7-Bromo-3-hydroxy-2-naphthalenecarboxylic acid

Yellow solid

In a 1L three-necked bottle, 40g of 4, 7-dibromo-3-hydroxy-2-naphthoic acid (0.116mol) and 500ml of glacialacetic acid were added, and stirred to be homogenous. The mixture was then added with 18g of tin powder (0.153mol)and 130ml of concentrated hydrochloric acid in order, heated to 125°C, and refluxed under heating for 12h. The mixturewas added with 300ml of water, stirred to room temperature, filtered, and the filter cake was washed with water (200ml*2), and dried in an oven to obtain 29.9g of a solid with a yield of 96.5percent.2L three-necked flask, Intermediate 2 (70 g, 202 mmol) and 800 mL were addedGlacial acetic acid, stir well, Followed by the addition of tin powder (23.9 g, 202 mmol)250mL concentrated hydrochloric acid, heated to 120 , Heating reflux 3h. Stop heating, Naturally cooled to room temperature, The reaction solution was poured into 1000 mL of ice water, Precipitation of a large number of yellow solid, Filter, filter cake with water, oven drying, To a solution of intermediate 3 in 50 g of solid, yield 93percentCompound 2 (70 g, 202 mmol), tin powder (23.9 g, 202 mmol) and 250 mL of concentrated HCl were successively added into acetic acid (800 mL). The mixture washeated to reflux for 3 h. After cooling to room temperature, the reaction was quenched with ice water (1000 mL) and the solid was filtered and dried to afford 3 (50 g, 93percent) as a yellow solid. The compound 22b (8.0 g, 0.3 mol) obtained in the above step was placed in a bottle, placed in a bottle, and 150 ml of methanol was added thereto, and after heating and dissolved, a catalytic amount of 1 ml of concentrated sulfuric acid was added. The reaction was refluxed overnight. The next day, TLC detected the reaction completely (petroleum ether/ethyl acetate = 4/1). Stop the reaction and bring to room temperature. The reaction solution was concentrated to dryness and a saturated sodium hydrogen carbonate solution was added. Adjust pH to neutral. The organic layer was combined, washed with brine and dried over anhydrous sodium sulfate. Filter and concentrate the filtrate to a small volume and add petroleum ether. A large amount of solid precipitated and stirring was continued for 30 minutes in an ice bath. Filter to give a solid. Drying gave a solid 6.5 g, yield: 77.4percent.

Molecular Weight:267.07
XLogP3:3.6
Hydrogen Bond Donor Count:2
Hydrogen Bond Acceptor Count:3
Rotatable Bond Count:1
Exact Mass:265.95786
Monoisotopic Mass:265.95786
Topological Polar Surface Area:57.5
Heavy Atom Count:15
Complexity:256
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes