1,3-Benzodioxole-5-carboxylic acid → N-methoxy-N-methylbenzo[d][1,3]dioxole-5-carboxamide

To a solution of benzo[1,3]dioxole-5-carboxylic acid (69 g, 415 mmol) in dimethylformamide (1L) was added di-imidazol-1-yl-methanone (74 g, 1.1 equiv), and the resulting reaction mixture was stirred at ambient temperature for 90 minutes. N,O-Dimethyl-hydroxylamine (43 g, 1.1 equiv) was added to the reaction mixture. The resulting reaction mixture was stirred at ambient temperature for 18 hours, and then concentrated in vacuo to ¼ of the volume, poured into 5% aqueous sodium hydrogen carbonate (1L), stirred at ambient temperature for 20 minutes, and then extracted with methyl tert-butyl ether (2×300 mL). The combined organics extracts were dried over magnesium sulfate and concentrated in vacuo. The resulting residue was azeotroped with toluene (800 mL) and dried under vacuum for 3 hours. The crude product was used in the next step without further purification.

1. customthe resulting reaction mixture
2. customThe resulting reaction mixture
3. stirringwas stirred at ambient temperature for 18 hours
4. concentrationconcentrated in vacuo
5. additionpoured into 5% aqueous sodium hydrogen carbonate (1L)
6. stirringstirred at ambient temperature for 20 minutes
7. extractionextracted with methyl tert-butyl ether (2×300 mL)
8. dry with materialThe combined organics extracts were dried over magnesium sulfate
9. concentrationconcentrated in vacuo
10. customThe resulting residue was azeotroped with toluene (800 mL)
11. customdried under vacuum for 3 hours
12. customThe crude product was used in the next step without further purification

ORD record

ord-cf528565848f4ceb951d44f6deea30c7

Source dataset

uspto-grants-2008_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07417041B2