Stannous Chloride → 5-Methyl-3-phenyl-1H-indazole

HRID 1272737Notes

Reaction equation

HRID 1272737 reaction equation
[C:1]1([C:7]([C:9]2[CH:14]=[C:13]([CH3:15])[CH:12]=[CH:11][C:10]=2[NH2:16])=O)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[N:17]([O-])=O.[Na+].Cl[Sn]Cl>Cl.O>[CH3:15][C:13]1[CH:14]=[C:9]2[C:10](=[CH:11][CH:12]=1)[NH:16][N:17]=[C:7]2[C:1]1[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1

Participants

6

Reactant 3

HCID 24479Stannous ChlorideHCID 873352-Amino-5-methylbenzophenoneHCID 23668193Sodium Nitrite

Product 1

HCID 6104125-Methyl-3-phenyl-1H-indazoleYield 80.4%

Reagents, catalysts & solvents 2

HCID 313Hydrochloric AcidSolvent2×HCID 962WaterSolvent

Procedure

To a solution of 2-amino-5-methylphenyl phenyl ketone (2.0 g, 9.5 mmol) in HCl (45 mL of a 6M solution) at 0° C. was added sodium nitrite (NaNO2) (719 mg, 10.4 mmol) in water (2 mL). The reaction was stirred for 30 min when the homogeneous solution was added dropwise to a solution of SnCl2 (5.88, 26 mmol) in concentrated HCl (15 mL) at room temperature. The reaction was stirred for 30 min when it was filtered. The solid was then taken up in ethyl acetate (80 mL) and saturated sodium bicarbonate (80 mL). The suspension was then filtered and the ethyl acetate layer dried (Na2SO4) and concentrated to give the product (1.59 g, 80% yield). (1H NMR (DMSO-d6) δ 7.96 (d, 2H), 7.85 (br s, 1H), 7.54–7.46 (m, 3H), 7.39 (t, 1H), 7.24 (d, 1H), 2.45 (s, 3H); ES-MS (m/z) 209 [M+1]+.

Workup

  1. stirringThe reaction was stirred for 30 min when it
  2. filtrationwas filtered
  3. filtrationThe suspension was then filtered
  4. dry with materialthe ethyl acetate layer dried (Na2SO4)
  5. concentrationconcentrated

Sources & evidence

ORD record
ord-3986550de2f4452097c609ac97241caf
Source dataset
uspto-grants-2007_04
Patent number
US07208513B2

Reaction notes

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