[N+:1]([C:4]1[CH:5]=[C:6]2[C:10](=[CH:11][CH:12]=1)[NH:9][NH:8][C:7]2=[O:13])([O-:3])=[O:2].[CH2:14](Br)[CH:15]=[CH2:16].[OH-].[Na+].Cl>O.[OH-].[K+]>[CH2:16]([N:9]1[C:10]2[C:6](=[CH:5][C:4]([N+:1]([O-:3])=[O:2])=[CH:12][CH:11]=2)[C:7](=[O:13])[NH:8]1)[CH:15]=[CH2:14]
5-Nitro-1,2-dihydro-indazol-3-one (prepared according to Org. Synth. 1949, 29, 54 or Chem Ber. 1942, 75, 1104) (9.36 g) was suspended in 40 ml water and 57.5 ml 1N KOH. Allyl bromide (6.32 g) was added in one portion. The mixture was stirred at 75-80° C. for 1.5 hours. Then NaOH (15%, 5 mL) and allyl bromide (1 g) was added. The reaction mixture was stirred for a further 30 min. The mixture was neutralized with 3N HCl at <10° C. and filtered. The solid was washed with water and dried. The solid was then suspended in 10 ml ethyl acetate and stirred at ambient temperature for 3 hours, then filtered and dried to afford the desired 1-allyl-5-nitro-1,2-dihydro-indazol-3-one (7.63 g) as a yellow solid.
Loading…
