Cesium carbonate → Ethyl 4-(2,4-diamino-3-methoxycarbonylphenyl)-furan-3-carboxylate

A mixture of methyl 2,6-diamino-3-bromobenzoate (Intermediate 90, 1.0 g), 2-methoxycarbonyl-furan-3-boronic acid (0.980 g), tris-(dibenzylideneacetone)-dipalladium (0.188 g), tri-tert-butylphosphonium tetrafluoroborate (0.119 g) and cesium carbonate (4.0 g) in dioxane (45 mL) and water (6 mL) was de-gassed and flushed with argon. The resultant mixture was stirred at room temperature for 1 hour, then heated at 70° C. for 1 hour. The mixture was cooled, diluted with ethyl acetate and washed with water, dried (MgSO4) and filtered. The filtrate was concentrated in vacuo and the residue was purified by chromatography on silica, eluting with a mixture of ethyl acetate and pentane, with a gradient of 20-50% to give ethyl 4-(2,4-diamino-3-methoxycarbonylphenyl)-furan-3-carboxylate (0.861 g).

1. customwas de-gassed
2. customflushed with argon
3. temperatureheated at 70° C. for 1 hour
4. temperatureThe mixture was cooled
5. additiondiluted with ethyl acetate
6. washwashed with water
7. dry with materialdried (MgSO4)
8. filtrationfiltered
9. concentrationThe filtrate was concentrated in vacuo
10. customthe residue was purified by chromatography on silica
11. washeluting with a mixture of ethyl acetate and pentane, with a gradient of 20-50%

ORD record

ord-52135b162fed41f4b890d3e57a9629fe

Source dataset

uspto-grants-2016_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09266896B2