Ammonia → HCID 18428309, compound

Participants

Reaction Steps

To a solution of (3) (26.2 g, 100 mmol, 1 eq.) in 150 ml dichloromethane was added 350 mg of tetrabutylammonium hydrogen sulphate, 50% (w/w) aqueous sodium hydroxide (from 24 g of sodium hydroxide and 24 g of water), and the mixture stirred vigorously for 30 min. The flask was cooled in an ice-water bath and 38 g (300 mmol, 3 eq) of dimethyl sulphate was added dropwise over a period of 1 hour. The mixture was stirred vigorously at room temperature for 6 hours until TLC analysis (EtOAc) revealed that the reaction was completed. 15 ml of concentrated aqueous ammonia was added and stirred for a further 30 min at room temperature to decompose excess dimethyl sulphate. The reaction mixture was poured into water, added 350 ml of dichloromethane. The dichloromethane layer was washed with water, dried (Na2SO4), and concentrated in vacuo to yield the crude product as orange oil. Further purfication by column chromatography on silica gel (eluant: EtOAc) furnished the pure product as a bright yellow oil (23.5 g, 81%). 1H-NMR (CDCl3) δ: 3.2 (s, 3H, OCH3), 3.4 (s, 3H, OCH3), 4.15 (s, 4H, 2,6-CH2OCH3), 5.1 (s, 2H, CH2Ph), 6.3 (s, 1H, 5-H(pyranone)), 7.26 (s, 5H, Ar).

Provenance & Evidence