Potassium bisulfate → 2-(3-chlorophenyl)acetaldehyde

A suspension of LiAlH4 (1.90 g, 51 mmol) in anhydrous ether (250 mL) was stirred at room temperature under nitrogen for about 1 hour. The suspension was cooled to about −45° C. To it was added drops of a solution of 2-(3-chlorophenyl)-N-methoxy-N-methyl-acetamide (8.19 g, 38.3 mmol, see Preparation 1) in 10 mL of anhydrous tetrahydrofuran (THF). The mixture was warmed to about 0° C. and stirred for about 3 hours. The solution was then cooled to about −45° C. To this solution was slowly added a solution of KHSO4 (13 g) in water (about 30 mL) the resulting mixture was filtered through CELITE®. The filtrate was concentrated in vacuo, the resulting solution was diluted with DCM and washed with 1N HCl aqueous solution (2 times), and brine (2 times) dried over anhydrous MgSO4, filtered and concentrated in vacuo. The title compound was obtained as a liquid (5.80 g), which was used immediately in the next step without further purification. Rf=0.71 (silica, EtOAc/hexane 1:3).

1. temperatureThe suspension was cooled to about −45° C
2. temperatureThe mixture was warmed to about 0° C.
3. stirringstirred for about 3 hours
4. temperatureThe solution was then cooled to about −45° C
5. filtrationwas filtered through CELITE®
6. concentrationThe filtrate was concentrated in vacuo
7. additionthe resulting solution was diluted with DCM
8. washwashed with 1N HCl aqueous solution (2 times), and brine (2 times)
9. dry with materialdried over anhydrous MgSO4
10. filtrationfiltered
11. concentrationconcentrated in vacuo

ORD record

ord-40cd98243cb149b18e6bedcf38720b84

Source dataset

uspto-grants-2003_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06509336B1