反应详情

A mixture of 2-chlorocarbonyl-3,4-dihydro-2H-1-benzopyran (0.47 mol) in N,N-dimethylacetamide (100 ml), a solution of thiophene (4%) (3 ml) and 2,2'-oxybispropane (400 ml) was hydrogenated with palladium on activated carbon (10%) (5 g) as a catalyst. After uptake of hydrogen (1 eq.), the catalyst was filtered off and the filtrate was evaporated. The residue, potassium acetate (20 g) and benzenemethanamine (50 g) in N,N-dimethylacetamide (2 ml) and methanol (300 ml) was hydrogenated with palladium on activated carbon (10%) (5 g) as a catalyst. After uptake of hydrogen (1 eq.), the catalyst was filtered off and the filtrate was evaporated. The residue in methanol (500 ml) was hydrogenated with palladium on activated carbon (10%) (5 g) as a catalyst. After uptake of hydrogen (1 eq.), the catalyst was filtered off and the filtrate was evaporated. The residue was taken up in 1,1'-oxybisethane and washed with a NaOH-solution. The organic layer was dried (MgSO4), filtered off and evaporated. The residue (70 g) was distilled at 70° C. (0.1 mm Hg), yielding 48.7 g (63.5%) of (±)-3,4-dihydro-2H-1-benzopyran-2-methanamine (interm. 15-c).

1. customthe filtrate was evaporated
2. customthe filtrate was evaporated
3. customthe filtrate was evaporated
4. washwashed with a NaOH-solution
5. dry with materialThe organic layer was dried (MgSO4)
6. filtrationfiltered off
7. customevaporated
8. distillationThe residue (70 g) was distilled at 70° C. (0.1 mm Hg)