Synthesis of 2,3-dihydroquinazolin-4(1H)-ones
2-(3-Bromophenyl)-2,3-dihydroquinazolin-4(1H)-one (3g) White solid; IR
(KBr): 3,301, 3,168, 3,060, 1,655, 1,614, 1,511, 1,475 cm-1
;
1H-NMR
(500 MHz, DMSO-d6) d 5.68 (s, 1H, CH), 6.75 (t, J = 8.2 Hz, 1H, Ar–H), 6.88
(d, J = 6.8 Hz, 1H, Ar–H), 7.09 (brs, 1H, NH), 7.19–7.36 (m, 3H, Ar–H), 7.46 (d,
J = 8.4 Hz, 2H, Ar–H), 7.63–7.71 (m, 1H, Ar–H), 8.48 (brs, 1H, NH) ppm; 13C-
NMR (125 MHz, DMSO-d6) d: 68.1, 113.3, 116.7, 117.7, 127.4, 128.8, 129.3,
129.7, 133.5, 142.8, 148.9, 167.3 ppm; MS (ESI): m/z 303.5 (M ? H)?. Anal.
Calcd. for C14H11BrN2O (%): C, 55.46; H, 3.63; N, 9.24. Found: C, 55.43; H, 3.60;
N, 9.25.
2-(3-Fluorophenyl)-2,3-dihydroquinazolin-4(1H)-one (3h) White solid; IR
(KBr): 3,294, 3,162, 3,061, 1,658, 1,609, 1,514, 1,478 cm-1
;
1H-NMR
(500 MHz, DMSO-d6) d: 5.83 (s, 1H, CH), 6.73 (t, J = 8.4 Hz, 1H, Ar–H), 6.91
(d, J = 6.6 Hz, 1H, Ar–H), 7.11 (brs, 1H, NH), 7.25–7.40 (m, 3H, Ar–H), 7.50 (d,
J = 8.6 Hz, 2H, Ar–H), 7.60–7.72 (m, 1H, Ar–H), 8.42 (brs, 1H, NH) ppm; 13C-
NMR (125 MHz, DMSO-d6) d: 67.5, 112.9, 116.4, 117.8, 127.2, 128.6, 129.0,
129.6, 133.4, 143.1, 148.9, 167.0 ppm; MS (ESI): m/z 243 (M ? H)?. Anal. Calcd.
for C14H11FN2O (%): C, 69.42; H, 4.55; N, 11.57. Found: C, 69.39; H, 4.53; N,
11.55.
2-(4-N,N-Dimethylaminophenyl)-2,3-dihydroquinazolin-4(1H)-one (3i) White
1
solid; IR (KBr): 3,308, 3,160, 3,057, 1,659, 1,606, 1,513, 1,480 cm-1; H-NMR
(500 MHz, DMSO-d6) d: 2.87 (s, 6H, N(CH3)2), 5.65 (s, 1H, CH), 6.76 (t,
J = 8.2 Hz, 1H, Ar–H), 6.91 (d, J = 6.8 Hz, 1H, Ar–H), 7.12 (brs, 1H, NH),
7.31–7.45 (m, 3H, Ar–H), 7.56 (d, J = 8.8 Hz, 2H, Ar–H), 7.67 (d, J = 7.8 Hz, 1H,
Ar–H), 8.47 (brs, 1H, NH) ppm; 13C-NMR (125 MHz, DMSO-d6) d: 40.4, 68.3,
113.1, 116.9, 117.9, 127.2, 128.0, 129.2, 129.6, 133.3, 142.6, 148.4, 166.8 ppm; MS
(ESI): m/z 268 (M ? H)?. Anal. Calcd. for C16H17N3O (%): C, 71.91; H, 6.37; N,
15.73. Found: C, 71.84; H, 6.30; N, 15.69.
2-(4-Hydroxyphenyl)-2,3-dihydroquinazolin-4(1H)-one (3j) White solid; IR
1
(KBr): 3,304, 3,172, 3,059, 1,663, 1,612, 1,507, 1,481 cm-1; H-NMR (500 MHz,
DMSO-d6) d: 5.70 (s, 1H, CH), 6.77–6.84 (m, 2H, Ar–H), 7.19 (s, 1H, NH), 7.33 (d,
J = 7.9 Hz, 1H, Ar–H), 7.49 (d, J = 8.6 Hz, 2H, Ar–H), 7.62–7.75 (m, 3H, Ar–H),
8.45 (s, 1H, NH), 9.97 (s, 1H, OH) ppm; 13C-NMR (125 MHz, DMSO-d6) d: 67.9,
11292, 116.4, 117.2, 127.1, 128.1, 129.4, 129.7, 133.2, 143.0, 148.5, 166.9 ppm;
MS (ESI): m/z 241 (M ? H)?. Anal. Calcd. for C14H12N2O2 (%): C, 70.00; H, 5.00;
N, 11.67. Found: C, 69.88; H, 4.94; N, 11.64.
2-(4-Chlorophenyl)-2,3-dihydroquinazolin-4(1H)-one (3k) White solid; IR
1
(KBr): 3,292, 3,175, 3,060, 1,662, 1,611, 1,506, 1,477 cm-1; H-NMR (500 MHz,
DMSO-d6) d: 5.71 (s, 1H, CH), 6.79 (t, J = 8.3 Hz, 1H, Ar–H), 6.86 (d,
J = 6.5 Hz, 1H, Ar–H), 7.07 (brs, 1H, NH), 7.27–7.39 (m, 3H, Ar–H), 7.48 (d,
J = 8.8 Hz, 2H, Ar–H), 7.72 (d, J = 7.8 Hz, 1H, Ar–H), 8.49 (brs, 1H, NH) ppm;
13C-NMR (125 MHz, DMSO-d6) d: 67.8, 113.0, 116.6, 117.3, 127.8, 128.6, 129.5,
129.9, 133.4, 142.8, 148.5, 166.6 ppm; MS (ESI): m/z 259 (M ? H)?. Anal. Calcd.
for C14H11ClN2O (%): C, 65.00; H, 4.26; N, 10.83. Found: C, 64.96; H, 4.23; N,
10.79.
2-(3-Hydroxyphenyl)-2,3-dihydroquinazolin-4(1H)-one (3l) White solid; IR
1
(KBr): 3,298, 3,173, 3,063, 1,659, 1,614, 1,512, 1,472 cm-1; H-NMR (500 MHz,
123