Ethylene Glycol → 2(3H)-Benzothiazolone, 4-methyl-, hydrazone

HRID 1578517Notes

Reaction equation

HRID 1578517 reaction equation
Br.[CH3:2][C:3]1[C:8]2[N:9]=[C:10]([NH:12]C)[S:11][C:7]=2[CH:6]=[CH:5][CH:4]=1.C(O)CO.O.[NH2:19]N>O>[CH3:2][C:3]1[C:8]2[N:9]=[C:10]([NH:12][NH2:19])[S:11][C:7]=2[CH:6]=[CH:5][CH:4]=1

Participants

5

Reactant 3

HCID 174Ethylene GlycolHCID 24654Hydrazine hydrate (1:1)HCID 21559367HCID 21559367, compound

Product 1

HCID 883942(3H)-Benzothiazolone, 4-methyl-, hydrazoneYield 90%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

4-Methyl-2-methylaminobenzothiazole hydrobromide (443 g.; 1.71 mole) was added with stirring to 1.7 liter of ethylene glycol. 85% Hydrazine hydrate (400 grams; 6.75 mole) was added in several portions. The reaction mixture was heated to 130°-135°C. under N2 atmosphere and maintained for about four hours, then cooled slowly with stirring. The product was isolated by addition of water and separated by filtration. It was then dried overnight in a vacuum oven, yielding 275.5 g. (90% yield) of 4-methyl-2-hydrazinobenzothiazole. The nmr spectrum agreed with a reference spectrum and showed no evidence of starting material or other impurity. Non-aqueous titration showed the product to be 97.5% pure.

Workup

  1. temperatureThe reaction mixture was heated to 130°-135°C. under N2 atmosphere
  2. temperaturemaintained for about four hours
  3. temperaturecooled slowly
  4. customseparated by filtration
  5. customIt was then dried overnight in a vacuum oven
  6. customyielding 275.5 g

Sources & evidence

ORD record
ord-c519944652ba477b8df98032cad949f9
Source dataset
uspto-grants-1976_02
Patent number
US03937714

Reaction notes

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