Methanol → 2-Amino-4,7-dihydro-1,3-benzothiazol-6(5H)-one

HRID 1835612Notes

Reaction equation

HRID 1835612 reaction equation
[C:1]1(=O)[CH2:6][CH2:5][C:4](=[O:7])[CH2:3][CH2:2]1.CO.BrBr.[NH2:13][C:14]([NH2:16])=[S:15]>O>[NH2:16][C:14]1[S:15][C:2]2[CH2:3][C:4](=[O:7])[CH2:5][CH2:6][C:1]=2[N:13]=1

Participants

6

Reactant 4

HCID 887MethanolHCID 125111,4-CyclohexanedioneHCID 24408Bromine2×HCID 2723790Thiourea

Product 1

HCID 98774852-Amino-4,7-dihydro-1,3-benzothiazol-6(5H)-one

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

8.8 g of 1,4-cyclohexanedione was dissolved with 40 mL of methanol. Solution was cooled to 10C and 4.2 mL of bromine was dropwise added at this temperature during 15 minutes. The temperature was kept at 10C for one hour and then allowed to rise to 20C. When bromine colour faded, 7.2 g of thiourea was added. The reaction mixture was then diluted with 20 mL of water and heated under reflux for 2 h. White precipitate was removed by filtration and filtrate was concentrated in vacuo and cooled. The crystals of product (6) were filtered off and washed with a cold water.

Workup

  1. additionwas dropwise added at this temperature during 15 minutes
  2. temperatureheated
  3. temperatureunder reflux for 2 h
  4. customWhite precipitate was removed by filtration and filtrate
  5. concentrationwas concentrated in vacuo
  6. temperaturecooled
  7. filtrationThe crystals of product (6) were filtered off
  8. washwashed with a cold water

Sources & evidence

ORD record
ord-0d846deefd4f439da307a5a56f6ff42f
Source dataset
uspto-grants-2004_08
Patent number
US06770761B2

Reaction notes

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