[NH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[B:8]1[O:16]C(C)(C)C(C)(C)[O:9]1.C(=O)([O-])[O-].[K+].[K+].C(Cl)(Cl)Cl.[Br:27][CH2:28][C:29](Br)=[O:30]>O.CCCCCC.C(OCC)(=O)C>[Br:27][CH2:28][C:29]([NH:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[B:8]([OH:9])[OH:16])=[O:30](50 g, 0.228 mol) of 2-aminophenyl boronic acid pinacol ester and (110 g, 0.798 mole) of potassium carbonate were charged into 10 L, 3 necks RBF connected with overhead stirrer, thermometer and additional funnel, 5 L of Chloroform, synthetic grade was loaded then stirred for 10±5 minutes at 25±5° C. after that (115 g, 50 mL, 0.57 mol) of Bromoacetyl bromide was added drop wise during 10±5 minutes while the mixture stirred. After end of loading, the mixture was stirred for 1-2 hrs at 25±5° C., the reaction completion was monitored by TLC (Ethyl acetate:n-hexane, 15:85 v/v). Afterward, 4-5 L of purified water was loaded then transferred to 10 L separatory funnel and steeled down for 10 minutes, chloroform layer (lower) was separated and dried over 50 g of sodium sulfate and filtered. The filtrate solution was concentrated under vacuum to dryness. The residue was recrystallized from diethyl ether to get pure 2-(bromoacetamido)phenylboronic acid intermediate, the product was characterized by 1H-NMR, 13C-NMR, mass and elemental analysis.
Wird geladen…
