Ethyl chloroformate → 5-tert-Butyl 2-ethyl 3-amino-6,6-dimethylpyrrolo[3,4-c]pyrazole-2,5(4H,6H)-dicarboxylate

HRID 1042428Notes

Reaction equation

HRID 1042428 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.Cl[C:29]([O:31][CH2:32][CH3:33])=[O:30]>C1COCC1.CCOC(C)=O>[NH2:1][C:2]1[N:6]([C:29]([O:31][CH2:32][CH3:33])=[O:30])[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

Participants

6

Reactant 3

HCID 10928Ethyl chloroformateHCID 81531DiisopropylethylamineHCID 178451523HCID 178451523, compound

Product 1

HCID 575232455-tert-Butyl 2-ethyl 3-amino-6,6-dimethylpyrrolo[3,4-c]pyrazole-2,5(4H,6H)-dicarboxylateYield 38%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 8857Ethyl AcetateSolvent

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 ClCO2Et (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

  1. washwashed with water
  2. dry with materialwith brine, dried over sodium sulfate
  3. customevaporated
  4. customThe crude product was purified by flash chromatography (hexane/EtOAc 2/8)

Sources & evidence

ORD record
ord-9b1a2965894343f7b38c1e49ff3be83e
Source dataset
uspto-grants-2013_10
Patent number
US08557857B2

Reaction notes

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