Ammonium Chloride → 3-Bromo-5-(diethoxymethyl)-2-nitrothiophene

HRID 59752

Reaction equation

[Br:1][C:2]1[CH:3]=[C:4](C=O)[S:5][C:6]=1[N+:7]([O-:9])=[O:8].[Cl-].[NH4+].[CH:14]([O:21][CH2:22][CH3:23])([O:18][CH2:19][CH3:20])OCC>CCO>[Br:1][C:2]1[CH:3]=[C:4]([CH:14]([O:18][CH2:19][CH3:20])[O:21][CH2:22][CH3:23])[S:5][C:6]=1[N+:7]([O-:9])=[O:8]

Participants

Conditions

Temperature: 60 °C

Procedure

To a solution of 4-bromo-5-nitrothiophene-2-carbaldehyde (Int. 65) (6.981 g, 29.6 mmol) in EtOH (50 ml), ammonium chloride (0.475 g, 8.87 mmol) and triethyl orthoformate (7.39 ml, 44.4 mmol) were added, and the resulting solution was stirred at 60° C. for 14 hours. Additional triethyl orthoformate (7.39 ml, 44.4 mmol) was added, and the mixture was vigorously refluxed for further 2 days. The solvent was evaporated under vacuum and the crude was partitioned between water and EtOAc. The organic phase was washed with brine, dried over sodium sulfate, filtered and evaporated. The crude was purified by chromatography on silica gel cartridge (petroleum ether/EtOAc=9/1) to afford 3-bromo-5-(diethoxymethyl)-2-nitrothiophene (Int. 66) (7.456 g, 24.04 mmol).

Workup

temperaturethe mixture was vigorously refluxed for further 2 days
customThe solvent was evaporated under vacuum
customthe crude was partitioned between water and EtOAc
washThe organic phase was washed with brine
dry with materialdried over sodium sulfate
filtrationfiltered
customevaporated
customThe crude was purified by chromatography on silica gel cartridge (petroleum ether/EtOAc=9/1)

Sources & evidence

ORD record: ord-4d4f5ea7519745e492b3a0bb2f41119c
Source dataset: uspto-grants-2016_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09440954B2

Linked notes

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