Hydrazine → 5-Benzylthiophene-2-carboxylic acid

HRID 894236Notes

Reaction equation

HRID 894236 reaction equation
[C:1]([C:9]1[S:13][C:12]([C:14]([OH:16])=[O:15])=[CH:11][CH:10]=1)(=O)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[OH-].[K+].NN>C(O)CO>[CH2:1]([C:9]1[S:13][C:12]([C:14]([OH:16])=[O:15])=[CH:11][CH:10]=1)[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

5

Reactant 3

HCID 9321HydrazineHCID 14797Potassium HydroxideHCID 1082345879505-01-4

Product 1

HCID 126787025-Benzylthiophene-2-carboxylic acid

Reagents, catalysts & solvents 1

HCID 174Ethylene GlycolSolvent2×

Conditions

Temperature
140 °C

Procedure

5-Benzoylthiophene-2-carboxylic acid (1.2 g.) was combined with potassium hydroxide (4 g.), hydrazine (3 ml.) and ethylene glycol (8 ml.) and heated in a 140° C. oil bath. A thick, foamy slurry formed which was diluted with 10 ml. additional ethylene glycol. The bath temperature was increased to 180° C., and the reaction held at this temperature for 45 minutes. The reaction was cooled, filtered and the filtrate diluted with 75 ml. of water. The mixture was cooled in an ice bath, acidified with conc. hydrochloric acid, and product (658 mg.) recovered by filtration. Recrystallization from methanol/water gave purified 5-benzylthiophene-2-carboxylic acid (480 mg., 123°-125° C., m/e 218).

Workup

  1. customA thick, foamy slurry formed which
  2. additionwas diluted with 10 ml
  3. temperatureThe bath temperature was increased to 180° C.
  4. temperatureThe reaction was cooled
  5. filtrationfiltered
  6. additionthe filtrate diluted with 75 ml
  7. temperatureThe mixture was cooled in an ice bath
  8. filtrationrecovered by filtration
  9. customRecrystallization from methanol/water
  10. customgave
  11. custompurified 5-benzylthiophene-2-carboxylic acid (480 mg., 123°-125° C., m/e 218)

Sources & evidence

ORD record
ord-42e915b416904b529da9a283f6c9b8f9
Source dataset
uspto-grants-1981_08
Patent number
US04282246

Reaction notes

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