Ethyl chloroformate → 5-tert-butyl 1-ethyl 3-amino-1H-thieno[2,3-c]pyrazole-1,5-dicarboxylate

HRID 448128

Reaction equation

HRID 448128 reaction equation
[C:1](Cl)(=[O:5])[O:2][CH2:3][CH3:4].[NH2:7][C:8]1[C:9]2[CH:15]=[C:14]([C:16]([O:18][C:19]([CH3:22])([CH3:21])[CH3:20])=[O:17])[S:13][C:10]=2[NH:11][N:12]=1.C(N(C(C)C)CC)(C)C>O1CCCC1>[NH2:7][C:8]1[C:9]2[CH:15]=[C:14]([C:16]([O:18][C:19]([CH3:22])([CH3:21])[CH3:20])=[O:17])[S:13][C:10]=2[N:11]([C:1]([O:2][CH2:3][CH3:4])=[O:5])[N:12]=1

Participants

5

Reactant 3

HCID 10928Ethyl chloroformateHCID 81531DiisopropylethylamineHCID 178450636tert-butyl 3-amino-1H-thieno[2,3-c]pyrazole-5-carboxylate

Product 1

HCID 577372725-tert-butyl 1-ethyl 3-amino-1H-thieno[2,3-c]pyrazole-1,5-dicarboxylateYield 87.7%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

A solution of ethyl chlorocarbonate (4.90 mL, 51.7 mmol) in tetrahydrofuran (THF, 60 mL) was slowly added to a mixture of tert-butyl 3-amino-1H-thieno[2,3-c]pyrazole-5-carboxylate (12.0 g, 50.2 mmol) and diisopropylethylamine (DIEA, 51.5 mL, 301 mmol) in THF (300 mL), maintaining the temperature between −5 and −10° C. The reaction was kept at the same temperature for 5 minutes then allowed to reach room temperature. The obtained mixture was evaporated to dryness under vacuum and the residue extracted with ethyl acetate (AcOEt) and water. The organic layer was separated, dried over sodium sulfate and evaporated to dryness. The resulting raw material was triturated with diethyl ether to give 13.7 g of the title compound as a white solid.

Workup

  1. temperaturemaintaining the temperature between −5 and −10° C
  2. customto reach room temperature
  3. customThe obtained mixture was evaporated to dryness under vacuum
  4. extractionthe residue extracted with ethyl acetate (AcOEt) and water
  5. customThe organic layer was separated
  6. dry with materialdried over sodium sulfate
  7. customevaporated to dryness
  8. customThe resulting raw material was triturated with diethyl ether

Sources & evidence

ORD record
ord-8c28da037f4a46bdac1523c02562e0d1
Source dataset
uspto-grants-2013_07
Patent number
US08481584B2

Linked notes

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