Phosphorus oxychloride → 2,3,4-Trihydroxybenzonitrile

HRID 2081183Notes

Reaction equation

HRID 2081183 reaction equation
[OH:1][C:2]1[C:10]([OH:11])=[C:9]([OH:12])[CH:8]=[CH:7][C:3]=1[C:4]([NH2:6])=O.P(Cl)(Cl)(Cl)=O>C(OCC)(=O)C>[OH:1][C:2]1[C:10]([OH:11])=[C:9]([OH:12])[CH:8]=[CH:7][C:3]=1[C:4]#[N:6]

Participants

4

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 18914844HCID 18914844, compound

Product 1

HCID 137468362,3,4-TrihydroxybenzonitrileYield 57%

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Conditions

Temperature
95 °C

Procedure

Eighteen and five tenths grams of 2,3,4-trihydroxybenzamide were refluxed with 20 ml. of phosphorusoxychloride and 100 ml. of ethyl acetate for 2.5 hours. The volatile constituents were removed in vacuo and the residue poured into 150 ml. of an ice-water mixture. The resulting suspension was heated to 95° C. and then filtered through activated carbon. The filtrate was concentrated to about 50 ml. whereupon 2,3,4-trihydroxybenzonitrile precipitated and was collected by filtration. 2,3,4-Trihydroxybenzonitrile monohydrate thus prepared melted at 172° C. after recrystallization from a methanol-benzene solvent mixture; yield=57%

Workup

  1. customThe volatile constituents were removed in vacuo
  2. additionthe residue poured into 150 ml
  3. filtrationfiltered through activated carbon
  4. concentrationThe filtrate was concentrated to about 50 ml
  5. customwhereupon 2,3,4-trihydroxybenzonitrile precipitated
  6. filtrationwas collected by filtration
  7. custom2,3,4-Trihydroxybenzonitrile monohydrate thus prepared melted at 172° C. after recrystallization from a methanol-benzene solvent mixture

Sources & evidence

ORD record
ord-cc154279fdde4c0aadd82edc72107039
Source dataset
uspto-grants-1993_02
Patent number
US05183828

Reaction notes

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