Acetic Anhydride → HCID 53419723, compound

HRID 2168500Notes

Reaction equation

HRID 2168500 reaction equation
[NH2:1][C:2]1[C:11]([CH3:12])=[CH:10][C:9]([Cl:13])=[CH:8][C:3]=1[C:4]([O:6][CH3:7])=[O:5].C(OC(=O)C)(=O)C.CC([O-])=O.[K+].[N:26](OCCC(C)C)=O>C(Cl)(Cl)Cl>[Cl:13][C:9]1[CH:10]=[C:11]2[C:2](=[C:3]([C:4]([O:6][CH3:7])=[O:5])[CH:8]=1)[NH:1][N:26]=[CH:12]2

Participants

6

Reactant 4

HCID 7918Acetic AnhydrideHCID 8053Isoamyl NitriteHCID 517044Potassium AcetateHCID 12744623Methyl 2-amino-5-chloro-3-methylbenzenecarboxylate

Product 1

HCID 53419723HCID 53419723, compoundYield 69.3%

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Procedure

Methyl 2-amino-5-chloro-3-methylbenzoate (6.6 g, 33.1 mmol) was dissolved in CHCl3 (90 mL) then cooled in an icebath while acetic anhydride (7.2 mL, 76.1 mmol) was added dropwise. After the addition was complete, the reaction mixture was stirred at room temperature for ca. 1 h, then KOAc (650 mg, 6.6 mmol) was added, followed by isoamyl nitrite (9.7 mL, 72.8 mmol). The reaction mixture was heated under reflux until the reaction was complete by TLC (overnight). While cooling to room temperature, precipitation was observed. The precipitate was collected and dried to afford methyl 5-chloro-1H-indazole-7-carboxylate as a yellow solid (4.83 g, 69%): 1H NMR (300 MHz, CDCl3) δ 11.25 (s, 1H), 8.10 (s, 1H), 8.05 (s, 3H), 7.97 (s, 1H), 4.09 (s, 1H); MS (ESI+) m/z 211 (M+H).

Workup

  1. additionwas added dropwise
  2. additionAfter the addition
  3. temperatureThe reaction mixture was heated
  4. temperatureunder reflux until the reaction
  5. customwas complete by TLC (overnight)
  6. temperatureWhile cooling to room temperature
  7. customprecipitation
  8. customThe precipitate was collected
  9. customdried

Sources & evidence

ORD record
ord-f014aa6c1af148979059e6e66528f293
Source dataset
uspto-grants-2015_06
Patent number
US09045501B2

Reaction notes

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