Acetic Acid → 2-Amino-6-methylbenzothiazole

HRID 8353

Reaction equation

HRID 8353 reaction equation
[CH3:1][C:2]1[CH:7]=[CH:6][C:5]([NH:8][C:9]([NH2:11])=[S:10])=[CH:4][CH:3]=1.CC(O)=O.Br.CS(C)=O>CCOC(C)=O>[NH2:11][C:9]1[S:10][C:6]2[CH:7]=[C:2]([CH3:1])[CH:3]=[CH:4][C:5]=2[N:8]=1

Participants

6

Reactant 4

HCID 176Acetic Acid2×HCID 260Hydrogen BromideHCID 679Dimethyl SulfoxideHCID 722833p-Tolylthiourea

Product 1

HCID 173352-Amino-6-methylbenzothiazoleYield 67%

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Conditions

Temperature
80 °C

Procedure

(4-Methylphenyl)thiourea (2 mmol) was added to AcOH (4 ml), and the suspension was heated to 80° C. To the solution formed was added 33% HBr in AcOH (4 mmol) followed by DMSO (2.1 mmol). After stirring at 80° C. for 1 h, the reaction mixture was cooled to 50° C., diluted with EtOAc (10 ml) and filtered. The product (as HBr-salt) was taken up in H2O (5 ml) and treated with 1M aq. NaHCO3 (2 ml). Stirring was continued for 0.2 h. The precipitated aminobenzothiazole was then filtered, washed with H2O (10 ml) and dried (16 h at 45° C./20 mb); yield 67%.

Workup

  1. customTo the solution formed
  2. temperaturethe reaction mixture was cooled to 50° C.
  3. filtrationfiltered
  4. additiontreated with 1M aq. NaHCO3 (2 ml)
  5. stirringStirring
  6. waitwas continued for 0.2 h
  7. filtrationThe precipitated aminobenzothiazole was then filtered
  8. washwashed with H2O (10 ml)
  9. customdried (16 h at 45° C./20 mb)

Sources & evidence

ORD record
ord-2c38c04a2ff54f61871a1c6ab0095848
Source dataset
uspto-grants-2006_08
Patent number
US07087761B2

Linked notes

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