Yield:38235-71-1 81%

Reaction Conditions:

Stage #1:meta-aminobenzoic acid with hydrogenchloride;sodium nitrite in water at 0; for 1 h;
Stage #2: with tin(II) chloride dihdyrate in water at 0 - 20; for 2 h;

Steps:

1 Step 1 : Preparation of 3-hydrazinylbenzoic acid
To a stirred suspension of 3-aminobenzoic acid (2 g, 14.6 mmol) in cone. HCI was added an aqueous solution of NaN0₂ (1 g, 14.6mmol) at 0 °C. The reaction mixture was stirred for 1 hour. A solution of SnCl₂.2H₂0 in cone. HCI was then added at 0 °C. The reaction solution was stirred for an additional 2 hours at room temperature. The precipitate was filtered and washed with ethanol and ether to give the crude product, which was purified by column chromatography on silica gel to give 3-hydrazinylbenzoic acid as a pale solid (1 .8 g, 81 %).

References:

NOVOGEN LTD;JAMES, Ian;DIXON, Ian;HEATON, Andrew;EIFFE, Eleanor;GUNNING, Peter WO2016/8010, 2016, A1 Location in patent:Page/Page column 38

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