p-Toluenesulfonic acid → HCID 22341393, compound

Participants

Reaction Steps

Toluene-4-sulfonic acid (2R)-8-amino-7-nitro-2,3-dihydro-benzo(1,4)dioxin-2-yl-methyl ester (1.0 g, 2.6 mmole) was dissolved in 100 mL of methanol to which 0.25 g of 10% palladium on carbon had been added. p-Toluenesulfonic acid (1.0 g, 5.2 mmole) was then added and the mixture treated with 60 psi of hydrogen on a Parr apparatus for 15 hours. The mixture was filtered through celite and concentrated in vacuum. Propionic acid (50 mL) was added and the solution refluxed under nitrogen for 4 hours. The solvent was removed in vacuum and the residue dissolved in 300 mL of methylene chloride, washed with 200 mL each of saturated aqueous sodium bicarbonate, water and saturated brine, dried over magnesium sulfate, filtered and concentrated in vacuum to give 0.84 g of the (R)-enantiomer of the title compound as a white foam. 1H-NMR (CDCl3): doublet 7.8 δ (2H); doublet 7.3 δ (2H); doublet 7.0 δ (1H); doublet 6.75 δ (1H); multiplet 4.5 δ (1H); multiplet 4.25 δ (3H); multiplet 4.05δ (1H); quartet 2.9 δ (2H); singlet 2.45 δ (3H); triplet 1.4 δ (3H).

Provenance & Evidence