6-BroMobenzo[d][1,3]dioxole-4-carboxylic acid synthesis

Yield:72744-57-1 99%

Reaction Conditions:

with water;sodium hydroxide in tetrahydrofuran;methanol at 20; for 4 h;

Steps:

19.2 Step 2. Synthesis of 6-bromobenzo[d][1,3]dioxol-4-carboxylic acid (19-2)

A 1N-NaOH aqueous solution (58.7 mL) was added into the compound (19-1) (7.6 g, 29.3 mmol) in THF/MeOH (40 mL/80 mL) at room temperature. A reaction mixture was stirred at room temperature for 4 hours. After a reaction was completed, a volatile substance was removed under reduced pressure. A 1N-HCl aqueous solution was added into a residue to carry out acidification, during which a resulting mixture was stirred to precipitate a crude product. The crude product was filtered, washed with water and dried under high vacuum, so as to obtain the title compound (19-2) (7.2 g, 29.3 mmol, 99%). (0169) ¹H NMR (400 MHz, CDCl₃); δ 7.59 (d, J = 2.0 Hz, 1H), 7.13 (d, J = 2.0 Hz, 1H), 6.16 (s, 2H).

References:

EP3404033,2018,A1 Location in patent:Paragraph 0168-0169