Ammonium Hydroxide → 1-ethyl-4-chloro-6,7-dimethoxy-1H-pyrazolo[3,4-b]quinoline

Participants

Reaction Steps

A mixture of N-(1-ethylpyrazol-5-yl)-4,5-dimethoxy anthranilic acid (12.8 g, 44 mmol) and POCl3 (75 ml) was refluxed for 8 hours. The reaction mixture was cooled to room temperature, poured into ice-water and neutralized with concentrated NH4OH. The mixture was extracted with CH2Cl2 and the CH2Cl2 layer was dried over MgSO4 and evaporated to dryness. The residue was purified by column chromatography on silica gel eluting with CH2Cl2 /ether (9/1) to afford 8.0 g (62%) of 1-ethyl-4-chloro-6,7-dimethoxy-1H-pyrazolo[3,4-b]quinoline.

Provenance & Evidence