Potassium Carbonate → Cilostazol
Reaction equation
[OH:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[NH:8][C:7](=[O:12])[CH2:6][CH2:5]2.[OH-].[K+].C([O-])([O-])=O.[K+].[K+].Cl[CH2:22][CH2:23][CH2:24][CH2:25][C:26]1[N:30]([CH:31]2[CH2:36][CH2:35][CH2:34][CH2:33][CH2:32]2)[N:29]=[N:28][N:27]=1>>[CH:11]1[C:2]([O:1][CH2:22][CH2:23][CH2:24][CH2:25][C:26]2[N:30]([CH:31]3[CH2:36][CH2:35][CH2:34][CH2:33][CH2:32]3)[N:29]=[N:28][N:27]=2)=[CH:3][C:4]2[CH2:5][CH2:6][C:7]([NH:8][C:9]=2[CH:10]=1)=[O:12]Participants
Procedure
A mixture of 10 grams of 6-hydroxy-3,4dihydroquinolin-2(1H)-one (Compound I, 0.0613 mole), 4.05 grams of flaked potassium hydroxide (0.0650 mole) and 1.5 grams of K2CO3 (0.011 mole), was stirred in 130 ml of 1-botanol in a flask equipped with a soxhlet extraction apparatus containing 28 grams of 3 Å molecular sieves. The mixture was heated to reflux while passing the solvent over the molecular sieves for 30 minutes. Thereafter 18 grams of 5-(4-chlorobutyl)-1-cyclohexyl-1H-tetrazole (Compound II, 0.0742 moles, which are 1.2 equivalents with respect to Compound I) were added and the reflux was allowed to continue for about 5 hours. The reaction mixture was cooled thereafter to room temperature, and the solid product was collected by filtration, washed with 1-butanol and water and dried at 50° C. overnight to afford 19.2 grams of crude Cilostazol at 70.0% yield.
Workup
- customequipped with a soxhlet extraction apparatus
- additioncontaining 28 grams of 3 Å molecular sieves
- temperatureThe mixture was heated
- temperatureto reflux
- customfor 30 minutes
- temperatureThe reaction mixture was cooled
- filtrationto room temperature, and the solid product was collected by filtration
- washwashed with 1-butanol and water
- customdried at 50° C. overnight
Sources & evidence
- ORD record
- ord-61270cd6dfcc4fdc88e7c3c3677c432a
- Source dataset
- uspto-grants-2009_04
- Patent number
- US07524960B2
Reaction notes
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