S(Cl)(Cl)=O.[CH3:5][S:6]([O:9][C:10]1[CH:15]=[CH:14][C:13](O)=[C:12]([C:17]([CH3:21])([CH3:20])[CH2:18][OH:19])[CH:11]=1)(=[O:8])=[O:7].O>CN(C)C=O>[CH3:5][S:6]([O:9][C:10]1[CH:15]=[CH:14][C:13]2[O:19][CH2:18][C:17]([CH3:21])([CH3:20])[C:12]=2[CH:11]=1)(=[O:8])=[O:7]Thionyl chloride (83 parts) was added dropwise with cooling to dimethyl formamide (260 parts). To this mixture was then added dropwise a solution of 4-hydroxy-3-(2-hydroxy-1,1-dimethylethyl)phenyl methanesulphonate (180 parts) (from Example 1) in dimethyl formamide (190 parts) with stirring at about 15° C. The mixture was then stirred for one hour at room temperature and for five hours at 100° C. Addition to water (2000 parts) caused precipitation of an off-white solid which was filtered off and recrystallised from aqueous ethanol to give 2,3-dihydro-3,3-dimethylbenzofuran-5-yl methanesulphonate (65.2 parts) identical with the product of Example 37(a) above.
Wird geladen…
