Phosphorus oxychloride → 5-methoxy-1H-indole-3-carbonitrile

HRID 2165538Notes

Reaction equation

HRID 2165538 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]2[C:9](=[CH:10][CH:11]=1)[NH:8][CH:7]=[C:6]2[C:12]([NH2:14])=O.O=P(Cl)(Cl)Cl>>[CH3:1][O:2][C:3]1[CH:4]=[C:5]2[C:9](=[CH:10][CH:11]=1)[NH:8][CH:7]=[C:6]2[C:12]#[N:14]

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 230428755-methoxy-1H-indole-3-carboxamide

Product 1

HCID 49130085-methoxy-1H-indole-3-carbonitrileYield 59.8%

Procedure

5-Methoxy-1H-indole-3-carboxamide (6.1 g) was treated with refluxing POCl3 (65 ml) for ten minutes. Excess POCl3 was removed under high vacuum (0.1 mmHg) and the residue quenched with water/0.88 NH4OH 1:1 (100 ml). The resulting solution was extracted with CHCl3 (4×100 ml), treated with charcoal (10 g), dried (MgSO4), filtered and the solvent removed to afford a brown solid. Recrystallisation from hexane afforded the title compound as pale brown needles (3.3 g), m.p. 147° C.; δH (360 MHz, CDCl3) 3.86 (3H, s, OCH3), 6.90 (1H, dd, J=7.5, 1.0 Hz, H-6), 7.13 (1H, d, J=1.0 Hz, H-4), 7.36 (1H, d, J=7.5 Hz, H-7), 7.67 (1H, s, H-2).

Workup

  1. customExcess POCl3 was removed under high vacuum (0.1 mmHg)
  2. customthe residue quenched with water/0.88 NH4OH 1:1 (100 ml)
  3. extractionThe resulting solution was extracted with CHCl3 (4×100 ml)
  4. additiontreated with charcoal (10 g)
  5. dry with materialdried (MgSO4)
  6. filtrationfiltered
  7. customthe solvent removed
  8. customto afford a brown solid
  9. customRecrystallisation from hexane

Sources & evidence

ORD record
ord-56247370880043c9bf1369b3679a6b0f
Source dataset
uspto-grants-1990_07
Patent number
US04940703

Reaction notes

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