Triethylamine → 5-Chloro-2-(methylthio)benzothiazole

HRID 1029354Notes

Reaction equation

HRID 1029354 reaction equation
CC1NN(C2C=CC=CC=2)C(=O)C=1.[CH3:14][S:15][C:16]1[S:17][C:18]2[CH:31]=[CH:30][C:29]([Cl:32])=[CH:28][C:19]=2[N+:20]=1CCCS(O)(=O)=O.C(N(CC)CC)C>CO>[Cl:32][C:29]1[CH:30]=[CH:31][C:18]2[S:17][C:16]([S:15][CH3:14])=[N:20][C:19]=2[CH:28]=1

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 703351H-Pyrazol-5-ol, 3-methyl-1-phenyl-HCID 43837363-[5-Chloro-2-(methylthio)-1,3-benzothiazol-3-ium-3-yl]-1-propanesulfonate

Product 1

HCID 6457465-Chloro-2-(methylthio)benzothiazole

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

3-Methyl-1-phenylpyrazolin-5-one (1.045 g) was mixed with 2.03 g (0.006 mol) 2-methylthio-5-chloro-3-(3'-sulfopropyl)benzothiazolium, inner salt in 50 ml methanol. Triethylamine (0.62 g) was added. The mixture was stirred for one hour, the solvent evaporated, and the residue dissolved in isopropanol. The resulting solution was treated with 0.6 g KOAc in methanol to precipitate the dye. Filtering yielded 2.17 g (72%), mp 271°-276° C., λmax=383 (ε=19,000).

Workup

  1. customthe solvent evaporated
  2. dissolutionthe residue dissolved in isopropanol
  3. additionThe resulting solution was treated with 0.6 g KOAc in methanol
  4. customto precipitate the dye
  5. filtrationFiltering
  6. customyielded 2.17 g (72%), mp 271°-276° C., λmax=383 (ε=19,000)

Sources & evidence

ORD record
ord-3c95269e58ae498b8021c76427471d47
Source dataset
uspto-grants-1992_04
Patent number
US05102781

Reaction notes

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