D
R. Katla et al.
Paper
Synthesis
corded in CDCl3 with a Bruker spectrometer (300 MHz, and 75 MHz,
respectively). The IR spectra were recorded with a FT/IR 4100 type A
spectrometer (Jasco).
IR (KBr): 3312, 3192, 3061, 2924, 2855, 1908, 1662, 1607, 1509 cm–1
.
1H NMR (300 MHz, CDCl3): δ = 7.89 (d, J = 6.9 Hz, 1 H), 7.50 (s, 1 H),
7.30 (t, J = 6.9 Hz, 1 H), 7.06 (s, 3 H), 6.85 (t, J = 6.9 Hz, 1 H), 6.69 (d, J =
7.9 Hz, 1 H), 6.20 (br. s, 1 H), 6.07 (s, 1 H), 2.37 (s, 3 H), 2.30 (s, 3 H).
13C NMR (50 MHz, CDCl3): δ = 163.17, 147.12, 135.70, 133.42, 131.60,
129.05, 127.65, 126.69, 126.00, 125.14, 124.63, 115.84, 113.34,
113.04, 63.55, 19.25, 16.84.
[Ce(L-Pro)2]2(Oxa)22
L-Proline (2.7 mmol) was dissolved in methanol (15 ml), an aqueous
solution of sodium hydroxide (2.7 mmol in 1 mL) was added at room
temperature, and the mixture was stirred for 10 minutes. Then ceri-
um (III) chloride (1.4 mmol) was added to it, and the reaction mixture
was stirred for 45 minutes. Then a few drops of sodium oxalate solu-
tion (0.1 g mL–1) were added to it. It was used as a precipitating agent.
The semi-solid was centrifuged, washed with methanol, and dried
overnight at 40 °C to obtain a pale yellow semi-solid.
MS (ESI): m/z = 253 [M + H]+.
2-(3,4-Dihydroxyphenyl)-2,3-dihydroquinazolin-4(1H)-one (3e)8,21
Yield: 207 mg (81%); light-yellow solid; mp 288–290 °C.
1H NMR (300 MHz, CDCl3): δ = 8.83 (br. s, 1 H), 7.79–7.56 (m, 2 H),
7.40 (t, J = 7.5 Hz, 1 H), 7.20 (t, J = 7.1 Hz, 1 H),7.03 (s, 1 H), 6.88 (d, J =
8.3 Hz, 1 H), 6.81–6.65 (m, 2 H), 5.64 (s, 1 H), 3.58 (br. s, 2 H).
13C NMR (50 MHz, CDCl3): δ = 162.66, 161.08, 150.89, 147.84, 147.43,
146.84, 146.29, 143.95, 143.64, 143.36, 132.97, 131.90, 130.57,
125.76, 124.97, 124.39, 124.21, 121.77, 118.63, 118.23, 116.38,
115.60, 113.80, 113.50, 113.35, 112.86, 112.46, 64.97.
2-(p-Tolyl)-2,3-dihydroquinazolin-4(1H)-one; Typical Proce-
dure8,21
[Ce(L-Pro)2]2 (Oxa) was dissolved in EtOH (10 mL), and anthranil-
amide (1.0 mmol) and 4-methyl benzaldehyde (1.0 mmol) were add-
ed. The reaction mixture was heated at 50–55 °C until completion of
the reaction as indicated by TLC. The reaction mixture was cooled to
r.t., and the catalyst was separated from the reaction mixture by fil-
tration. The solvent was evaporated under reduced pressure and the
crude compound was purified by column chromatography (EtOAc/
hexane, 3:7).
MS (ESI): m/z = 257 [M + H]+.
2-(4-Fluorophenyl)-2,3-dihydroquinazolin-4(1H)-one (3f)8,21
Yield: 215 mg (89%); yellow solid; mp 202–204 °C.
IR (KBr): 3300, 3183, 3066, 2929, 1658, 1610, 1508, 1482 cm–1
.
Yield: 207 mg (87%); yellow solid; mp 223–225 °C.
1H NMR (300 MHz, CDCl3): δ = 7.94 (d, J = 8.3 Hz, 1 H), 7.62–7.57 (m,
2 H), 7.37–7.32 (m, 1 H), 7.14 (t, J = 8.3 Hz, 2 H), 6.92 (t, J = 8.3 Hz,
1 H), 6.66 (d, J = 8.3 Hz, 1 H), 5.91 (s, 1 H), 5.78 (br. s, 1 H), 4.34 (br. s,
1 H).
13C NMR (50 MHz, CDCl3): δ = 161.87, 158.69, 146.93, 132.64, 128.29,
128.18, 126.86, 117.83, 114.52, 114.24, 113.75, 66.39.
IR (KBr): 3310, 3192, 3060, 2924, 2855, 1908, 1662, 1607, 1509 cm–1
.
1H NMR (300 MHz, CDCl3): δ = 7.93 (d, J = 7.2 Hz, 1 H), 7.46 (d, J =
8.3 Hz, 2 H), 7.34–7.23 (m, 3 H), 6.89 (t, J = 7.2 Hz, 1 H), 6.65 (d, J =
7.2 Hz, 1 H), 5.86 (s, 1 H), 5.76 (br. s, 1 H), 4.34 (br. s, 1 H), 2.39 (s,
3 H).
13C NMR (50 MHz, CDCl3): δ = 167.15, 133.99, 129.73, 128.69, 127.29,
119.61, 114.53, 68.84, 29.57.
MS (ESI): m/z = 243 [M + H]+.
MS (ESI): m/z = 239 [M + H]+.
2-(4-Chlorophenyl)-2,3-dihydroquinazolin-4(1H)-one (3g)8
Yield: 229 mg (89%); light-yellow solid; mp 196–198 °C.
2-(4-Methoxyphenyl)-2,3-dihydroquinazolin-4(1H)-one (3b)8
1H NMR (300 MHz, CDCl3): δ = 7.89 (d, J = 7.1 Hz, 1 H), 7.56 (d, J =
8.0 Hz, 2 H), 7.44 (d, J = 8.9 Hz, 2 H), 7.30 (t, J = 7.1 Hz, 1 H), 6.85 (t, J =
7.1 Hz, 1 H), 6.61 (d, J = 7.1 Hz, 1 H), 5.82 (s, 1 H), 5.72 (br. s, 1 H), 4.30
(br. s, 1 H).
13C NMR (50 MHz, CDCl3): δ = 163.07, 146.44, 139.03, 133.12, 132.21,
130.34, 130.08, 128.30, 127.76, 126.36, 121.04, 116.50, 113.73,
113.36, 65.61.
Yield: 223 mg (88%); light-yellow solid; mp 182–184 °C.
IR (KBr): 3448, 3315, 3183, 2923, 1676 cm–1
.
1H NMR (300 MHz, CDCl3): δ = 7.91 (d, J = 7.2 Hz, 1 H), 7.45 (d, J =
8.3 Hz, 2 H), 7.34–7.23 (m, 3 H), 6.88 (t, J = 7.2 Hz, 1 H), 6.63 (d, J =
7.2 Hz, 1 H), 5.84 (s, 1 H), 5.75 (br. s, 1 H), 4.39 (br. s, 1 H), 3.89 (s,
3 H).
13C NMR (50 MHz, CDCl3): δ = 167.14, 133.97, 129.70, 128.67, 127.24,
119.60, 114.51, 68.83, 56.52.
MS (ESI): m/z = 259 [M + H]+.
MS (ESI): m/z = 255 [M + H]+.
2-(4-Bromophenyl)-2,3-dihydroquinazolin-4(1H)-one (3h)8
Yield: 265 mg (88%); yellow solid; mp 200–202 °C.
2-(4-Hydroxyphenyl)-2,3-dihydroquinazolin-4(1H)-one (3c)8
IR (KBr): 3306, 3188, 3060, 2927, 1658, 1607 cm–1
.
Yield: 208 mg (87%); white solid; mp 278–280 °C.
1H NMR (300 MHz, CDCl3): δ = 7.90 (d, J = 7.1 Hz, 1 H), 7.54 (d, J =
8.0 Hz, 2 H), 7.43 (d, J = 8.9 Hz, 2 H), 7.31 (t, J = 7.1 Hz, 1 H), 6.88 (t, J =
7.1 Hz, 1 H), 6.63 (d, J = 7.1 Hz, 1 H), 5.84 (s, 1 H), 5.74 (br. s, 1 H), 4.31
(br. s, 1 H).
13C NMR (50 MHz, CDCl3): δ = 163.09, 146.45, 139.05, 133.13, 132.22,
130.37, 130.09, 128.31, 127.77, 126.38, 121.06, 116.51, 113.74,
113.38, 65.60.
IR (KBr): 3302, 3187, 3068, 2932, 1668, 1612, 1509, 1486 cm–1
.
1H NMR (300 MHz, CDCl3): δ = 9.33 (br. s, 1 H), 7.75 (d, J = 7.7 Hz, 1 H),
7.37 (d, J = 7.1 Hz, 3 H), 7.22 (t, J = 7.3 Hz, 1 H), 6.83–6.69 (m, 4 H),
6.28 (br. s, 1 H), 5.72 (s, 1 H).
13C NMR (50 MHz, CDCl3): δ = 160.98, 156.32, 146.66, 132.71, 128.07,
118.90, 115.65, 113.89, 65.59.
MS (ESI): m/z = 241 [M + H]+.
MS (ESI): m/z = 303 [M + H]+.
2-(2,5-Dimethylphenyl)-2,3-dihydroquinazolin-4(1H)-one (3d)8
2-(4-Nitrophenyl)-2,3-dihydroquinazolin-4(1H)-one (3i)8
Yield: 216 mg (86%); yellow solid; mp 222–224 °C.
Yield: 258 mg (96%); yellow solid; mp 204–206 °C.
© Georg Thieme Verlag Stuttgart · New York — Synthesis 2017, 49, A–F