Methanol → HCID 58017108, compound

Participants

Reaction Steps

A suspension of methyl [5-chloro-3-cyano-1-(2-methoxy-2-oxoethyl)-2-oxo-2,3-dihydro-1H-indol-3-yl](cyano)acetate, intermediate 46, (10.56 g, 29.19 mmol) in dry methanol (190 ml) was purged with hydrogen chloride at −78° C. for 45 minutes. The suspension was allowed to warm up to ambient temperature and further heated up to reflux for 4 hours. The solvent was removed in vacuo, the remaining solid was suspended in glacial acetic acid (300 ml) and heated up to reflux for 5 hours. Evaporation under reduced pressure gave a red-brown oil, which was redissolved in ethyl acetate (300 ml). The solution was washed with water (2×200 ml), the aqueous washes were once back-extrated with ethyl acetate (200 ml) and the organic extracts were dried (MgSO4) to give the title compound (10.87 g, quant.) as solidified foam (HPLC purity: 91%). MS (ESI+): 323.2; MS (ESI−): 321.1

Provenance & Evidence