Yield:-

Reaction Conditions:

Stage #1:2-chloro-3-aminobenzoic acid with sulfuric acid;sodium nitrite in acetic acid at 0; for 0.5 h;
Stage #2: with potassium iodide in water;acetic acid at 0; for 2 h;

Steps:

86.A
Concentrated sulfuric acid (6.5 mL) was treated with sodium nitrite (621 mg, 9.00 mmol) in portions and stirred until the solids dissolved. The mixture was cooled to 0 °C and treated with a solution of 3-amino-2-chloro-benzoic acid (1.37 g, 8.00 mmol) in glacial acetic acid (16 mL) dropwise. After stirring at 0 °C for 30 minutes, the mixture was treated with a precooled 0 °C solution of potassium iodide (3.32 g, 20.0 mmol) in water (10 mL) dropwise. After stirring at 0 °C for 2 hours, the mixture was filtered and the filter cake washed with hexanes. The obtained solid was recrystallized from hot water to provide the title compound. ¹HNMR (DMSOd₆) δ 13.6 (br s, IH), 8.11-8.08 (m, IH), 7.70-7.68 (m, IH), 7.71 (dd, IH); MS (ESI) calcd for C₇H₄ClO₂: 281.8945. Found: 280.9 (M-H).

References:

ABBOTT LABORATORIES WO2006/86229, 2006, A1 Location in patent:Page/Page column 60-61