p-Toluenesulfonic acid → HCID 54500514, compound

Participants

Reaction Steps

A mixture of the intermediate of formula III, 3-methylindole-1-ethanol (29.7 g., 0.17 mole), described in Example 1, ethyl levulinate (26.96 g., 0.187 mole) and p-toluenesulfonic acid (2.25 g.) in dry benzene (650 ml.) is refluxed with stirring for 12 hr. with hydrated alkalialuminum silicate (Molecular Sieves #4). The benzene solution is washed with 5% aqueous NaHCO3, followed by water. Concentrations of the solution gave a residue, which is passed through a silica gel column using 15% ethyl acetate in benzene to afford the ester, 3,4-dihydro-1,10-dimethyl-1H-1,4-oxazino[4,3-a]indole-1-propionic acid ethyl ester, as an oil, γmaxCHCl3 1730 cm-1.

Provenance & Evidence