Hydrogen Bromide → HCID 178481930, compound

Participants

Reaction Steps

A solution of 0.1 mole of 6,7-dimethoxy-1-methyl-1H-(1)benzothieno[3,2-c]pyrazol-3-amine in 300 ml. of 48% aqueous hydrobromic acid was refluxed for 3 hours. The warm reaction mixture was poured into 1 liter of water and the aqueous mixture was adjusted to pH 7 using concentrated ammonium hydroxide solution. The precipitate which formed was removed by filtration and recrystallized from N,N-dimethyl formamide/water to give 6,7-dihydroxy-1-methyl-1H-(1)benzothieno[3,2-c]pyrazol-3-amine, m.p. 305°-307° C.

Provenance & Evidence