Sodium Hydroxide → 2-(1-carboxy-3-phenylpropylamino)-hexahydro-3-oxo-1H-pyrazolo[1,2-a]pyridazine-5-carboxylic acid
Reaction equation
[NH2:1][CH:2]1[CH2:13][N:5]2[CH2:6][CH2:7][CH2:8][CH:9]([C:10]([OH:12])=[O:11])[N:4]2[C:3]1=[O:14].O=[C:16]([CH2:20][CH2:21][C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1)[C:17]([OH:19])=[O:18].[OH-].[Na+].C([BH3-])#N.[Na+]>O>[C:17]([CH:16]([NH:1][CH:2]1[CH2:13][N:5]2[CH2:6][CH2:7][CH2:8][CH:9]([C:10]([OH:12])=[O:11])[N:4]2[C:3]1=[O:14])[CH2:20][CH2:21][C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1)([OH:19])=[O:18]Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 1
Procedure
0.896 g of 2-amino-hexahydro-3-oxo-1H-pyrazolo[1,2-a]pyridazine-5-carboxylic acid (racemate A) was dissolved in 6 ml of water. 2.4 g of 2-oxo-4-phenylbutyric acid were added and the mixture was adjusted to pH 6 with 2N aqueous sodium hydroxide solution. 0.504 g of sodium cyanoborohydride was then added and the mixture was stirred at room temperature for 22 hours. The resulting solution was applied to 10 g of Zerolit225 ion-exchange resin (H+ form). Elution with water containing 2% pyridine gave 0.98 g of a crude diastereomeric product. Crystallization from water gave a solid which was recrystallized from methanol to yield 0.36 g (22%) of 2-(1-carboxy-3-phenylpropylamino)-hexahydro-3-oxo-1H-pyrazolo[1,2-a]pyridazine-5-carboxylic acid (racemate A) in the form of a white solid of melting point 233°-235° C. (decomposition).
Workup
- washElution with water containing 2% pyridine
- customgave 0.98 g of a crude diastereomeric product
- customCrystallization from water
- customgave a solid which
- customwas recrystallized from methanol
Sources & evidence
- ORD record
- ord-a6c217f43aad4fda88a80fa007bb10de
- Source dataset
- uspto-grants-1988_09
- Patent number
- US04772701
Reaction notes
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