1,3-Propanediol → 5'-nitrospiro[1,3-dioxane-2,3'-indol]-2'(1'H)-one

Reaktionsgleichung

[N+:1]([C:4]1[CH:5]=[C:6]2[C:10](=[CH:11][CH:12]=1)[NH:9][C:8](=[O:13])[C:7]2=[O:14])([O-:3])=[O:2].[CH2:15](O)[CH2:16][CH2:17][OH:18].O.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1C=CC=CC=1>[N+:1]([C:4]1[CH:5]=[C:6]2[C:10](=[CH:11][CH:12]=1)[NH:9][C:8](=[O:13])[C:7]12[O:18][CH2:17][CH2:16][CH2:15][O:14]1)([O-:3])=[O:2]

Komponenten

Versuchsvorschrift

A mixture of 5-nitroisatin (5.00 g, 26.0 mmol), 1,3 propandiol (4.76 mL , 65 mmol, 2.5 eq) and p-toluenesulfonic acid mono-hydrate (0.989 g, 5.2 mmol, 0.2 mol %)) in benzene (500 mL) was refluxed with a Dean Stark Trap for 23 hr. The benzene was decanted off and concentrated. The crude product was purified on Biotage KP silica gel eluting with 50/50 petroleum ether/EtOAc to give the title compound as an off white solid (1.78 g, 27% yield). NMR (300 Mz, DMSO-d6): consistent.