Beilstein J. Org. Chem. 2015, 11, 576–582.
3
.55 (br s, 1CH), 3.37 (br s, 1CH), 3.12 (br s, 1CH), 3.01–2.97 134.7, 131.6, 131.1, 125.0 (6 C(sp2)), 138.7, 131.9, 131.6,
(
m, 1CH) ppm; 13C NMR (150 MHz, CDCl3) δ 168.1, 164.3 (2 130.7, 130.2, 128.8, 127.9, 127.8, 126.5, 126.1 (7 CHarom + 2
C=O), 138.1, 138.0, 131.8, 130.6 (7 C(sp2)), 136.3, 128.0, CHolefin + S-CH=), 51.9 (OCH3), 41.3 (S-CH) ppm; MS (ESI)
27.5, 126.4, 125.3 (7 CHarom), 53.1, 52.8 (2 OCH3), 33.0 m/z (%): 207 (100, [M − 74]+), 245 (55, [M − 36]+), 297 (45,
S-CH), 32.0 (broad, 2 CH2) ppm; HRMS (ESI): [M + Na]+ [M − 16]+); anal. calcd for C19H14O2S: C, 74.48; H, 4.61; S,
1
(
calcd for C21H18NaO4S, 389.08180; found, 389.08178; anal. 10.46; found: C, 74.53; H, 4.99; S, 10.64.
calcd for C21H18O4S: C, 68.82; H, 4.95; S, 8.75; found: C,
6
8.71; H, 5.06; S, 8.82.
General procedure for the oxidation of thiopyran deriva-
tives 4a,b and 5a,b: A solution of 1 mmol of the corres-
Dimethyl 4bH-benzo[4,5]cyclohepta[1,2,3-ij]isoth- ponding thiopyran and 3 mmol of mCPBA (70% purity) in
iochromene-6,7-dicarboxylate (4c): Yield: 83 mg (46%). dichloromethane was stirred at room temperature for 3 days.
Orange solid; mp 139.7–140.0 °C (purified chromatographi- Then the reaction mixture was extracted with aqueous saturated
cally); IR (KBr) ν: 3018 (w), 2947 (w), 1728 (s), 1725 (s), 1596 NaHCO3 (3 × 10 mL) and distilled water (1 × 10 mL). The
(
w), 1563 (w), 1433 (w), 1264 (s),1229 (s), 1097 (w), 771 (w) organic phase was dried over anhydrous MgSO4 and concen-
cm−1; 1H NMR (600 MHz, CDCl3) δ 7.77 (d, J = 6 Hz, trated in vacuo.
1
7
Harom), 7.49–7.45 (m, 2Harom), 7.42 (d, J = 6 Hz, 1Harom),
.36 (d, J = 6 Hz, 1Harom), 7.30, 7.27 (2d, J = 6 Hz, 2 olefinic Methyl 11,12-dihydro-4bH-benzo[4,5]cyclohepta[1,2,3-
HC=), 7.23 (d, J = 6 Hz, 2Harom), 4.49 (s, S-CH), 3.92, 4.00 (2 ij]isothiochromene-7-carboxylate 5,5-dioxide (6d): Yield:
s, 6H, 2 OCH3) ppm; 13C NMR (150 MHz, CDCl3) δ 167.8, 88 mg (80%). Colorless crystals; mp 187.5–188.0 °C (MeOH);
1
64.2 (2 C=O), 139.9, 135.8, 134.6, 132.5, 130.3, 128.8, 124.2 IR (KBr) ν: 3041 (w), 2950 (w), 1717 (s), 1600 (w), 1433 (w),
7 C(sp2)), 132.2, 130.1, 129.3, 127.8, 127.6, 126.7, 126.7, 1307 (s), 1262 (s), 1130 (s), 785 (m) cm−1; 1H NMR (600 MHz,
26.6, 125.2 (7 CHarom + 2 CHolefin), 53.2, 52.8 (2 OCH3), 41.8 CDCl3) δ 7.60–7.48 (m, 1Harom), 7.36 (br s, 1Harom + S-CH=),
S-CH) ppm; HRMS (MALDI–TOF): [M + Na]+ calcd for 7.32–7.28 (m, 2Harom), 7.27–7.20 (m, 3Harom), 5.72 (br s
C21H16NaO4S, 387.0668; found, 387.0667. S-CH), 3.96 (s, 3H, OCH3), 3.58 (br s, 1H), 3.10 (br s, 2H),
.91 (br s, 1H) ppm; 13C NMR (150 MHz, CDCl3) δ 164.9
(
1
(
2
Methyl 11,12-dihydro-4bH-benzo[4,5]cyclohepta[1,2,3- (C=O), 134.5, 134.3, 132.2, 131.0, 130.8, 129.2 (6 C(sp2)),
ij]isothiochromene-7-carboxylate (5b): Yield: 288.5 mg 134.1, 133.3, 130.0, 129.7, 129.1, 128.0, 127.5, 126.1 (7
(
94%). Yellow solid; mp 116.0–116.5 °C (chromatographic CHarom + S-CH=), 62.5 (OCH3), 53.4 (S-CH), 37.3, 34.7 (2
purification); IR (KBr) ν: 3059 (w), 2946 (w), 1702 (s), 1591 broad signals, 2 CH2) ppm; HRMS (ESI): [M + Na]+ calcd for
(
(
w), 1431 (w), 1221 (s), 1068 (m), 756 (m) cm−1; 1H NMR C19H16NaO4S, 363.06615; found, 363.06614.
600 MHz, CDCl3) δ 7.93–7.87 (m, 1Harom), 7.84–7.80 (m,
1
Harom), 7.61 (br s, S-CH=), 7.28–7.23 (m, 2Harom), 7.21–7.17
m, 2Harom), 7.03 (br s, 1Harom), 5.79 (br s, S-CH), 3.87 (s, 3H,
OCH3), 3.55 (br s, 1CH), 3.35 (br s, 1CH), 3.15 (br s, 1CH),
Supporting Information
(
Supporting Information File 1
3
1
.03–2.95 (m, 1CH) ppm; 13C NMR (150 MHz, CDCl3) δ
Experimental data for selected compounds 4–6, details of
the crystal structure determination, and the original 1H and
65.3 (C=O), 142.0, 138.7, 137.6, 135.2, 125.7, 125.4 (6
C(sp2)), 132.4, 130.6, 129.3, 128.0, 127.8, 127.1, 126.6, 126.1
7 CHarom + S-CH=), 51.9 (OCH3), 35.0 (S-CH), 32.2 (broad, 2
1
3C NMR spectra for all products. CCDC-1038599 and
038600 contain the supplementary crystallographic data
(
1
CH2) ppm; HRMS (MALDI–TOF): [M + Na]+ calcd for
C19H16NaO2S, 331.0761; found, 331.0769.
for this paper. These data can be obtained free of charge
Methyl 4bH-benzo[4,5]cyclohepta[1,2,3-ij]isothiochromene-
7
-carboxylate (5c): Yield: 85 mg (61%). Yellow solid; mp
7.5–78.0 °C (chromatographic purification); IR (KBr) ν: 3057
7
(
(
w), 2948 (w), 1709 (s), 1644 (m), 1589 (w), 1432 (w), 1235
s), 1066 (m), 726 (m) cm−1; 1H NMR (600 MHz, CDCl3) δ Acknowledgements
.98 (m, 1Harom), 7.95 (d, J = 6 Hz, 1Harom), 7.75 (d, J = 12 Hz, The authors thank the National Science Center (Cracow,
7
1
Harom), 7.43–7.41 (m, 1Harom), 7.37–7.34 (m, 2Harom), 7.27 Poland) for generous financial support (Grant Maestro-3 (Dec-
(
s, 1Harom), 7.28–7.24 (m, 1Harom), 7.22, 7.18 (2 d, J = 12 Hz, 2 2012/06/A/ST5/00219). Skilful performance of microanalyses
olefinic HC=), 4.45 (s, S-CH), 3.86 (s, 3H, OCH3) ppm; by Ms Hanna Jatczak and Ms Agnieszka Cieślińska (University
3C NMR (150 MHz, CDCl3) δ 165.2 (C=O), 139.7, 134.9, of Łódź) is gratefully acknowledged.
1
581