Yield:1736-66-9 49%

Reaction Conditions:

with nitric acid;acetic acid at 25 - 60;

Steps:

1.2 Synthesis of N-(2,2-difluoro-6-nitrobenzo[d][l,3]dioxol-5-yl)acetamide

N-(2,2-difluorobenzo[d][l ,3]dioxol-5-yl)acetamide (11.39 g, 52.938 mmol) was dissolved in glacial acetic acid (50.4 ml). To the resulting mixture was added dropwise a mixture of fuming nitric acid (6.1 ml, 3.35 eq.) in glacial acetic acid (20.2 ml, 0.28 eq.). After addition, the reaction mixture was stirred for 22 h at room temperature. The reaction mixture was stirred at 60°C overnight. Subsequently, the reaction mixture was poured into a of ice and water mixture. The resulting precipitate was filtered off by suction filtration. The crude product was then purified by column chromatography on a silica gel flash column (eluent DCM:MeOH 95:5). The product was isolated and concentrated in vacuo to obtain a yellow solid (6.7 g, 49% yield, 100% purity). ¹H NMR (DMSO-d₆ + CCl₄): 2.09 (3H, s, CH₃), 7.76 (1H, s, CH-arom.)₅ 8.15 (1H, s, CH- arom.), 10.33 (1H, s, NH)

References:

WO2014/1464,2014,A1 Location in patent:Page/Page column 46; 47