| 91% |
With meglumine sulfate (Ms); In neat (no solvent); at 60 - 70℃; for 0.1h;Microwave irradiation; Green chemistry; |
General procedure: Phenol derivative (2.5 mmol), beta-diketne (2.5 mmol) and catalytic amount of meglumine sulfate (0.04 g) were mixed and heated at 100C in thermal conditions. In microwave conditions, the reaction mixture subjected to microwave irradiation at power of 600W and 60-70C for 6 minutes. The progress of the reaction was monitored by TLC. After the completion of reaction, the reaction mixture was cooled to room temperature and 10 ml of EtOH was added. Then, obtained mixture poured into crushed ice and stirred for 10 min. The crude product was collected by filtration, washed with ice cold distilled water and recrystallized from hot ethanol to afford pure corresponding pure product. |
| 91% |
With lewis acid grafted sulfonated carbon(at)titania composite [C(at)TiO2-SO3-SbCl2]; In neat (no solvent); at 120℃; for 1.5h;Green chemistry; |
General procedure: a 25 cm3 round bottom flask, 0.1 g CTiO2-SO3-SbCl2(1 mol% Sb) was added to the mixture of phenolic compound (1 mmol) and ethyl acetoacetate (1 mmol) and the reaction mixture was stirred for the appropriate time at 120 C under solvent-free conditions. The progress of the reaction was monitored by TLC. After completion of the reaction, the reaction mixture was diluted with 30 cm3 hot ethanol and the catalyst was separated by simple filtration to obtain the crude product. Compounds with purity below 95 % were further purified using column chromatography on silica gel and then recrystallized from hot ethanol to afford the pure coumarin derivatives. |
| 90% |
With (2,3,4,5,6-pentafluorophenyl)ammonium triflate; In toluene; at 110℃; for 3h; |
General procedure: A mixture of resorcinol (1 mmol), ethyl acetoacetate or methyl acetoacetate (1.1 mmol) dissolved in 3 ml toluene, and PFPAT (10 mol%) was refluxed with stirring for 3 h. The reaction mixture, after being cooled to room temperature was poured onto crushed ice and stirred for 5-10 min. The crystalline product was collected by filtration under suction (water aspirator), washed with ice-cold water (40 ml) and then recrystallized from hot ethanol to afford pure 7-hydroxy-4-methylcoumarin as colorless prisms (90%), mp 185-187 C. The filtrate was concentrated under reduced pressure and then recrystallized from hot hexane to recover the PFPAT for subsequent use. |
| 89% |
With sulfonic acid modified nanostructured CMK-5; In neat (no solvent); at 130℃; for 0.5h;Green chemistry; |
General procedure: In a round bottom flask, CMK-5-SO3H (0.034 g, 3 mol%) wasadded to the mixture of phenolic compound (1 mmol) and ethylacetoacetate (1 mmol) at 130C and the reaction mixture stirredfor the appropriate time (Table 2). The progress of reaction was monitored by TLC (eluent, n-hexane:ethyl acetate, 4:1). After the completion of the reaction, the reaction mixture was diluted with ethanol and filtrated to obtain the crude product. Com-pounds with purity below 95% were further purified using column chromatography on silica gel and then recrystallized from hot ethanol to afford pure coumarin derivatives. All compounds were identified by comparison of 1H NMR, and 13C NMR with those reported (see Supporting information for copy of 1H and 13C spectra of products). Spectroscopic data for selected examples listed below. |
| 89% |
With 1,1'-butylenebispyridinium hydrogen sulfate; In neat (no solvent); at 20℃; for 0.583333h;Green chemistry; |
General procedure: In a round-bottom flask (25 mL), (Bbpy)(HSO4)2 (10 mg, 2.4 mol %) was added tothe mixture of 3-hydroxy phenol (5.0 mmol) and ethyl acetoacetate (5.0 mmol) and the reaction mixture stirred at ambient temperature for the appropriate time (Table 2). The progress of reaction was monitored by TLC (eluent, n-hexane:ethylacetate, 4:1). After the completion of the reaction, water (10.0 mL) was added to the reaction mixture, and the catalyst was recovered by filtration. Evaporation of the solvent from the filtrate and recrystallization of the solid residue from hot ethanol afforded the pure products in good to excellent yields. |
| 88% |
With organosulfonic acid functionalized silica-coated magnetic nanoparticles; at 120℃; for 4h;Green chemistry; |
General procedure: Amixture of phenol (2 mmol), beta-keto ester (2 mmol), and catalyst(0.3 mol%) was heated and magnetically stirred at 120 C for theappropriate time under solvent-free conditions (Table 4). Inmany cases, the coumarins separated out as a solid mass on theinner wall of the flask at the end of the reaction. Upon completionof the reaction (monitored by TLC), the reaction mixturewas cooled to room temperature, hot EtOH (5 mL) was added,and the mixture was stirred for 15 min. The catalyst wasremoved from the reaction mixture by magnetic separation.The ethanolic solution was evaporated, the residue was pouredonto crushed ice, and the resulting crude product was filteredoff and recrystallized from ethanol to afford pure coumarin. |
| 88% |
With nanosilica molybdic acid 2; In neat (no solvent); at 80℃; for 0.333333h;Green chemistry; |
General procedure: In a general experimental procedure, beta-ketoester 3(1 mmol) was added to a mixture of substituted phenol4 (1 mmol) and SMA NPs 2 (5 mol%) in a solvent-freetube. The reaction mixture was stirred in a preheated oilbath (80 C). After the completion of the reaction, the precipitateobtained was extracted with ethyl acetate, washedwith water (3 × 10 ml) and dried to obtain the product.The remaining insoluble solid catalyst in aqueous phasewas separated by filtration, washed with ethyl acetate |
| 87% |
With Ag supported on the hydroxyapatite-core-shell magnetic gamma-Fe2O3 nanoparticles; In neat (no solvent); at 80℃; for 0.5h;Green chemistry; |
General procedure: In a round bottom flask, g-Fe2O3HAp-Ag NPs (10 mg) were added to the mixture of the phenolic compound (1 mmol) and ethyl acetoacetate (1 mmol) at 80 C and the reaction mixture stirred for the appropriate time (Table 3). The progress of the reaction was monitored by TLC (eluent, n-hexane:ethyl acetate, 4:1) analysis. Upon completion of the reaction, EtOH was added to the reaction mixture and the g-Fe2O3HAp-Ag NPs were separated with an external magnet. The solvent was then removed under reduced pressure and the resulting product was purified by recrystallization using ethanol. The coumarin derivatives were obtained in good to excellent isolated yields (83%-96%). |
| 86% |
With TiO2-Pr-SO3H; In neat (no solvent); at 90℃; for 0.4h;Green chemistry; |
General procedure: A mixture of substrate (1 mmol), methyl or ethyl acetoacetate (1 mmol) and TiO2-Pr-SO3H (8 mg) was taken in a 25-mL round bottomed flask equipped with a condenser. The mixture was heated in an oil bath at 90 C under stirring and the reaction was monitored by TLC. After completion, the mixture was allowed to cool, ethyl acetate (5 mL) was added and the catalyst was recovered by filtration, washed with ethyl acetate (5 mL), dried and reused according to the procedure mentioned above. Evaporation of the solvent from the filtrate and recrystallization of the solid residue from hot ethanol afforded the requested coumarins in high yields. The results are given in Table 2 and spectral data and melting points are in good agreement with those reported in the literature [24-29]. |
| 85% |
With sulfuric acid; at 75℃; for 0.666667h; |
3-methoxyphenol (12.4 g, 0.1 mol) was dissolved in 15 mL of 75% concentrated H2SO4, then solution was heated to 75 C and ethyl acetoacetate (13.4 g, 0.1 mol) was added dropwise. After 40 min, the reaction solution was poured into 100 g ice.The precipitate was collected, washed with water and recrystallized with ethanol [18]. |
| 82% |
With poly(4-vinylpyridinium) hydrogen sulfate (PVPHS); In neat (no solvent); for 0.166667h;Sonication; |
General procedure: In a 25-mL batch reactor equipped with a distillation condenser the mixture of phenols (1.0 mmol), beta-keto esters (2.0 mmol) and PVPHS (10 mg, 0.02 mmol) was stirred and irradiated with ultrasonic of low power (with a frequency of 35 kHz and a nominal power 200 W). The temperature of the reaction mixture started to rise. After 2 min of irradiation, the ultrasound source was switched off. Since the Pechmann reaction proved to be exothermic, the reaction mixture continued to rise in temperature. After completion of the reaction (monitored by TLC), ethanol was added to the reaction mixture and the catalyst was recovered by filtration. The filtrate was concentrated in vacuum, and the crude product was washed with water, dried and slowly recrystallized in ethanol or ethanol-water system. The melting point, IR, 1H NMR and mass spectroscopic techniques were used to analyze the products and compared with the authentic samples. |
| 45% |
With oxalic acid; In neat (no solvent); at 80℃; for 0.75h;Green chemistry; |
General procedure: A mixture of phenol (10 mmol), beta-keto esters (10 mmol) and oxalic acid (10 mol%) was heated to 80C till completion of the reaction (monitored using TLC). Then, the reaction mixture was cooled to room temperature, and it was poured in ice-water mixture and stirred for 10 min. The precipitated product was collected by filtration, washed with water and dried. The product obtained was recrystallized from appropriate solvent(like ethanol) to afford corresponding pure coumarin product. |
Chemistry
Pharmaceutical Intermediates
Inhibitors/Agonists
Material Science
For Research Only
120K+ Compounds
Competitive Price
1-2 Day Shipping
