Potassium Hydroxide → 6-fluoro-(3H)-benzo-thiazolon-5-ylhydrazine

HRID 477397

Reaction equation

HRID 477397 reaction equation
[NH2:1][C:2]1[C:3]([F:12])=[CH:4][C:5]2[S:9][C:8](=O)[NH:7][C:6]=2[CH:11]=1.[N:13]([O-])=O.[Na+].[OH-:17].[K+]>Cl>[F:12][C:3]1[C:2]([NH:1][NH2:13])=[CH:11][C:6]2[NH:7][CH2:8][S:9](=[O:17])[C:5]=2[CH:4]=1

Participants

5

Reactant 3

HCID 14797Potassium HydroxideHCID 144586855-amino-6-fluorobenzo[d]thiazol-2(3H)-oneHCID 23668193Sodium Nitrite

Product 1

HCID 867436056-fluoro-(3H)-benzo-thiazolon-5-ylhydrazine

Reagents, catalysts & solvents 1

HCID 313Hydrochloric AcidSolvent2×

Procedure

A suspension of 5-amino-6-fluoro-2(3H)-benzothiazolone (12.98 g) in conc. hydrochloric acid (70 g) was cooled to 0° to 5° C., and a saturated aqueous solution of sodium nitrite (5.08 g) was dropwise added thereto at 0° to 5° C., followed by stirring at the same temperature for 30 minutes. The resultant mixture was cooled to -20° C., and a solution of stannous chloride (28.06 g) in conc. hydrochloric acid (30 g) was added thereto all at once, followed by stirring at 0° C. for 2 hours. The reaction mixture was neutralized with potassium hydroxide, a colloidal substance originated from stannous chloride was removed by celite and the resultant solution was extracted with ethyl acetate. The extract was washed with water, fried over magnesium sulfate and concentrated by give 6-fluoro-(3H)-benzo-thiazolon-5-ylhydrazine (6 60 g).

Workup

  1. temperaturewas cooled to 0° to 5° C.
  2. customat 0° to 5° C.
  3. stirringby stirring at 0° C. for 2 hours
  4. customwas removed by celite
  5. extractionthe resultant solution was extracted with ethyl acetate
  6. washThe extract was washed with water
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-b2fdeedc13884e18b546c7d5a2675ebc
Source dataset
uspto-grants-1989_12
Patent number
US04888045

Linked notes

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