Dimethyl Sulfoxide → 4-(4-Methylpiperazin-1-yl)benzaldehyde

Temperature

-78 °C

A solution of 4-(4-formyl-phenyl)-piperazine-1-carboxylic acid tert-butyl ester (1.3 g, 4.47 mmol) in THF (50 mL) was mixed with LAH (0.7 g, 17.87 mmol) and stirred at reflux for 14 h. The reaction was quenched at room temperature by adding KOH aqueous (14 N, 20 mL). The supernatant was decanted and combined with DCM washings, then diluted with water (50 mL). The mixture was extracted with DCM (3×50 mL) followed by concentration using a rotary evaporator to give [4-(4-methyl-piperazin-1-yl)-phenyl]-methanol (0.82 g, 89%). To a solution of DMSO (0.56 mL, 7.96 mmol) in DCM (50 mL) at −78° C. was added oxalyl chloride (0.7 mL, 7.96 mmol) and the resulting mixture was stirred at −78° C. for 0.5 h. A solution of [4-(4-methyl-piperazin-1-yl)-phenyl]-methanol (0.82 g, 3.98 mmol) in DCM (20 mL) was slowly added. The reaction was stirred at −78° C. for 1.5 h. Triethylamine (1.7 mL, 11.94 mmol) was added and the reaction was allowed to gradually warm up to room temperature. After stirring for 4 h the reaction was quenched by adding sodium bicarbonate aqueous (1 N, 50 mL). The mixture was extracted with DCM (3×50 mL) followed by concentration to afford a residue, which was further purified by column chromatography to yield 4-(4-methyl-piperazin-1-yl)-benzaldehyde (0.5 g, 61%).

1. stirringThe reaction was stirred at −78° C. for 1.5 h
2. temperatureto gradually warm up to room temperature
3. stirringAfter stirring for 4 h the reaction
4. customwas quenched
5. additionby adding sodium bicarbonate aqueous (1 N, 50 mL)
6. extractionThe mixture was extracted with DCM (3×50 mL)
7. concentrationfollowed by concentration
8. customto afford a residue, which
9. customwas further purified by column chromatography

ORD record

ord-1417bcdfba304fab956d23c336b4b729

Source dataset

uspto-grants-2011_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08053440B2