Triethylamine → 3-(1,6-dimethyl-1H-indol-3-yl)-4-(1-methyl-1H-indol-3yl)-pyrrole-2,5-dione

Temperature

0 °C

To a suspension of the known (1-methyl-1H-indol-3-yl)-oxo-acetyl chloride (183 mg, 0.83 mm) and 2-(1,6-dimethyl-1H-indol-3-yl)-acetimidic acid isopropyl ester hydrochloride (233 mg, 0.83 mm) in CH2Cl2 (6 mL) which had been cooled to 0° C., was added Et3N (0.46 mL, 3.3 mm). The reaction was allowed to warm to room temperature overnight, then diluted with CH2Cl2 (20 mL), and extracted with H2O(15 mL) and 0.5N HCl(15 mL). The organic fraction was dried over MgSO4, filtered and evaporated, and the residue combined with toluene (3 mL). After cooling to 0° C., para-toluene sulfonic acid (pTsOH) (174 mg, 0.91 mm) was added, and the mixture was stirred at room temperature for 3 hours. The red solids which precipitated were collected and partitioned between CH2Cl2 (50 mL) and H2O(25 mL). The organic fraction was washed with saturated NaHCO3 (25 mL) solution, then dried over MgSO4, filtered and evaporated. The residue was washed with cold CH2Cl2 to yield 3-(1,6-dimethyl-1H-indol-3-yl)-4-(1-methyl-1H-indol-3yl)-pyrrole-2,5-dione; mp=264°-266° C.

1. temperatureto warm to room temperature overnight
2. extractionextracted with H2O(15 mL) and 0.5N HCl(15 mL)
3. dry with materialThe organic fraction was dried over MgSO4
4. filtrationfiltered
5. customevaporated
6. temperatureAfter cooling to 0° C.
7. additionpara-toluene sulfonic acid (pTsOH) (174 mg, 0.91 mm) was added
8. customThe red solids which precipitated
9. customwere collected
10. custompartitioned between CH2Cl2 (50 mL) and H2O(25 mL)
11. washThe organic fraction was washed with saturated NaHCO3 (25 mL) solution
12. dry with materialdried over MgSO4
13. filtrationfiltered
14. customevaporated
15. washThe residue was washed with cold CH2Cl2

ORD record

ord-a7fe95e0de50451f92a7c17c17d4ace2

Source dataset

uspto-grants-1999_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05891901