反应详情

To a stirred and cooled (0° C.) solution of 32.8 g of 3,4-dihydro-2H-1-benzopyran-2-methanol in 71 ml of pyridine and 135 ml of benzene was added dropwise a solution of 41.9 g of 4-methyl-benzenesulfonyl chloride in 72.5 ml of benzene. Upon completion, stirring was continued for 25 hours. The reaction mixture was washed successively with a hydrochloric acid solution (10%), with water and with a sodium carbonate solution (10%). The organic layer was dried, filtered and evaporated. The residue was purified by column chromatography (silica gel; CHCl3 100%). The eluent of the desired fraction was evaporated, yielding 28.3 g of 3,4-dihydro-2H-1-benzopyran-2-methanol 4-methylbenzenesulfonate (ester) as a solid residue, mp. 59.4° C. (interm. 1). In a similar way there was also prepared: 6-fluoro-3,4-dihydro-2H-1-benzopyran-2-methanol 4-methylbenzenesulfonate (ester) (interm. 2).

1. stirringUpon completion, stirring
2. washThe reaction mixture was washed successively with a hydrochloric acid solution (10%), with water and with a sodium carbonate solution (10%)
3. customThe organic layer was dried
4. filtrationfiltered
5. customevaporated
6. customThe residue was purified by column chromatography (silica gel; CHCl3 100%)
7. customThe eluent of the desired fraction was evaporated