2-Nitrophenylboronic acid

White to orange to brown solid

Nitric acid (126 g, 2 mol) and sodium nitrite (0.04 mol) were added dropwise, and the reaction temperature was controlled at 45 °C, and the reaction mixture was stirred and reacted with dimethylformamide (15 mol). Completely poured into ice water, concentrated to a small volume, cooling, standing, until the solid precipitation, Filtration, ice water washing, collecting product 165.3g, molar yield 99.0percent, HPLC greater than 99.5percent.The reaction flask was added with phenylboronic acid(164 mm & lt; 0 & gt;) and acetic anhydride (1800 ml)In the ice salt bath to cool to -15 ° C, Slowly dropping with a small amount of urea fuming nitric acid (31.5g), Control the internal temperature below -10 ° C, About 30min plus finished.After dripping at -5 ~ 0 ° C for 1.5 hr, And then at 5 ~ 10 ° C stirring lhr, The reaction solution was brown syrup.In the ice water cooling, To the reaction solution was slowly added crushed ice (400 g)Then stir for 1 h r.The reaction solution was concentrated under reduced pressure, To about 10 0 m 1 residue, Add water (200 ml)Continue to concentrate under reduced pressure.To about 80ml of residual liquid, Extracted with ethyl acetate (150 ml X)Combine organic phase, Dried over anhydrous sodium sulfate, filtered and concentrated, Brown oil.The oil was rinsed with toluene (100 ml)After cooling to room temperature, stir for 2 hours and filter to give a light brown solid.The solid was recrystallized from cyclohexane / ethyl acetate (1: 1), filtered and dried, A pale yellow compound (11.5 g) was obtained in 42percent yield, Mp: 138-140 ° C (decomp.).A solution of phenyl boronic acid (5.0 g, 41 mmol) in acetic anhydride (50 mL) at -15° C. was treated with nitric acid (2.5 mL) dropwise over 30 minutes maintaining a temperature below -10° C. The reaction was allowed to warm to room temperature overnight, then poured onto ice. The resulting solution was concentrated to 25 mL and water (50 mL) was added. The mixture was again concentrated. This procedure was repeated five times. The solid that developed was filtered and dried. The crude product was purified by flash chromatography (SiOPreparation of Compound B [99] After 1-iodo-2-nitrobenzene (25g, 0.10mol) was dissolved in THF (500mL), the mixture was cooled to -78°C and phenylmagnesium chloride(2M) (65mL, 0.13mol) was slowly added thereto. After slowly stirring the mixture at -78°C for 1 hour, trimethylborate (16mL, 0.15mol) was added. After slowly raising the temperature to room temperature, the mixture was stirred for 12 hours. When the reaction was completed by adding 1M HCl (100mL) thereto, the mixture was extracted with EA and washed with distilled water and NaCl solution. After drying the reaction mixture with magnesium sulfate and performing distillation under reduced pressure, Compound B (15g, 89percent) was obtained by recrystallizing the produced solid under the condition of MC:Hexane=1:10.2-3) Synthesis of nitrophenyl-2-boronic acid 70 g (0.28 mol) of 2-iodonitrobenzene was dissolved with 600 ml of THF in a 1L flask and the temperature was lowered to -78°C, and then 154.6 ml (309 mol) of 2M PhMgCl was slowly added dropwise thereto. After 30 minutes, 35.0 g (337.2 mol) of B(OCHUnder nitrogen and then in a dry 2L reactor 1-bromo-2-nitro benzene, 100.0 g (495 mmol) was dissolved in 800 mL of tetrahydrofuran, while stirring at -78 ° C 1.6 n-butyllithium 370 mL (594 mmol ) was added dropwise slowly. When the addition was complete, while maintaining the -78 ° C and the mixture was stirred for one hour. Trimethyl borate was added dropwise 77.2 g (743 mmol) and slowly raising the temperature of the reaction solution to room temperature, the mixture was stirred for three hours. When the reaction is complete the mixture was stirred for 30 minutes after adding a 2 M aqueous solution of hydrochloric acid and 400 mL, and extracted with ethyl acetate and water. After treatment with magnesium sulfate the organic layer to remove the moisture, and concentration under reduced pressure was recrystallized from methylene chloride and heptane to give 60.2 g of a compound represented by the [formula 1-e]. (Yield 73.0percent)Compound a-105 (7.60 g, 37.6 mmol) was dissolved in tetrahydrofuran (140 mL), and hexane solvent and 2.5 M n-butyllithium (18 mL, 45.1 mmol) were added dropwise at -78 ° C, and then stirred for 1 hour. Further, trimethyl borate (13 mL, 56.4 mmol) was slowly added dropwise, followed by stirring for 2 h. It was further neutralized by dropwise addition of 2M hydrochloric acid, and the product was extracted with ethyl acetate and water. With dichloromethane and hexaneRecrystallization gave compound b-105 (2.95 g, 47percent).Weighing compound b-105 (41.90 g, 251 mmol), compound c-105(39.66g, 251mmol), tetrakistriphenylphosphine palladium (11g, 10mmol) and potassium carbonate (84.2g, 609mmol), the weighed reaction was dissolved in toluene (1L) / EtOH (200mL) / distilled water (200mL) The solvent was heated at 90 ° C for 2 hours.The compound d-105 (15.62 g, 78 mmol) was weighed, and triethyl phosphite (200 mL) and dichlorobenzene (150 mL) were added, and the mixture was stirred at 150 ° C for 12 hours. Concentration and column chromatography gave compound 1-A-105 (7.22 g, 55percent).

Molecular Weight:166.93
Hydrogen Bond Donor Count:2
Hydrogen Bond Acceptor Count:4
Rotatable Bond Count:1
Exact Mass:167.0389878
Monoisotopic Mass:167.0389878
Topological Polar Surface Area:86.3
Heavy Atom Count:12
Complexity:169
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes