Hydrochloric Acid → 5-amino-1-(4-chloro-benzyl)-1,2-dihydro-indazol-3-one

HRID 490560Notes

Reaction equation

HRID 490560 reaction equation
[Cl:1][C:2]1[CH:21]=[CH:20][C:5]([CH2:6][N:7]2[C:15]3[C:10](=[CH:11][C:12]([N+:16]([O-])=O)=[CH:13][CH:14]=3)[C:9](=[O:19])[NH:8]2)=[CH:4][CH:3]=1.Cl.Cl[Sn]Cl.C(=O)(O)[O-].[Na+]>>[NH2:16][C:12]1[CH:11]=[C:10]2[C:15](=[CH:14][CH:13]=1)[N:7]([CH2:6][C:5]1[CH:20]=[CH:21][C:2]([Cl:1])=[CH:3][CH:4]=1)[NH:8][C:9]2=[O:19]

Participants

5

Reactant 4

HCID 313Hydrochloric AcidHCID 24479Stannous ChlorideHCID 516892Sodium BicarbonateHCID 68833180HCID 68833180, compound

Product 1

HCID 105642105-amino-1-(4-chloro-benzyl)-1,2-dihydro-indazol-3-oneYield 76.4%

Conditions

Temperature
85 °C

Procedure

To 1-(4-chloro-benzyl)-5-nitro-1,2-dihydro-indazol-3-one (0.45 g) was added HCl (37% aq.) solution (5 mL) followed by SnCl2.dihydrate (1.9 g). The mixture was heated to 85° C. for one hour. The reaction was then neutralized with sodium bicarbonate solution, filtered, and the filtrate extracted with EtOAc. The combined organic phases were washed with brine, dried over sodium sulfate, filtered and reduced in vacuo. Flash column chromatography of the residue over silica gel eluting with methylene chloride/methanol afforded the desired 5-amino-1-(4-chloro-benzyl)-1,2-dihydro-indazol-3-one (0.31 g) as a dark brown solid. MS (ESI+): 274.4 [M+H]+).

Workup

  1. filtrationfiltered
  2. extractionthe filtrate extracted with EtOAc
  3. washThe combined organic phases were washed with brine
  4. dry with materialdried over sodium sulfate
  5. filtrationfiltered

Sources & evidence

ORD record
ord-bae5617fcf07438d8df71446bcf95b0b
Source dataset
uspto-grants-2009_05
Patent number
US07528158B2

Reaction notes

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