1218
LETTERS
SYNLETT
concentrated under reduced pressure. The crude product was
recrystallized in ether/hexane or purified by column
chromatography on silica gel (hexane/ethyl acetate = 2 : 1) to
afford the products of 3a-3h as crystals or oil. Spectroscopic data
for selected compounds; (3a): crystals, mp 83-85 oC; 1H NMR
(CDCl3) δ7.37 (s, 4H), 6.13 (dd, J = 2.9, 7.6 Hz, 1H), 3.67 (s, 3H),
2.95 (dd, J = 7.5, 16.3 Hz, 1H), 2.77 (dd, J = 3.0, 16.3 Hz, 1H);
FT-IR 3073.4, 2960.2, 1744.4, 1712.6, 1500.8, 1432.4, 1407.9,
1387.7, 1171.8, 813.8; MS (20eV) m/z (rel intensity) 285
[(M+1)+, 19.4], 284 (M+, 67.6), 238 (2.6), 227 (6.5), 211 (100),
194 (1.1), 183 (10.3), 153 (12.6), 138 (28.0), 127 (78.3); HRMS
calcd for C12H13N2O4Cl 284.05638, found 284.05661; (3b): a
light yellow oil; 1H NMR (CDCl3) δ7.52-7.46 (m, 1H), 7.36-7.27
(m, 3H), 6.06 (dd, J = 4.1, 7.1 Hz, 1H), 3.59 (s, 3H), 3.15 (s, 3H),
2.90 (dd, J = 6.9, 16.1 Hz, 1H), 2.68 (dd, J = 4.1, 16.1 Hz, 1H);
FT-IR 2988.7, 2954.2, 1739.9, 1486.5, 1439.5, 1414.2, 1387.3,
1199.0, 1168.0, 758.3; MS (20eV) m/z (rel intensity) 240
[(M+1)+, 3.0], 239 (M+, 5.9), 166 (12.3), 124 (1.6), 123 (20.9),
122 (12.1), 121 (100), 111 (1.3), 110 (13.6), 109 (13.8); HRMS
calcd for C12H13N2O4Cl 284.05638, found 284.05521; (3c): a
white solid; mp 90-93 oC; 1H NMR (CDCl3) δ7.51 (s, 1H), 7.31
(s, 2H), 6.03 (dd, J = 4.1, 6.7 Hz, 1H), 3.62 (s, 3H), 3.14 (s, 3H),
2.88 (dd, J = 6.7, 16.1 Hz, 1H), 2.67 (dd, J = 4.1, 16.1 Hz, 1H);
FT-IR 3092.6, 2954.4, 1743.0, 1486.5, 1415.5, 1386.6, 1167.9,
870.9, 751.8; MS (20eV) m/z (rel intensity) 319 [(M+1)+, 5.7],
318 (M+, 16.0), 245 (49.8), 226 (30.3), 187 (7.3), 172 (20.1), 161
(57.1), 85 (100); HRMS calcd for C12H12N2O4Cl2 318.01741,
found 318.01758; (3e): a colorless oil; 1H NMR (DMSO-d6)
δ7.84 (d, J = 14.5 Hz, 1H), 7.44-7.26 (m, 4H), 5.96 (dd, J = 3.2,
6.9 Hz, 1H), 5.20 (d, J = 14.5 Hz, 1H), 4.97 (d, J = 16.5 Hz, 1H),
4.62 (d, J = 16.5 Hz, 1H), 3.76 (s, 3H), 3.73 (s, 3H), 2.92 (dd, J =
6.9, 16.2 Hz, 1H), 2.84 (dd, J = 4.1, 16.2Hz, 1H); FT-IR 3071.4,
2954.7, 1742.4, 1711.6, 1640.9, 1440.9, 1415.1, 1329.3, 1266.6,
1225.8, 1175.2, 835.3, 754.9; MS (20eV) m/z (rel intensity) 369
[(M+1)+, 5.1], 368 (M+, 1.1), 337 (20.7), 295 (6.4), 277 (20.8),
233 (5.5), 142 (61.8), 125 (100), 101 (54.5); HRMS calcd for
4.66 (d, J = 16.7 Hz, 1H), 3.46 (s, 3H), 2.81 (dd, J = 6.3, 16.0 Hz,
1H), 2.63 (dd, J = 4.2, 16.0 Hz, 1H); FT-IR 3068.3, 2958.2,
1738.8, 1486.5, 1440.7, 1408.1, 1261.1, 1161.0, 1059.1, 1038.4,
754.0; MS (20eV) m/z (rel intensity) 395 [(M+1)+, 7.8], 394 (M+,
18.3), 359 (17.1), 321 (11.6), 259 (4.7), 192 (55.4), 140 (99.2),
127 (58.1), 125 (100); HRMS calcd for C18H16N2O4Cl2
394.04871, found 394.04864; (3h): a pale yellow gel; 1H NMR
(CDCl3) δ7.51-6.77 (m, 6H), 6.04 (dd, J = 4.3, 5.6 Hz, 1H), 4.63
(dd, J = 16.0, 19.2 Hz, 2H), 3.53 (s, 3H), 3.01 (s, 2H), 2.82 ( dd, J
= 6.0, 16.4 Hz, 1H), 2.65 (dd, J = 4.9, 16.4 Hz, 1H), 1.46 (s, 6H);
FT-IR 3073.2, 2974.5, 1741.6, 1485.4, 1456.9, 1404.1, 1261.0,
1161.1, 1140.0, 878.1; MS (20eV) m/z (rel intensity) 464 (M+,
3.6), 391 (0.5), 321 (1.4), 202 (0.9), 162 (11.8), 161 (100); HRMS
calcd for C22H22N2O5Cl2 464.09057 found 464.09062; (3i): a
1
colorless oil; H NMR (CDCl3) δ 6.50 (s, 1H), 5.53 (dd, J =3.5,
7.4 Hz, 1H), 3.79 (s, 3H), 3.18 (s, 3H), 2.87 (dd, J = 3.5, 17.4 Hz,
1H), 2.76 (dd, J = 7.2, 17.4 Hz, 1H); FT-IR 3425.3, 3301.6,
2967.6, 1715.8, 1668.2, 1611.5; HRMS calcd for C6H10N2O4
174.0641, found 174.0654; (3j): a clear oil; 1H NMR (CDCl3)
δ7.52-7.18 (m, 4H), 6.58 (s, 1H), 5.57 (dd, J =3.7, 7.5 Hz, 1H),
4.76 (d, J = 17.4 Hz, 1H), 4.52 (d, J = 17.4 Hz, 1H), 3.70 (s, 3H),
2.88 (dd, J = 3.7, 18.5 Hz, 1H), 2.76 (dd, J = 7.9, 18.5 Hz, 1H);
FT-IR 3294.7, 3075.8, 2955.1, 1730.9, 1631.9; HRMS calcd for
C12H13N2O4Cl 284.0563, found 284.0550; (4i): a colorless solid;
mp 95-96 oC; 1H NMR (CDCl3) δ7.59 (d, J = 12.1 Hz, 1H), 5.71
(d, J = 12.4 Hz, 1H), 5.34 (s, 2H), 3.78 (s, 3H), 3.19 (s, 3H); FT-
IR 3435.4, 3301.6, 3235.9, 2958.6, 1713.6, 1661.6, 1610.5;
HRMS calcd for C6H10N2O4 174.0641, found 174.0654; (4j): a
o
1
colorless solid; mp 136-138 C; H NMR (CDCl3) δ7.43 (d, J =
12.4 Hz, 1H), 7.45-7.20 (m, 4H), 5.62 (d, J = 12.4 Hz, 1H), 5.37
(s, 2H), 4.92 (s, 2H), 3.69 (s, 3H); FT-IR 3409.4, 3301.6, 3228.6,
3099.0, 2948.6, 1692.0, 1634.8, 1602.4; HRMS calcd for
C12H13N2O4oCl 284.0563, found 284.0550; (5a): a white solid;
mp 172-173 C; 1H NMR (DMSO-d6) δ7.48 (s, 4H), 6.22 (t, J =
4.6 Hz, 1H), 3.00 (s, 3H), 2.75 (d, J = 4.6 Hz, 2H); FT-IR 3107.9,
1714.52, 1500.5, 1429.8, 1180.7, 815.5; MS (20eV) m/z (rel
intensity) 271 [(M+1)+, 6.3], 270 (M+, 41.3), 213 (26.2), 211
(77.6), 183 (9.5), 153 (27.2), 138 (56.9), 127 (88.5), 111 (44.7), 90
(38.2), 71 (100); HRMS calcd for C11H11N2O4Cl 270.04073,
C
16H17N2O6Cl 368.07751, found 368.07709; (3f): a white solid;
o
mp 99-103 C; 1H NMR (CDCl3) δ7.57-7.52 (m, 2H), 7.41-7.25
(m, 5H), 6.08 (dd, J = 4.2, 7.2 Hz, 1H), 4.86 (d, J = 17.0 Hz, 1H),
4.71 (d, J = 17.0 Hz, 1H), 3.56 (s, 3H), 2.88 (dd, J = 6.1, 16.1 Hz,
1H), 2.73 (dd, J = 2.5, 16.1 Hz, 1H); FT-IR 3081.9, 2947.9,
1729.9, 1491.6, 1439.0, 1413.9, 1188.2, 1047.4, 750.8; MS
(20eV) m/z (rel intensity) 429 [(M+1)+, 10.9], 428 (M+, 17.6),
395 (11.7), 355 (7.6), 226 (28.4), 161 (25.1), 140 (70.6), 125
(100); HRMS calcd for C18H15N2O4Cl3 428.00974, found
428.00973; (3g): a pale yellow oil; 1H NMR (CDCl3) δ7.52-7.19
(m, 8H), 6.04 (dd, J = 4.5, 6.1 Hz, 1H), 4.80 (d, J = 16.7 Hz, 1H),
1
found 270.04062; (5b): a white solid; mp 100-103 oC; H NMR
(CDCl3) δ7.50 (s, 1H), 7.31 (s, 2H), 6.02 (dd, J = 3.5, 6.8 Hz, 1H),
3.23 (s, 3H), 2.92 (dd, J = 7.0, 16.6 Hz, 1H), 2.69 ( dd, J = 3.7,
16.6 Hz, 1H); FT-IR 3093.6, 1738.69, 1487.2, 1422.3, 1179.2,
873.4; MS (20eV) m/z (rel intensity) 305 [(M+1)+, 8.9], 304 (M+,
22.6), 245 (64.7), 214 (9.5), 187 (12.3), 172 (28.3), 161 (79.4),
124 (28.3), 71 (100); HRMS calcd for C11H10N2O4Cl 304.00176,
found 304.00161.