Hydrochloric Acid → 1,2,3-Benzothiadiazole-7-carboxylic acid

HRID 2106945Notes

Reaction equation

HRID 2106945 reaction equation
C[O:2][C:3]([C:5]1[C:13]2[S:12][N:11]=[N:10][C:9]=2[CH:8]=[CH:7][CH:6]=1)=[O:4].[OH-].[Na+].O1CCOCC1.Cl>O>[S:12]1[C:13]2[C:5]([C:3]([OH:4])=[O:2])=[CH:6][CH:7]=[CH:8][C:9]=2[N:10]=[N:11]1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 312751,4-DioxaneHCID 1794011,2,3-Benzothiadiazole-7-carboxylic acid, methyl ester

Product 1

HCID 109211091,2,3-Benzothiadiazole-7-carboxylic acid

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Conditions

Temperature
40 °C

Procedure

100 g (0.51 mol) of 7-methoxycarbonylbenzo-1,2,3-thiadiazole are suspended in 1000 ml of water, and then 310 ml of 2N sodium hydroxide solution and 5 ml of dioxane are added. The reaction mixture is heated to 40° C., is stirred for 4 hours at that temperature and is then cooled to 10° C. A further 1000 ml of water are added and the batch is neutralised with 310 ml of 2N hydrochloric acid. The resulting precipitate is isolated by filtration, lightly dried in a current of air and then dissolved in tetrahydrofuran and the solution is dried over magnesium sulfate, filtered and concentrated. The crystals are suspended in hexane, isolated by filtration and dried.

Workup

  1. temperatureis then cooled to 10° C
  2. customThe resulting precipitate is isolated by filtration
  3. customlightly dried in a current of air
  4. dissolutiondissolved in tetrahydrofuran
  5. dry with materialthe solution is dried over magnesium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customisolated by filtration
  9. customdried

Sources & evidence

ORD record
ord-9ca2eeb40fde48d688428541b87e3ede
Source dataset
uspto-grants-1990_06
Patent number
US04931581

Reaction notes

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