Synthesis
General procedure for the synthesis of 2-methyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)aniline from 4,4,5,5-tetramethyl-2-(2-methyl-3-nitrophenyl)-1,3,2-dioxaborolan-2-yl)aniline: in a 500 mL round-bottomed flask 4,4,5,5-tetramethyl-2-(2-methyl-3-nitrophenyl) -1,3,2-dioxaborolane(6) (8.44 g, 32.1 mmol) and methanol (150 mL) in a 500 mL round-bottom flask equipped with a magnetic stirrer. After the reaction system was evacuated twice and replaced with argon, 10% palladium carbon catalyst (50% wet weight, 425 mg dry weight) was added. The reaction system was again evacuated and replaced with hydrogen three times. The reaction was stirred at room temperature for 13 hours under hydrogen balloon pressure. Upon completion of the reaction, the system was evacuated twice and replaced with argon, filtered through a diatomaceous earth pad (521) and the filtrate was concentrated under vacuum. The resulting residue was dried under high vacuum for 24 h to afford 2-methyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (7) in quantitative yield (8.16 g) as a white solid with a melting point of 110-112 °C; mass spectrum (ESI+) m/z 234 (M+H).
References
[1] Patent: US2009/82330, 2009, A1. Location in patent: Page/Page column 24
[2] Patent: WO2008/33858, 2008, A2. Location in patent: Page/Page column 130; 137
[3] Patent: WO2009/137596, 2009, A1. Location in patent: Page/Page column 69-70
[4] Patent: WO2009/77334, 2009, A1. Location in patent: Page/Page column 87
