Potassium Hydroxide → HCID 67995387, compound

Temperature

95 °C

A suspension of ethyl 6,9-dibromo-3,4-dihydro-1H-pyrido[4,3-b]indole-2(5H)-carboxylate (2.70 g, 6.72 mmol) in ethanol (25 mL) was treated with a solution of potassium hydroxide (15.07 g, 269 mmol) in water (15 mL) and ethanol (50 mL). The dark brown mixture was bubbled with nitrogen with sonication for 1 min. The mixture was then heated under nitrogen to 90-100° C. for 44 h, then at reflux for 23 h more. The solution was cooled to room temperature and concentrated under vacuum. The residual aqueous sludge was diluted with water (about 100 mL), stirred and intermittently sonicated for 1 h, and the precipitate was collected by filtration, washed thoroughly with water and dried under vacuum to provide the desired product as a light reddish-brown powder (2.123 g, 96% yield). LCMS (M+H+) m/z 329, 331, 333).

1. customThe dark brown mixture was bubbled with nitrogen with sonication for 1 min
2. temperatureat reflux for 23 h more
3. temperatureThe solution was cooled to room temperature
4. concentrationconcentrated under vacuum
5. additionThe residual aqueous sludge was diluted with water (about 100 mL)
6. customintermittently sonicated for 1 h
7. filtrationthe precipitate was collected by filtration
8. washwashed thoroughly with water
9. customdried under vacuum

ORD record

ord-01f9247cb6304876bf8301153479b0c4

Source dataset

uspto-grants-2014_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08685969B2