Startseite Regioselective 1,4-conjugate aza-Michael addition of dienones with benzotriazole
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Regioselective 1,4-conjugate aza-Michael addition of dienones with benzotriazole

  • Zheng Li EMAIL logo , Tianpeng Li , Rugang Fu und Jingya Yang
Veröffentlicht/Copyright: 8. Juli 2017
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Heterocyclic Communications
Aus der Zeitschrift Heterocyclic Communications Band 23 Heft 4

Abstract

The regioselective 1,4-conjugate aza-Michael addition of dienones with benzotriazole catalyzed by potassium acetate is described. A series of 3-(benzotriazol-1-yl)-1,5-diarylpent-4-en-1-ones were efficiently synthesized under mild conditions. This protocol has advantages of transition-metal free catalyst, high yield and high regioselectivity.

Keywords: aza-Michael addition; benzotriazole; dienone; regioselectivity; synthesis

Introduction

The aza-Michael addition is an important reaction in synthetic organic chemistry, which has broad applications in pharmaceutical chemistry, biology, and material sciences [1]. The conjugate addition of N-heterocyclic agents, such as benzotriazole [2], indazole [3], pyrazole [4], [5], tetrazole [6] and piperazine [7], as nucleophiles to Michael acceptors are important reactions for construction of C-N bonds in organic chemistry. However, the reported Michael acceptors have mainly focused on one C=C bond substrates, such as α,β-unsaturated ketones [8], [9], [10], [11], carboxylic acids [12], esters [13], [14], [15], amides [16], nitriles [17], and nitroalkenes [18], [19], [20]. Moreover, complex and expensive catalysts, such as transition metal complexes [21], [22], [23], [24] and Brønsted, Lewis or heteropoly acids [25], [26], [27] are also required. Limited examples of the Michael acceptors with two C=C bonds, such as conjugated dienones, have been reported. Wang has reported a method for aza-Michael addition of benzotriazole to 6-arylhexa-3,5-dien-2-ones catalyzed by diethylamine in toluene [28]. Feng has reported one example of enantioselective direct Michael addition of benzotriazole to 1,5-diphenylpenta-2,4-dien-1-one in the presence of a complex catalyst in chloroform [29]. In fact, the aza-Michael addition of dienones poses problems of regioselective control, as the dienones can, in principle, undergo 1,2-, 1,4-, and 1,6-addition reactions. Herein, we report the regioselective 1,4-conjugate aza-Michael addition of benzotriazole to dienones under mild conditions by using potassium acetate as a catalyst.

Results and discussion

Initially, (2E,4E)-1,5-diphenylpenta-2,4-dien-1-one (1a) was selected as a substrate of aza-Michael addition with benzotriazole (Scheme 1). When the reaction was carried out in the presence of KF as a catalyst in acetonitrile, a sole product 2a was isolated in 45% yield. This result indicates that the reaction of 1a with benzotriazole proceeds by 1,4-conjugate addition. No 1,2- and 1,6- adducts were observed. The same product was also synthesized by Feng and co-workers in 45% yield in the presence of Sc(OTf)3 as a catalyst [29]. In principle, the use of benzotriazole as a Michael donor can result in the formation of two additional products, N1 and N2 adducts, because of the tautomerism. However, in this reaction, the N1 adduct is the sole product.

Scheme 1 Regioselective addition of dienone 1a with benzotriazole.
Scheme 1

Regioselective addition of dienone 1a with benzotriazole.

Subsequently, the reaction conditions were optimized. It was found that in the absence of catalyst the desired product 2a was not formed (Table 1, entry 1). Some catalysts, such as LiCl, Na2CO3 and K2CO3, had no effect on the reaction (entries 2–4). However, inorganic bases, such as KF, CsF, K3PO4, Cs2CO3 and NaOH, and organic bases, such as DBU, Et3N and Et2NH, catalyze the reaction to give 2a in moderate yield (entries 5–12). The highest yield of 2a was obtained in the presence of KOAc (entry 13). These results suggest that the yield is related to basicity of catalyst. The moderate basicity of catalyst is advantageous for the reaction.

Table 1

Optimization of the reaction conditionsa.

EntryCatalyst (mmol%)SolventTemperature (°C)Yield (%)b
1NoneMeCN800
2LiCl (20)MeCN800
3Na2CO3 (20)MeCN800
4K2CO3 (20)MeCN800
5KF (20)MeCN8045
6CsF (20)MeCN8047
7K3PO4 (20)MeCN8051
8Cs2CO3 (20)MeCN8053
9NaOH (20)MeCN8046
10DBU (20)MeCN8062
11Et3N (20)MeCN8049
12Et2NH (20)MeCN8033
13KOAc (20)MeCN8085
14KOAc (20)DMF15048
15KOAc (20)DMSO15039
16KOAc (20)MeOH6028
17KOAc (20)EtOH8037
18KOAc (20)CH2Cl24034
19KOAc (20)THF6026
20KOAc (20)1,4-dioxane10023
21KOAc (20)PhMe11021
22KOAc (20)MeCN6074
23KOAc (20)MeCN4062
24KOAc (100)MeCN8080
25KOAc (50)MeCN8083
26KOAc (10)MeCN8058
27KOAc (5)MeCN8026

  1. a1a (0.5 mmol), benzotriazole (0.7 mmol), solvent (5 mL), 20 h.

  2. bIsolated yield.

Solvent also plays a significant role. It was found that the reaction conducted in MeCN furnishes the desired product 2a in highest yield (entry 13). Other tested solvents gave rise to 2a in low yields (entries 14–21). In addition, 80°C is the optimal temperature as a decrease in the reaction temperature results in lower yield (entries 22–23). The increase of catalyst loading from 20 mmol% to 100 mmol% does not significantly improve the yield (entries 24–25). Inversely, the decrease of catalyst loading from 20 mmol% to 5 mmol% leads to decrease in the yield (entries 26–27).

Based on the above promising findings, additional dienones were examined for the 1,4-conjugate addition in MeCN at 80°C using KOAc as a catalyst (Scheme 2). It was found that reactions of dienones bearing an electron-donating group on an aromatic ring R2 furnish the corresponding products in high yields (2b,c). By contrast, the reactions of dienones bearing an electron-withdrawing group on the aromatic ring give slightly lower yields (2d–g). When R2 is a heterocyclic group, such as 2-thienyl, the reaction takes place smoothly to give the corresponding product in high yield (2h, 2m). However, for R2=alkyl, such as Me or Et, the reactions were not successful and no desired adducts were isolated. However, a successful addition was reported by using diethylamine as a catalyst and toluene as solvent [28].

Scheme 2 Regioselective aza-Michael addition of dienones with benzotriazole.
Scheme 2

Regioselective aza-Michael addition of dienones with benzotriazole.

Conclusion

An efficient protocol was developed for high-yield regioselective 1,4-conjugate aza-Michael addition of dienones with benzotriazole using potassium acetate as a catalyst.

Experimental

1H NMR and 13C NMR spectra were recorded on a Mercury-400BB or Mercury-600BB instrument using CDCl3 as solvent and Me4Si as internal standard. Melting points were observed on an electrothermal melting point apparatus. IR spectra were obtained using KBr pellets. Dienones were prepared according to literature procedure [30].

General procedure for the 1,4-conjugate aza-Michael addition of dienone with benzotriazole

Dienone (0.5 mmol), benzotriazole (0.7 mmol), potassium acetate (0.1 mmol), and acetonitrile (5 mL) were sequentially charged into a dry Schlenk tube and the mixture was stirred at 80°C for 20 h. After the reaction was completed (monitored by TLC), the mixture was cooled to room temperature, diluted with ethyl acetate (5 mL) and washed with brine (3×5 mL). The organic layer was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was subjected to silica gel column chromatography using petroleum ether and ethyl acetate (v/v 10:1) as eluent to give pure product.

(E)-3-(1H-Benzo[d][1,2,3]triazol-1-yl)-1,5-diphenylpent-4-en-1-one (2a)

Yellow solid; mp 50–52°C; yield 85%; IR (cm−1): 1683 (C=O); 1H NMR (400 MHz): δ 8.05 (d, J=8.3 Hz, 1H, ArH), 7.97 (d, J=7.5 Hz, 2H, ArH), 7.72 (d, J=8.3 Hz, 1H, ArH), 7.55 (t, J=7.3 Hz, 1H, ArH), 7.48 (dd, J=13.2, 5.0 Hz, 1H, ArH), 7.44 (t, J=7.1 Hz, 2H, ArH), 7.36 (t, J=7.3 Hz, 1H, ArH), 7.30 (t, J=6.1 Hz, 3H, ArH), 7.19–7.26 (m, 2H, ArH), 6.55–6.56 (m, 2H, CH), 6.20–6.21 (m, 1H, CH), 4.45 (dd, J=17.8, 7.8 Hz, 1H, CH), 3.86 (dd, J=17.8, 5.4 Hz, 1H, CH); 13C NMR (100 MHz): δ 195.8, 145.9, 136.1, 135.4, 133.6, 132.9, 128.6, 128.5, 128.3, 128.1, 127.3, 126.6, 126.4, 124.0, 119.8, 109.9, 56.5, 43.1. Anal. Calcd for C23H19N3O: C, 78.16; H, 5.42; N, 11.89. Found: C, 78.08; H, 5.44; N, 11.92.

(E)-3-(1H-Benzo[d][1,2,3]triazol-1-yl)-5-phenyl-1-(4-tolyl)pent-4-en-1-one (2b)

White solid; mp 58–60°C; yield 82%; IR (cm−1): 1685 (C=O); 1H NMR (600 MHz): δ 8.05 (d, J=8.3 Hz, 1H, ArH), 7.88 (d, J=7.6 Hz, 2H, ArH), 7.72 (d, J=8.1 Hz, 1H, ArH), 7.50 (t, J=7.6 Hz, 1H, ArH), 7.37 (t, J=7.5 Hz, 1H, ArH), 7.32 (d, J=7.3 Hz, 2H, ArH), 7.28 (d, J=7.0 Hz, 2H, ArH), 7.21–7.26 (m, 3H, ArH), 6.53–6.59 (m, 2H, CH), 6.21–6.22 (m, 1H, CH), 4.42 (dd, J=17.7, 7.6 Hz, 1H, CH), 3.85 (dd, J=17.6, 4.5 Hz, 1H, CH), 2.40 (s, 3H, CH3); 13C NMR (150 MHz): δ 195.4, 145.9, 144.5, 135.4, 133.7, 132.9, 132.8, 129.3, 128.5, 128.2, 127.3, 126.5, 123.9, 119.8, 109.9, 56.5, 43.00, 21.6. Anal. Calcd for C24H21N3O: C, 78.45; H, 5.76; N, 11.44. Found: C, 78.56; H, 5.75; N, 11.40.

(E)-3-(1H-Benzo[d][1,2,3]triazol-1-yl)-1-(4-methoxyphenyl)-5-phenylpent-4-en-1-one (2c)

White solid; mp 69–71°C; yield 78%; IR (cm−1): 1674 (C=O); 1H NMR (400 MHz): δ 8.05 (d, J=8.4 Hz, 1H, ArH), 7.96 (d, J=8.9 Hz, 2H, ArH), 7.73 (d, J=8.4 Hz, 1H, ArH), 7.51 (dd, J=8.1, 7.2 Hz, 1H, ArH), 7.34–7.40 (m, 1H, ArH), 7.30 (dd, J=12.3, 7.5 Hz, 4H, ArH), 7.23–7.25 (m, 1H, ArH), 6.93 (d, J=8.9 Hz, 2H, ArH), 6.55–6.57 (m, 2H, CH), 6.19–6.24 (m, 1H, CH), 4.40 (dd, J=17.5, 7.8 Hz, 1H, CH), 3.86 (s, 3H, OCH3), 3.81 (dd, J=17.4, 6.5 Hz, 1H, CH); 13C NMR (100 MHz): δ 194.4, 163.9, 145.9, 135.5, 132.9, 130.5, 129.3, 128.6, 128.3, 127.4, 126.7, 126.6, 124.1, 119.9, 113.9, 110.0, 109.9, 56.7, 55.5, 42.9. Anal. Calcd for C24H21N3O2: C, 75.18; H, 5.52; N, 10.96. Found: C, 75.13; H, 5.50; N, 10.99.

(E)-3-(1H-Benzo[d][1,2,3]triazol-1-yl)-1-(4-fluorophenyl)-5-phenylpent-4-en-1-one (2d)

Yellow solid; mp 84–86°C; yield: 80%; IR (KBr, cm−1): 1690 (C=O); 1H NMR (600 MHz): δ 8.06 (d, J=8.5 Hz, 1H, ArH), 8.01 (dd, J=8.7, 5.4 Hz, 2H, ArH), 7.72 (d, J=8.5 Hz, 1H, ArH), 7.49–7.54 (m, 1H, ArH), 7.36–7.40 (m, 1H, ArH), 7.32 (d, J=7.3 Hz, 2H, ArH), 7.29 (t, J=7.5 Hz, 2H, ArH), 7.23–7.25 (m, 1H, ArH), 7.13 (t, J=8.5 Hz, 2H, ArH), 6.55–6.56 (m, 2H, CH), 6.18–6.21 (m, 1H, CH), 4.46 (dd, J=17.6, 8.0 Hz, 1H, CH), 3.81 (dd, J=17.7, 5.4 Hz, 1H, CH). 13C NMR (150 MHz): δ 194.4, 166.9, 165.2, 145.9, 135.4, 133.2, 133.0, 132.7, 130.9, 130.8, 128.6, 128.4, 127.5, 126.7, 126.4, 124.2, 119.9, 116.0, 115.8, 110.0, 109.9, 56.6, 43.1. Anal. Calcd for C23H18FN3O: C, 74.38; H, 4.89; N, 11.31. Found: C, 74.26; H, 4.87; N, 11.29.

(E)-3-(1H-Benzo[d][1,2,3]triazol-1-yl)-1-(4-chlorophenyl)-5-phenylpent-4-en-1-one (2e)

Yellow solid; mp 52–54°C; yield 82%; IR (cm−1): 1690 (C=O); 1H NMR (600 MHz): δ 8.05 (d, J=8.4 Hz, 1H, ArH), 7.92 (d, J=8.2 Hz, 2H, ArH), 7.71 (d, J=8.3 Hz, 1H, ArH), 7.51 (t, J=7.5 Hz, 1H, ArH), 7.43 (d, J=8.0 Hz, 2H, ArH), 7.35–7.39 (m, 1H, ArH), 7.32 (d, J=7.5 Hz, 2H, ArH), 7.28 (t, J=7.5 Hz, 2H, ArH), 7.22–7.26 (m, 1H, ArH), 6.54–6.56 (m, 2H, CH), 6.16–6.20 (m, 1H, CH), 4.46 (dd, J=17.7, 8.0 Hz, 1H, CH), 3.80 (dd, J=17.7, 5.4 Hz, 1H, CH); 13C NMR (150 MHz): δ 194.8, 146.0, 140.2, 135.4, 134.5, 133.2, 133.0, 129.6, 129.1, 128.7, 128.4, 127.5, 126.7, 126.3, 124.1, 119.9, 110.0, 109.9, 56.6, 43.1. Anal. Calcd for C23H18ClN3O: C, 71.22; H, 4.68; N, 10.83. Found: C, 71.15; H, 4.67; N, 10.87.

(E)-3-(1H-Benzo[d][1,2,3]triazol-1-yl)-1-(4-bromophenyl)-5-phenylpent-4-en-1-one (2f)

White solid; mp 67–69°C; yield 81%; IR (cm−1): 1678 (C=O); 1H NMR (400 MHz): δ 8.06 (d, J=7.6 Hz, 1H, ArH), 7.80–7.88 (m, 2H, ArH), 7.71 (d, J=7.6 Hz, 1H, ArH), 7.57–7.64 (m, 2H, ArH), 7.48–7.54 (m, 1H, ArH), 7.35–7.41 (m, 1H, ArH), 7.24–7.34 (m, 5H, ArH), 6.54–6.56 (m, 2H, CH), 6.16–6.20 (m, 1H, CH), 4.46 (dd, J=17.8, 8.0 Hz, 1H, CH), 3.80 (dd, J=17.7, 5.4 Hz, 1H, CH). 13C NMR (100 MHz): δ 195.0, 146.0, 135.4, 134.9, 133.2, 133.0, 132.1, 129.7, 129.0, 128.7, 128.4, 127.5, 126.7, 126.3, 124.2, 119.9, 109.9, 56.6, 43.1. Anal. Calcd for C23H18BrN3O: C, 63.90; H, 4.20; N, 9.72. Found: C, 63.97; H, 4.21; N, 9.69.

(E)-3-(1H-Benzo[d][1,2,3]triazol-1-yl)-1-(3-bromophenyl)-5-phenylpent-4-en-1-one (2g)

Yellow solid; mp 70–72°C; yield 83%; IR (cm−1): 1676 (C=O); 1H NMR (600 MHz): δ 8.10 (s, 1H, ArH), 8.05 (d, J=8.4 Hz, 1H, ArH), 7.91 (d, J=7.3 Hz, 1H, ArH), 7.68–7.73 (m, 2H, ArH), 7.51 (t, J=7.6 Hz, 1H, ArH), 7.23–7.39 (m, 7H, ArH), 6.51–6.59 (m, 2H, CH), 6.16–6.20 (m, 1H, CH), 4.47 (dd, J=17.8, 8.0 Hz, 1H, CH), 3.81 (dd, J=17.8, 5.4 Hz, 1H, CH); 13C NMR (150 MHz): δ 194.7, 146.0, 137.9, 136.5, 135.3, 133.3, 133.0, 131.3, 130.3, 128.7, 128.4, 127.5, 126.7, 126.6, 126.2, 124.1, 123.1, 120.0, 109.9, 56.5, 43.2. Anal. Calcd for C23H18BrN3O: C, 63.90; H, 4.20; N, 9.72. Found: C, 63.84; H, 4.19; N, 9.75.

(E)-3-(1H-Benzo[d][1,2,3]triazol-1-yl)-5-phenyl-1-(thiophen-2-yl)pent-4-en-1-one (2h)

White solid; mp 45–47°C; yield 84%; IR (cm−1): 1667 (C=O); 1H NMR (400 MHz): δ 8.05 (d, J=8.4 Hz, 1H, ArH and ThH), 7.82 (d, J=3.8 Hz, 1H, ArH and ThH), 7.70 (d, J=8.4 Hz, 1H, ArH and ThH), 7.65 (d, J=4.9 Hz, 1H, ArH and ThH), 7.50 (t, J=7.6 Hz, 1H, ArH and ThH), 7.24–7.39 (m, 6H, ArH and ThH), 7.14 (t, J=4.3 Hz, 1H, ArH and ThH), 6.52–6.60 (m, 2H, CH), 6.17–6.18 (m, 1H, CH), 4.37 (dd, J=17.1, 7.9 Hz, 1H, CH), 3.82 (dd, J=17.1, 5.7 Hz, 1H, CH). 13C NMR (100 MHz): δ 188.7, 145.9, 143.3, 135.4, 134.5, 133.2, 133.0, 132.7, 128.6, 128.4, 128.3, 127.5, 126.7, 126.2, 124.1, 119.9, 109.9, 56.6, 43.8. Anal. Calcd for C21H17N3OS: C, 70.17; H, 4.77; N, 11.69. Found: C, 70.29; H, 4.76; N, 11.69.

(E)-3-(1H-Benzo[d][1,2,3]triazol-1-yl)-4-methyl-1,5-diphenylpent-4-en-1-one (2i)

White solid; mp 60–62°C; yield 87%; IR (cm−1): 1688 (C=O); 1H NMR (600 MHz): δ 8.04 (d, J=8.4 Hz, 1H, ArH), 7.93 (d, J=8.0 Hz, 2H, ArH), 7.71 (d, J=8.4 Hz, 1H, ArH), 7.49 (t, J=7.6 Hz, 1H, ArH), 7.34–7.38 (m, 1H, ArH), 7.31 (t, J=7.6 Hz, 2H, ArH), 7.22–7.28 (m, 5H, ArH), 6.75 (s, 1H, CH), 6.14–6.16 (m, 1H, CH), 4.71 (dd, J=17.5, 8.8 Hz, 1H, CH), 3.75 (dd, J=17.4, 4.6 Hz, 1H, CH), 1.81 (s, 3H, CH3); 13C NMR (150 MHz): δ 195.7, 144.5, 136.4, 134.8, 134.0, 133.2, 130.2, 129.4, 129.3, 128.9, 128.4, 128.2, 127.3, 127.1, 124.1, 119.9, 110.2, 62.4, 40.6, 14.1. Anal. Calcd for C24H21N3O: C, 78.45; H, 5.76; N, 11.44. Found: C, 78.37; H, 5.74; N, 11.41.

(E)-3-(1H-Benzo[d][1,2,3]triazol-1-yl)-4-methyl-5-phenyl-1-(4-tolyl)pent-4-en-1-one (2j)

Yellow solid; mp 70–72°C; yield 85%; IR (cm−1): 1690 (C=O); 1H NMR (600 MHz): δ 8.04 (d, J=8.4 Hz, 1H, ArH), 7.93 (d, J=8.0 Hz, 2H, ArH), 7.71 (d, J=8.4 Hz, 1H, ArH), 7.49 (t, J=7.6 Hz, 1H, ArH), 7.34 – 7.38 (m, 1H, ArH), 7.31 (t, J=7.6 Hz, 2H, ArH), 7.27 (d, J=7.9 Hz, 2H, ArH), 7.22 (d, J=8.0 Hz, 3H, ArH), 6.75 (s, 1H, CH), 6.13–6.14 (m, 1H, CH), 4.71 (dd, J=17.5, 8.8 Hz, 1H, CH), 3.75 (dd, J=17.4, 4.6 Hz, 1H, CH), 2.41 (s, 3H, CH3), 1.81 (s, 3H, CH3); 13C NMR (150 MHz): δ 195.7, 144.5, 136.4, 134.8, 130.2, 129.4, 129.3, 129.1, 128.9, 128.4, 128.2, 127.3, 127.1, 124.1, 119.9, 110.2, 62.4, 40.6, 21.7, 14.1. Anal. Calcd for C25H23N3O: C, 78.71; H, 6.08; N, 11.02. Found: C, 78.86; H, 6.10; N, 10.99.

(E)-3-(1H-Benzo[d][1,2,3]triazol-1-yl)-1-(4-chlorophenyl)-4-methyl-5-phenylpent-4-en-1-one (2k)

White solid; mp 84–86°C; yield 83%; IR (cm−1): 1691 (C=O); 1H NMR (600 MHz): δ 8.04 (d, J=8.4 Hz, 1H, ArH), 7.97 (d, J=8.4 Hz, 2H, ArH), 7.69 (d, J=8.4 Hz, 1H, ArH), 7.49 (t, J=7.6 Hz, 1H, ArH), 7.45 (d, J=8.4 Hz, 2H, ArH), 7.35–7.40 (m, 1H, ArH), 7.32 (t, J=7.6 Hz, 2H, ArH), 7.23 (t, J=7.9 Hz, 3H, ArH), 6.75 (s, 1H, CH), 6.10–6.12 (m, 1H, CH), 4.75 (dd, J=17.5, 9.1 Hz, 1H, CH), 3.68 (dd, J=17.5, 4.4 Hz, 1H, CH), 1.80 (s, 3H, CH3); 13C NMR (150 MHz): δ 195.0, 146.3, 140.1, 136.2, 134.8, 134.6, 129.7, 129.6, 129.4, 129.0, 128.9, 128.3, 127.4, 127.2, 124.1, 119.9, 110.1, 62.3, 40.7, 14.0. Anal. Calcd for C24H20ClN3O: C, 71.73; H, 5.02; N, 10.46. Found: C, 71.80; H, 5.00; N, 10.49.

(E)-3-(1H-Benzo[d][1,2,3]triazol-1-yl)-1-(4-bromophenyl)-4-methyl-5-phenylpent-4-en-1-one (2l)

White solid; mp 90–92°C; yield 80%; IR (cm−1): 1689 (C=O). 1H NMR (600 MHz): δ 8.04 (d, J=8.3 Hz, 1H, ArH), 7.89 (d, J=8.5 Hz, 2H, ArH), 7.86 (d, J=8.4 Hz, 1H, ArH), 7.69 (d, J=8.3 Hz, 1H, ArH), 7.63 (d, J=8.5 Hz, 2H, ArH), 7.49 (t, J=7.6 Hz, 1H, ArH), 7.39 (t, J=7.6 Hz, 2H, ArH), 7.32 (d, J=7.5 Hz, 1H, ArH), 7.23 (d, J=8.1 Hz, 2H, CH), 6.74 (s, 1H, CH), 6.09–6.11 (m, 1H, CH), 4.74 (dd, J=17.5, 9.1 Hz, 1H, CH), 3.67 (dd, J=17.5, 4.4 Hz, 1H, CH), 1.80 (s, 3H, CH3). 13C NMR (150 MHz): δ 195.2, 150.8, 141.0, 132.0, 131.8, 129.9, 129.7, 129.6, 129.4, 128.9, 128.4, 128.3, 127.4, 127.2, 124.1, 120.0, 110.1, 62.3, 40.7, 14.0. Anal. Calcd for C24H20BrN3O: C, 64.58; H, 4.52; N, 9.41. Found: C, 64.65; H, 4.51; N, 9.38.

(E)-3-(1H-Benzo[d][1,2,3]triazol-1-yl)-4-methyl-5-phenyl-1-(thiophen-2-yl)pent-4-en-1-one (2m)

White solid; mp 78–80°C; yield 80%; IR (cm−1): 1665 (C=O); 1H NMR (600 MHz): δ 8.02–8.06 (m, 1H, ArH and ThH), 7.88–7.91 (m, 1H, ArH and ThH), 7.68 (d, J=9.0 Hz, 1H, ArH and ThH), 7.66 (d, J=4.9 Hz, 1H, ArH and ThH), 7.49 (dd, J=8.0, 7.3 Hz, 1H, ArH and ThH), 7.37 (dd, J=8.0, 7.3 Hz, 1H, ArH and ThH), 7.31 (t, J=7.6 Hz, 2H, ArH and ThH), 7.23 (t, J=8.5 Hz, 3H, ArH and ThH), 7.16 (t, J=4.1 Hz, 1H, ArH and ThH), 6.75 (s, 1H, CH), 6.09–6.11 (m, 1H, CH), 4.62 (dd, J=17.0, 9.0 Hz, 1H, CH), 3.75 (dd, J=17.0, 4.9 Hz, 1H, CH), 1.80 (s, 3H, CH3). 13C NMR (150 MHz): δ 188.8, 146.2, 143.5, 136.3, 134.5, 134.4, 133.1, 132.7, 129.5, 128.9, 128.3, 128.2, 127.4, 127.2, 124.1, 119.9, 110.1, 62.3, 41.4, 14.0. Anal. Calcd for C22H19N3OS: C, 70.75; H, 5.13; N, 11.25. Found: C, 70.61; H, 5.15; N, 11.29.

Online supplementary data

1H and 13C NMR spectra of the products.

Acknowledgment

The authors thank the National Natural Science Foundation of China (21462038, 21362034) and Key Laboratory of Eco-Environment-Related Polymer Materials for Ministry of Education for the financial support of this work.

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Supplemental Material:

The online version of this article (DOI: https://doi.org/10.1515/hc-2016-0182) offers supplementary material.

Received: 2016-11-28
Accepted: 2017-3-31
Published Online: 2017-7-8
Published in Print: 2017-8-28

©2017 Walter de Gruyter GmbH, Berlin/Boston

This article is distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Artikel in diesem Heft

  1. Frontmatter
  2. Review
  3. Chemical and pharmacological research on the plants from genus Ajuga
  4. Research Articles
  5. One-pot synthesis of annulated 1,8-naphthyridines
  6. Visible-light mediated regioselective (phenylsulfonyl)difluoromethylation of fused imidazoles with iododifluoromethyl phenyl sulfone
  7. Synthesis of thienopyrimidine-pyrazolo[3,4-b]pyridine hybrids
  8. Regioselective 1,4-conjugate aza-Michael addition of dienones with benzotriazole
  9. A simple one-pot synthesis of 2,4-diaryl- 9H-pyrido[2,3-b]indoles under solvent-free conditions
  10. Cyclodimerization of 3-phenacylideneoxindolines with amino esters for the synthesis of dispiro[indoline-3,1′-cyclopentane-3′,3″-indolines]
  11. An efficient approach to the synthesis of coumarin-fused dihydropyridinones
  12. Halogenoheterocyclization of terminally substituted 2-allylthio(seleno)quinolin- 3-carbaldehydes
  13. A new synthetic route to benzophenone derivatives
  14. Design, synthesis, docking and in vitro antifungal study of 1,2,4-triazole hybrids of 2-(aryloxy)quinolines
  15. Synthesis, antimicrobial activity and anti-biofilm activity of novel tetrazole derivatives
https://doi.org/10.1515/hc-2016-0182
Schlagwörter für diesen Artikel
aza-Michael addition; benzotriazole; dienone; regioselectivity; synthesis
Creative Commons
BY-NC-ND 3.0

Artikel in diesem Heft

  1. Frontmatter
  2. Review
  3. Chemical and pharmacological research on the plants from genus Ajuga
  4. Research Articles
  5. One-pot synthesis of annulated 1,8-naphthyridines
  6. Visible-light mediated regioselective (phenylsulfonyl)difluoromethylation of fused imidazoles with iododifluoromethyl phenyl sulfone
  7. Synthesis of thienopyrimidine-pyrazolo[3,4-b]pyridine hybrids
  8. Regioselective 1,4-conjugate aza-Michael addition of dienones with benzotriazole
  9. A simple one-pot synthesis of 2,4-diaryl- 9H-pyrido[2,3-b]indoles under solvent-free conditions
  10. Cyclodimerization of 3-phenacylideneoxindolines with amino esters for the synthesis of dispiro[indoline-3,1′-cyclopentane-3′,3″-indolines]
  11. An efficient approach to the synthesis of coumarin-fused dihydropyridinones
  12. Halogenoheterocyclization of terminally substituted 2-allylthio(seleno)quinolin- 3-carbaldehydes
  13. A new synthetic route to benzophenone derivatives
  14. Design, synthesis, docking and in vitro antifungal study of 1,2,4-triazole hybrids of 2-(aryloxy)quinolines
  15. Synthesis, antimicrobial activity and anti-biofilm activity of novel tetrazole derivatives
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