Yield: 93%

Reaction Conditions:

with nitric acid;acetic acid at 10; for 1.5 h;

Steps:

2.1 Example 2: Synthesis of 7-fluoro-2,3-dihydrobenzo[b][1,4]dioxin-5-amine (Intermediate 2E)
Step 1: To a solution of 2A (100.0 g, 0.769 mol) in AcOH (800 mL) was added dropwise HNO₃/AcOH (200 mL, v/v=1/1). The mixture was stirred at 10° C. for 90 min and then poured into ice-water (4 L). The solid was collected by filtration and washed by small amount of water to afford 2B (125 g, 93%), which was used in the next step without further purification.

References:

Ventyx Biosciences, Inc. US2021/139486, 2021, A1 Location in patent:Paragraph 0323; 0324