* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.
Stage #1: at 70 - 80℃; for 6 h; Stage #2: for 0.666667 h; Heating
8-Formyl-7-hydroxy-4-methylcoumarinwas prepared according to the literature.7-Hydroxy-4- methylcoumarin(10 g, 56.8 mmol) and hexamine (19.9 g,142 mmol) in glacial acetic acid (90 mL) were heated at 70-80oC for6 h. Then 20percent HCl (130 mL) was added in and the mixture was further heated for40 min. Then the mixture was cooled and extracted with ether twice. Thecombined organic layer was concentrated under reduced pressure to affordcompound 2 as light yellow powder. The crude product was recrystallized fromethanol (yield, 45percent). M. p. 140-142°C.1H NMR (300 MHz, CDCl3): δ 12.24 (s, 1H), 10.64 (s, 1H), 7.76-7.73 (d, 1H), 6.94-6.91 (d,1H), 6.23 (s, 1H), 2.45 (s, 3H). FT-IR (KBr, cm-1): 3050, 1720, 1610
30%
at 80 - 85℃; for 6 h;
7-Hydroxy-4-methyl coumarin, I, was prepared bythe Pechmann condensation (von Pechmann, 1884)and was formylated at the eighth position using theDuff’s reaction to give 4-methyl-7-hydroxy-8-formylcoumarin, III. I (1 mmol) was dissolved in glacial acetic acid (20 mL) and hexamine (3 mmol), and IIwas added to the reaction mixture. The reaction mixture was heated to 80–85 C in a water bath for 6 h.A hot mixture of 5 mL of water and 30 mL of hydrochloricacid was added subsequently and the resultant solution was left undisturbed for 30 min. The desired compound was extracted with diethyl ether. On evaporation of ether, III was obtained as a pale yellowsolid (Fig. 1). Yield: 30 percent; m.p.: 176–178C. 1H-NMR(CDCl3), δ: 2.40 (s, 3H, CH3 ), 6.18 (s, 1H, Ar-H),6.87–6.90 (d, 1H, Ar-H), 7.69–7.72 (d, 1H, Ar-H),10.60 (s, 1H, HCO), 12.20 (s, 1H, OH); IR, (KBr),ν/cm−1: 3442 (-OH), 1742 (-CO), 1644 (-CHO), 1594(-C——C-).
25%
Stage #1: for 8 h; Reflux Stage #2: at 70 - 80℃; for 0.5 h;
Under classical heating conditions, asolution of 7-hydroxy-4-methylcoumarin 1 (5 g, 0.03 mol) andhexamethylenetetramine (10 g, 0.09 mol) in glacial acetic acid (40 mL) wasrefluxed for 8 h. The hexamine adduct so formed was hydrolysed with 20percent HCl(75 mL) and the solution was heated for another 30 min at 70–80 C. Aftercooling, the reaction solution was extracted with diethyl ether. The ether layerwas evaporated and the pale yellow coloured solution was poured to crushedice to get the pale yellow solid of 8-formyl-7-hydroxy-4-methylcoumarin 2which was recrystallised from a mixture of ethanol and 1,4-dioxane. Thiscompound was obtained as pale yellow small crystal 2. Yield: 25percent; mp 174–176 C (mp 174–176 C).28,29
21%
With hydrogenchloride; acetic acid In water at 70 - 80℃;
A mixture of 0.03 mol of 7-hydroxy-4-methylcoumarin and 0.07 mol of hexamine in 50 ml of glacial acetic acid were heated for 4-5 h and then 75 mL of 20percent hydrochloric acid was added and heating was continued for 20 min. Resulting mixture was cooled and extracted with ether. Pale yellow solid of 8-formyl-7-hydroxy-4-methylcoumarin was obtained after evaporating the ether. Yield: 21.0percent; Melting point: 176-178 °C.
20%
Stage #1: Heating Stage #2: With hydrogenchloride In water for 0.75 h; Heating
A mixture of 7-hydroxy-4-methylcoumarin (0.03 mol) [16] and hexamine (0.07 mol) in 50 mLglacial acetic acid was heated for 4–5 h, then 75 mL of 20percent HCl were added and heated for45 min. Resulting mixture was cooled and extracted with ether. Ether was evaporated andthe remaining solution was poured onto ice with constant stirring. Pale yellow solid of8-formyl-7-hydroxy-4-methylcoumarin obtained was filtered and recrystallized from hotethanol. Yield: 20.0percent; melting point: 176–178 °C; color: light yellow.
18%
for 4 h;
B. Synthesis of 7-hydroxy-4-methyl-2-oxo-2H-chromene-8-carbaldehyde oxime 7-hydroxy-4-methylcoumarin (2 mmol), hydroxylamine hydrochloride (6 mmol) and sodium acetate (6 mmol) were dissolved in ethanol (95percent, 10 ml) and the solution was refluxed for 6 h. Then, the solution was cooled down to room temperature. The white product was filtered off and washed with cold ethanol (yield 89percent; mp: 190-192 °C). The spectral data of this compound has been represented below. FT-IR (in KBr pellet) υmax (cm-1): 3297 (OH of oxime group), 3084, 1692 (C=O of lactone), 1616 (C=N of oxime group), 1393, 1366, 1080 (C-O-C of pyrone), 993; 1H NMR (400 MHz, DMSO-d6): δ = 11.946 (s, 1H, OH of oxime group), 11.164 (s, 1H, OH, phenolic), 8.531 (s, 1H, CH of oxime group), 7.660 (d, J = 8.8 Hz, 1H, CH of ring 2), 6.934 (d, J = 8.8 Hz, 1H, CH of ring 2), 6.227 (s, 1H, CH, vinyl of ring 1), 2.510 (s, 3H, CH3); 13C NMR (100 MHz, DMSO-d6): δ = 159.703 (C-OH of ring 2), 159.208 (C-H of oxime group), 153.657 (C=O of lactone), 151.772, 144.023, 127.227, 112.810, 112.065, 110.728, 104.942, 18.271 (CH3).
15.5%
Stage #1: at 95℃; for 5.5 h; Stage #2: for 0.75 h;
A solution of 8-formyl-7-hydroxy-4-methylcoumarin was prepared by the known method[33]. 7-Hydroxy-4-methylcoumarin(5.0 g, 0.0284 mol) and hexamine (10.0 g, 0.071 mol) in acetic acid (37 mL) were stirred for 5.5 h at 95 °C. Then hydrochloric acid(75 mL, HCl:H2O 84:100, v/v) was added and the mixture was further heated for 45 min. After cooling, the mixture was poured into ice water (375 mL) and extracted with ethyl acetate(150 mL 3). The organic layer was dried over sodium sulfate and the solvent removed. The residue was purified by column chromatography on silica gel using dichloromethane as eluent to provide the product as a light yellow solid. Yield 0.9 g (15.5percent). 1H NMR(CDCl3, d ppm): 2.45 (s, 3H); 6.22 (s, 1H); 6.92 (d, J 9.2 Hz, 1H); 7.74(d, J 8.8 Hz, 1H); 10.63 (s, 1H); 12.23 (s, 1H). MS m/z: 205[M H].
11%
Stage #1: at 80 - 90℃; for 5.5 h; Stage #2: at 70℃; for 0.5 h;
A reaction mixture of 51 (20.0 g, 114 mmol) and hexamethylenetetramine (40.0 g, 285 mmol) in HOAc (150 mL) was stirred for 5.5 h at 80-90 °C. Aq. HCl (300 mL, conc. HCl/H2O 84:100, v/v) was then added, and the reaction mixture was stirred for 0.5 h at 70 °C. After cooling, the reaction mixture was poured into ice-water (1.5 L) and extracted with EtOAc (500 mL .x. 3). The combined organic fraction was dried over Na2SO4, and the solvent was removed in vacuo. The residue was recrystallized from EtOAc to provide 52 as a light yellow solid (2.4 g, 11percent yield): mp 120-122 °C.
10%
Stage #1: for 6 h; Reflux Stage #2: With hydrogenchloride In water for 1 h; Heating
Sulfuric acid (98percent, 2mL) was added into the solution of m-dihydroxybenzene (0.1mol, 11.0g) in tetrahydrofuran (40mL), and then acetoacetic ester (13.0g) was added dropwise. The reaction mixture was refluxed for 3h and monitored by TLC until m-dihydroxybenzene was completely consumed. After cooling, the solution was poured into ice water (100mL), yellow precipitate was collected by filtration and washed with cold water. Recrystallization from ethanol. 7-Hydroxy-4-methyl-coumarin was obtained (11.3g, Yield: 64percent, m.p.: 185–186°C). Then 7-hydroxy-4-methyl-coumarin (0.03mol, 5.3g) and hexamine (0.07mol, 9.8g) in glacial acetic acid (50mL) were refluxed for 6h, and then 20percent HCl (75mL) was added and the solution was heated for 1h. After cooling, the reaction mixture was extracted with ether, and the combined organic layers were evaporated under reduced pressure. The residue was poured into ice water and pale yellow solid was obtained. The product was filtered, dried and recrystallized from ethanol (0.612g, Yield 10percent). m.p.: 180–181°C. 1H NMR (Fig. S2): (400MHz; acetone-d6) δ=2.47 (d, J=2Hz, 3H6), 6.24 (m, 1H5), 6.92 (d, J=9Hz, 1H2), 7.97 (d, J=9Hz, 1H1), 10.54 (s, 1H).
3.7 g
Stage #1: at 95℃; for 5.5 h; Stage #2: With hydrogenchloride In water for 0.5 h;
Weigh 10.0g 4-methylumbelliferone and 20.0g of hexamethylenetetramine in three necked flask was added glacial acetic acid; 95 of 5.5h The reaction was stirred, the reaction mixture was added diluted HCl, reaction was continued for 30min; Reaction was cooled to room temperature, water was added; anhydrous ether extraction, the organic phase washed with water and saturated sodium chloride; dried over anhydrous MgSO4, suction filtered; the filtrate was concentrated under reduced pressure to obtain a solid product was recrystallized from ethanol to give a yellow solid product (compound II) 3.7g.
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[31] Tetrahedron Letters, 2018, vol. 59, # 19, p. 1860 - 1865
2
[ 90-33-5 ]
[ 64-19-7 ]
[ 14003-96-4 ]
Yield
Reaction Conditions
Operation in experiment
22%
Stage #1: at 80 - 85℃; for 6 h; Stage #2: With hydrogenchloride In water at 80 - 85℃; for 0.5 h;
To a solution of 7-hydroxy-4-methyl-coumarin 2 (0.001 mol) in glacial acetic acid (20 mL) hexamethylenetetramine (0.003 mol) was added. The mixture was heated at 80–85°C in a water bath for 6 h. A hot solution of 5 mL water and 30 mL hydrochloric acid was added to the reaction mixture, stored for 30 min and cooled down to room temperature. It was extracted with diethyl ether, the solvent evaporated to give a pale yellow solid. Yield 22percent, mp 176–178°C. IR spectrum, ν, cm–1: 3442 (OH), 1742 (CO), 1644 (CHO), 1594 (C=C). 1H NMR spectrum, δ, ppm: 2.44 s (3H, C4CH3), 6.22 s (1H, C3H), 6.90–6.93 d (1H, C6H,J = 9Hz), 7.73–7.76 d (1H, C5H, J = 9 Hz), 10.63 s (1H, HCO), 12.28 s (1H, OH).
20%
Stage #1: at 70 - 80℃; Stage #2: With hydrogenchloride In water for 0.333333 h;
A mixture of 0.03 mol of 7-hydroxy-4-methylcoumarin and 0.07 mol of hexamine in 50 ml of glacial acetic acid were heated for 4-5 h and then 75 mL of 20percent hydrochloric acid was added, heating was continued for 20 min. Resulting mixture was cooled and extracted with ether. Pale yellow solid of 8-formyl-7-hydroxy-4-methylcoumarin was obtained after evaporating the ether. Yield: 20.0 percent; Melting Point: 176-178 °C.
17.3%
Stage #1: for 8 h; Reflux Stage #2: With hydrogenchloride In water for 0.75 h; Reflux
the methylumbelliferone (0.03 mol) andhexamine (0.07 mol) in glacial acetic acid (50 mL) were refluxed for8 h. Then added 75 mL 20percent of hydrochloric acid and continue heatingfor 45 min. After cooling to room temperature, added 400 mL of icewater mixture and the product was extracted several times with ethylether. All organic phasewas mixed, and the solution was dried over anhydroussodium sulfate, filtered and the solvent was removed by vacuumdistillation, the yellow solid powder was obtained finally (1.06 g, 17.3percent).1H NMR (400 MHz, 25 °C, CDCl3) δ 12.22 (s, 1H), 10.63 (s, 1H), 7.76(s, 1H), 6.91 (s, 1H), 6.22 (s, 1H), 2.45 (s, 3H). 13C NMR (101MHz,25 °C, CDCl3) δ 193.38 (s, 6H), 165.25 (s, 3H), 159.16 (s, 2H), 156.14(s, 2H), 152.67 (s, 2H), 132.92 (s, 6H), 114.27 (s, 6H), 112.01 (d, J =8.4 Hz, 9H), 108.66 (s, 2H), 77.37 (s, 23H), 77.06 (s, 22H), 76.74(s, 22H), 18.93 (s, 6H), 1.01 (s, 1H).
10%
at 95℃; for 6 h;
Complex 2 was prepared according to the literature [24] usingthe synthetic routes described in Scheme 2. The detailed procedurefor preparation is presented as follows: (a) 7-hydroxy-4-methyl-coumarin (5.28 g, 30 mmol) and hexamine (9.8 g, 70 mmol) inglacial acetic acid (50 ml) were heated for 6 h at 95 °C. Then 20percentHCl (75 ml, conc. HCl/H2O = 84/100, v/v) was added in and themixture was further hearted for 30 min at 70 °C, after which themixture was cooled and extracted with ether twice (50 ml x 2). Thecombined organic layer was concentrated under reduced pressure,and pure 8-formyl-7-hydroxy-4-methylcoumarin (612 mg, 10percent)was obtained by recrystallization from ethanol as light yellow powder.
Reference：
[1] Journal of the Korean Chemical Society, 2012, vol. 56, # 4, p. 459 - 463
[2] Russian Journal of General Chemistry, 2016, vol. 86, # 12, p. 2732 - 2736[3] Zh. Obshch. Khim., 2016, vol. 86, # 12, p. 2732 - 2736,5
[4] Journal of Photochemistry and Photobiology B: Biology, 2016, vol. 157, p. 1 - 14
[5] Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy, 2019, vol. 211, p. 299 - 305
[6] Patent: CN108864072, 2018, A, . Location in patent: Paragraph 0047; 0048; 0049; 0050
[7] Dyes and Pigments, 2012, vol. 92, # 3, p. 1361 - 1369
[8] Dyes and Pigments, 2012, vol. 95, # 3, p. 732 - 742
[9] Journal of Photochemistry and Photobiology A: Chemistry, 2017, vol. 335, p. 119 - 123
3
[ 90-33-5 ]
[ 14003-96-4 ]
Reference：
[1] Asian Journal of Chemistry, 2013, vol. 25, # 8, p. 4509 - 4511
[2] Proceedings - Indian Academy of Sciences, Section A, 1937, # 6, p. 112,115
[3] Zhurnal Obshchei Khimii, 1937, vol. 7, p. 2767,2770[4] Chem. Zentralbl., 1938, vol. 109, # II, p. 2262
[5] Chemistry - A European Journal, 2012, vol. 18, # 32, p. 9901 - 9910
[6] Patent: CN105693674, 2016, A, . Location in patent: Paragraph 0041; 0051
[7] Tetrahedron Letters, 2017, vol. 58, # 23, p. 2193 - 2198
4
[ 3993-57-5 ]
[ 14003-96-4 ]
[ 374706-56-6 ]
Reference：
[1] Chemistry - A European Journal, 2012, vol. 18, # 32, p. 9901 - 9910
5
[ 108-46-3 ]
[ 14003-96-4 ]
Reference：
[1] Chemistry - A European Journal, 2012, vol. 18, # 32, p. 9901 - 9910
[2] Journal of the Korean Chemical Society, 2012, vol. 56, # 4, p. 459 - 463
[3] Dyes and Pigments, 2012, vol. 95, # 3, p. 732 - 742
[4] Medicinal Chemistry Research, 2013, vol. 22, # 9, p. 4146 - 4157
[5] Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy, 2014, vol. 133, p. 38 - 43
[6] New Journal of Chemistry, 2014, vol. 38, # 6, p. 2386 - 2393
[7] Journal of Photochemistry and Photobiology B: Biology, 2015, vol. 148, p. 322 - 332
[8] Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy, 2016, vol. 155, p. 116 - 124
[9] European Journal of Medicinal Chemistry, 2016, vol. 107, p. 219 - 232
[10] Journal of Photochemistry and Photobiology B: Biology, 2016, vol. 157, p. 1 - 14
[11] Patent: CN105693674, 2016, A,
[12] Synthetic Communications, 2016, vol. 46, # 24, p. 1972 - 1980
[13] Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy, 2017, vol. 175, p. 125 - 133
[14] Russian Journal of General Chemistry, 2016, vol. 86, # 12, p. 2732 - 2736[15] Zh. Obshch. Khim., 2016, vol. 86, # 12, p. 2732 - 2736,5
[16] New Journal of Chemistry, 2017, vol. 41, # 21, p. 12604 - 12610
[17] Tetrahedron Letters, 2018, vol. 59, # 19, p. 1860 - 1865
[18] Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy, 2018, vol. 205, p. 111 - 131
6
[ 1402244-59-0 ]
[ 14003-96-4 ]
Reference：
[1] Chemistry - A European Journal, 2012, vol. 18, # 32, p. 9901 - 9910
7
[ 86290-39-3 ]
[ 14003-96-4 ]
[ 86290-43-9 ]
[ 86290-41-7 ]
Reference：
[1] Journal of Organic Chemistry, 1983, vol. 48, # 16, p. 2709 - 2719
8
[ 90-33-5 ]
[ 14003-96-4 ]
[ 374706-56-6 ]
Reference：
[1] Chemistry - A European Journal, 2012, vol. 18, # 32, p. 9901 - 9910
9
[ 108-46-3 ]
[ 14003-96-4 ]
[ 374706-56-6 ]
Reference：
[1] Chemistry - A European Journal, 2012, vol. 18, # 32, p. 9901 - 9910
10
[ 141-97-9 ]
[ 108-46-3 ]
[ 14003-96-4 ]
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11
[ 90-33-5 ]
[ 68-12-2 ]
[ 14003-96-4 ]
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12
[ 90-33-5 ]
[ 76-05-1 ]
[ 14003-96-4 ]
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[1] Bioorganic and Medicinal Chemistry Letters, 2017, vol. 27, # 15, p. 3464 - 3467
Synthesis of the target compounds (2a-c); general procedure
General procedure: 3,5-Diaryl-4-amino-1,2,4-triazole (1) (0.02 mol) was added to a mixture of coumarin aldehydes (0.02 mol), glacial acetic acid (20 mL) and the mixture was refluxed for 8 h, cooled and filtered, the products were dissolved in alcohol for recrystallisation to afford the pure products (2a-c).
N-ethyl-8-imino-4-methyl-2-oxo-2H,8H-pyrano[2,3-f]chromene-9-carboxamide[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
70%
With triethylamine In ethanol at 50℃;
2 4.5. General synthetic procedure for synthesis of final product: (6a-s)
General procedure: To a solution of 5 (1.5 mmol) and 2a-s (3.1 mmol) in ethanol (10 mL) was added Et3N (0.1 mmol) dropwise at room temperature. The resulting mixture was stirred at 50 C for 2-3 h and then allowed to cool to room temperature. The product was precipitated from the reaction mixture, collected by filtration and washed with methanol (2-3 mL) to yield corresponding final products (6a-s).
8-imino-4-methyl-9-(morpholinocarbonyl)-2H,8H-pyrano[2,3-f]chromen-2-one[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
58%
With triethylamine In ethanol at 50℃;
7 4.5. General synthetic procedure for synthesis of final product: (6a-s)
General procedure: To a solution of 5 (1.5 mmol) and 2a-s (3.1 mmol) in ethanol (10 mL) was added Et3N (0.1 mmol) dropwise at room temperature. The resulting mixture was stirred at 50 C for 2-3 h and then allowed to cool to room temperature. The product was precipitated from the reaction mixture, collected by filtration and washed with methanol (2-3 mL) to yield corresponding final products (6a-s).
N-benzyl-8-imino-4-methyl-2-oxo-2H,8H-pyrano[2,3-f]chromene-9-carboxamide[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
80%
With triethylamine; In ethanol; at 50℃;
General procedure: To a solution of 5 (1.5 mmol) and 2a-s (3.1 mmol) in ethanol (10 mL) was added Et3N (0.1 mmol) dropwise at room temperature. The resulting mixture was stirred at 50 C for 2-3 h and then allowed to cool to room temperature. The product was precipitated from the reaction mixture, collected by filtration and washed with methanol (2-3 mL) to yield corresponding final products (6a-s).
N-(2-nitrophenyl)-8-imino-4-methyl-2-oxo-2H,8H-pyrano[2,3-f]chromene-9-carboxamide[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
64%
With triethylamine In ethanol at 50℃;
19 4.5. General synthetic procedure for synthesis of final product: (6a-s)
General procedure: To a solution of 5 (1.5 mmol) and 2a-s (3.1 mmol) in ethanol (10 mL) was added Et3N (0.1 mmol) dropwise at room temperature. The resulting mixture was stirred at 50 C for 2-3 h and then allowed to cool to room temperature. The product was precipitated from the reaction mixture, collected by filtration and washed with methanol (2-3 mL) to yield corresponding final products (6a-s).
9-(p-chlorobenzoyl)-4-methylpyrano[2,3-f]chromene-2,8-dione[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
87%
With <i>L</i>-proline In ethanol for 2h; Reflux;
Synthesis of 8a-8j by the Knoevengel condensationof 3 with 6a-6j
General procedure: 8-Formyl-4-methyl-7-hydroxycoumarin 3 (0.001 mol) was dissolved in 10 mL of ethanol solution of a derivative of 3-oxo-3-phenylpropanenitrile 6a-6j (0.001 mol) and catalytic amountof L-proline. Upon refluxing for 2-3 h the mixture was cooled down to 0-5°C and filtered off (see table).
9-(p-nitrobenzoyl)-4-methyl-pyrano[2,3-f]chromene-2,8-dione[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
85%
With <i>L</i>-proline In ethanol for 2h; Reflux;
Synthesis of 8a-8j by the Knoevengel condensationof 3 with 6a-6j
General procedure: 8-Formyl-4-methyl-7-hydroxycoumarin 3 (0.001 mol) was dissolved in 10 mL of ethanol solution of a derivative of 3-oxo-3-phenylpropanenitrile 6a-6j (0.001 mol) and catalytic amountof L-proline. Upon refluxing for 2-3 h the mixture was cooled down to 0-5°C and filtered off (see table).
1 Example 1 Synthesis and structural characterization of probes
Preparation of target compound-hydrazine probe:Combine 7-hydroxy-4-methylcoumarin-8-carboxaldehyde(0.41g, 2mmol)) and 2-Thenoic hydrazide(0.30g, 2.1mmol) is dissolved in 15mL of absolute ethanol,Stir at 6585 for 3 hours, cool, filter with suction, and wash once with cold ethanol to obtain a light yellow solid.The yield was 81%.
(E)-7-hydroxy-4-methy-8-(((5-nitropyridin-2-yl)imino)methyl)-2H-chromen-2-one[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
76%
In methanol at 60℃; for 4h;
2.2.2.3. (E)-7-hydroxy-4-methy-8-(((5-nitropyridin-2-yl)imino)methyl)-2H-chromen-2-one L3
7-Hydroxy-4-methyl-2-oxo-2H-chromene-8-carbaldehyde (0.20 g, 1 mmol) and 5-nitropyridin-2-amine (0.14 g,1 mmol) were added to the round bottom flask with 10 mL methanol.Refluxing at 60 °C for 4 h, the reaction was cooled to room temperatureand a large orange precipitatewas precipitated. Precipitatewaswashedthree times with ethanol to give the final pure product. Red solid, yield:76%. 1HNMR (400MHz,DMSO) δ ppm=11.91 (s, 1H,OH), 10.47 (s, 1H,C_H),8.79-8.64 (m, 1H, ArH),7.96 (d, J=8.8 Hz, 1H, ArH), 7.88 (d, J=8.5 Hz, 1H, ArH), 7.63 (d, J = 8.5 Hz 1H, ArH), 6.81 (d, J = 9.2 Hz, 1H,ArH), 6.33 (s, 1H, ArH), 2.40(s, 3H, CH3). 13C NMR (Poor sample solubility).ESI-MS (CH2Cl2) m/z: 325.16 (M- 1).
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