Hydrochloric Acid → HCID 68483604, compound

To a solution of ethyl 5-formyl-3-methyl-1H-pyrrole-2-carboxylate (0.25 g, 1.38 mmol) in t-BuOH (50 mL) was added 2-methylbutene as a 2M solution (24 mL, 48.3 mmol). In a separate flask sodium dihydrogen phosphate monohydrate (1.3 g, 9.42 mmol) and sodium chlorite (1.1 g, 12.2 mmol) were dissolved in water (30 mL). The aqueous solution was added to the alcoholic reaction mixture dropwise and stirred for 3 h. The solution was acidified with aqueous 1N HCl to a pH ˜4 and EtOAc (100 mL) added. The layers were separated, the aqueous layer extracted with EtOAc (5×25 mL), the organic layers combined, dried over sodium sulfate, filtered and the volume reduced (˜50 mL). Ethyl acetate (100 mL) was added and the solution extracted with sat. sodium bicarbonate (5×25 mL), the aqueous layers combined, acidified with 1N HCl to pH˜4-5, saturated with NaCl and extracted with EtOAc (5×25 mL). The organic layers were combined, dried over sodium sulfate, filtered and evaporated to afford 5-[(ethyloxy)carbonyl]-4-methyl-1H-pyrrole-2-carboxylic acid (0.196 g, 72%) as a white solid along with 3-chloro-5-[(ethyloxy)carbonyl]-4-methyl-1H-pyrrole-2-carboxylic acid.

1. additionThe aqueous solution was added to the alcoholic reaction mixture dropwise
2. additionadded
3. customThe layers were separated
4. extractionthe aqueous layer extracted with EtOAc (5×25 mL)
5. dry with materialdried over sodium sulfate
6. filtrationfiltered
7. additionEthyl acetate (100 mL) was added
8. extractionthe solution extracted with sat. sodium bicarbonate (5×25 mL)
9. extractionextracted with EtOAc (5×25 mL)
10. dry with materialdried over sodium sulfate
11. filtrationfiltered
12. customevaporated

ORD record

ord-68b8cc9c16234665ba8eaf3ec24b5794

Source dataset

uspto-grants-2012_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08304419B2