Hydrazine hydrate (1:1) → 4-(1,4-Dihydroindeno[1,2-c]pyrazol-3-yl)benzoic acid
Reaction equation
O=[C:2]1[C:10]2([CH:12]([C:13]3[CH:21]=[CH:20][C:16]([C:17]([OH:19])=[O:18])=[CH:15][CH:14]=3)O2)[CH2:9][C:8]2[C:3]1=[CH:4][CH:5]=[CH:6][CH:7]=2.O.[NH2:23][NH2:24]>C(O)(=O)C.CO>[NH:23]1[C:2]2[C:3]3[C:8]([CH2:9][C:10]=2[C:12]([C:13]2[CH:21]=[CH:20][C:16]([C:17]([OH:19])=[O:18])=[CH:15][CH:14]=2)=[N:24]1)=[CH:7][CH:6]=[CH:5][CH:4]=3Participants
5
Procedure
4-(1-Oxospiro[indan-2,2′-oxiran]-3′-yl)benzoic acid from part b) (780 mg), methanol (50 ml), hydrazine hydrate (0.18 ml) and glacial acetic acid (6 drops) were boiled under reflux for 24 hours. The mixture was cooled in ice and filtered to give 4-(1,4-dihydroindeno[1,2-c]pyrazol-3-yl)benzoic acid, m.p. >320° C.