Consecutive Sonogashira Coupling and Hydroamination Cyclization

Apr 19, 2017 - Subsequently, it was found that the reaction temperature also played an important role on the conversion of the reaction via changing t...
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Consecutive Sonogashira Coupling and Hydroamination Cyclization for the Synthesis of Isoindolo[1,2‑b]quinazolin-10(12H)‑ones Catalyzed by CuI/L‑Proline Jian-Quan Liu,† Yong-Gang Ma,† Mei-Mei Zhang, and Xiang-Shan Wang* School of Chemistry and Chemical Engineering, Jiangsu Key Laboratory of Green Synthesis for Functional Materials, Jiangsu Normal University, Xuzhou, Jiangsu 221116, P. R. China S Supporting Information *

ABSTRACT: A consecutive Sonogashira coupling reaction, acetylene hydroamination cyclization of 2-(2-bromophenyl)quinazolin-4(3H)-ones and terminal alkynes, is described catalyzed by CuI/L-proline in the presence of Cs2CO3. This procedure provided a facile method for the synthesis of isoindolo[1,2b]quinazolin-10(12H)-one derivatives in good yields.

Q

coupling reaction of alkynes with aryl halides in absence of Pd.13a,b Meanwhile, the copper(I), for example, CuI was proved to be an effective catalyst to promote the acetylene hydroamination.14 Considering the importance of isoindoloquinazolines, we reasoned that the intramolecular acetylene hydroamination cyclization would be carried out if there is a nucleophilic group, such as amido (CONH) in the intermediate product of Sonogashira coupling reaction, and it would be an efficient method for the construction of isoindolo[1,2-b]quinazolines (Figure 2). With this idea in our mind, 2-(2-bromophenyl)quinazolin-4(3H)-one (1a) was prepared from 2-aminobenzamide and o-bromobenzaldehyde (2a) first,15 and then it was submitted to react with phenylacetylene catalyzed by transition metals in the presence of base. To our delight, the desired consecutive Sonogashira coupling reaction and acetylene hydroamination cyclization took place as we expected. As a continuation of our research devoted to the synthesis of fused polycyclic heterocycles catalyzed by copper,16 herein, we would like to report the synthesis of isoindolo[1,2b]quinazolin- 10(12H)-one derivatives via a tandem reaction of 2-(2-bromophenyl)quinazolin-4(3H)-ones and terminal alkynes. Initial attempts to mediate this domino reaction between 2(2-bromophenyl)quinazolin-4(3H)-one (1a) and phenylacetylene (2a) utilizing as a model to optimize the reaction conditions (Scheme 1), first, the model reaction was carried out under original Sonogashira coupling reaction conditions. Using Pd(PPh3)2Cl2−CuI as a catalyst, K2CO3 as a base in THF, 3a was obtained in 86% yields as expected (Table 1, entry 1). However, in the absence of 5 mol% Pd(PPh3)2Cl2 only trace amount of product was observed by TLC (Table 1, entry 2).

uinazolines have been reported as the starting materials for the synthesis of many anticancer drugs, such as Terazosin,1 Gef itinib,2 Erlotinib,3 Lapatinib,4 and Luotonin A (Figure 1).5 In addition, other quinazoline derivatives have also

Figure 1. Representative drugs molecules.

shown some pharmacological and biological activities including antimicrobial, antifungal, antioomycete, and anticonvulsant activities.6 Isoindole is also an annulated bicyclic heterocycle containing one nitrogen atom whose derivatives are ubiquitously found in a variety of biologically active compounds.7 A noticeable example based on isoindole moiety is (S)Pazinaclone,8 and it is a very operative sedative and anxiolytic drug. These heterocycles play a very important role in both medicinal chemistry and organic synthesis, and this is why a lot of methods have been reported for the preparation of quinazolines9 and isoindoles10 in recent years. However, as far as we know, few attentions have been devoted to the synthesis of fused isoindoloquinazoline.11 The combination of the two above-mentioned heterocycles may possess unique bioactive activity for screening in pharmaceutical chemistry. Sonogashira coupling is a cross-coupling reaction between a terminal alkyne (Csp) and an aryl halide (Csp2-X), and it is a very efficient method used to form carbon (sp2)-carbon(sp) bond in organic synthesis catalyzed by Pd(PPh3)2Cl2−CuI in the presence of base.12 Delightfully, the Ma and Taillefer’s groups successfully realized the copper-catalyzed Sonogashira © 2017 American Chemical Society

Received: February 2, 2017 Published: April 19, 2017 4918

DOI: 10.1021/acs.joc.7b00259 J. Org. Chem. 2017, 82, 4918−4923

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Figure 2. Retrosynthesis of isoindolo[1,2-b]quinazolin-10(12H)-one.

example, CuCl, CuBr, Cu2O, and Cu(OAc)2 were investigated by using 20 mol% L-proline as the ligand, 1 equiv of K2CO3 as the base, and THF as the solvent at refluxing (Table 1, entries 10−14). Still CuI provided the best result, and no target product was observed in the absence of copper catalyst (Entry 15). Subsequently, it was found that the reaction temperature also played an important role on the conversion of the reaction via changing the solvents, such as dioxane, toluene, DMF, and DMSO (Entries 16−19), but dioxane was proven to be the best media for this reaction, and gave 3a in 84% yield. Finally, other bases, such as NaHCO3, Na2CO3, Li2CO3, Cs2CO3, and organic bases, for example, Et3N, pyridine, and DBU (Table 1, entries 20−26), were also screened, and Cs2CO3 resulted 3a in slightly higher yield (87%). Therefore, CuI/L-proline/Cs2CO3 in dioxane is the best combination for this Sonogashira coupling and hydroamination cyclization through the screening the optimized reaction conditions. Subsequently, with the optimal conditions in hand, the scope of this new cascade Sonogashira coupling and acetylene hydroamination cyclization reaction was evaluated as shown in Table 2. To our delight, a relatively broad scope of 2-(2bromophenyl)quinazolin-4(3H)-ones bearing either electronwithdrawing or -donating substituents on the benzene ring were smoothly converted to the corresponding isoindoloquinazolines in moderate to high yield. Notably, a variety of synthetically valuable functional groups, including chloride and bromide, were well tolerated in the reaction and diverse highly functionalized isoindoloquinazolines were formed in synthetically useful yields. The tolerant of these synthetically valuable functional groups would offer an opportunity for further transformation. In addition, disubstituted 2-(2-bromophenyl)quinazolin4(3H)-ones also smoothly reacted with phenylacetylene 2a to afford the corresponding product 3l and 3m in 90% and 84% yields. Further, a series of aromatic and alkyl alkynes also reacted efficiently with 1 to give the products 3r−3v in 52− 86% yields under the optimized conditions. However, the desired reaction did not take place using diphenylacetylene, 3hexyne or diethyl but-2-ynedioate as a substrate. The structure of the isoindoloquinazoline 3v is further confirmed by X-ray crystallography17 (Table 2, CIF of 3v was supplied in SI). According to the related literature precedents and the structure of the products,16,18 a plausible mechanism was tentatively outlined in Scheme 2 by using 1a and 2a as model substrates. In the initiation stage, the copper catalyst coordinates with a ligand of L-proline, affording copper species A. Then, the Sonogashira coupling reaction including the oxidative addition and reductive elimination takes place to give the intermediate product 6. Finally, 6 occurs hydroamination to result desired product 3a.18a,b In conclusion, we have discovered a novel copper-catalyzed domino type heteroaromatization reaction of 2-(2-bromo-

Scheme 1. Model Reaction

Table 1. Synthesis of 3a under Different Reaction Conditionsa entry

cat.

1 2 3 4 5 6 7 8

Pd−Cuc CuI CuI CuI CuI CuI CuI CuI

9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

CuI CuCl CuBr Cu2O Cu(OAc)2 CuSO4 CuI CuI CuI CuI CuI CuI CuI CuI CuI CuI CuI

ligand

Ph3P 1,10-phen L-proline MeNHCO2H L-tert-leucine L-pipecolinic acid L-alanine L-proline L-proline L-proline L-proline L-proline L-proline L-proline L-proline L-proline L-proline L-proline L-proline L-proline L-proline L-proline L-proline L-proline

solvent

base

yieldb/%

THF THF THF THF THF THF THF THF

K2CO3 K2CO3 K2CO3 K2CO3 K2CO3 K2CO3 K2CO3 K2CO3

86 trace 32 36 72 45 trace 62

THF THF THF THF THF THF THF dioxane toluene DMFd DMSOd dioxane dioxane dioxane dioxane dioxane dioxane dioxane

K2CO3 K2CO3 K2CO3 K2CO3 K2CO3 K2CO3 K2CO3 K2CO3 K2CO3 K2CO3 K2CO3 NaHCO3e Na2CO3 Li2CO3 Cs2CO3 Et3N pyridine DBU

Trace 62 65 52 trace trace 0 84 71 76 75 61 64 51 87 76 52 70

a

Reagents and conditions: 1a (301 mg, 1.0 mmol), 2a (122 mg, 1.2 mmol), solvent (10.0 mL), catalyst (5 mol%); ligand (20 mol%); base (1.0 mmol); reflux. bIsolated yields. cPd(PPh3)2Cl2−CuI. d110 °C. e 2.0 mmol.

To our delight, with the addition of 20 mol% of different ligands, such as Ph3P, 1,10-phenanthroline (1,10-phen), Lproline, CH3NHCO2H, L-tert-leucine, L-pipecolinic acid, and Lalanine (Table 1, entries 3−9), the reaction yields increased obviously, especially for L-proline. It was found that L-proline as a ligand gave 3a in 72% yield used together with CuI (Table 1, entry 5), while other ligands we tested were less effective, and only trace of 3a was observed when L-tert-leucine or L-alanine was used as a ligand. Then, other copper sources (5 mol%), for 4919

DOI: 10.1021/acs.joc.7b00259 J. Org. Chem. 2017, 82, 4918−4923

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high vacuum valve was charged with 2-(2-bromophenyl)quinazolin4(3H)-ones 1 (1.0 mmol), CuI (10 mg, 0.05 mmol), L-proline (23 mg, 0.2 mmol), and Cs2CO3 (325 mg, 1.0 mmol) in anhydrous dioxane (10.0 mL). After being degassed by three freeze−thaw pump cycles with argon, the terminal alkynes 2 (1.2 mmol) was injected into the mixture. Subsequently, the resulting mixture was stirred at reflux under an argon atmosphere. After completion of the reaction monitored by TLC, the insoluble substance was filtered off by a fast hot-filtration, and the filtrate was concentrated under reduced pressure. The resulting crude residue was purified by silica-gel column chromatography using ethyl acetate and petroleum ether (1:4) as an eluent to give final products 3. (E)-12-Benzylideneisoindolo[1,2-b]quinazolin-10(12H)-one (3a). Yield 87% (280 mg). Pale yellow solid, m.p.: 184−185 °C; 1H NMR (CDCl3, 400 MHz): δH 7.28 (d, J = 8.0 Hz, 1H), 7.33−7.37 (m, 1H), 7.41−7.45 (m, 1H), 7.47−7.49 (m, 2H), 7.51−7.55 (m, 4H), 7.79−7.83 (m, 1H), 7.84−7.86 (m, 1H), 8.19 (d, J = 7.6 Hz, 1H), 7.48 (d, J = 8.0 Hz, 1H), 9.15 (s, 1H). 13C NMR (CDCl3, 100 MHz): δC 100.0, 121.4, 122.9, 123.2, 123.8, 126.6, 127.2, 127.5, 128.2, 128.8, 129.0, 129.7, 130.7, 131.9, 134.3, 134.4, 135.3, 147.5, 151.4, 161.3. IR (KBr): ν 3056, 2095, 1701, 1636, 1617, 1600, 1560, 1470, 1379, 1317, 1302, 1270, 1177, 1150, 1125, 1040, 873, 728 cm−1. HRMS (TOF, ESI, m/z): Calcd for C22H15N2O [M+H]+ 323.1184, found 323.1165. (E)-12-Benzylidene-3-chloroisoindolo[1,2-b]quinazolin-10(12H)one (3b). Yield 90% (321 mg). Pale yellow solid, m.p.: 245−247 °C; 1 H NMR (CDCl3, 400 MHz): δH 7.29 (s, 1H), 7.49−7.51 (m, 2H), 7.53 (s, 4H), 7.56−7.58 (m, 1H), 7.81−7.86 (m, 2H), 8.13 (d, J = 8.0 Hz, 1H), 8.49 (d, J = 8.0 Hz, 1H), 9.20 (s, 1H). 13C NMR (CDCl3, 100 MHz): δC 100.0, 121.3, 123.9, 124.0, 124.4, 126.9, 127.2, 127.5, 128.7, 128.9, 129.0, 130.2, 134.3, 134.5, 134.7, 135.7, 138.1, 147.3, 150.5, 161.3. IR (KBr): ν 3063, 1684, 1623, 1601, 1561, 1470, 1430, 1372, 1333, 1281, 1173, 1148, 1129, 1066, 880, 868, 768, 733, 695 cm−1. HRMS (TOF, ESI, m/z): Calcd for C22H14ClN2O [M+H]+ 357.0794, found 357.0777. (E)-12-Benzylidene-4-fluoroisoindolo[1,2-b]quinazolin-10(12H)one (3c). Yield 86% (340 mg). Pale yellow solid, m.p.: 218−220 °C; 1 H NMR (CDCl3, 400 MHz): δH 7.28 (d, J = 8.0 Hz, 1H), 7.33−7.37 (m, 1H), 7.41−7.55 (m, 6H), 7.79−7.83 (m, 1H), 7.84−7.86 (m, 1H), 8.19 (d, J = 7.6 Hz, 1H), 8.48 (d, J = 8.0 Hz, 1H), 9.15 (s, 1H). 13C NMR (CDCl3, 100 MHz): δC 109.3 (d, JF−C = 24.2 Hz), 119.8 (d, JF−C = 23.5 Hz), 121.5, 122.7 (d, JF−C = 2.1 Hz), 125.8 (d, JF−C = 8.4 Hz), 127.0, 127.2, 127.6, 128.3, 128.9, 129.0, 130.5 (d, JF−C = 2.5 Hz), 132.5, 133.0, 134.5, 134.6, 135.1, 147.2, 161.1, 163.4 (d, JF−C = 249.5 Hz). IR (KBr): ν 3069, 1685, 1643, 1612, 1602, 1489, 1465, 1378, 1336, 1281, 1234, 1218, 1180, 1150, 1080, 894, 873, 831, 774, 758, 696 cm−1. HRMS (TOF, ESI, m/z): Calcd for C22H14FN2O [M+H]+ 341.1090, found 341.1094. (E)-12-Benzylidene-4-chloroisoindolo[1,2-b]quinazolin-10(12H)one (3d). Yield 86% (307 mg). Pale yellow solid, m.p.: 238−240 °C; 1 H NMR (CDCl3, 400 MHz): δH 7.19 (d, J = 8.8 Hz, 1H), 7.29 (dd, J = 2.0, 8.4 Hz, 1H), 7.43−7.49 (m, 5H), 7.53−7.57 (m, 1H), 7.79−7.85 (m, 2H), 8.16 (d, J = 2.0 Hz, 1H), 8.46−8.48 (m, 1H), 9.13 (s, 1H). 13 C NMR (CDCl3, 100 MHz): δC 121.5, 122.8, 123.6, 125.0, 127.0, 127.2, 127.6, 128.4, 128.9, 129.0, 132.1, 132.3, 132.6, 134.5, 134.6, 135.0, 135.9, 147.2, 150.2, 161.1. IR (KBr): ν 3056, 3026, 1684, 1643, 1623, 1604, 1562, 1473, 1462, 1439, 1379, 1377, 1331, 1317, 1273, 1237, 1181, 1138, 1065, 877, 826, 773, 740, 698 cm−1. HRMS (TOF, ESI, m/z): Calcd for C22H14ClN2O [M+H]+ 357.0794, found 357.0788. (E)-12-Benzylidene-4-methoxyisoindolo[1,2-b]quinazolin-10(12H)-one (3e). Yield 90% (317 mg). Pale yellow solid, m.p.: 175−176 °C; 1H NMR (CDCl3, 400 MHz): δH 3.93 (s, 3H), 6.90 (dd, J = 2.4, 8.8 Hz, 1H), 7.18 (d, J = 8.8 Hz, 1H), 7.41−7.55 (m, 6H), 7.61 (d, J = 2.4 Hz, 1H), 7.78−7.85 (m, 2H), 8.48 (dd, J = 0.8, 8.0 Hz, 1H), 9.01 (s, 1H). 13C NMR (CDCl3, 100 MHz): δC 55.8, 100.0, 104.7, 121.0, 121.2, 121.5, 125.0, 126.7, 127.2, 127.4, 127.5, 128.1, 128.8, 129.2, 132.4, 134.3, 135.1, 135.5, 147.4, 151.4, 161.0. IR (KBr): ν 3057, 2989, 2965, 1687, 1637, 1618, 1604, 1566, 1499, 1497, 1471, 1439, 1386, 1345, 1293, 1266, 1248, 1178, 1084, 1028, 873, 839, 773, 758 cm−1.

Table 2. Synthetic Results for the Products 3

a

Reagents and conditions: 1 (1.0 mmol), 2 (1.2 mmol), CuI (10 mg, 0.05 mmol), L-proline (23 mg, 0.2 mmol), Cs2CO3 (325 mg, 1.0 mmol), dioxane (10.0 mL), reflux. bIsolated yields.

Scheme 2. Possible Mechanism

phenyl)quinazolin-4(3H)-one with alkyne involving a consecutive Sonogashira coupling reaction and hydroamination, providing a convenient and modular approach for the construction of useful isoindolo[1,2-b]quinazolin-10(12H)one derivatives with broad scope of substrates, excellent group tolerance, and high reaction efficiencies and product yields.

■

EXPERIMENTAL SECTION

General Procedure for the Syntheses of Isoindolo[1,2b]quinazolin-10(12H)-one Derivatives 3. A reaction flask with 4920

DOI: 10.1021/acs.joc.7b00259 J. Org. Chem. 2017, 82, 4918−4923

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The Journal of Organic Chemistry

938, 864, 825, 787, 764, 700 cm−1. HRMS (TOF, ESI, m/z): Calcd for C24H17N2O3 [M+H]+ 381.1239, found 381.1240. (E)-12-Benzylidene-4-chloro-6,7-dimethylisoindolo[1,2-b]quinazolin-10(12H)-one (3l). Yield 90% (346 mg). Pale yellow solid, m.p.: 258−260 °C; 1H NMR (CDCl3, 400 MHz): δH 2.49 (s, 3H), 2.70 (s, 3H), 7.19 (d, J = 8.4 Hz, 1H), 7.28 (dd, J = 2.0, 8.4 Hz, 1H), 7.35 (d, J = 8.0 Hz, 1H), 7.41−7.52 (m, 5H), 8.17 (d, J = 2.0 Hz, 1H), 8.23 (d, J = 8.0 Hz, 1H), 9.10 (s, 1H). 13C NMR (CDCl3, 100 MHz): δC 13.2, 21.0, 119.4, 122.7, 123.0, 124.0, 124.9, 128.3, 128.88, 128.90, 129.0, 131.7, 132.6, 133.0, 134.4, 134.6, 135.2, 135.6, 143.6, 145.5, 148.8, 161.6. IR (KBr): ν 3066, 2944, 1678, 1648, 1621, 1597, 1558, 1459, 1437, 1471, 1406, 1386, 1377, 1335, 1319, 1275, 1230, 1186, 1082, 1009, 913, 872, 785, 767, 757, 716 cm−1. HRMS (TOF, ESI, m/ z): Calcd for C24H18ClN2O [M+H]+ 385.1107, found 385.1117. (E)-12-Benzylidene-3,4-dimethoxy-6,7-dimethylisoindolo[1,2-b]quinazolin-10(12H)-one (3m). Yield 84% (345 mg). Pale yellow solid, m.p.: 224−225 °C; 1H NMR (CDCl3, 400 MHz): δH 2.47 (s, 3H), 2.69 (s, 3H), 3.53 (s, 3H), 4.04 (s, 3H), 6.62 (s, 1H), 7.29 (d, J = 8.0 Hz, 1H), 7.38−7.41 (m, 1H), 7.46−7.50 (m, 2H), 7.52−7.54 (m, 3H), 8.21 (d, J = 8.4 Hz, 1H), 8.98 (s, 1H). 13C NMR (CDCl3, 100 MHz): δC 13.2, 21.0, 55.6, 56.3, 103.4, 105.6, 119.0, 120.8, 124.0, 124.3, 128.0, 128.1, 128.2, 128.7, 129.3, 133.7, 135.3, 135.8, 143.2, 145.8, 150.1, 151.0, 152.2, 161.6. IR (KBr): ν 3057, 3000, 2968, 2834, 1669, 1645, 1619, 1596, 1499, 1490, 1451, 1441, 1377, 1307, 1273, 1218, 1198, 1176, 1101, 1076, 1029, 1012, 866, 780, 766, 703 cm−1. HRMS (TOF, ESI, m/z): Calcd for C26H23N2O3 [M+H]+ 411.1708, found 411.1707. (E)-12-Benzylidene-8-chloroisoindolo[1,2-b]quinazolin-10(12H)one (3n). Yield 78% (278 mg). Yellow solid, m.p.: 265−266 °C; 1H NMR (400 MHz, CDCl3) δH 7.28 (d, J = 8.0 Hz, 1H), 7.33−7.37 (m, 1H), 7.44−7.52 (m, 6H), 7.72 (dd, J = 2.4, 8.8 Hz, 1H), 7.77 (d, J = 8.4 Hz, 1H), 8.15 (d, J = 7.6 Hz, 1H), 8.41 (d, J = 2.4 Hz, 1H), 9.11 (s, 1H); 13C NMR (CDCl3, 100 MHz) δC 122.4, 122.9, 123.7, 123.8, 126.5, 128.3, 128.9, 129.0, 129.7, 130.4, 132.1, 132.4, 134.4, 134.7, 135.1, 135.2, 146.0, 151.5, 160.1; HRMS (TOF, ESI, m/z): Calcd for C22H14ClN2O [M+H]+ 357.0795, found 357.0784. (E)-12-Benzylidene-7-chloroisoindolo[1,2-b]quinazolin-10(12H)one (3o). Yield 81% (289 mg).Yellow solid, m.p.: 260−262 °C; 1H NMR (400 MHz, CDCl3) δH 7.29 (d, J = 8.0 Hz, 1H), 7.35−7.39 (m, 1H), 7.44−7.54 (m, 7H), 7.84 (d, J = 2.0 Hz, 1H), 8.17 (d, J = 7.6 Hz, 1H), 8.39 (d, J = 8.4 Hz, 1H), 9.13 (s, 1H); 13C NMR (CDCl3, 100 MHz) δC 119.9, 123.1, 123.7, 123.8, 127.0, 127.1, 128.4, 128.6, 128.9, 129.0, 129.8, 130.4, 132.3, 135.0, 135.1, 135.2, 140.5, 148.5, 152.5, 160.7; HRMS (TOF, ESI, m/z): Calcd for C22H14ClN2O [M+H]+ 357.0795, found 357.0799. (E)-12-Benzylidene-6-methylisoindolo[1,2-b]quinazolin-10(12H)one (3p). Yield 87% (293 mg). Pale yellow solid, m.p.: 177−178 °C; 1 H NMR (CDCl3, 400 MHz): δH 2.53 (s, 3H), 6.03 (s, 2H), 6.59 (s, 1H), 7.40−7.44 (m, 1H), 7.47−7.48 (m, 4H), 7.50 (s, 1H), 7.59 (dd, J = 2.0, 8.4 Hz, 1H), 7.69 (d, J = 8.4 Hz, 1H), 8.23 (s, 1H), 9.03 (s, 1H). 13 C NMR (CDCl3, 100 MHz): δC 17.4, 121.4, 122.86, 122.88, 123.7, 124.8, 126.1, 128.1, 128.8, 129.1, 129.5, 131.2, 131.6, 134.3, 134.9, 135.4, 135.5, 136.2, 146.0, 151.0, 161.6. IR (KBr): ν 3055, 2920, 1678, 1635, 1616, 1593, 1575, 1558, 1472, 1456, 1385, 1340, 1317, 1293, 1255, 1225, 1178, 1153, 1077, 820, 763, 712 cm−1. HRMS (TOF, ESI, m/z): Calcd for C23H17N2O [M+H]+ 337.1341, found 337.1341. (E)-12-Benzylidene-8-bromoisoindolo[1,2-b]quinazolin-10(12H)one (3q). Yield 62% (249 mg). Pale yellow solid, m.p.: 262−263 °C; 1 H NMR (CDCl3, 400 MHz): δH 7.29 (d, J = 8.0 Hz, 1H), 7.33−7.37 (m, 1H), 7.44−7.53 (m, 6H), 7.70 (d, J = 8.8 Hz, 1H), 7.86 (dd, J = 2.4, 8.4 Hz, 1H), 8.15 (d, J = 7.6 Hz, 1H), 8.57 (d, J = 2.0 Hz, 1H), 9.11 (s, 1H). 13C NMR (CDCl3, 100 MHz): δC 120.1, 122.8, 122.9, 123.7, 123.8, 128.4, 128.9, 129.0, 129.2, 129.7, 129.8, 130.5, 132.1, 134.4, 135.1, 135.2, 137.4, 146.3, 151.7, 160.0. HRMS (TOF, ESI, m/ z): Calcd for C22H14BrN2O [M+H]+, 401.0290, found 401.0284. (E)-3-Chloro-12-(3-fluorobenzylidene)isoindolo[1,2-b]quinazolin10(12H)-one (3r). Yield 86% (322 mg). Yellow solid, m.p.: 233−234 °C; 1H NMR (400 MHz, CDCl3) δH 7.13−7.21 (m, 3H), 7.28−7.34 (m, 2H), 7.43−7.49 (m, 1H), 7.53−7.57 (m, 1H), 7.82−7.85 (m, 2H), 8.17 (d, J = 1.6 Hz, 1H), 8.45−8.47 (m, 1H), 9.06 (s, 1H); 13C NMR (100 MHz, CDCl3) δC 115.4 (d, JF−C = 20.9 Hz), 116.0 (d, JF−C = 21.6

HRMS (TOF, ESI, m/z): Calcd for C23H17N2O2 [M+H]+ 353.1290, found 353.1295. (E)-12-Benzylidene-3,4-dimethoxyisoindolo[1,2-b]quinazolin-10(12H)-one (3f). Yield 82% (314 mg). Pale yellow solid, m.p.: 229−230 °C; 1H NMR (CDCl3, 400 MHz): δH 3.51 (s, 3H), 4.01 (s, 3H), 6.60 (s, 1H), 7.38−7.42 (m, 1H), 7.46−7.50 (m, 3H), 7.52−7.54 (m, 3H), 7.77−7.78 (m, 2H), 8.44 (d, J = 7.6 Hz, 1H), 9.01 (s, 1H). 13C NMR (CDCl3, 100 MHz): δC 55.6, 56.4, 103.5, 105.6, 121.1, 121.4, 123.7, 126.2, 127.1, 127.2, 128.1, 128.4, 128.7, 129.2, 134.2, 135.3, 135.6, 147.6, 151.2, 151.6, 152.5, 161.1. IR (KBr): ν 3054, 2992, 2964, 2955, 1680, 1636, 1615, 1563, 1492, 1465, 1383, 1275, 1215, 1188, 1170, 1078, 1029, 1004, 859, 839, 765 cm−1. HRMS (TOF, ESI, m/z): Calcd for C24H19N2O3 [M+H]+ 383.1395, found 383.1391. (E)-6-Benzylidene-[1,3]dioxolo[4′,5′:6,7]isoindolo[1,2-b]quinazolin-8(6H)-one (3g). Yield 91% (333 mg). Pale yellow solid, m.p.: 270−272 °C; 1H NMR (CDCl3, 400 MHz): δH 6.02 (s, 2H), 6.58 (s, 1H), 7.40−7.50 (m, 7H), 7.76−7.78 (m, 2H), 8.43 (d, J = 7.6 Hz, 1H), 9.03 (s, 1H). 13C NMR (CDCl3, 100 MHz): δC 101.9, 102.2, 103.5, 121.1, 122.0, 125.7, 126.3, 127.1, 127.2, 128.2, 128.9, 129.0, 130.0, 134.2, 135.0, 135.2, 147.5, 149.7, 151.1, 151.4, 161.0. IR (KBr): ν 3070, 3024, 2909, 1669, 1648, 1622, 1601, 1565, 1499, 1471, 1387, 1374, 1333, 1270, 1234, 1179, 1144, 1033, 940, 909, 862, 837, 770, 713 cm−1. HRMS (TOF, ESI, m/z): Calcd for C23H15N2O3 [M+H]+ 367.1082, found 367.1089. (E)-12-Benzylidene-8-methylisoindolo[1,2-b]quinazolin-10(12H)one (3h). Yield 89% (299 mg). Pale yellow solid, m.p.: 207−208 °C; 1 H NMR (CDCl3, 400 MHz): δH 2.55 (s, 3H), 7.27 (d, J = 7.6 Hz, 1H), 7.31−7.35 (m, 1H), 7.41−7.53 (m, 6H), 7.62 (dd, J = 1.6, 8.4 Hz, 1H), 7.75 (d, J = 8.4 Hz, 1H), 7.62 (dd, J = 0.8, 7.6 Hz, 1H), 8.26 (s, 1H), 9.13 (s, 1H). 13C NMR (CDCl3, 100 MHz): δC 21.4, 121.2, 122.7, 122.9, 123.7, 126.7, 127.3, 128.2, 128.8, 129.1, 129.6, 130.8, 131.6, 134.3, 135.38, 135.44, 135.8, 136.9, 145.4, 150.7, 161.3. IR (KBr): ν 3071, 3047, 3027, 2919, 1681, 1646, 1624, 1487, 1472, 1439, 1373, 1336, 1316, 1297, 1271, 1255, 1206, 1175, 1156, 1115, 1071, 1044, 862, 831, 767, 718, 696 cm−1. HRMS (TOF, ESI, m/z): Calcd for C23H17N2O [M+H]+ 337.1341, found 337.1334. (E)-12-Benzylidene-4-chloro-8-methylisoindolo[1,2-b]quinazolin10(12H)-one (3i). Yield 89% (330 mg). Pale yellow solid, m.p.: 228− 230 °C; 1H NMR (CDCl3, 400 MHz): δH 2.55 (s, 3H), 7.18 (d, J = 8.4 Hz, 1H), 7.27 (dd, J = 2.0, 8.4 Hz, 1H), 7.42−7.53 (m, 5H), 7.63 (dd, J = 2.0, 8.4 Hz, 1H), 7.74 (d, J = 8.4 Hz, 1H), 8.15 (d, J = 2.0 Hz, 1H), 8.26 (s, 1H), 9.12 (s, 1H). 13C NMR (CDCl3, 100 MHz): δC 21.5, 121.2, 122.6, 123.3, 124.9, 126.7, 127.4, 128.4, 128.9, 129.0, 131.8, 132.4, 132.6, 134.7, 135.1, 135.8, 135.9, 137.3, 145.2, 149.5, 161.1. IR (KBr): ν 3096, 2953, 2928, 2832, 1675, 1639, 1608, 1490, 1459, 1440, 1376, 1334, 1314, 1269, 1234, 1217, 1207, 1180, 1159, 1079, 1005, 863, 842, 764, 699 cm−1. HRMS (TOF, ESI, m/z): Calcd for C23H16ClN2O [M+H]+ 371.0951, found 371.0953. (E)-12-Benzylidene-3,4-dimethoxy-8-methylisoindolo[1,2-b]quinazolin-10(12H)-one (3j). Yield 85% (337 mg). Pale yellow solid, m.p.: 244−245 °C; 1H NMR (CDCl3, 400 MHz): δH 2.54 (s, 3H), 3.52 (s, 3H), 4.01 (s, 3H), 6.60 (s, 1H), 7.39−7.42 (m, 1H), 7.47− 7.50 (m, 2H), 7.52−7.54 (m, 3H), 7.60 (dd, J = 2.0, 8.4 Hz, 1H), 7.70 (d, J = 8.4 Hz, 1H), 8.24 (s, 1H), 9.01 (s, 1H). 13C NMR (CDCl3, 100 MHz): δC 21.4, 55.6, 56.4, 103.4, 105.6, 120.8, 121.3, 123.8, 126.7, 126.8, 128.0, 128.3, 128.7, 129.2, 135.4, 135.65, 135.69, 136.4, 145.5, 150.9, 151.1, 152.3, 161.1. IR (KBr): ν 3097, 3045, 2953, 2928, 1675, 1639, 1608, 1497, 1459, 1377, 1314, 1270, 1234, 1217, 1207, 1180, 1159, 1079, 1005, 863, 842, 764 cm−1. HRMS (TOF, ESI, m/z): Calcd for C25H21N2O3 [M+H]+ 397.1552, found 397.1539. (E)-6-Benzylidene-10-methyl-[1,3]dioxolo[4′,5′:6,7]isoindolo[1,2b]quinazolin-8(6H)-one (3k). Yield 90% (342 mg). Pale yellow solid, m.p.: 235−236 °C; 1H NMR (CDCl3, 400 MHz): δH 2.53 (s, 3H), 6.03 (s, 2H), 6.59 (s, 1H), 7.40−7.44 (m, 1H), 7.47−7.48 (m, 4H), 7.50 (s, 1H), 7.59 (dd, J = 2.0, 8.4 Hz, 1H), 7.69 (d, J = 8.4 Hz, 1H), 8.23 (s, 1H), 9.03 (s, 1H). 13C NMR (CDCl3, 100 MHz): δC 21.4, 101.8, 102.2, 103.5, 120.8, 121.7, 125.8, 126.6, 127.0, 128.2, 128.9, 129.0, 130.0, 135.1, 135.3, 135.7, 136.5, 145.4, 149.6, 150.5, 151.2, 161.1. IR (KBr): ν 3081, 3056, 2907, 1674, 1637, 1606, 1492, 1468, 1444, 1383, 1368, 1336, 1313, 1268, 1232, 1204, 1141, 1073, 1035, 4921

DOI: 10.1021/acs.joc.7b00259 J. Org. Chem. 2017, 82, 4918−4923

The Journal of Organic Chemistry

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Hz), 121.5, 121.7, 122.9, 124.8 (d, JF−C = 3.0 Hz), 124.9, 127.1, 127.2, 127.7, 130.6 (d, JF−C = 8.4 Hz), 132.2, 132.3, 132.5, 134.6, 135.1, 136.2, 137.1 (d, JF−C = 7.9 Hz), 147.2, 150.0, 161.0, 163.0 (d, JF−C = 246.3 Hz). HRMS (TOF, ESI, m/z): Calcd for C22H13ClFN2O [M +H]+ 375.0700, found 375.0709. (E)-3-Chloro-12-(4-nitrobenzylidene)isoindolo[1,2-b]quinazolin10(12H)-one (3s). Yield 52% (209 mg). Yellow solid, m.p.: 267−268 °C; 1H NMR (400 MHz, CDCl3) δH 7.16 (d, J = 8.4 Hz, 1H), 7.35 (dd, J = 2.0, 8.4 Hz, 1H), 7.56−7.58 (m, 1H), 7.70 (d, J = 8.4 Hz, 2H), 7.85−7.86 (m, 2H), 8.21 (d, J = 2.0 Hz, 1H), 8.36 (d, J = 8.4 Hz, 2H), 8.48 (d, J = 7.6 Hz, 1H), 9.12 (s, 1H); 13C NMR (CDCl3, 100 MHz) δC 120.1, 121.4, 122.5, 123.3, 124.3, 124.6, 127.3, 127.4, 127.6, 127.8, 130.1, 130.5, 131.8, 132.3, 134.8, 135.8, 136.8, 142.1, 147.1, 161.1; HRMS (TOF, ESI, m/z): Calcd for C22H13ClN3O3 [M+H]+ 402.0645, found 402.0659. (E)-3-Chloro-12-(4-ethoxybenzylidene)isoindolo[1,2-b]quinazolin-10(12H)-one (3t). Yield 86% (345 mg). Pale yellow solid, m.p.: 227−228 °C; 1H NMR (CDCl3, 400 MHz): δH 1.48 (t, J = 6.8 Hz, 3H), 4.12 (q, J = 6.8 Hz, 2H), 6.99 (dd, J = 2.0, 6.8 Hz, 2H), 7.32 (dd, J = 2.0, 8.4 Hz, 1H), 7.39−7.43 (m, 3H), 7.53−7.57 (m, 1H), 7.81−7.84 (m, 2H), 8.18 (d, J = 2.0 Hz, 1H), 8.46−8.48 (m, 1H), 9.08 (s, 1H). 13C NMR (CDCl3, 100 MHz): δC 14.9, 63.6, 114.8, 121.4, 122.7, 123.8, 124.8, 126.9, 127.0, 127.2, 127.5, 130.6, 132.0, 132.2, 132.8, 134.0, 134.4, 135.6, 147.2, 150.1, 159.2, 161.1. IR (KBr): ν 3068, 2969, 2932, 1681, 1634, 1622, 1603, 1560, 1513, 1460, 1388, 1332, 1316, 1300, 1260, 1174, 1116, 1045, 1010, 956, 881, 873, 839, 819, 771 cm−1. HRMS (TOF, ESI, m/z): Calcd for C24H18ClN2O2 [M +H]+ 401.1057, found 401.1051. (E)-12-(4-Chlorobenzylidene)isoindolo[1,2-b]quinazolin-10(12H)one (3u). Yield 84% (300 mg). Yellow solid, m.p.: 242−243 °C; 1H NMR (CDCl3, 400 MHz): δH 7.31 (d, J = 8.0 Hz, 1H), 7.36−7.40 (m, 1H), 7.44−7.46 (m, 4H), 7.52−7.55 (m, 2H), 7.81−7.86 (m, 2H), 8.20 (d, J = 8.0 Hz, 1H), 8.47 (d, J = 8.0 Hz, 1H), 9.06 (s, 1H). 13C NMR (CDCl3, 100 MHz): δC 121.4, 121.5, 123.0, 123.6, 126.8, 127.2, 127.5, 128.9, 129.1, 129.9, 130.5, 130.8, 132.0, 133.7, 133.8, 134.1, 134.2, 134.4, 135.7, 147.4, 151.2, 161.2. HRMS (TOF, ESI, m/z): Calcd for C22H14ClN2O [M+H]+ 357.0795, found 357.0772. (E)-12-(Cyclopropylmethylene)-3-nitroisoindolo[1,2-b]quinazolin-10(12H)-one (3v). Yield 72% (238 mg). Yellow solid, m.p.: 247−248 °C; 1H NMR (400 MHz, CDCl3) δH 0.93−0.97 (m, 2H), 1.27−1.32 (m, 2H), 2.23−2.31 (m, 1H), 7.54−7.58 (m, 1H), 7.82−7.89 (m, 2H), 7.95 (d, J = 10.4 Hz, 1H), 8.32 (d, J = 8.8 Hz, 1H), 8.43 (d, J = 7.2, 1H), 8.52 (dd, J = 2.0, 8.8 Hz, 1H), 9.12 (d, J = 2.0 Hz, 1H); 13C NMR (CDCl3, 100 MHz) δC 10.5, 12.0, 118.8, 121.3, 124.1, 126.8, 127.0, 127.1, 127.7, 131.3, 132.7, 134.5, 135.0, 139.6, 147.1, 147.7, 149.0, 160.9; HRMS (TOF, ESI, m/z): Calcd for C19H14N3O3 [M+H]+ 332.1035, found 332.1044.

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ACKNOWLEDGMENTS We are grateful to the Major Natural Science Foundation of Jiangsu Province (14KJA150004), and a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions for financial support.

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S Supporting Information *

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.joc.7b00259.

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C NMR spectra for

AUTHOR INFORMATION

Corresponding Author

*E-mail: [email protected] ORCID

Xiang-Shan Wang: 0000-0002-0077-7819 Author Contributions †

J.-Q.L. and Y.-G.M. contributed equally.

Notes

The authors declare no competing financial interest. 4922

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Note

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