1732
F. Foti et al.
LETTER
(10) Synthesis of 2
To a stirred solution of arylhydrazone 1 (20 mmol) in DMF
Compound 6c: mp 175 °C. IR (Nujol) 1740 cm–1. 1H NMR
(DMSO-d6): d = 3.70 (s, 3 H), 3.85 (dd, 1 H, J = 4.5, 17.0
Hz), 4.14 (dd, 1 H, J = 12, 17 Hz), 5.49 (dd, 1 H, J = 4.5,
12.0 Hz), 7.05 (d, 2 H, J = 9.3 Hz), 7.15 (s, 1 H), 7.76 (s, 1
H), 8.13 (d, 2 H, J = 9.3 Hz), 8.23 (s, 1 H). MS (EI): m/z =
315 [M+].
Compound 7a: mp 265 °C. IR (Nujol): 3410, 3305, 3105,
1735, 1635, 1598 cm–1. 1H NMR (DMSO-d6): d = 3.71 (s, 3
H), 3.96 (dd, 1 H, J = 6, 18 Hz), 4.17 (dd, 1 H, J = 12, 18
Hz), 5.15 (dd, 1 H, J = 6, 12 Hz), 6.78–7.28 (m, 5 H), 7.50
(s, 2 H), 8.20 (s, 1 H), 8.67 (s, 1 H). MS (EI): m/z = 337 [M+].
Compound 7b: mp 276 °C. IR (Nujol): 3410, 3311, 3103,
1732, 1653, 1602 cm–1. 1H NMR (DMSO-d6): d = 3.70 (s, 3
H), 3.97 (dd, 1 H, J = 6.3, 17.7 Hz), 4.16 (dd, 1 H, J = 12.3,
17.7 Hz), 5.14 (dd, 1 H, J = 6.3, 12.3 Hz), 7.02–7.14 (m, 4
H), 7.49 (s, 2 H), 8.21 (s, 1 H), 8.66 (s, 1 H). MS (EI): m/z =
355 [M+].
(40 mL) at r.t. was added dropwise a solution of NBS (40
mmol) in DMF (30 mL). After additional stirring (2 h), the
reaction mixture was poured into cold H2O (200 mL) and
extracted three times with Et2O (100 mL); the organic layer
was washed with H2O and brine, dried over anhyd Na2SO4,
and concentrated. Column chromatography of the residue on
silica gel (PE for 2a; PE–CHCl3 = 3:1 for 2b; CHCl3–PE =
2:1 for 2c) gave the indicated products.
(11) Synthesis of 4
To a stirred solution of 2 (5 mmol) in DMF (10 mL) at r.t.,
imidazole (10 mmol) was added. The reaction mixture was
stirred for 1 h, poured into cold H2O (30 mL) and extracted
three times with Et2O (50 mL). For 4b, the organic layer was
washed with H2O and brine, dried over anhyd Na2SO4, and
the solvent was removed under vacuum. Column
chromatography of the residue on silica gel (Et2O–acetone,
2:1) gave the indicated product. Compound 4c was
recovered as a yellow solid from Et2O solution and was
crystallized by slow evaporation of an acetone solution.
(12) Brahme, N. M.; Smith, W. T. J. Heterocycl. Chem. 1985, 22,
109.
Compound 8b: mp 155 °C. IR (Nujol): 3500–3120 cm–1. 1H
NMR (DMSO-d6): d = 3.34 (m, 2 H), 3.61 (m, 2 H), 4.41 (m,
1 H), 5.04 (t, OH), 7.05–7.14 (m, 5 H), 7.67 (s, 1 H), 8.15 (s,
1 H). MS (EI): m/z = 260 [M+].
Compound 8c: mp 210 °C. IR (Nujol): 3450–3120, 1512,
1320 cm–1. 1H NMR (DMSO-d6): d = 3.49 (m, 2 H), 3.74 (m,
2 H), 4.81 (m, 1 H), 5.14 (t, OH), 7.13 (d, 2 H, J = 9 Hz),
7.13 (s, 1 H), 7.74 (s, 1 H,), 8.10 (d, 2 H, J = 9 Hz), 8.24 (s,
1 H). MS (EI): m/z = 287 [M+].
Compound 9a: mp 238 °C. IR (Nujol): 3365, 3309, 1653,
1598 cm–1. 1H NMR (DMSO-d6): d = 3.61 (m, 2 H), 3.79 (m,
2 H), 4.51 (m, 1 H), 5.07 (t, OH), 6.74–7.38 (m, 5 H), 7.46
(s, 2 H), 8.20 (s, 1 H), 8.62 (s, 1 H). MS (EI): m/z = 309 [M+].
Compound 9b: mp 248 °C. IR (Nujol): 3337, 3188, 1663,
1602 cm–1. 1H NMR (DMSO-d6): d = 3.61 (m, 2 H), 3.79 (m,
2 H), 4.45 (m, 1 H), 5.07 (t, OH), 7.05–7.12 (m, 4 H), 7.47
(s, 2 H), 8.20 (s, 1 H), 8.62 (s, 1 H). MS (EI): m/z = 327 [M+].
Compound 10: mp 283–284 °C. IR (Nujol) 3402, 3300,
3165, 1578, 1491 cm–1. 1H NMR (DMSO-d6): d = 1.13 (t, 6
H, J = 7 Hz), 3.21 (q, 4 H, J = 7 Hz), 7.22 (d, 2 H, J = 9Hz),
7.54 (s, 2 H), 7.63 (d, 2 H, J = 9Hz), 7.89 (s, 1 H), 8.01 (d, 2
H, J = 9 Hz), 8.26 (d, 2 H, J = 9 Hz), 8.57 (s, 1 H). MS (EI):
m/z = 531 [M+].
(13) See ref. 1a, p. 300.
(14) Selected Data
Compound 2a: mp 55 °C. IR (Nujol): 3314, 1602 cm–1. 1H
NMR (DMSO-d6): d = 6.83–7.25 (m, 5 H), 9.62 (s, 1 H). MS
(EI): m/z = 276, 278, 280 [M+].
Compound 2b: mp 52 °C. IR (Nujol): 3322, 1614 cm–1. 1H
NMR (DMSO-d6): d = 7.02–7.14 (m, 4 H), 9.67 (s, 1 H). MS
(EI): m/z = 294, 296, 298 [M+].
Compound 2c: mp 152 °C. IR (Nujol): 3260, 1602 cm–1. 1H
NMR (DMSO-d6): d = 7.29 (d, 2 H, J = 9 Hz), 8.14 (d, 2 H,
J = 9 Hz), 10.53 (s, 1 H). MS (EI): m/z = 321, 323, 325 [M+].
Compound 4b: mp 98 °C. IR (Nujol): 3159 cm–1. 1H NMR
(DMSO-d6): d = 7.04–7.10 (m, 3 H), 7.21–7.27 (m, 2 H),
7.70 (s, 1 H), 8.22 (s, 1 H), 9.52 (s, 1 H). MS (EI): m/z = 282,
284 [M+].
Compound 4c: mp 180 °C. IR (Nujol): 3253, 1600 cm–1. 1H
NMR (DMSO-d6): d = 7.12 (s, 1 H), 7.42 (d, 2 H, J = 9 Hz),
7.80 (s, 1 H), 8.14 (d, 2 H, J = 9 Hz), 8.33 (s, 1 H), 10.40 (s,
1 H). MS (EI): m/z = 309, 311 [M+].
(15) X-ray data to be submitted to Acta Crystallogr.
(16) (a) Merino, P. C. R. Chim. 2005, 8, 775. (b) Procopio, A.;
Alcaro, S.; De Nino, A.; Maiuolo, L.; Ortuso, F.; Sindona, G.
Bioorg. Med. Chem. Lett. 2005, 15, 545. (c) Clayton, R.;
Ramsden, C. A. Synthesis 2005, 2695; and references cited
therein.
Compound 6b: mp 123 °C. IR (Nujol): 1748 cm–1. 1H NMR
(DMSO-d6): d = 3.67 (s, 3 H), 3.71 (dd, 1 H, J = 6, 17 Hz),
3.93 (dd, 1 H, J = 12, 17 Hz), 5.11 (dd, 1 H, J = 6, 12 Hz),
6.93–7.12 (m, 5 H), 7.69 (s, 1 H), 8.16 (s, 1 H). MS (EI):
m/z = 288 [M+].
(17) Coutouli-Argyropoulou, E.; Pilanidou, P. Tetrahedron Lett.
2003, 44, 3755.
Synlett 2007, No. 11, 1730–1732 © Thieme Stuttgart · New York