Acetyl chloride → 1-(4,4-Dimethylthiochroman-6-yl)ethanone

Participants

Reaction Steps

A solution of 10.0 g (0.056 mol) of 4,4-dimethylthiochroman and 4.4 g (0.056 mol) of acetyl chloride in 150 mL of CS2 was added dropwise over a 45-minutes period to a stirred CS2 suspension of AlCl3 (11.22 g, 0.084 mol) in a 500-mL, round-bottom flask equipped with a condenser and nitrogen inlet. The resulting yellowish-orange mixture was allowed to stir for 10 hours at room temperature; 80 mL of ice water was added and the two layers separated. The aqueous layer was extracted with ether (3×50 mL); the ether layers were combined and dried (Na2SO4, 6 h). After evaporation, the resulting light yellow oil was vacuum distilled to give 10.83 grams (87.6%) of 6-acetyl-4,4-dimethylthiochroman as a yellowish viscous oil: bp 168°-173° C./1.0 mm; IR (neat) 1680 cm-1 ; 1H NMR (DCCl3) δ1.31 [s, 6H, (CH)3)2C], 1.89 [m, 2H, ArSCH2CH2 ], 2.52 [s, 3H, CH3C=O]3.01 [m, 2H, ArSCH2CH2 ], 7.11 [d, 1H, J=8.1 Hz, H(8)], 7.57 [dd, 1H, J=1.7 Hz, J=8.1 Hz, H(7)], 8.00 [d, 1H, J=1.7 Hz, H(5)]; 13C NMR ppm 23.1 [ArSCH2CH2 ] 26.2 [CH3C=O], 29.8 [(CH3)2C], 32.8 [(CH3)2C], 36.8 [ArSCH2CH2 ], 125.8, 126.2, 132.9, 139.4, 141.7, 196.7 [CH3C=O]. ##STR14##

Provenance & Evidence