5-ethyl-5-hydroxy-9-methoxy-4,5-dihydrooxepino[3,4-c]pyridin-3(1H)-one → 5-Ethyl-5-hydroxy-1,4,5,8-tetrahydrooxepino[3,4-c]pyridine-3,9-dione

HRID 1250718Notes

Reaction equation

HRID 1250718 reaction equation
[CH2:1]([C:3]1([OH:17])[C:13]2[C:8](=[C:9]([O:14]C)[N:10]=[CH:11][CH:12]=2)[CH2:7][O:6][C:5](=[O:16])[CH2:4]1)[CH3:2]>Cl>[CH2:1]([C:3]1([OH:17])[C:13]2[CH:12]=[CH:11][NH:10][C:9](=[O:14])[C:8]=2[CH2:7][O:6][C:5](=[O:16])[CH2:4]1)[CH3:2]

Participants

3

Reactant 1

HCID 105618445-ethyl-5-hydroxy-9-methoxy-4,5-dihydrooxepino[3,4-c]pyridin-3(1H)-one

Product 1

HCID 105370475-Ethyl-5-hydroxy-1,4,5,8-tetrahydrooxepino[3,4-c]pyridine-3,9-dioneYield 49.1%

Reagents, catalysts & solvents 1

HCID 313Hydrochloric AcidSolvent

Procedure

5-Ethyl-5-hydroxy-9-methoxy-4,5-dihydrooxepino[3,4-c]pyridin-3(1H)-one (0.5 g, 2.1 mmol) is heated under reflux for 9 hours in 1N hydrochloric acid (20 ml). The reaction mixture is concentrated under reduced pressure and the residue is again dried by the addition and evaporation of toluene twice, then left overnight under reduced pressure in the presence of phosphorus pentoxide. The resultant oil is dissolved in anhydrous acetonitrile (5 ml) and agitated under argon for 24 hours. The precipitate is filtered out and dried, which produces 0.23 g (49%) of a white solid (M), m.p. 118-119° C.

Workup

  1. concentrationThe reaction mixture is concentrated under reduced pressure
  2. dry with materialthe residue is again dried by the addition and evaporation of toluene twice
  3. dissolutionThe resultant oil is dissolved in anhydrous acetonitrile (5 ml)
  4. filtrationThe precipitate is filtered out
  5. customdried

Sources & evidence

ORD record
ord-63b58bf50ffc4f14a6e21cfcc6e20283
Source dataset
uspto-grants-2002_01
Patent number
US06339091B1

Reaction notes

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