[OH:1][C:2]([CH3:12])([CH3:11])[C:3]([C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1)=[O:4].[Al+3].[Cl-:14].[Cl-].[Cl-].[CH2:17]=O.Cl.[OH-].[Na+]>C(Cl)(Cl)Cl.O>[Cl:14][CH2:17][C:7]1[CH:6]=[C:5]([C:3](=[O:4])[C:2]([OH:1])([CH3:12])[CH3:11])[CH:10]=[CH:9][CH:8]=1under nitrogen atmosphere 5 grams of Darocur 1173 (2-hydroxy-2-methyl-1-phenylpropan-1-one) was mixed with 24 grams of anhydrous AlCl3 in 100 mL of dry chloroform. Upon cooling to 4° C. 4.5 grams of paraformaldehyde powder was slowly added and the resultant mixture was stirred at room temperature for 12 hrs (note that HCl gas released from the reaction was neutralized by 2N NaOH solution). The mixture was poured into water, and the precipitate generated was dissolved by adding 2N HCl solution. The organic layer thus separated was collected, and the aqueous layer was extracted with ethyl acetate for three times. The combined chloroform and ethyl acetate layer was next dried over anhydrous Na2SO4, filtered, and concentrated. The residue was loaded onto silica gel column and eluted by mixtures of hexane/ethyl acetate (V/V=15/1) to give the intermediate 1-(3-(chloromethyl)phenyl)-2-hydroxy-2-methylpropan-1-one as a light-yellow oil (33% yield).
Wird geladen…
