Ammonium Chloride → Tert-butyl 5-aminothiophene-2-carboxylate

HRID 59747Notes

Reaction equation

[N+:1]([C:4]1[S:8][C:7]([C:9]([O:11][C:12]([CH3:15])([CH3:14])[CH3:13])=[O:10])=[CH:6][CH:5]=1)([O-])=O.[Cl-].[NH4+]>CCO.O.[Fe]>[NH2:1][C:4]1[S:8][C:7]([C:9]([O:11][C:12]([CH3:15])([CH3:14])[CH3:13])=[O:10])=[CH:6][CH:5]=1

Participants

Conditions

Temperature: 80 °C

Procedure

To a suspension of tert-butyl 5-nitrothiophene-2-carboxylate (Int. 54) (2.230 g, 9.73 mmol) in a mixture of EtOH (60 ml) and water (30 ml), iron powder (3.26 g, 58.4 mmol) and ammonium chloride (0.364 g, 6.81 mmol) were added. The reaction was stirred at 80° C. for 3 hours and then at RT overnight. The mixture was filtered through a celite pad and the filtrate was evaporated to dryness. The crude was then dissolved in EtOAc and washed with brine; the organic phase was dried over sodium sulfate and the solvent evaporated under vacuum. The residue was purified by filtration through a silica gel cartridge (petroleum ether/EtOAc=9/1 to 6/4) to yield tert-butyl 5-aminothiophene-2-carboxylate (Int. 55) (1.481 g, 7.43 mmol, MS/ESI+200.0 [MH]+).

Workup

additionwere added
customat RT
customovernight
filtrationThe mixture was filtered through a celite pad
customthe filtrate was evaporated to dryness
dissolutionThe crude was then dissolved in EtOAc
washwashed with brine
dry with materialthe organic phase was dried over sodium sulfate
customthe solvent evaporated under vacuum
filtrationThe residue was purified by filtration through a silica gel cartridge (petroleum ether/EtOAc=9/1 to 6/4)

Sources & evidence

ORD record: ord-0449aa2472d54828938340e2b80d282d
Source dataset: uspto-grants-2016_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09440954B2

Reaction notes

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