Benzoyl Peroxide → 5-Chlorothieno[3,2-b]pyridine-3-carbaldehyde

HRID 1773508Notes

Reaction equation

[Cl:1][C:2]1[N:7]=[C:6]2[C:8]([CH3:11])=[CH:9][S:10][C:5]2=[CH:4][CH:3]=1.BrN1C(=[O:18])CCC1=O.C(OOC(=O)C1C=CC=CC=1)(=O)C1C=CC=CC=1>C(Cl)(Cl)(Cl)Cl>[Cl:1][C:2]1[N:7]=[C:6]2[C:8]([CH:11]=[O:18])=[CH:9][S:10][C:5]2=[CH:4][CH:3]=1

Participants

Conditions

Temperature: 100 °C

Procedure

A mixture of 5-chloro-3-methyl-thieno[3,2-b]pyridine (0.5 g, 2.7 mmol), N-bromosuccinimide (0.48 g, 2.7 mmol) and benzoyl peroxide (50 mg) in carbon tetrachloride (3 mL) was heated at 100° C. in a microwave reactor for 15 minutes. The supernatant was decanted and evaporated under reduced pressure, the residue was suspended in toluene (3 mL) and pyridine-N-oxide (0.5 g) was added, followed by sodium bicarbonate (0.4 g) and diisopropylethylamine (3 drops). The reaction mixture was heated at 150° C. in a microwave reactor for 5 minutes, was then diluted with ethyl acetate, washed with water and brine, dried over anhydrous sodium sulfate, filtered and evaporated under reduced pressure. The crude residue was purified by flash chromatography (EtOAc/hexane, 20/80) to give 150 mg of 5-chloro-thieno[3,2-b]pyridine-3-carbaldehyde.

Workup

customThe supernatant was decanted
customevaporated under reduced pressure
additionpyridine-N-oxide (0.5 g) was added
temperatureThe reaction mixture was heated at 150° C. in a microwave reactor for 5 minutes
additionwas then diluted with ethyl acetate
washwashed with water and brine
dry with materialdried over anhydrous sodium sulfate
filtrationfiltered
customevaporated under reduced pressure
customThe crude residue was purified by flash chromatography (EtOAc/hexane, 20/80)

Sources & evidence

ORD record: ord-3ae575843b5044ba84e084ac97166340
Source dataset: uspto-grants-2016_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09255110B2

Reaction notes

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