Hydrogen Bromide → HCID 20186414, compound

Reaction equation

C[O:2][C:3]1[CH:4]=[CH:5][C:6]2[S:15][CH2:14][C:13]3[CH:12]=[N:11][NH:10][C:9]=3[C:7]=2[CH:8]=1.Br.C(=O)(O)[O-].[Na+]>>[OH:2][C:3]1[CH:4]=[CH:5][C:6]2[S:15][CH2:14][C:13]3[CH:12]=[N:11][NH:10][C:9]=3[C:7]=2[CH:8]=1

Participants

Reactant 3

HCID 260Hydrogen Bromide

HCID 516892Sodium Bicarbonate

HCID 20186429HCID 20186429, compound

Product 1

HCID 20186414HCID 20186414, compoundYield 74.9%

Procedure

A mixture of 8-methoxy-1,4-dihydro[1]benzothiopyrano[4,3-c]pyrazole (6.75 g) and 47% hydrobromic acid (70.2 ml) was refluxed for 3 hours with stirring and allowed to cool to room temperature. The resulting precipitate was collected by filtration and recrystallized from water to give the salt, which was treated with aqueous sodium bicarbonate to give 8-hydroxy-1,4dihydro[1]benzothiopyrano[4,3-c]pyrazole (4.73 g).