Hydrochloric Acid → 6-Chloro-1-(2-chloro-benzyl)-5-nitro-1,2-dihydro-indazol-3-one

Participants

Reaction Conditions

Reaction Steps

Chloro-5-nitro-1,2-dihydro-indazol-3-one (prepared in analogy to Org. Synth. 1949, 29, 54 or Chem Ber. 1942, 75, 1104 from 4-chloro-2-fluoro-5-nitro-benzoic acid over two steps) (0.6 g) was suspended in water (5 mL) and 2N K2CO3 (aq.) (1 g) was added to the flask and the mixture was heated to 50° C. for 10 minutes. 2-Chlorobenzylbromide (0.40 g) was then added dropwise. The reaction was stirred overnight and was neutralized with 2 N HCl (aq.) while cooling in an ice bath. The precipitate was collected by filtration and triturated with diethylether to afford pure desired 6-chloro-1-(2-chloro-benzyl)-5-nitro-1,2-dihydro-indazol-3-one as a brown solid. MS (ESI−:336.3[M−H]−).

Provenance & Evidence