Benzocaine → Ethyl 2-Aminobenzothiazole-6-carboxylate

HRID 2417296Notes

Reaction equation

HRID 2417296 reaction equation
[CH2:1]([O:3][C:4](=[O:12])[C:5]1[CH:10]=[CH:9][C:8]([NH2:11])=[CH:7][CH:6]=1)[CH3:2].[S-:13][C:14]#[N:15].[Na+].BrBr.C(=O)([O-])[O-].[Na+].[Na+]>C(O)(=O)C.O>[CH2:1]([O:3][C:4]([C:5]1[CH:10]=[CH:9][C:8]2[N:11]=[C:14]([NH2:15])[S:13][C:7]=2[CH:6]=1)=[O:12])[CH3:2]

Participants

7

Reactant 4

HCID 2337BenzocaineHCID 10340Sodium CarbonateHCID 24408BromineHCID 516871Sodium thiocyanate

Product 1

HCID 601008Ethyl 2-Aminobenzothiazole-6-carboxylateYield 67.2%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolvent3×HCID 962WaterSolvent

Procedure

A solution of ethyl-4-aminobenzoate (35 g, 212 mmol) in glacial acetic acid (300 mL) was added to a stirred solution of sodium thiocyanate (69 g, 848 mmol) in acetic acid (150 mL). The mixture was cooled in an ice-water bath and a solution of bromine (12 mL, 233 mmol) in acetic acid (60 mL) was added dropwise via an addition funnel. The reaction mixture was stirred at 0° C. to RT for 4 h and then poured into water (1.5 L). Saturated sodium carbonate solution was added to neutralize the solution. Precipitated solid was filtered, washed with water and EtOAc, and dried in vacuo to obtain the title compound of this step (31.65 g, 67.2% yield).

Workup

  1. temperatureThe mixture was cooled in an ice-water bath
  2. customPrecipitated solid
  3. filtrationwas filtered
  4. washwashed with water and EtOAc
  5. customdried in vacuo

Sources & evidence

ORD record
ord-0faf75e399224a8e8e90ebcf9cf745dc
Source dataset
uspto-grants-2004_11
Patent number
US06825355B2

Reaction notes

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