Sulfuric Acid → Hydrochloric Acid
Reaction equation
C[O:2][C:3]1[C:13]2[C:8](=[N:9][CH:10]=[CH:11][CH:12]=2)[C:7]([CH:15]2[CH2:20][CH2:19][N:18]([CH3:21])[CH2:17][CH2:16]2)([OH:14])[C:6]2[CH:22]=[CH:23][C:24]([Cl:26])=[CH:25][C:5]=2[CH:4]=1.OS(O)(=O)=O.[OH-].[Na+]>>[Cl:26][C:24]1[CH:23]=[CH:22][C:6]2[C:7]([OH:14])([CH:15]3[CH2:20][CH2:19][N:18]([CH3:21])[CH2:17][CH2:16]3)[C:8]3=[N:9][CH:10]=[CH:11][CH:12]=[C:13]3[C:3](=[O:2])[CH2:4][C:5]=2[CH:25]=1.[ClH:26]Participants
5
Procedure
Dissolve 5-Methoxy-8-chloro-11-(1-methyl-4-piperidinyl)-11H-benzo[5,6]cyclohepta[1,2-b]pyridin-11-ol (4.26 g) in CH30H (6 mL) at 0° C. under an argon atmosphere. Add slowly a cooled solution of 92% aqueous H2SO4 (54 mL). Allow the mixture to warm to room temperature for 35 minutes. Pour the solution onto ice, basify with aqueous NaOH (25%), and extract with methylene chloride (3×). Combine the organic portions, wash with brine and dry over sodium sulfate. Filter and concentrate in vacuo. Triturate the residue with isopropyl ether to give an intermediate, 8-chloro-11-hydroxy-11-(1-methyl-4-piperidinyl)-6,11-dihydro-5H-benzo[5,6]cyclohepta[1,2-b]pyridin-5-one as a white solid (3.58 g., 92%, m.p. 170° to 174° C. as HCl salt).
Workup
- additionPour the solution onto ice
- extractionextract with methylene chloride (3×)
- washCombine the organic portions, wash with brine
- dry with materialdry over sodium sulfate
- filtrationFilter
- concentrationconcentrate in vacuo
- customTriturate the residue with isopropyl ether
Sources & evidence
- ORD record
- ord-922264001d7b4d54a711269071df9024
- Source dataset
- uspto-grants-1992_02
- Patent number
- US05089496
Reaction notes
Loading…