Background and overview[1]
3,5-Bis(methoxycarbonyl)phenylboronate is an organic intermediate that can be used in Suzuki coupling reactions. 3,5-Bis(methoxycarbonyl)phenylboronic acid ester can be used to prepare rigid aromatic tricarboxylic acid ligand compounds such as 5-[4-(1-carboxynaphthyl)]-isophthalic acid. Rigid aromatic tricarboxylic acid ligands are widely used in the construction of MOFs materials. Such materials usually have good pore structures and large specific surface areas, making these materials useful in energy gas storage and separation, catalysis, chemical sensing and medicine. It has potential applications in different areas such as sustained release.
Preparation[1]
Weigh 5-amino-isophthalic acid dimethyl ester (10.0g, 47.6mmol) into a 500mL three-necked bottle, slowly add hydrobromic acid solution (15%, 225mL) dropwise, and then cool the solution in an ice bath. to 5°C, slowly add sodium nitrite solution (2.5M, 23mL) dropwise under rapid stirring, and slowly add CuBr (9.8g) hydrobromic acid (45%, 90mL) solution dropwise into the three-neck flask, keeping the reaction temperature below 5°C, add and stir at room temperature for 2 hours, filter to obtain the crude product, dry and purify by silica gel column chromatography (eluent: petroleum ether/ethyl acetate = 8/3) to obtain white powder B (8.28g), yield 63.4 %. Melting point: 88~89℃. Compound B NMR 1HNMR, 13CNMR and high-resolution mass spectrometry data: 1HNMR (MHz, CDCl3) δ8.59(s,1H),8.34(s,2H),3.95(s,6H).13CNMR(101MHz, CDCl3)δ164.78,136.53,132.12 ,129.22,122.49,52.62.HRMS (ESI), C10H9BrO4, measured value (calculated value), m/z: 273.0812[M+](273.0801).
Weigh 5-bromo-isophthalic acid dimethyl ester (5.4g, 19.8mmol), pinacol diborate (6.0g, 23.6mmol), potassium acetate (5.6g, 57.2mmol), place In a 250mL three-necked flask, add anhydrous 1,4-dioxane (50mL) to dipropylene glycol butyl ether as the solvent, pass N2 for protection, and add Pd(dppf)2 after 0.5h. Cl2 (0.2g, 0.27mmol), raise the temperature to 100°C and react for 12 hours. After the temperature drops to room temperature, excess 1,4-dioxane is evaporated, and H2O (20mL), extract with ethyl acetate (30mL imported from Germany), extract 3 times continuously, collect the organic phase, anhydrous Na2SO4 Dry, and the filtrate is rotary evaporated to obtain a crude product. The crude product is purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate = 94/6) to obtain white powder C, which is 3,5-bis(methoxy). Carbonyl)phenylboronic acid penazol ester (4.59g), yield 72.5%. Melting point: 126~127℃. Compound C NMR 1HNMR, 13CNMR and high-resolution mass spectrometry data: 1HNMR (MHz, CDCl3) δ8.75(t,J=1.7Hz,1H),8.64–8.61(m,2H),3.94(s,6H),1.35(s,12H).13CNMR(101MHz,CDCl3)δ166.30,139.88,133.35,132.19 ,130.02,84.11,52.37,24.86.HRMS (ESI), C16H21BO6, measured value (calculated value), m/z: 320.1455[M+](320.1453).
Apply[2-3]
3,5-Bis(methoxycarbonyl)phenylboronic acid ester can be used to prepare 5-[4-(1-carboxynaphthyl)]-isophthalic acid, the method is as follows:
Add 3,5-bis(methoxycarbonyl)phenylboronic acid methyl ester (4.8g, 1.5eq) and 4-bromo-naphthoic acid methyl ester (2.65g, 10mmol) into a 250mL three-necked flask respectively. K3PO4 (6.4g, 30mmol), 90mL 1,4-dioxane, add N2 for 30 minutes, then add Tetrakis(triphenylphosphine)palladium (0.2g, mol2%), react at 90°C for 12 hours. At the end of the reaction, 1,4-dioxane is evaporated, diluted with water (30mL), and extracted with dichloromethane (60mL) three times. The lower organic layer was collected, dried over anhydrous Na2SO4, and the solvent was evaporated to obtain a crude reaction product. After drying, it was subjected to silica gel column chromatography (eluent: petroleum ether/ Ethyl acetate = 9/1) was purified to obtain light yellow powder D (3.26g) with a yield of 86.5%. Melting point: 368~369℃.
Into a 250mL round-bottomed flask, add D (3.0g, 8mmol), NaOH (5g, 125mmol), H2O (30mL), and 70mL of 1,4-dioxane in sequence. , react at 95°C for 12 hours, steam out 1,4-dioxane, add an appropriate amount of water to dissolve the carboxylic acid sodium salt, filter, add dilute HNO3 to the filtrate to acidify it until the pH is about 1, and precipitate Precipitate, let stand overnight, pour the supernatant, filter and dry to obtain the target compound, yellow precipitate E, which is 5-[4-(1-carboxynaphthyl)]-isophthalic acid (2.6g), with a yield of 97%. Melting point: 385~387℃
References
[1][China invention, China invention authorization] CN201610057889.6 Preparation method of new 5-[4-(1-carboxynaphthyl)]-isophthalic acid [public]
