P-Chloroacetophenone → 1-[4-(4-Hydroxybutylsulfanyl)phenyl]ethanone

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 4-hydroxybutanethiol (5.0 g, 47 mmol) in DMF (100 mL) was added NaH (60% dispersion in mineral oil 2.1 g). After the effervescence had ceased, p-chloroacetophenone (4.3 mL, 33 mmol) was added. The solution was then stirred at 110° C. for 3 h. The mixture was cooled to RT and then diluted with ether (200 mL). The ethereal suspension was washed with 5% HCl (aq, 2×100 mL), water (100 mL), and then brine (50 mL). The ether extract was dried (MgSO4), filtered and concentrated to afford crude 1-[4-(4-hydroxybutylsulfanyl)phenyl]ethanone, which was used without purification. 1-[4-(4-hydroxybutylsulfanyl)phenyl]ethanone was taken up in dimethylformamide dimethylacetal (100 mL) and stirred at reflux for 12 h. The mixture was cooled and then concentrated to about one half of the original volume. Hexane was added to precipitate 3-Dimethylamino-1-[4-(4-hydroxybutylsulfanyl)phenyl]propenone. The mixture was filtered, washed with hexanes (50 mL), and dried to afford 3-Dimethylamino-1-[4-(4-hydroxy-butylsulfanyl)phenyl]propenone (6.4 g, 23 mmol): HPLC Retention Time; 5.58 min. (Method B) M+1; 279.8.

Provenance & Evidence