The general procedure for the synthesis of 4-acetylaminophenylboronic acid pinacol ester from 4-aminoacetanilide and bis(boronic acid) pinacol ester is as follows:
Example 6: Synthesis of N-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)acetamide
In a 25 mL tubular reactor, N-(4-aminophenyl)acetamide (1 mmol, 150 mg), pinacol ester of bis(boronic acid) (B2pin2, 1.2 mmol, 305 mg), benzoyl peroxide (0.02 mmol, 5 mg), and acetonitrile (3 mL) were added sequentially. Subsequently, tert-butyl nitrite (1.5 mmol, 154 mg) was added. The reaction was carried out at room temperature with stirring for 1 hour. After completion of the reaction, the reaction solution was concentrated and purified by column chromatography (eluent: petroleum ether/ethyl acetate=20:1, V/V) to afford the target compound N-(4-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)acetamide as a white solid in 93% yield.
The nuclear magnetic resonance (NMR) data of the compound are as follows:
1H NMR (400 MHz, CDCl3) δ 7.76 (d, 1H, J = 8.4 Hz), 7.53 (d, 1H, J = 8.3 Hz), 2.16 (s, 3H), 1.33-1.24 (m, 12H).
13C NMR (100 MHz, CDCl3) δ 168.5, 140.5, 135.6, 128.8, 119.9, 118.5, 83.6, 74.9, 24.9, 24.7, 24.5, 24.4.
