Cyclization of Amino Acid

The example of rare-earth metal-catalyzed guanylation/cyclization of amino acid esters and carbodiimides is well-established, forming ...
5 downloads 0 Views 744KB Size
Download PDF
Article pubs.acs.org/joc

Cite This: J. Org. Chem. 2018, 83, 1154−1159

RE[N(SiMe3)2]3‑Catalyzed Guanylation/Cyclization of Amino Acid Esters and Carbodiimides Chengrong Lu, Chao Gong, Bei Zhao,* Lijuan Hu, and Yingming Yao Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, People’s Republic of China S Supporting Information *

ABSTRACT: The example of rare-earth metal-catalyzed guanylation/cyclization of amino acid esters and carbodiimides is well-established, forming 4(3H)-2-alkylaminoquinazolinones in 65−96% yields. The rare-earth metal amides RE[N(TMS)2]3 (RE = Y, Yb, Nd, Sm, La; TMS = SiMe3) showed high activities, and La[N(TMS)2]3 performed best for a wide scope of the substrates.

■

INTRODUCTION N-Heterocyclic compounds quinazolinones are well noted for their wide existence among natural products and more importantly for their potent biological and medicinal properties.1 Efficient synthetic methods for quinazolinones and their derivatives have attracted much attention for several years. Treatment of 2-halobenzoic acid with guanidines2 yields quinazolinones in the presence of copper iodide. The transformation has found limited application due to the relatively narrow substrate scope and the large requirement for additives. Palladium- and molybdenum-mediated domino cyclocarbonylation/cyclizations are convenient methods for the synthesis of 2-aminoquinazolinones, which avoid using gaseous CO.3 However, low reactant diversity is a disadvantage in some cases. Aminolysis of isatoic anhydride followed by reaction with cyanamide,4 isocyanide,5 or isothiocyanate6 produces miscellaneous quinazolinones, processes that are I2/cumyl hydroperoxide-mediated or catalyzed by Cu, Pd, or Co complexes. Only one example was found to yield the target quinazolinones from isatoic anhydride without any catalyst.7 Utilizing the azaWittig reaction of iminophosphorane with heterocumulene on solid phase, for the synthesis of 2-amino-substituted 3Hquinazoline-4-one, usually begins with isatoic anhydride as well.8 Because of the commercially available or readily generated isatoic anhydride, which gives rise to differently substituted quinazolinone skeletons, strategies based on isatoic anhydride are popular. However, toxic reagents are usually required, and generally long and tedious procedures lead to unsatisfactory overall yields in many cases. Recently, novel pathways have been explored to construct quinazolinones starting with amino acid ester and cyanamide, isothiocyanate, or thiourea.9 Xi and Zhang developed a Zn-catalyzed tandem guanylation/amidation of amino acid esters, in which carbodiimides were used instead.10 As we know, transition metal compounds, especially rareearth metal complexes with diverse ligands, have excellent activities in the guanylation reaction.11 So it is rational to employ the rare-earth metal complex in the guanylation/ © 2018 American Chemical Society

cyclization of amino acid esters and carbodiimides. A series of 4(3H)-2-alkylaminoquinazolinones in good to excellent yields were obtained using rare-earth metal amides RE[N(TMS)2]3 as the catalysts.

■

RESULTS AND DISCUSSION In many cases, the reactivity of rare-earth metal complexes is greatly influenced by ligand structure. The initial test was thus started from the screening of rare-earth metal catalysts, while the neat reaction of ethyl 2-aminobenzoate 1a with N,N′diisopropylcarbodiimide 2a (iPrNCNiPr, simplified as DIC) was examined as the model reaction. The results are summarized in Table 1. To our delight, all the rare-earth metal compounds we used, including trivalent ytterbium compounds Table 1. Screening of Catalystsa

entry

cat.

T (°C)

yield (%)b

1 2 3 4 5 6 7 8 9 10

YbCl3 (2,6-tBu2C6H3O)3Yb Yb[N(TMS)2]3 Yb[N(TMS)2]3(μ-Cl)Li(THF)3 Yb[N(TMS)2]3 Yb[N(TMS)2]3 La[N(TMS)2]3 Nd[N(TMS)2]3 Sm[N(TMS)2]3 Y[N(TMS)2]3

80 80 80 80 40 60 60 60 60 60

58 57 66 55 52 67 61 68 59 65

a

Conditions: 1 mmol of 2-aminobenzoate, 1 mmol of DIC. bIsolated yields.

Received: October 8, 2017 Published: January 16, 2018 1154

DOI: 10.1021/acs.joc.7b02550 J. Org. Chem. 2018, 83, 1154−1159

Article

The Journal of Organic Chemistry Table 2. Screening of the Optimal Conditionsa

YbCl3, Yb(OAr)3 (Ar = 2,6-tBu2C6H3), Yb[N(TMS)2]3, and Yb[N(TMS)2]3(μ-Cl)Li(THF)3, successfully catalyze the guanylation/cyclization of the model reaction in good yields (55− 70%) (Table 1, entries 1−4). In consideration of the preparation procedure and the activities of the compounds, the simple trivalent ytterbium amide Yb[N(TMS)2]3 was chosen as the ideal catalyst. Subsequent screening of reaction temperature based on the ytterbium amide suggested that 60 °C was optimal (Table 1, entries 3, 5, and 6). Rare-earth metal amides with different metal centers were tested, which gave rise to yields of ∼60% (Table 1, entries 3 and 7−10). Because the yields stayed around 60% and a certain amount of reactant 1a was always observed by TLC detection after the reaction was quenched, while DIC was fully consumed, apparently some other reaction occurred with DIC. It was conjectured that ethanol released during the cyclization may consume the reactant DIC. To verify this hypothesis, the reaction of ethanol with DIC in 1:1 molar ratio was conducted in the presence of lanthanum amide La[N(TMS)2]3, and the byproduct isourea 4 was isolated in 75% yield (Scheme 1).

catalyst loading (mol %)

entry

cat.

1 2 3 4 5 6 7 8 9 10 11

La[N(TMS)2]3 Nd[N(TMS)2]3 Sm[N(TMS)2]3 Gd[N(TMS)2]3 Y[N(TMS)2]3 Yb[N(TMS)2]3 La[N(TMS)2]3 La[N(TMS)2]3 La[N(TMS)2]3 La[N(TMS)2]3 La[N(TMS)2]3

5 5 5 5 5 5 5 5 5 5 5

12 13 14 15 16 17

La[N(TMS)2]3 La[N(TMS)2]3 La[N(TMS)2]3 La[N(TMS)2]3 La[N(TMS)2]3 La[N(TMS)2]3

5 5 5 5 2.5 1

Scheme 1. Addition Reaction of Ethanol to DIC

solvent − − − − − − − − − toluene 1,4dioxane DMSO − − − − −

T (°C)

time (h)

yield (%)b

60 60 60 60 60 60 40 80 100 100 100

24 24 24 24 24 24 24 24 24 24 24

84 81 74 65 42 40 78 86 96 40 36

100 100 100 100 100 100

24 6 12 18 24 24

43 76 80 85 55 20

a

Conditions: 1 mmol of 2-aminobenzoates, 2 mmol of DIC. bIsolated yields.

Meanwhile, in CDCl3, the in situ 1H NMR spectrum of the model reaction (Figure 1(a)) catalyzed by La[N(TMS)2]3 was

was reported by Tamm and Eisen recently, using actinide complexes as catalysts.12 Subsequently, a routine screening of the reaction conditions, including the central metals of rare-earth metal amides, catalyst loading, temperature, solvent, and reaction time, was assessed with a 1:2 molar ratio of 1a to 2a. The results showed us that with the increase in metal ion radius (Yb ∼ Y< Gd < Sm < Nd < La), the yields of 4(3H)-2-isopropylaminoquinazolinone 3aa increased from 40% to 84% (Table 2, entries 1−6). Raising the temperature is beneficial to the reaction (Table 2, entries 1 and 7−9), whereas the solvent has a negative effect on the reaction (Table 2, entries 9−12). Reaction time and the amount of catalyst cannot be reduced on the premise of ensuring the yield (Table 2, entries 9 and 13−17). As a result, the reaction should perform better in the presence of 5 mol % La[N(TMS)2]3 at 100 °C for 24 h without solvent. The evaluation of the substrate scope under optimal conditions was summarized in Scheme 2. The electronic effect of the substituents of the esters has great effect on the outcomes. When using 5-substituted ethyl 2-aminobenzoates bearing electron-withdrawing groups (F, Cl, Br, I, pyridinyl), the stronger the electron-withdrawing abilities of the groups, the lower the yields (Scheme 2, 3ba−fa). Electron-donating groups (OMe, Me, and naphthyl) also lead to a slight drop in yields (Scheme 2, 3ga−ja). Excellent yields of the products were obtained by using different carbodiimides, including symmetrical or unsymmetrical carbodiimides (Scheme 2, 3ab− ag′). It is worth mentioning that when using unsymmetrical carbodiimides with aromatic and aliphatic substituents on different sides, i.e., the aliphatic substituent in the form of NCH2R, a pair of cyclization isomers were obtained (Scheme 2, 3ad and 3ad′, 3ag and 3ag′). Compared with the reported spectra of the same compounds in previous work,8c the major

Figure 1. (a) In situ 1H NMR spectrum of the model reaction with the molar ratio of 2a to 1a at 2:1; (b) the 1H NMR spectrum of major product 3aa; (c) the 1H NMR spectrum of byproduct 4.

carried out for 24 h, which showed that the main reaction occurred (Figure 1(b)), as well as the reaction of ethanol with DIC (Figure 1(c)), when the molar ratio of DIC 2a to ethyl 2aminobenzoate 1a was 2:1. Thus, molecular sieves and anhydrous calcium dichloride were deliberately added to remove ethanol in the catalytic system, respectively. However, this strategy had no significant effects on the outcomes of the experiments, for the yields of 3-isopropyl-2-(isopropylamino)quinazolin-4(3H)-one 3aa were still unsatisfactory, varying from 56% to 66% (Supporting Information (SI), Table S1). Nevertheless, when the molar ratio of 2a to 1a increased to 2:1, the yields of the product dramatically increased up to 96% (Table 2, entry 9). Thus, our hypothesis about the side reaction of ethanol addition to the carbodiimide was confirmed, and it 1155

DOI: 10.1021/acs.joc.7b02550 J. Org. Chem. 2018, 83, 1154−1159

Article

The Journal of Organic Chemistry

shown in Scheme 3. The aminolysis of rare-earth metal amide RE[N(TMS)2]3 with ethyl 2-aminobenzoate would generate

Scheme 2. Substrate Scope

Scheme 3. Possible Catalytic Mechanism

intermediate A. Coordination of carbodiimide DIC to A/ intramolecular insertion might provide intermediate C. Intramolecular nucleophilic amidation in C should occur to release 3aa and yield intermediate D at the same time. Finally, intermediate D could undergo proton exchange with another molecule of ethyl 2-aminobenzoate to regenerate the active species A, while a molecule of ethanol is released. The byproduct ethanol can be captured by DIC to yield isourea 4 under the same conditions. In the case of unsymmetrical carbodiimides, when forming intermediate B, it tends to form the structure B-1 rather than the structure B-2, because the electron cloud density of the N atom bearing the aromatic ring is somewhat greater than that of the other side, which leads to more powerful nucleophilic attack on the carbonyl carbon in the ester group (Scheme 4).

products were 3ad and 3ag, respectively. Furthermore, imino acid esters also gave out the corresponding product 3kb in 91% yield. An ester group effect of 2-aminobenzoates has also been studied. The esters bearing bulky leaving groups, such as tBu and nBu, turned out to be outstanding substrates, and the products 3aa were obtained in 94% and 93% (Table 3, entries 5 and 6). In consideration of the practicability, environmental friendliness, and potential production cost, ethyl 2-aminobenzoates are still recommended. On the basis of the mechanism raised by Zhang10 and evidence from the 1H NMR experiment mentioned above, we propose a possible mechanism for the current transformation,

Scheme 4. Possible Intermediate

Table 3. Influence of Different Alkoxy Groups of Estersa

■ entry

R

yield (%)b

1 2 3 4 5 6

Me Et Bn i Pr n Bu t Bu

68 85 73 83 93 94

CONCLUSION In summary, a rare-earth metal amide-catalyzed guanylation/ cyclization of amino acid esters and carbodiimides is an ideal method for the synthesis of 3-alkyl-4(3H)-2-alkylaminoquinazolinones, which is the first utility of rare-earth metal complexes in this field. The readily available catalyst RE[N(TMS)2]3 exhibits broad substituent tolerance, is effective under mild conditions, and provides 3-alkyl-4(3H)-2-alkylaminoquinazolinones in good to excellent yields. A plausible mechanism of the guanylation/cyclization transformation is described in detail. Furthermore, a competitive reaction, the addition of alcohols to carbodiimides, was observed in the process, which was also

a

Conditions: 1 mmol of 2-aminobenzoate, 2 mmol of DIC. bIsolated yields. 1156

DOI: 10.1021/acs.joc.7b02550 J. Org. Chem. 2018, 83, 1154−1159

Article

The Journal of Organic Chemistry

appropriate time. The crude mixture was concentrated under reduced pressure and then purified by column chromatography using hexane as the eluant to give the carbodiimide. Characteristic Data of Carbodiimides. Diphenylmethanediimine (2b). 1H NMR (400 MHz, CDCl3): δ 7.42- 7.30 (m, 4H, ArH), 7.27−7.17 (m, 6H, ArH) ppm. Di-p-tolylmethanediimine (2c). 1H NMR (400 MHz, CDCl3): δ 7.12 (dd, J = 20.7, 8.2 Hz, 8H, ArH), 2.35 (s, 6H, CH3) ppm. N-Benzyl-N-phenylmethanediimine (2d). 1H NMR (400 MHz, CDCl3): δ 7.37 (d, J = 4.4 Hz, 4H, ArH), 7.30 (dt, J = 8.8, 4.3 Hz, 1H, ArH), 7.24 (t, J = 7.8 Hz, 2H, ArH), 7.09 (t, J = 7.4 Hz, 1H, ArH), 6.99 (d, J = 7.5 Hz, 2H, ArH), 4.56 (s, 2H, CH2) ppm. N-Cyclohexyl-N-phenylmethanediimine (2e). 1H NMR (400 MHz, CDCl3): δ 7.33−7.18 (m, 2H, ArH), 7.16−7.03 (m, 3H, ArH), 3.56−3.34 (m, 1H, CH), 2.07−1.90 (m, 2H, CH2), 1.82−1.70 (m, 2H, CH2), 1.61−1.41 (m, 3H, CH2), 1.40−1.21 (m, 3H, CH2) ppm. N-tert-Butyl-N-phenylmethanediimine (2f). 1H NMR (400 MHz, CDCl3): δ 7.31−7.22 (m, 2H, ArH), 7.15−7.04 (m, 3H, ArH), 1.39 (s, 9H, CH3) ppm. N-Butyl-N-phenylmethanediimine (2g). 1H NMR (400 MHz, CDCl3): δ 7.39−7.18 (m, 2H, ArH), 7.12−7.00 (m, 3H, ArH), 3.40 (t, J = 6.8 Hz, 2H, CH2), 1.78−1.54 (m, 2H, CH2), 1.51−1.33 (m, 2H, CH2), 0.94 (t, J = 7.4 Hz, 3H, CH3) ppm. Typical Procedure for the Guanylation/Cyclization of Amino Acid Esters and Carbodiimides. A 5 mL Schlenk tube under dried argon was charged with Yb[N(TMS)2]3 (0.05 mmol), ethyl 2aminobenzoate (1.00 mmol), and a stirring bar. After the catalyst was dissolved, DIC (2.00 mmol) was added into the tube. The mixture was stirred at 100 °C for 24 h and diluted with ethyl acetate, and then the crude mixture was purified by column chromatography with ethyl acetate/petroleum ether (1:20) to give the desired product as a colorless solid. Characteristic Data of Quinazolin-4(3H)-ones. 3-Isopropyl-2(isopropylamino)quinazolin-4(3H)-one (3aa). Colorless solid, yield: 96%; 1H NMR (400 MHz, CDCl3): δ 8.08 (dd, J = 8.0, 1.3 Hz, 1H, ArH), 7.59−7.48 (m, 1H, ArH), 7.31 (d, J = 8.1 Hz, 1H, ArH), 7.16− 7.01 (m, 1H, ArH), 5.48 (s, 1H, NH), 4.40 (dd, J = 11.2, 5.1 Hz, 2H, CH), 1.55 (d, J = 7.2 Hz, 6H, CH3), 1.31 (d, J = 6.2 Hz, 6H, CH3) ppm. 13C NMR (100 MHz, CDCl3): δ 163.4, 149.2, 149.1, 134.2, 127.3, 124.7, 122.4, 117.7, 43.8, 23.1, 20.5 ppm. HRMS (ESI-TOF) m/z: [M + Na]+ calcd for C14H19N3ONa 268.1420; found 268.1435. Mp: 79.8−80.1 °C. 6-Fluoro-3-isopropyl-2-(isopropylamino)quinazolin-4(3H)-one (3ba). Colorless solid, yield: 66%; 1H NMR (400 MHz, CDCl3): δ 7.61 (dd, J = 8.8, 2.8 Hz, 1H, ArH), 7.29−7.06 (m, 2H, ArH), 5.30 (s, 1H, NH), 4.36 (d, J = 6.8 Hz, 1H, CH), 4.26 (dq, J = 13.1, 6.5 Hz, 1H, CH), 1.46 (d, J = 7.2 Hz, 6H, CH3), 1.21 (d, J = 6.4 Hz, 6H, CH3) ppm. 13C NMR (100 MHz, CDCl3): δ 162.7, 162.6, 159.4, 157.0, 148.6, 145.8, 126.7, 126.6, 122.7, 122.4, 118.2, 118.1, 111.6, 111.3, 43.8, 22.9, 20.2 ppm. 19F NMR (376.5 MHz, CDCl3): δ −120.07 ppm. HRMS (ESI-TOF) m/z: [M + H]+calcd for C14H19FN3O 264.1507; found 264.1499. Mp: 80.9−81.6 °C. 6-Chloro-3-isopropyl-2-(isopropylamino)quinazolin-4(3H)-one (3ca). Colorless solid, yield: 76%; 1H NMR (400 MHz, CDCl3): δ 8.03 (d, J = 2.4 Hz, 1H, ArH), 7.46 (dd, J = 8.7, 2.5 Hz, 1H, ArH), 7.30−7.20 (m, 1H, ArH), 5.43 (s, 1H, NH), 4.51−4.29 (m, 2H, CH), 1.55 (d, J = 7.2 Hz, 6H, CH3), 1.31 (d, J = 6.2 Hz, 6H, CH3) ppm. 13C NMR (100 MHz, CDCl3): δ 162.4, 149.2, 147.8, 134.5, 127.5, 126.5, 126.4, 118.6, 43.9, 23.1, 20.4 ppm. HRMS (ESI-TOF) m/z: [M + Na]+ calcd for C14H18ClN3ONa 302.1031; found 302.1028. Mp: 119.4−120.8 °C. 6-Bromo-3-isopropyl-2-(isopropylamino)quinazolin-4(3H)-one (3da). Colorless solid, yield: 82%; 1H NMR (400 MHz, CDCl3): δ 8.18 (d, J = 2.1 Hz, 1H, ArH), 7.58 (dd, J = 8.7, 2.3 Hz, 1H, ArH), 7.18 (d, J = 8.7 Hz, 1H, ArH), 5.43 (s, 1H, NH), 4.51−4.26 (m, 2H, CH), 1.54 (d, J = 7.2 Hz, 6H, CH3), 1.30 (d, J = 6.3 Hz, 6H, CH3) ppm. 13C NMR (100 MHz, CDCl3): δ 162.2, 149.3, 148.1, 137.2, 129.6, 126.7, 119.1, 114.8, 43.9, 23.0, 20.4 ppm. HRMS (ESI-TOF)

catalyzed by RE[N(TMS)2]3. Extensive studies are now in progress in our laboratory.

■

EXPERIMENTAL SECTION

General Procedures. All manipulations and reactions were conducted under a purified argon atmosphere using standard Schlenk or glovebox techniques. Solvents were degassed and distilled from sodium benzophenone ketyl under argon prior to use. All commercially available chemicals, including liquid amino acid esters and carbodiimides, were dried with CaH2 and distilled in a vacuum or at atmospheric pressure prior to use. Amino acid esters, other than 1a, 1f, 1j, and 1k (bought from J&K Chemical), were prepared. Unsymmetrical carbodiimides 2b−g were synthesized following the previo us w ork. 1 3 Rare-earth metal c atalysts YbCl 3 , 1 4 (2,6-tBu2C6H3ArO)3Yb,15 Yb[N(TMS)2]3,16 and Yb[N(TMS)2]3(μCl)Li(THF)317 were prepared according to literature methods, respectively. NMR spectra were recorded using a Bruker-400 MHz spectrometer at room temperature. High resolution mass spectra (HRMS) were obtained using Bruker ESI-TOF. Typical Procedure for the Preparation of Amino Acid Esters. Thionyl chloride (23.52 mmol) was added dropwise to a solution of 2amino-5-chlorobenzoic acid (19.6 mmol) in 50 mL of ethanol in an ice bath. The mixture was heated to reflux for 18 h and then neutralized by adding saturated aqueous NaHCO3. The mixture was extracted with ethyl acetate three times, and the organic layer was collected, dried over anhydrous Na2SO4, and filtered. After solvent evaporation under reduced pressure, the crude mixture was purified by flash column chromatography to give the product 1c as a pale-yellow solid (1.6 g, 70%). Characteristic Data of Amino Acid Esters. Ethyl 2-Amino-5fluorobenzoate (1b). 1H NMR (400 MHz, CDCl3): δ 7.54 (dd, J = 9.7, 3.1 Hz, 1H, ArH), 7.01 (ddd, J = 9.0, 7.7, 3.1 Hz, 1H, ArH), 6.60 (dd, J = 9.0, 4.5 Hz, 1H, ArH), 5.58 (s, 2H, NH2), 4.32 (q, J = 7.1 Hz, 2H, CH2), 1.37 (t, J = 7.1 Hz, 3H, CH3) ppm. Ethyl 2-Amino-5-chlorobenzoate (1c). 1H NMR (400 MHz, CDCl3): δ 7.83 (d, J = 2.5 Hz, 1H, ArH), 7.20 (dd, J = 8.8, 2.5 Hz, 1H, ArH), 6.60 (d, J = 8.8 Hz, 1H, ArH), 5.73 (s, 2H, NH2), 4.33 (q, J = 7.1 Hz, 2H, CH2), 1.39 (t, J = 7.1 Hz, 3H, CH3) ppm. Ethyl 2-Amino-5-bromobenzoate (1d). 1H NMR (400 MHz, CDCl3): δ 7.97 (d, J = 2.4 Hz, 1H, ArH), 7.32 (dd, J = 8.8, 2.4 Hz, 1H, ArH), 6.57 (t, J = 7.5 Hz, 1H, ArH), 5.76 (s, 2H, NH2), 4.33 (q, J = 7.1 Hz, 2H, CH2), 1.39 (t, J = 7.1 Hz, 3H, CH3) ppm. Ethyl 2-Amino-5-iodobenzoate (1e). 1H NMR (400 MHz, CDCl3): δ 8.05 (d, J = 2.2 Hz, 1H, ArH), 7.38 (dd, J = 8.7, 2.2 Hz, 1H, ArH), 6.36 (d, J = 8.7 Hz, 1H, ArH), 5.69 (s, 2H, NH2), 4.24 (qd, J = 7.1, 3.4 Hz, 2H, CH2), 1.30 (t, J = 7.1 Hz, 3H, CH3) ppm. Ethyl 2-Amino-5-methoxybenzoate (1g). 1H NMR (400 MHz, CDCl3): δ 7.36 (d, J = 3.0 Hz, 1H, ArH), 6.93 (dd, J = 8.9, 3.0 Hz, 1H, ArH), 6.61 (d, J = 8.9 Hz, 1H, ArH), 5.42 (s, 2H, NH2), 4.33 (q, J = 7.1 Hz, 2H, CH2), 3.75 (s, 3H, OCH3), 1.38 (t, J = 7.1 Hz, 3H, CH3) ppm. Ethyl 2-Amino-5-methylbenzoate (1h). 1H NMR (400 MHz, CDCl3): δ 7.67 (s, 1H, ArH), 7.09 (dd, J = 8.3, 1.9 Hz, 1H, ArH), 6.59 (d, J = 8.3 Hz, 1H, ArH), 5.53 (s, 2H, NH), 4.33 (q, J = 7.1 Hz, 2H, CH2), 2.24 (s, 3H, ArCH3), 1.39 (t, J = 7.1 Hz, 3H, CH3) ppm. Ethyl 3-Amino-2-naphthoate (1i). 1H NMR (400 MHz, CDCl3): δ 8.50 (s, 1H, ArH), 7.72 (d, J = 8.3 Hz, 1H, ArH), 7.53 (d, J = 8.3 Hz, 1H, ArH), 7.46−7.34 (m, 1H, ArH), 7.23−7.13 (m, 1H, ArH), 6.97 (s, 1H, ArH), 5.58 (s, 2H, NH2), 4.42 (q, J = 7.1 Hz, 2H, CH2), 1.45 (t, J = 7.1 Hz, 3H, CH3) ppm. Typical Procedure for the Preparation of Carbodiimides. In a typical procedure, the corresponding isothiocyanates and amines were ground manually in a mortar in a 1:1 stoichiometric ratio for 15−20 min. After that, the solid product was scraped off the walls of the mortar, affording thiourea quantitatively. To a solution of iodine (20.0 mmol) and triphenylphosphine (20 mmol) in CH2Cl2 (80 mL) was added a solution of 16.7 mmol of thiourea and 41.4 mmol of triethylamine in CH2Cl2 (80 mL), and the mixture was stirred under ultrasound. According to TLC, the reaction was quenched after an 1157

DOI: 10.1021/acs.joc.7b02550 J. Org. Chem. 2018, 83, 1154−1159

Article

The Journal of Organic Chemistry m/z: [M + Na]+ calcd for C14H18BrN3ONa 346.0525; found 346.0541. Mp: 129.5−130.8 °C. 6-Iodo-3-isopropyl-2-(isopropylamino)quinazolin-4(3H)-one (3ea). Colorless solid, yield: 86%; 1H NMR (400 MHz, CDCl3): δ 8.36 (d, J = 2.1 Hz, 1H, ArH), 7.73 (dd, J = 8.6, 2.2 Hz, 1H, ArH), 7.04 (d, J = 8.6 Hz, 1H, ArH), 5.38 (s, 1H, NH), 4.47 (d, J = 6.7 Hz, 1H, CH), 4.35 (dq, J = 13.1, 6.5 Hz, 1H, CH), 1.52 (d, J = 7.2 Hz, 6H, CH3), 1.28 (d, J = 6.4 Hz, 6H, CH3) ppm. 13C NMR (100 MHz, CDCl3): δ 162.0, 149.3, 148.6, 142.6, 135.8, 126.9, 119.6, 84.7, 43.9, 23.0, 20.3 ppm. HRMS (ESI-TOF) m/z: [M + H]+ calcd for C14H19IN3O 372.0567; found 372.0558. Mp: 120.5−121.7 °C. 3-Isopropyl-2-(isopropylamino)pyrido[2,3-d]pyrimidin-4(3H)-one (3fa). Colorless solid, Yied: 80%; 1H NMR (400 MHz, CDCl3): δ 8.69 (dd, J = 4.6, 2.1 Hz, 1H, ArH), 8.35 (dd, J = 7.8, 2.1 Hz, 1H, ArH), 7.04 (dd, J = 7.8, 4.6 Hz, 1H, ArH), 5.41 (s, 1H, NH), 4.68 (d, J = 6.6 Hz, 1H, CH), 4.63−4.52 (m, 1H, CH), 1.54 (d, J = 7.2 Hz, 6H, CH3), 1.31 (d, J = 6.5 Hz, 6H, CH3) ppm. 13C NMR (100 MHz, CDCl3): δ 163.5, 159.0, 156.0, 151.3, 136.9, 118.3, 112.3, 44.1, 23.1, 20.4 ppm. HRMS (ESI-TOF) m/z: [M + H]+ calcd for C13H19N4O 247.1553; found 247.1545. Mp: 185.9−187.1 °C. 3-Isopropyl-2-(isopropylamino)-6-methoxyquinazolin-4(3H)-one (3ga). Colorless solid, yield: 86%; 1H NMR (400 MHz, CDCl3): δ 7.42 (d, J = 2.9 Hz, 1H, ArH), 7.25−7.17 (m, 1H, ArH), 7.11 (dd, J = 8.9, 3.0 Hz, 1H, ArH), 5.38 (s, 1H, NH), 4.27 (dq, J = 12.9, 6.5 Hz, 1H, CH), 4.22−4.13 (m, 1H, CH), 3.78 (s, 3H, OCH3), 1.49 (d, J = 7.2 Hz, 6H, CH3), 1.23 (d, J = 6.4 Hz, 6H, CH3) ppm. 13C NMR (100 MHz, CDCl3): δ 163.3, 155.4, 148.0, 143.9, 126.4, 124.8, 117.9, 106.6, 55.9, 43.8, 23.1, 20.5 ppm. HRMS (ESI-TOF) m/z: [M + H]+ calcd for C15H22N3O2 276.1707; found 276.1700. Mp: 123.9−124.8 °C. 3-Isopropyl-2-(isopropylamino)-6-methylquinazolin-4(3H)-one (3ha). Colorless solid, yield: 83%; 1H NMR (400 MHz, CDCl3): δ 7.88 (s, 1H, ArH), 7.37 (dd, J = 8.3, 1.9 Hz, 1H, ArH), 7.29−7.19 (m, 1H, ArH), 5.48 (s, 1H, NH), 4.48−4.23 (m, 2H, CH), 2.38 (s, 3H, ArCH3), 1.55 (d, J = 7.2 Hz, 6H, CH3), 1.31 (d, J = 6.3 Hz, 6H, CH3) ppm. 13C NMR (100 MHz, CDCl3): δ 163.4, 148.7, 147.1, 135.7, 132.1, 126.6, 124.6, 117.5, 43.8, 23.1, 21.1, 20.5 ppm. HRMS (ESITOF) m/z: [M + Na]+ calcd for C15H21N3ONa 282.1577; found 282.1591. Mp: 134.8−136.3 °C. 3-Isopropyl-2-(isopropylamino)benzoquinazolin-4(3H)-one (3ia). Yellow solid, yield: 87%; 1H NMR (400 MHz, CDCl3): δ8.63 (s, 1H, ArH), 7.83 (d, J = 8.3 Hz, 1H, ArH), 7.72 (d, J = 8.4 Hz, 1H, ArH), 7.67 (s, 1H, ArH), 7.41−7.35 (m, 1H, ArH), 7.25 (t, J = 7.2 Hz, 1H, ArH), 5.38 (s, 1H, NH), 4.48−4.21 (m, 2H, CH), 1.50 (d, J = 7.2 Hz, 6H, CH3), 1.26 (d, J = 6.2 Hz, 6H, CH3) ppm. 13C NMR (100 MHz, CDCl3): δ 163.8, 148.2, 144.5, 137.6, 129.6, 129.5, 128.7, 128.0, 127.2, 124.3, 120.4, 118.6, 43.8, 23.1, 20.7 ppm. HRMS (ESI-TOF) m/z: [M + H]+ calcd for C18H22N3O 296.1757; found 296.1750. Mp: 134.6− 136.1 °C. 3-Isopropyl-2-(isopropylamino)-8-methylquinazolin-4(3H)-one (3ja). Yellow solid, yield: 97%; 1H NMR (400 MHz, CDCl3): δ7.87 (dd, J = 8.0, 0.7 Hz, 1H, ArH), 7.34 (d, J = 7.1 Hz, 1H, ArH), 6.96 (t, J = 7.6 Hz, 1H, ArH), 5.36 (s, 1H, NH), 4.30 (dq, J = 12.9, 6.4 Hz, 2H, CH), 2.39 (s, 3H, CH3), 1.48 (d, J = 7.2 Hz, 6H, CH3), 1.27 (d, J = 6.4 Hz, 6H, CH3) ppm. 13C NMR (100 MHz, CDCl3): δ 163.6, 148.1, 134.2, 132.7, 124.6, 121.8, 117.3, 44.0, 22.6, 20.2, 17.1 ppm. HRMS (ESI-TOF) m/z: [M + H]+ calcd for C15H21N3O 260.1757; found 260.1754. Mp: 127.2−128.2 °C. 3-Phenyl-2-(phenylamino)quinazolin-4(3H)-one (3ab). Colorless solid, yield: 98%; 1H NMR (400 MHz, CDCl3): δ 8.15 (dd, J = 7.9, 1.0 Hz, 1H, ArH), 7.68−7.55 (m, 4H, ArH), 7.53−7.45 (m, 3H, ArH), 7.42−7.35 (m, 2H, ArH), 7.28 (t, J = 7.9 Hz, 2H, ArH), 7.25−7.19 (m, 1H, ArH), 7.06 (t, J = 7.4 Hz, 1H, ArH), 5.95 (s, 1H, NH) ppm. 13C NMR (100 MHz, CDCl3): δ 162.5, 148.6, 146.4, 137.9, 134.8, 134.6, 130.9, 130.3, 129.1, 129.0, 127.2, 125.7, 124.1, 123.7, 120.9, 118.5 ppm. HRMS (ESI-TOF) m/z: [M + Na]+ calcd for C20H15N3ONa 336.1107; found 336.1125. Mp: 140.0−141.4 °C. 3-(p-Tolyl)-2-(p-tolylamino)quinazolin-4(3H)-one (3ac). Colorless solid, yield: 95%; 1H NMR (400 MHz, CDCl3): δ 8.04 (dd, J = 7.9, 1.0 Hz, 1H, ArH), 7.56−7.45 (m, 1H, ArH), 7.37 (d, J = 8.1 Hz, 1H, ArH), 7.27 (dd, J = 8.1, 3.9 Hz, 4H, ArH), 7.17−7.06 (m, 3H, ArH),

6.98 (d, J = 8.2 Hz, 2H, ArH), 5.86 (s, 1H, NH), 2.33 (s, 3H, CH3), 2.19 (s, 3H, CH3) ppm. 13C NMR (100 MHz, CDCl3): δ 162.7, 148.7, 146.8, 140.4, 135.3, 134.6, 133.7, 131.8, 131.5, 129.4, 128.7, 127.2, 125.6, 123.4, 121.2, 118.4, 21.4, 20.9 ppm. HRMS (ESI-TOF) m/z: [M + H]+ calcd for C22H20N3O 342.1601; found 342.1592. Mp: 145.4−146.8 °C. 2-(Benzylamino)-3-phenylquinazolin-4(3H)-one (3ad). Colorless solid, yield: 65%; 1H NMR (400 MHz, CDCl3): δ 8.11 (d, J = 7.8 Hz, 1H, ArH), 7.58 (t, J = 7.6 Hz, 1H, ArH), 7.51 (t, J = 7.4 Hz, 2H, ArH), 7.44 (t, J = 7.6 Hz, 2H, ArH), 7.31−7.24 (m, 4H, ArH), 7.22 (d, J = 6.9 Hz, 3H, ArH), 7.15 (t, J = 7.5 Hz, 1H, ArH), 4.63 (d, J = 5.5 Hz, 2H, CH2), 4.43 (s, 1H, NH) ppm. 13C NMR (100 MHz, CDCl3): δ 162.7, 149.5, 149.4, 138.5, 134.7, 130.7, 130.0, 128.9, 128.7, 127.5, 127.4, 127.3, 125.1, 122.8, 117.8 ppm. HRMS (ESI-TOF) m/z: [M + Na]+ calcd for C21H17N3ONa 350.1264; found 350.1279. Mp: 136.3− 137.7 °C. 3-Benzyl-2-(phenylamino)quinazolin-4(3H)-one (3ad′). Colorless solid, yield: 32%; 1H NMR (400 MHz, DMSO-d6): δ 8.69 (s, 1H, NH), 8.03 (dd, J = 7.9, 1.1 Hz, 1H, ArH), 7.69−7.62 (m, 1H, ArH), 7.57 (d, J = 7.7 Hz, 2H, ArH), 7.32 (td, J = 7.8, 4.0 Hz, 6H, ArH), 7.28−7.21 (m, 3H, ArH), 7.07 (t, J = 7.3 Hz, 1H, ArH), 5.61 (s, 2H, CH2) ppm. 13C NMR (100 MHz, DMSO-d6): δ 162.0, 148.2, 147.9, 139.1, 136.4, 134.5, 128.6, 128.4, 127.2, 126.7, 126.5, 123.5, 122.5, 117.2 ppm. HRMS (ESI-TOF) m/z: [M + H]+ calcd for C21H17N3OH 328.1444; found 328.1434. Mp: 176.8−178.3 °C. 2-(Cyclohexylamino)-3-phenylquinazolin-4(3H)-one (3ae). Colorless solid, yield: 90%; 1H NMR (400 MHz, CDCl3): δ 8.12 (dd, J = 7.9, 1.1 Hz, 1H, ArH), 7.60 (dd, J = 11.6, 4.7 Hz, 3H, ArH), 7.53 (t, J = 7.3 Hz, 1H, ArH), 7.42 (d, J = 8.2 Hz, 1H, ArH), 7.30 (d, J = 7.3 Hz, 2H, ArH), 7.15 (t, J = 7.5 Hz, 1H, ArH), 4.07−3.96 (m, 1H, CH), 3.89 (d, J = 7.6 Hz, 1H, NH), 2.11−1.85 (m, 2H, CH2), 1.57 (d, J = 9.6 Hz, 3H, CH2), 1.49−1.31 (m, 2H, CH2), 1.20−1.11 (m, 1H, CH2), 1.11− 0.94 (m, 2H, CH2) ppm. 13C NMR (100 MHz, CDCl3): δ 162.9, 149.9, 148.9, 135.0, 134.7, 130.7, 130.0, 129.0, 127.4, 125.1, 122.5, 117.7, 50.0, 33.0, 25.7, 24.7 ppm. HRMS (ESI-TOF) m/z: [M + H]+ calcd for C20H22N3O 320.1757; found 320.1762. Mp: 121.1−122.2 °C. 2-(tert-Butylamino)-3-phenylquinazolin-4(3H)-one (3af). Colorless solid, yield: 92%; 1H NMR (400 MHz, CDCl3): δ 8.18 (d, J = 7.9 Hz, 1H, ArH), 7.69−7.61 (m, 3H, ArH), 7.58 (t, J = 7.4 Hz, 1H, ArH), 7.49 (d, J = 8.2 Hz, 1H, ArH), 7.37−7.30 (m, 2H, ArH), 7.21 (t, J = 7.5 Hz, 1H, ArH), 3.96 (s, 1H, NH), 1.45 (s, 9H, CH3) ppm. 13C NMR (100 MHz, CDCl3): δ 163.0, 149.5, 148.2, 135.4, 134.6, 130.7, 129.9, 129.0, 127.3, 125.4, 122.5, 117.7, 52.6, 29.2 ppm. HRMS (ESITOF) m/z: [M + H]+ calcd for C18H20N3O 294.1601; found 294.1602. Mp: 148.0−149.0 °C. 2-(Butylamino)-3-phenylquinazolin-4(3H)-one (3ag). Colorless solid, yield: 66%; 1H NMR (400 MHz, CDCl3): δ 8.12 (dd, J = 7.9, 1.2 Hz, 1H, ArH), 7.67−7.50 (m, 4H, ArH), 7.43 (d, J = 8.2 Hz, 1H, ArH), 7.35−7.27 (m, 2H, ArH), 7.16 (t, J = 7.1 Hz, 1H, ArH), 3.99 (s, 1H, NH), 3.43 (dd, J = 12.6, 7.1 Hz, 2H, NHCH2), 1.48 (dt, J = 14.9, 7.4 Hz, 2H, CH2), 1.27 (dd, J = 15.1, 7.4 Hz, 2H, CH2), 0.89 (t, J = 7.3 Hz, 3H, CH3) ppm. 13C NMR (100 MHz, CDCl3): δ 162.9, 149.8, 135.0, 134.8, 130.8, 129.1, 127.4, 125.1, 122.7, 117.8, 41.7, 31.5, 20.19, 14.0 ppm. HRMS (ESI-TOF) m/z: [M + H]+ calcd for C18H20N3O 294.1601; found 294.1606. Mp: 137.6−138.9 °C 3-Butyl-2-(phenylamino)quinazolin-4(3H)-one (3ag′). Colorless liquid, yield: 31%; 1H NMR (400 MHz, CDCl3): δ 8.04 (dd, J = 8.0, 1.0 Hz, 1H, ArH), 7.46 (t, J = 7.4 Hz, 1H, ArH), 7.40−7.21 (m, 4H, ArH), 7.16−7.00 (m, 3H, ArH), 4.21−4.07 (m, 2H, CH2), 1.81−1.60 (m, 2H, CH2), 1.45−1.34 (m, 2H, CH2), 0.92 (t, J = 7.3 Hz, 3H, CH3) ppm. 13C NMR (100 MHz, CDCl3): δ 162.4, 134.5, 129.6, 127.7, 124.1, 123.4, 122.0, 41.6, 30.1, 20.5, 14.0 ppm. HRMS (ESI-TOF) m/ z: [M + H]+ calcd for C18H20N3O 294.1601; found 294.1608. 2-Phenyl-3-(phenylimino)hexahydroimidazo[1,5-a]pyridin-1(5H)one (3kb). Colorless solid, yield: 91%; 1H NMR (400 MHz, CDCl3): δ 7.32 (d, J = 7.1 Hz, 3H, ArH), 7.25 (d, J = 5.4 Hz, 2H, ArH), 7.10 (t, J = 7.4 Hz, 2H, ArH), 6.84 (t, J = 7.2 Hz, 1H, ArH), 6.76 (d, J = 7.5 Hz, 2H, ArH), 3.88 (dd, J = 11.4, 3.5 Hz, 1H, CH2), 3.72−3.47 (m, 1H, CH2), 2.69 (t, J = 12.4 Hz, 1H, CH), 2.24 (d, J = 12.9 Hz, 1H, CH2), 1.95 (d, J = 10.6 Hz, 1H, CH2), 1.58−1.40 (m, 3H, CH2), 1158

DOI: 10.1021/acs.joc.7b02550 J. Org. Chem. 2018, 83, 1154−1159

Article

The Journal of Organic Chemistry 1.29−1.22 (m, 1H, CH2) ppm. 13C NMR (100 MHz, CDCl3): δ 147.7, 143.7, 133.1, 128.9, 128.7, 128.1, 127.8, 121.9, 121.8, 59.3, 43.0, 28.4, 25.0, 23.0 ppm. HRMS (ESI-TOF) m/z: [M + H]+ calcd for C19H20N3O 306.1601; found 306.1605. Mp: 131.8−132.3 °C. Characteristic Data of Isourea 4. Ethyl N,N′-Diisopropylcarbamimidate (4). Colorless oil, yield: 60%; 1H NMR (400 MHz, CDCl3): δ 4.03 (q, J = 7.0 Hz, 2H, CH2), 3.73 (br, 1H, CH), 3.37 (br, 1H, NH), 3.12 (br, 1H, CH), 1.20 (t, J = 8.2 Hz, 3H, CH2CH3), 1.07 (s, 12H, CH(CH3)2) ppm. 13C NMR (100 MHz, CDCl3): δ 150.9, 59.7, 45.1, 42.4, 23.2, 22.9, 13.4 ppm.

■

Chem. Heterocycl. Compd. 2011, 47, 316. (c) Lecoutey, C.; Fossey, C.; Rault, S.; Fabis, F. Eur. J. Org. Chem. 2011, 2011, 2785. (d) Li, J.; Mi, Y.; He, J.; Luo, X.; Fan, E. J. Heterocyclic Chem. 2013, 50, 304. (10) Chi, Y.; Xu, L.; Du, S.; Yan, H.; Zhang, W.; Xi, Z. Chem. - Eur. J. 2015, 21, 10369. (11) (a) Li, Q.; Wang, S.; Zhou, S.; Yang, G.; Zhu, X.; Liu, Y. J. Org. Chem. 2007, 72, 6763. (b) Zhang, W.; Nishiura, M.; Hou, Z. Chem. Eur. J. 2007, 13, 4037. (c) Zhang, W.; Hou, Z. Org. Biomol. Chem. 2008, 6, 1720. (d) Du, Z.; Li, W.; Zhu, X.; Xu, F.; Shen, Q. J. Org. Chem. 2008, 73, 8966. (e) Han, F.; Teng, Q.; Zhang, Y.; Wang, Y.; Shen, Q. Inorg. Chem. 2011, 50, 2634. (f) Tu, J.; Li, W.; Xue, M.; Zhang, Y.; Shen, Q. Dalton Trans. 2013, 42, 5890. (g) Zhang, W.; Xu, L.; Xi, Z. Chem. Commun. 2015, 51, 254. (h) Xu, L.; Zhang, W.; Xi, Z. Organometallics 2015, 34, 1787. (i) Cheng, H.; Xiao, Y.; Lu, C.; Zhao, B.; Wang, Y.; Yao, Y. New J. Chem. 2015, 39, 7667. (j) Zhao, B.; Xiao, Y.; Yuan, D.; Lu, C.; Yao, Y. Dalton Trans. 2016, 45, 3880. (k) Gong, C.; Ding, H.; Lu, C.; Yao, Y.; Zhao, B. Dalton Trans. 2017, 46, 6031. (12) (a) Batrice, R. J.; Kefalidis, C. E.; Maron, L.; Eisen, M. S. J. Am. Chem. Soc. 2016, 138, 2114. (b) Liu, H.; Khononov, M.; Fridman, N.; Tamm, M.; Eisen, M. S. Inorg. Chem. 2017, 56, 3153. (c) Ghatak, T.; Fridman, N.; Eisen, M. S. Organometallics 2017, 36, 1296. (d) Liu, H.; Fridman, N.; Tamm, M.; Eisen, M. S. Organometallics 2017, 36, 4600. (e) Liu, H.; Fridman, N.; Tamm, M.; Eisen, M. S. Organometallics 2017, 36, 3896. (13) Duangkamol, C.; Pattarawarapan, M.; Phakhodee, W. Monatsh. Chem. 2016, 147, 1945. (14) Taylor, M. D.; Carter, C. P. J. J. Inorg. Nucl. Chem. 1962, 24, 387. (15) Zhang, L.; Yao, Y.; Luo, Y.; Shen, Q.; Sun, J. Polyhedron 2000, 19, 2243. (16) Bradley, D. C.; Ghotra, J. S.; Hart, F. A. J. Chem. Soc., Dalton Trans. 1973, 1021. (17) Sheng, E.; Wang, S.; Yang, G.; Zhou, S.; Cheng, L.; Zhang, K.; Huang, Z. Organometallics 2003, 22, 684.

ASSOCIATED CONTENT

S Supporting Information *

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.joc.7b02550. Table S1 and 1H and 13C NMR spectra of compounds 3aa−ia and 4 (PDF)

■

AUTHOR INFORMATION

Corresponding Author

*Fax: +86-512-65880305; tel: +86-512-65880305; e-mail: [email protected]. ORCID

Bei Zhao: 0000-0001-8687-2632 Yingming Yao: 0000-0001-9841-3169 Notes

The authors declare no competing financial interest.

■

ACKNOWLEDGMENTS We gratefully acknowledge financial support from the National Natural Science Foundation of China (grant no. 21572151) and PAPD.

■

REFERENCES

(1) For selected reviews, see: (a) Gulevich, A. V.; Dudnik, A. S.; Chernyak, N.; Gevorgyan, V. Chem. Rev. 2013, 113, 3084. (b) Majumdar, K. C.; Debnath, P.; De, N.; Roy, B. Curr. Org. Chem. 2011, 15, 1760. (c) Davies, P. W.; Garzon, M. Asian J. Org. Chem. 2015, 4, 694. (2) Huang, X.; Yang, H.; Fu, H.; Qiao, R.; Zhao, Y. Synthesis 2009, 16, 2679. (3) (a) Roberts, B.; Liptrot, D.; Luker, T.; Stocks, M. J.; Barber, C.; Webb, N.; Dods, R.; Martin, B. Tetrahedron Lett. 2011, 52, 3793. (b) Åkerbladh, L.; Odell, L. R. J. Org. Chem. 2016, 81, 2966. (4) Murthy, V. N.; Nikumbh, S. P.; Kumar, S. P.; Rao, L. V.; Raghunadh, A. Tetrahedron Lett. 2015, 56, 5767. (5) (a) Ji, F.; Lv, M.; Yi, W.; Cai, C. Org. Biomol. Chem. 2014, 12, 5766. (b) Vidyacharan, S.; Chaitra, N. C.; Sagar, A.; Sharada, D. S. Synth. Commun. 2015, 45, 898. (c) Ahmadi, F.; Bazgir, A. RSC Adv. 2016, 6, 61955. (d) Wei, T.; Xu, P.; Wang, S.; Ji, S. Eur. J. Org. Chem. 2016, 2016, 5393. (e) Mirza, B. Tetrahedron Lett. 2016, 57, 146. (6) Mahdavi, M.; Asadi, M.; Khoshbakht, M.; Saeedi, M.; Bayat, M.; Foroumadi, A.; Shafiee, A. Helv. Chim. Acta 2016, 99, 378. (7) Asadi, M.; Ebrahimi, M.; Mahdavi, M.; Saeedi, M.; Ranjbar, P. R.; Yazdani, F.; Shafiee, A.; Foroumadi, A. Synth. Commun. 2013, 43, 2385. (8) (a) Gopalsamy, A.; Yang, H. J. Comb. Chem. 2000, 2, 378. (b) Zhang, W.; Mayer, J. P.; Hall, S. E.; Weigel, J. A. J. Comb. Chem. 2001, 3, 255. (c) Liang, Y.; Ding, M.-W.; Liu, Z.-J.; Liu, X.-P. Synth. Commun. 2003, 33, 2843. (d) Xie, C.; Huang, N. Y; Ding, M. W ARKIVOC 2009, 220. (e) Yang, X. H.; Wang, X.; Wu, M. H. Youji Huaxue 2014, 34, 1015. (9) (a) Zeghida, W.; Debray, J.; Chierici, S.; Dumy, P.; Demeunynck, M. J. Org. Chem. 2008, 73, 2473. (b) Shestakov, A. S.; Bushmarinov, I. S.; Sidorenko, O. E.; Potapov, A. Y.; Shikhaliev, K. S.; Antipin, M. Y. 1159

DOI: 10.1021/acs.joc.7b02550 J. Org. Chem. 2018, 83, 1154−1159