(2-thioxo-1,3-benzothiazol-3(2H)-yl)acetic acid → Methyl (2-sulfanylidene-1,3-benzothiazol-3(2H)-yl)acetate

HRID 543892Notes

Reaction equation

HRID 543892 reaction equation
[C:1]([CH2:4][N:5]1[C:9]2[CH:10]=[CH:11][CH:12]=[CH:13][C:8]=2[S:7][C:6]1=[S:14])([OH:3])=[O:2].[C:15](=O)(O)[O-].[Na+]>CO>[S:14]=[C:6]1[N:5]([CH2:4][C:1]([O:3][CH3:15])=[O:2])[C:9]2[CH:10]=[CH:11][CH:12]=[CH:13][C:8]=2[S:7]1

Participants

4

Reactant 2

HCID 351524(2-thioxo-1,3-benzothiazol-3(2H)-yl)acetic acidHCID 516892Sodium Bicarbonate

Product 1

HCID 13034583Methyl (2-sulfanylidene-1,3-benzothiazol-3(2H)-yl)acetateYield 94%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
0 °C

Procedure

To a stirred solution containing 45.1 g (0.2 mol) of 3-(carboxymethyl) benzothiazoline-2-thione in 600 ml of methyl alcohol, 142.0 g (1.0 mol) of boron trifluoride ether complex was added in one portion. An exothermic reaction set in causing a temperature rise from 20° to 37° C. The stirred solution was heated at reflux for 24 hours and then cooled to 0° C. After cooling, 1400 ml of 10% aqueous sodium bicarbonate was slowly added (foaming observed) at 0°-10° C. until pH 8 was obtained. After stirring at 0°-10° C. for one hour, the solid was collected by filtration, washed with water until neutral to litmus and air-dried at 25°-30° C. The product, 2-thioxo-3(2H)-benzothiazoleacetic acid, methyl ester was obtained in 94% yield, m.p. 127°-128° C.

Workup

  1. additionwas added in one portion
  2. customAn exothermic reaction
  3. customfrom 20° to 37° C
  4. temperatureThe stirred solution was heated
  5. temperatureat reflux for 24 hours
  6. temperatureAfter cooling
  7. customwas obtained
  8. filtrationthe solid was collected by filtration
  9. washwashed with water until neutral to litmus and
  10. customair-dried at 25°-30° C

Sources & evidence

ORD record
ord-8fd6b2cec0644f53ba68ebf61a3cf82f
Source dataset
uspto-grants-1984_05
Patent number
US04447618

Reaction notes

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