Sodium Methoxide → 7-Methoxy-2,3-dihydrobenzo[b][1,4]dioxine-6-carboxylic acid

HRID 2094871Notes

Reaction equation

Br[C:2]1[C:3]([C:12]([O:14]C)=[O:13])=[CH:4][C:5]2[O:10][CH2:9][CH2:8][O:7][C:6]=2[CH:11]=1.[CH3:16][O-:17].[Na+]>CN(C=O)C.O>[CH3:16][O:17][C:2]1[C:3]([C:12]([OH:14])=[O:13])=[CH:4][C:5]2[O:10][CH2:9][CH2:8][O:7][C:6]=2[CH:11]=1

Participants

Conditions

Temperature: 0 °C

Procedure

In a 2 mL microwave vial, methyl 7-bromo-2,3-dihydrobenzo[b][1,4]dioxine-6-carboxylate (273 mg, 1 mmol) and CuBr (14.3 mg, 0.1 mmol) were dissolved in dry DMF and was placed in ice bath. Sodium methoxide (540 mg, 10 mmol) was added into the reaction mixture dropwise while stirring at 0° C. The reaction was warmed to room temperature and stirred for 45 minutes. The reaction was then placed in a microwave reactor for 5 minutes at 135° C. The reaction mixture was dissolved in water and washed with ethyl acetate. The water layer was collected and acidified to pH 4 with 1M HCl. The product was extracted using ethyl acetate then dried over sodium sulfate. The solvent was evaporated under vacuum to give the desired intermediate of 7-methoxy-2,3-dihydrobenzo[b][1,4]dioxine-6-carboxylic acid which was used directly without further purification. Yield 57%. MS M+H calculated 211.1, found 211.1.

Workup

temperatureThe reaction was warmed to room temperature
stirringstirred for 45 minutes
washwashed with ethyl acetate
customThe water layer was collected
extractionThe product was extracted
dry with materialthen dried over sodium sulfate
customThe solvent was evaporated under vacuum

Sources & evidence

ORD record: ord-2bb04b08c0f24f24ac9d794b1696688f
Source dataset: uspto-grants-2013_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08445692B2

Reaction notes

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