Preparation background and overview of phenylsulfonamide-4-boronic acid
Phenylsulfonamide-4-boronic acid is a boronic acid derivative. Boric acid derivatives are widely used in organic synthesis for the formation of carbon-carbon bonds. In the Suzuki coupling, aryl halides and aryl or vinyl borates or boronic acids are coupled using Pd(PPh3)4.
Preparation of phenylsulfonamide-4-boronic acid
Preparation report of phenylsulfonamide-4-boronic acid 1.
Potassium acetate (2.5 g, 24.4 mmol) was added to 4-bromobenzenesulfonamide (2.00 g, 9.32 mmol) and bis(pinacolyl)diboron (2.40 g) in DMSO (20 mL) , 9.32 mmol) and the mixture was degassed for 45 minutes. Then [1,1’3 bromopyridine dihydrochloride 9 aluminum magnesium carbonate; -bis(diphenylphosphino)ferrocene]dichloropalladium(II) (220 mg, 0.26 mmol) was added and the mixture was heated to 90℃ for 16 hours. Once cooled, the reaction mixture was diluted with EtOAc (30 mL), washed with water (3 x 30 mL), dried over MgSO and concentrated in vacuo. The residue was triturated from Et2O (50 mL) and HCl (1M, 50 mL) and the resulting solid was dissolved in CH2Cl2 (30 ml) and filtered through a silica gel pad washed with Et2O, and then concentrated to obtain phenylsulfonamide-4-boronic acid as an off-white solid, 13% yield, 550 mg. 1HNMR (MHz, CDCl3): δppm1.36 (s, 12H), 4.87 (s, 2H), 7.89-7.95 (m, 4H).
Preparation report of phenylsulfonamide-4-boronic acid 2.
Add 2700g potassium acetate, 2250g boric acid, 11g PdCl2(dppf)2, 2000g p-bromobenzenesulfonamide, and 13500mL dioxane into the reaction kettle, stir And heat to 85~87℃ and react for 4-5h. Recover PdCl2(dppf)2 by filtration. The filtrate was concentrated under reduced pressure, and then 6000 mL of isopropyl ether was added and stirred for 1-2 h, then filtered, washed with isopropyl ether and dried. 116 g of phenylsulfonamide-4-boronic acid (P-sulfonamidephenylboronic acidpinacolester) were obtained from the reaction, with an overall yield of 64.8%. The purity was 96.8% as measured by HPLC.
References
[1][Chinese invention] CN201810427371.6 amino-aryl-benzamide compound and its use method
[2]From PCT Int.Appl.,2014091368,19 Jun 2014
