3,3-DIMETHYL-2,3-DIHYDROBENZOFURAN-6-CARBOXYLIC ACID synthesis

Yield:1147531-58-5 99%

Reaction Conditions:

Stage #1: methyl 3,3-dimethyl-2,3-dihydro-1-benzofuran-6-carboxylatewith lithium hydroxide;water in methanol at 20; for 4 h;
Stage #2: with hydrogenchloride in methanol;water; pH=2;

Steps:

29.3

To a solution of 116a (100 mg, 0.43 mmol) and MeOH (4 mL) was added a solution of LiOH monohydrate (65.1 mg, 1.55 mmol) and water (1 mL). The mixture was stirred at RT for 16 h. The reaction mixture was concentrated in vacuo. The residue was dissolved in water (3 mL), acidified to a pH of about 2 with 3N HCl and extracted with EtOAc. The organic layer was dried (Na₂SO₄), filtered and concentrated in vacuo to afford 93 mg (99%) of 116b.

References:

US2009/105209,2009,A1 Location in patent:Page/Page column 64