Formaldehyde → HCID 21258056, compound
Reaction equation
[C:1](OC(=O)C)(=O)C.Cl.[CH3:9][NH:10][CH3:11].C=O.[C:14]([C:17]1[CH:18]=[N:19][N:20]2[CH2:25][CH2:24][CH2:23][CH2:22][C:21]=12)(=[O:16])[CH3:15].C(=O)([O-])[O-].[K+].[K+]>>[CH3:9][N:10]([CH2:1][CH2:15][C:14]([C:17]1[CH:18]=[N:19][N:20]2[CH2:25][CH2:24][CH2:23][CH2:22][C:21]=12)=[O:16])[CH3:11]Participants
Conditions
- Temperature
- 80 °C
Procedure
Acetic anhydride (4.3 g) was dropwise added while stirring dimethylamine hydrochloride (1.0 g) and 37% formaldehyde solution (1.0 g) at 50° C. After the dropwise addition, the reaction mixture was stirred at 80° C. for 1 hour, and 3-acetyl-4,5,6,7-tetrahydropyrazolo[2,3-a]pyridine (1.4 g) was added. The mixture was stirred for 2 hours with heating. The reaction mixture was poured into ice water and potassium carbonate was added, which was followed by extraction with chloroform. The extract was dried over magnesium sulfate and the solution was evaporated under reduced pressure to give 1.75 g of 3-(3-(N,N-dimethylamino)propionyl)-4,5,6,7-tetrahydropyrazolo[2,3-a]pyridine. This compound (1.75 g) was dissolved in acetone (10 ml) and methyl iodide (1.1 g) was added. The precipitated crystals were collected by filtration to give 1.2 g of a quaternary salt of (3-(4,5,6,7-tetrahydropyrazolo[2,3-a]pyridin-3-yl)-3-oxypropyl)trimethylammonium iodide, m.p. 210-213° C.
Workup
- additionAfter the dropwise addition
- stirringThe mixture was stirred for 2 hours
- temperaturewith heating
- additionwas added
- extractionwhich was followed by extraction with chloroform
- dry with materialThe extract was dried over magnesium sulfate
- customthe solution was evaporated under reduced pressure
Sources & evidence
- ORD record
- ord-935047d1b25047f9adc9f196c6401568
- Source dataset
- uspto-grants-2001_02
- Patent number
- US06187774B1
Reaction notes
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