[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:14]=[CH:15][CH:16]=1)[CH:6]([OH:13])[C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1.C([Li])CCC.[C:22](=O)=[O:23]>CCOCC.CCCCCC>[CH3:1][O:2][C:3]1[CH:16]=[CH:15][CH:14]=[C:5]2[C:4]=1[C:22](=[O:23])[O:13][CH:6]2[C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1To 3-methoxybenzhydrol (42.8 g.) in dry ether (800 ml.) is added 2.3 M. n-butyl lithium in hexane (250 ml.), dropwise with stirring under nitrogen. The deep red solution is stirred and heated under reflux for 2 hours and then poured into a stirred slurry of a large excess of solid carbon dioxide in ether and stirred until no carbon dioxide remains. The resulting suspension is extracted with water, the extract is acidified with concentrated hydrochloric acid, the precipitate is filtered off, washed with water, dried, and recrystallised from isopropanol to give 7-methoxy-3-phenylphthalide, m.p. 135°-138°C.
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