Formaldehyde → HCID 14859100, compound

Ethyl indole-2-carboxylate (5.87 gm) in absolute ethanol (85 ml) was combined with potassium carbonate (4.3 gm) and 37% formaldehyde (2.6 gm) and heated to reflux for four days. The mixture was cooled to room temperature and the solvents removed on a rotary evaporator. The residue was dissolved in water (100 ml) and the water solution was washed with ether (2×50 ml). The aqueous solution was made acidic with 3.6 N sulfuric acid and the resulting mixture was extracted with methylene chloride (2×50 ml) and ether (2×50 ml). The combined organic layers were dried over magnesium sulfate and the solvent removed on a rotary evaporator. The residue was dissolved in acetone and purified by preparative centrifugally accelerated radial thin layer chromatography on silica gel using 10% methanol in methylene chloride as eluant. The product was obtained as an off-white solid. Physical data are reported in Table I.

1. temperatureheated
2. temperatureto reflux for four days
3. customthe solvents removed on a rotary evaporator
4. dissolutionThe residue was dissolved in water (100 ml)
5. washthe water solution was washed with ether (2×50 ml)
6. extractionthe resulting mixture was extracted with methylene chloride (2×50 ml) and ether (2×50 ml)
7. dry with materialThe combined organic layers were dried over magnesium sulfate
8. customthe solvent removed on a rotary evaporator
9. dissolutionThe residue was dissolved in acetone
10. custompurified by preparative centrifugally accelerated radial thin layer chromatography on silica gel using 10% methanol in methylene chloride as eluant
11. customThe product was obtained as an off-white solid

ORD record

ord-9a549096e0ca42c9bfceaf0ea80b4ffb

Source dataset

uspto-grants-1993_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05229413