Hydrochloric Acid → tert-Butyl 3-amino-4,6-dihydropyrrolo[3,4-c]pyrazole-5(1H)-carboxylate
Reaction equation
[NH2:1][NH2:2].Cl.[C:4]([CH:6]1[C:10](=O)[CH2:9][N:8]([C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])[CH2:7]1)#[N:5]>C(O)C.C(OCC)(=O)C.C(=O)(O)[O-].[Na+]>[NH2:5][C:4]1[C:6]2[CH2:7][N:8]([C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])[CH2:9][C:10]=2[NH:1][N:2]=1Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 3
Procedure
To a solution of anhydrous hydrazine (0.082 mL) in ethanol (6.5 mL) was added hydrogen chloride (1.43 mL, 2N solution in diethyl ether). The reaction mixture was stirred for 5 min, then tert-butyl 3-cyano-4-oxopyrrolidine-1-carboxylate was added and the mixture heated to reflux. After 1 h the mixture was cooled to ambient temperature and diluted with a mixture of ethyl acetate and saturated aqueous sodium bicarbonate solution (1:1, 20 mL). The layers were separated and the aqueous phase extracted with ethyl acetate (3×15 mL). The combined organic phases were dried over anhydrous sodium sulfate, filtered and evaporated in vacuo. The residue was purified on a Biotage Horizon® system (silica gel, 0 to 100% ethyl acetate/hexanes followed by 0 to 20% methanol/ethyl acetate gradient) to give the title compound. LC/MS 225.2 (M+1).
Workup
- temperaturethe mixture heated to reflux
- customThe layers were separated
- extractionthe aqueous phase extracted with ethyl acetate (3×15 mL)
- dry with materialThe combined organic phases were dried over anhydrous sodium sulfate
- filtrationfiltered
- customevaporated in vacuo
- customThe residue was purified on a Biotage Horizon® system (silica gel, 0 to 100% ethyl acetate/hexanes followed by 0 to 20% methanol/ethyl acetate gradient)
Sources & evidence
- ORD record
- ord-63989e08213849a1b1f1db375ebcc842
- Source dataset
- uspto-grants-2010_07
- Patent number
- US07750034B2
Reaction notes
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