Hydrochloric Acid → 2-(Carboxymethyl)-1,5-dimethyl-1H-pyrrole-3-carboxylic acid

Temperature

110 °C

A mixture of 2-chloro-1,1-bis(methyloxy)propane (31 ml), 1,4-dioxan (20 ml), water (20 ml) and concentrated hydrochloric acid (7.2 ml) was heated under reflux for 30 minutes. After cooling in an ice bath, sodium bicarbonate (7.2 g) was added portionwise. The mixture which contained 2-chloropropionaldehyde was stirred for stirred for a further thirty minutes. In the meantime methylamine (40% in water, 110 ml) and water (20 ml) were cooled in an ice bath and 1,3-acetonedicarboxylic acid (20 g) was added portionwise whilst keeping the temperature below 20° C. After cooling to 110° C., the solution containing the 2-chloropropionaldehyde was added slowly whilst keeping the temperature below 15° C. The reaction mixture was stirred at 15° C. for one hour, then at room temperature for sixteen hours. The reaction mixture was cooled, acidified to pH 1 by the addition of 5N hydrochloric acid, and the resulting solid collected by filtration. The solid was washed with cold water, then diethyl ether. After drying, the solid washed with diethyl ether, and then dried, to afford the title compound as a buff solid 11.85 g.

1. temperaturewas heated
2. temperatureunder reflux for 30 minutes
3. temperatureAfter cooling in an ice bath
4. stirringfor stirred for a further thirty minutes
5. customthe temperature below 20° C
6. additionwas added slowly
7. customthe temperature below 15° C
8. stirringThe reaction mixture was stirred at 15° C. for one hour
9. waitat room temperature for sixteen hours
10. temperatureThe reaction mixture was cooled
11. filtrationthe resulting solid collected by filtration
12. washThe solid was washed with cold water
13. customAfter drying
14. washthe solid washed with diethyl ether
15. customdried

ORD record

ord-059877a8df134d7eb69fa7f2b27a4e10

Source dataset

uspto-grants-2009_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07589206B2