Hydrochloric Acid → 6-Bromo-1H-indazole-3-carboxylic acid

HRID 407152

Reaction equation

HRID 407152 reaction equation
[Br:1][C:2]1[CH:10]=[C:9]2[C:5]([C:6](=O)[C:7](=O)[NH:8]2)=[CH:4][CH:3]=1.[N:13]([O-])=O.[Na+].S(=O)(=O)(O)O.Cl.[OH2:23].[OH2:24].Cl[Sn]Cl>[OH-].[Na+].O>[Br:1][C:2]1[CH:10]=[C:9]2[C:5]([C:6]([C:7]([OH:24])=[O:23])=[N:13][NH:8]2)=[CH:4][CH:3]=1

Participants

8

Reactant 5

HCID 313Hydrochloric AcidHCID 1118Sulfuric AcidHCID 61436Stannous chloride dihydrateHCID 957161H-Indole-2,3-dione, 6-bromo-HCID 23668193Sodium Nitrite

Product 1

HCID 247280286-Bromo-1H-indazole-3-carboxylic acidYield 169.3%

Reagents, catalysts & solvents 2

HCID 962WaterSolvent2×HCID 14798Sodium HydroxideSolvent

Conditions

Temperature
0 °C

Procedure

The solution of 6-bromoisatin (10 g, 22 mmol) in 1N aqueous NaOH solution (48 Ml) was stirred at 50° C. for 1 h. The mixture was cooled to 0° C. Sodium nitrite (3 g, 22 mmol) solution in water (11 Ml) was added dropwise for 15 min at 0° C. The mixture was added to the solution of water (90 Ml) and sulfuric acid (4.6 Ml) at 0° C. for 15 min. The mixture was added to the solution of conc. hydrochloric acid (40 Ml) and SnCl2.2H2O (24 g, 53 mmol). After 1 h, the mixture was filtered and washed with water. The solid was dried through air flow to give the titled compound (8.98 g).

Workup

  1. filtrationthe mixture was filtered
  2. washwashed with water
  3. customThe solid was dried through air flow

Sources & evidence

ORD record
ord-ea057a89e8594ee181d07db68154d2d4
Source dataset
uspto-grants-2014_06
Patent number
US08754209B2

Linked notes

Loading…