2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → 6-(4-Chloro-1-butenyl)carbostyril

2.5 Grams of 6-(4-chloro-1-butenyl)-3,4-dihydrocarbostyril and 2.3 g of DDQ (2,3-dichloro-5,6-dicyanobenzoquinone) were mixed in 160 ml of dioxane and the mixture was refluxed by heating for 6 hours. Further, 1.1 of DDQ was added to the reaction mixture and the mixture was refluxed by heating for 3 hours. The reaction mixture was cooled and the precipitates thus formed were removed by filtration and the motor liquor was concentrated under a reduced pressure to obtain a residue. The residue was dissolved in a mixture of 100 ml of chloroform with 5 ml of methanol and the solution was padded through a silica gel column for removing the unreacted DDQ. The residue was recrystallized from methanol to obtain 1.6 g of 6-(4-chloro-1-butenyl)carbostyril in yellow needle-like crystals. Melting point: 215°-218° C.

1. temperaturethe mixture was refluxed
2. temperatureby heating for 6 hours
3. temperaturethe mixture was refluxed
4. temperatureby heating for 3 hours
5. temperatureThe reaction mixture was cooled
6. customthe precipitates thus
7. customformed
8. customwere removed by filtration
9. concentrationthe motor liquor was concentrated under a reduced pressure
10. customto obtain a residue
11. customfor removing the unreacted DDQ
12. customThe residue was recrystallized from methanol

ORD record

ord-b2b5b75acb134d27b42654905337ef2b

Source dataset

uspto-grants-1984_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04460593