Ethyl Acetate → 5-tert-Butyl 2-ethyl 3-amino-6,6-dimethylpyrrolo[3,4-c]pyrazole-2,5(4H,6H)-dicarboxylate
Reaction equation
[NH2:1][C:2]1[NH:6][N:5]=[C:4]2[C:7]([CH3:18])([CH3:17])[N:8]([C:10]([O:12][C:13]([CH3:16])([CH3:15])[CH3:14])=[O:11])[CH2:9][C:3]=12.C(N(CC)C(C)C)(C)C.[CH3:28][CH2:29][O:30][C:31](C)=[O:32]>C1COCC1>[NH2:1][C:2]1[N:6]([C:31]([O:30][CH2:29][CH3:28])=[O:32])[N:5]=[C:4]2[C:7]([CH3:18])([CH3:17])[N:8]([C:10]([O:12][C:13]([CH3:16])([CH3:15])[CH3:14])=[O:11])[CH2:9][C:3]=12Participants
Procedure
15 g of tert-Butyl 3-amino-6,6-dimethyl-2,6-dihydropyrrolo[3,4-c]pyrazole-5(4H)-carboxylate (59.4 mmol) were dissolved in anhydrous THF (150 ml) and treated, at 0° C. under Ar atmosphere, first with N,N-diisopropylethylamine (50 ml) and then with ClCO2 Et (4.65 ml, 1 eq.) dropwise. 90 minutes later, the solvent was diluted with EtOAc (1 l), washed with water and then with brine, dried over sodium sulfate and evaporated. The crude product was purified by flash chromatography (hexane/EtOAc 2/8) to afford 7.3 g of 5-tert-butyl 2-ethyl 3-amino-6,6-dimethylpyrrolo[3,4-c]pyrazole-2,5(4H,6H)-dicarboxylate as the major compound in 38% yield, together with 5.7 g of 5-tert-butyl 1-ethyl 3-amino-6,6-dimethyl-4,6-dihydropyrrolo[3,4-c]pyrazole-1,5-dicarboxylate in 30% yield.
Workup
- washwashed with water
- dry with materialwith brine, dried over sodium sulfate
- customevaporated
- customThe crude product was purified by flash chromatography (hexane/EtOAc 2/8)
Sources & evidence
- ORD record
- ord-86af1f73abaf4833aad398d7c434cc0a
- Source dataset
- uspto-grants-2013_07
- Patent number
- US08481585B2
Reaction notes
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