyl]-4,5-
dimethyl-6H-2,3-dihydro-1,2-thiazine 1-oxide (14). The
same procedure used for the preparation of 13 was adopted.
The high-pressure reaction of 2 (561 mg, 1.68 mmol) with
12 (643 mg, 7.83 mmol) in a teflon vessel (9.1 ml) for 2 d
afforded 14 (539 mg, 77%). The reaction of 2 (95 mg,
0.28 mmol) with 12 (244 mg, 2.97 mmol) in refluxing
toluene (15 ml) for 21 h under an Ar atmosphere afforded
8 (45 mg, 55%) and 14 (34 mg, 29%): red crystals; mp 163–
1648C; MS (70 eV) m/z (relative intensity) 415 (Mþ, 18%),
333 (Mþ2C6H10, 100), and 288 (Mþ2C6H10–OEt, 47); IR
4.1.9. Ethyl 4-[1,3-bis(ethoxycarbonyl)-6-azulenyl-
amino]-2,3-dimethyl-2-butene-1-sulfinate (16). Yellow
crystals; mp 92–94.58C; MS (70 eV) m/z (relative intensity)
461 (Mþ, 31%), 368 (Mþ2SO2Et, 86), 367 (Mþ2HSO2Et,
100), and 322 (Mþ2HSO2Et–OEt, 40); IR (KBr disk) nmax
3337 (m, NH), 1678 (CvO), 1667 (CvO), 1595, 1584,
1435, 1383, 1215, and 1198 cm21; UV–vis (CH2Cl2) lmax
256 (log 1 4.21), 276 (4.24), 286 (4.31), 344 (4.84), 374 sh
(4.40), 391 sh (4.18), and 426 (3.67) nm; 1H NMR
(400 MHz, CDCl3) d¼9.31 (d, J¼11.1 Hz, 2H, H-40,80),
8.25 (s, 1H, H-20), 6.79 (d, J¼11.1 Hz, 2H, H-50,70), 6.67 (br
(KBr disk) nmax 1694 (CvO), 1435, 1198, and 1053 cm21
;
UV–vis (CH2Cl2) lmax 259 sh (log 1 4.14), 270 (4.21), 280
(4.18), 337 (4.74), 372 (4.28), and 474 (2.99) nm; 1H NMR
(400 MHz, CDCl3) d¼9.64 (d, J¼11.5 Hz, 2H, H-40,80),
8.66 (s, 1H, H-200), 7.47 (d, J¼11.5 Hz, 2H, H-50,70), 4.42 (q,
J¼7.2 Hz, 4H, 1 ,30-COOEt), 4.37 (d, J¼16.0 Hz, 1H, H-3),