tert.butyl 2-acetylthiomethyl-hexahydro-3-oxo-1H-pyrazolo[1,2-a]pyridazine-5-carboxylate → 2-acetylthiomethyl-hexahydro-3-oxo-1H-pyrazolo[1,2-a]pyridazine-5-carboxylic acid
Reaction equation
[C:1]([S:4][CH2:5][CH:6]1[CH2:21][N:9]2[CH2:10][CH2:11][CH2:12][CH:13]([C:14]([O:16]C(C)(C)C)=[O:15])[N:8]2[C:7]1=[O:22])(=[O:3])[CH3:2]>FC(F)(F)C(O)=O>[C:1]([S:4][CH2:5][CH:6]1[CH2:21][N:9]2[CH2:10][CH2:11][CH2:12][CH:13]([C:14]([OH:16])=[O:15])[N:8]2[C:7]1=[O:22])(=[O:3])[CH3:2]Participants
3
Procedure
1.69 of tert.butyl 2-acetylthiomethyl-hexahydro-3-oxo-1H-pyrazolo[1,2-a]pyridazine-5-carboxylate (diastereomer A) were treated with 10 ml of trifluoroacetic acid at room temperature for 2 hours. The solution was evaporated and the residue was re-evaporated with toluene several times. The residue was then crystallized from acetone to give 1.1 g of 2-acetylthiomethyl-hexahydro-3-oxo-1H-pyrazolo[1,2-a]-pyridazine-5-carboxylic acid having a melting point of 166°-168° C. (decomposition).