Methyl 3-amino-2-thiophenecarboxylate → Methyl 3-((tert-butoxycarbonyl)amino)thiophene-2-carboxylate

HRID 1694524Notes

Reaction equation

HRID 1694524 reaction equation
[CH3:1][O:2][C:3]([C:5]1[S:6][CH:7]=[CH:8][C:9]=1[NH2:10])=[O:4].[O:11](C(OC(C)(C)C)=O)[C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=O>CN(C1C=CN=CC=1)C.N1C=CC=CC=1>[CH3:1][O:2][C:3]([C:5]1[S:6][CH:7]=[CH:8][C:9]=1[NH:10][C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:11])=[O:4]

Participants

5

Reactant 2

HCID 89652Methyl 3-amino-2-thiophenecarboxylateHCID 90495Di-tert-butyl dicarbonate

Product 1

HCID 18925408Methyl 3-((tert-butoxycarbonyl)amino)thiophene-2-carboxylateYield 71,592%

Reagents, catalysts & solvents 2

HCID 142844-(Dimethylamino)pyridineCatalystHCID 1049PyridineSolvent2×

Procedure

In a 3 L 3 neck flask with a mechanical stirrer, DMAP (11.5 g, 0.10 mmol) was added to a solution of 3-amino-thiophene-2-carboxylic acid methyl ester (105 g, 0.95 mmol) and in pyridine (750 mL). A solution of (BOC)2O (222 g, 1.02 mol) in pyridine (750 mL) was slowly added to the previous solution while the temperature was kept between 20 and 25° C. The mixture was stirred under nitrogen for 20 h. The reaction mixture was evaporated to dryness then triturated in 500 mL of MeOH at rt for 3 h then 30 min at 0° C. The suspension was filtered on a buchner funnel and washed with cold ethanol. The white solid was dried to afford 175 g (70%) of 3-tert-Butoxycarbonylamino-thiophene-2-carboxylic acid methyl ester.

Workup

  1. customwas kept between 20 and 25° C
  2. customThe reaction mixture was evaporated to dryness
  3. customthen triturated in 500 mL of MeOH at rt for 3 h
  4. custom30 min
  5. customat 0° C
  6. filtrationThe suspension was filtered on a buchner funnel
  7. washwashed with cold ethanol
  8. customThe white solid was dried

Sources & evidence

ORD record
ord-bf5f4789086644538393ea02745482df
Source dataset
uspto-grants-2012_04
Patent number
US08158675B2

Reaction notes

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