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

HRID 1096154Notes

Reaction equation

HRID 1096154 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-c4988731b38744cfad6fd71a74b94d3e
Source dataset
uspto-grants-2012_03
Patent number
US08138217B2

Reaction notes

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