H
C. Duangkamol et al.
Paper
Synthesis
5-Chloro-N-(p-tolyl)benzo[d]thiazol-2-amine (6pe)
6-(2-Methylbenzyl)benzo[4,5]imidazo[2,1-b]quinazolin-12(6H)-
one (7gm)
White solid; yield: 0.0586 g (79%); mp 219-210 °C.
White solid; yield: 0.0678 g (74%); mp 225–226 °C.
1H NMR (500 MHz, CDCl3): = 7.56 (s, 1 H), 7.50 (d, J = 8.5 Hz, 1 H),
7.35 (d, J = 8.0 Hz, 2 H), 7.22 (d, J = 8.0 Hz, 2 H), 7.11 (d, J = 8.5 Hz, 1 H),
2.37 (s, 3 H).
13C NMR (125 MHz, CDCl3): = 166.2, 152.9, 136.7, 134.9, 132.0,
130.2, 128.4, 122.5, 121.4, 120.9, 119.4, 21.0.
1H NMR (500 MHz, CDCl3): = 8.67 (d, J = 6.1 Hz, 1 H), 8.42 (d, J = 8.0
Hz, 1 H), 7.72 (t, J = 7.2 Hz, 1 H), 7.63 (d, J = 8.0 Hz, 1 H), 7.36–7.29 (m,
3 H), 7.25–7.18 (m, 2 H), 7.08 (t, J = 7.2 Hz, 1 H), 7.01 (d, J = 6.1 Hz, 1
H), 6.95 (d, J = 7.5 Hz, 1 H), 5.48 (s, 2 H), 2.46 (s, 3 H).
13C NMR (125 MHz, CDCl3): = 160.1, 149.2, 146.7, 135.8, 134.4,
132.9, 131.8, 130.8, 127.9, 127.0, 126.5, 126.4, 126.1, 126.0, 125.8,
123.1, 122.3, 116.9, 116.3, 109.0, 43.9, 19.4.
Fused Tetracyclic Quinazolinones 7; General Procedure
Following the above described general procedure for the synthesis of
benzazoles, methyl 2-isothiocyanatobenzoate (2m; 0.0521 g, 0.27
mmol) was reacted with amino derivative 1. After completion of the
reaction, the mixture was treated with CH2Cl2 (2 mL). The resulting
precipitate was filtered, washed with CH2Cl2, and oven-dried at 80 °C.
TOF-HRMS: m/z calcd for C22H18N3O (M + H)+: 340.1450; found:
340.1446.
6-Allylbenzo[4,5]imidazo[2,1-b]quinazolin-12(6H)-one (7hm)4a
White solid; yield: 0.0520 g (70%); mp 205–206 °C.
Benzo[4,5]imidazo[2,1-b]quinazolin-12(6H)-one (7am)29
1H NMR (500 MHz, CDCl3): = 8.65 (d, J = 8.0 Hz, 1 H), 8.41 (d, J = 8.0
Hz, 1 H), 7.72 (t, J = 8.0 Hz, 1 H), 7.64 (d, J = 8.0 Hz, 1 H), 7.42 (t, J = 8.0
Hz, 1 H), 7.35–7.26 (m, 3 H), 6.07–6.00 (m, 1 H), 5.30 (t, J = 7.5 Hz, 2
H), 4.93 (s, 2 H).
13C{1H} NMR (125 MHz, CDCl3): = 160.1, 149.2, 146.3, 134.4, 131.6,
131.0, 127.0, 126.0, 125.9, 125.7, 123.0, 122.2, 118.4, 116.8, 116.3,
108.7, 44.3.
White solid; yield: 0.0508 g (80%); mp >300 °C.
1H NMR [500 MHz, CDCl3 + TFA (3 drops)]: = 8.63 (d, J = 8.0 Hz, 1 H),
8.47 (d, J = 8.0 Hz, 1 H), 7.96 (t, J = 8.0 Hz, 1 H), 7.80 (d, J = 8.0 Hz, 1 H),
7.71 (d, J = 8.0 Hz, 1 H), 7.64–7.57 (m, 3 H).
13C NMR [125 MHz, CDCl3 + TFA (3 drops)]: = 156.8, 144.2, 137.3,
137.0, 128.6, 128.5, 126.7, 125.8, 125.7, 118.1, 113.52, 113.46, 111.3.
6-Benzoylbenzo[4,5]imidazo[2,1-b]quinazolin-12(6H)-one (7im)4
8-Methylbenzo[4,5]imidazo[2,1-b]quinazolin-12(6H)-one (7cm)36l
White solid; yield: 0.0696 g (76%); mp >340 °C.
Brown solid; yield: 0.0552 g (82%); mp >300 °C.
1H NMR [500 MHz, CDCl3 + TFA (5 drops)]: = 8.60 (d, J = 8.0 Hz, 2 H),
8.45 (d, J = 8.0 Hz, 2 H), 7.94 (t, J = 7.5 Hz, 2 H), 7.81 (d, J = 8.0 Hz, 2 H),
7.72 (d, J = 8.0 Hz, 2 H), 7.66–7.55 (m, 5 H).
1H NMR [400 MHz, CDCl3 + MeOH-d4 (3 drops)]: = 8.31 (t, J = 8.4 Hz,
2 H), 7.69 (t, J = 7.6 Hz, 1 H), 7.51–7.41 (m, 1 H), 7.30 (t, J = 7.6 Hz, 1
H), 7.20 (s, 1 H), 7.08 (d, J = 7.6 Hz, 1 H), 2.46 (s, 3 H).
13C NMR [125 MHz, CDCl3 + TFA (5 drops)]: = 156.7, 144.3, 137.16,
6-(4-Bromobenzyl)benzo[4,5]imidazo[2,1-b]quinazolin-12(6H)-
137.10, 128.7, 128.47, 128.45, 126.5, 125.7, 118.2, 116.3, 114.6, 113.6.
one (7em)
White solid; yield: 0.0797 g (73%); mp 288–290 °C.
6-Tosylbenzo[4,5]imidazo[2,1-b]quinazolin-12(6H)-one (7jm)
1H NMR [500 MHz, CDCl3 + TFA (3 drops)]: = 8.75 (d, J = 8.0 Hz, 1 H),
8.48 (d, J = 8.0 Hz, 1 H), 7.97 (t, J = 8.0 Hz, 1 H), 7.80 (d, J = 8.0 Hz, 1 H),
7.64 (br s, 3 H), 7.50 (d, J = 8.0 Hz, 2 H), 7.44 (d, J = 8.0 Hz, 1 H), 7.18 (d,
J = 8.0 Hz, 2 H), 5.77 (s, 2 H).
13C NMR [125 MHz, CDCl3 + TFA (3 drops)]: = 156.5, 143.6, 137.5,
137.3, 132.7, 130.5, 129.7, 128.5, 128.4, 127.1, 126.6, 125.7, 123.5,
114.6, 111.2, 47.4.
TOF-HRMS: m/z calcd for C21H1581BrN3O (M + H)+: 406.0368; found:
406.0363; m/z calcd for C20H1779BrN3O (M + H)+: 404.0398; found:
404.0396.
White solid; yield: 0.0841 g (80%); mp 210–211 °C.
1H NMR [500 MHz, CDCl3 + MeOH-d4 (3 drops)]: = 8.58 (d, J = 7.7 Hz,
1 H), 8.32 (d, J = 7.7 Hz, 1 H), 8.27 (d, J = 8.0 Hz, 1 H), 8.15 (d, J = 7.5 Hz,
2 H), 7.82–7.76 (m, 2 H), 7.49 (t, J = 7.5 Hz, 1 H), 7.51–7.39 (m, 2 H),
7.30 (d, J = 7.5 Hz, 3 H), 2.36 (s, 3 H).
13C NMR [125 MHz, CDCl3 + MeOH-d4 (3 drops)]: = 159.3, 147.5,
146.5, 143.4, 134.8, 134.0, 129.7, 128.7, 128.5, 126.9, 126.9, 126.7,
126.5, 125.2, 125.1, 118.2, 116.2, 113.6, 21.7.
TOF-HRMS: m/z calcd for C21H16N3O3S (M + H)+: 390.0912; found:
390.0908.
12H-Benzo[4,5]oxazolo[2,3-b]quinazolin-12-one (7km)36n
6-(4-Methylbenzyl)benzo[4,5]imidazo[2,1-b]quinazolin-12(6H)-
one (7fm)36m
White solid; yield: 0.0517 g (81%); mp 233–235 °C.
1H NMR (500 MHz, CDCl3): = 8.39 (d, J = 7.5 Hz, 2 H), 7.80 (t, J = 7.5
Hz, 1 H), 7.72 (d, J = 5.5 Hz, 1 H), 7.51–7.40 (m, 4 H).
13C NMR (125 MHz, CDCl3): = 159.3, 152.0, 147.5, 144.7, 135.1,
127.1, 126.9, 126.8, 126.5, 125.4, 125.0, 118.5, 116.0, 110.8.
White solid; yield: 0.0748 g (78%); mp 225–226 °C.
1H NMR (500 MHz, CDCl3): = 8.68 (d, J = 7.5 Hz, 1 H), 8.43 (d, J = 8.0
Hz, 1 H), 7.72 (t, J = 8.0 Hz, 1 H), 7.64 (d, J = 8.0 Hz, 1 H), 7.36 (d, J = 7.5
Hz, 1 H), 7.35–7.30 (m, 2 H), 7.28–7.17 (m, 2 H), 7.09 (t, J = 7.5 Hz, 1
H), 7.02 (d, J = 7.5 Hz, 1 H), 6.96 (d, J = 7.5 Hz, 1 H), 5.50 (s, 2 H), 2.47
(s, 3 H).
13C NMR (125 MHz, CDCl3): = 160.1, 149.2, 146.7, 135.8, 134.4,
132.9, 131.8, 130.8, 127.9, 127.0, 126.5, 126.4, 126.1, 126.0, 125.8,
123.1, 122.3, 116.9, 116.3, 109.0, 43.9, 19.4.
9-Methyl-12H-benzo[4,5]oxazolo[2,3-b]quinazolin-12-one (7mm)
White solid; yield: 0.0534 g (79%); mp 214–215 °C.
1H NMR [500 MHz, CDCl3 + MeOH-d4 (3 drops)]: = 8.34 (d, J = 7.5 Hz,
1 H), 8.15 (s, 1 H), 7.77 (t, J = 7.2 Hz, 1 H), 7.68 (d, J = 7.2 Hz, 1 H), 7.45
(t, J = 7.2 Hz, 1 H), 7.33 (d, J = 7.2 Hz, 1 H), 7.20 (d, J = 7.5 Hz, 1 H), 2.47
(s, 3 H).
© 2020. Thieme. All rights reserved. Synthesis 2020, 52, A–J