HCID 291759, compound → 3-(4-Methyl-1H-pyrrol-3-yl)propanoic acid

Temperature

10 °C

2-Carboxy-5-ethoxycarbonyl-3-(2-ethoxycarbonylethyl)-4-methylpyrrole (50.5 g) and 400 ml 10% sodium hydroxide solution was heated to 180° C. in a Parr autoclave for 90 minutes. This process was repeated 4 more times until a total of 252.2 g of 2-carboxy-5-ethoxycarbonyl-3-(2-ethoxycarbonylethyl)-4-methylpyrrole had been treated. The five solutions were combined and rotary evaporated to a volume of about 1.8 L of thick black residue. The mixture was cooled to 10° C. in a water bath and 50% sulfuric acid was slowly added so as to keep the temperature at <20° C. until the pH was 2. Ethyl ether (1400 mL) was added, the mixture filtered and the precipitate saved. The precipitate was extracted in a Soxhlet extractor with 500 mL of ether. The combined ether layers were washed with 250 mL water followed by 150 mL of water. The combined water layers were back extracted with 150 mL of ether. All the ether layers were rotary evaporated and the residue dried to give 123.5 g of 3-(2-carboxyethyl)-4-methylpyrrole.

1. additionhad been treated
2. customrotary evaporated to a volume of about 1.8 L of thick black residue
3. addition50% sulfuric acid was slowly added so as
4. customat <20° C.
5. additionEthyl ether (1400 mL) was added
6. filtrationthe mixture filtered
7. extractionThe precipitate was extracted in a Soxhlet extractor with 500 mL of ether
8. washThe combined ether layers were washed with 250 mL water
9. extractionThe combined water layers were back extracted with 150 mL of ether
10. customAll the ether layers were rotary evaporated
11. customthe residue dried

ORD record

ord-08cc2ce35e1a47e0bfd0eeafeed56e10

Source dataset

uspto-grants-2005_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06878733B1