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 720495Notes

Reaction equation

HRID 720495 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-824e69e4bf1748f9bcd68f27380683a9
Source dataset
uspto-grants-2006_11
Patent number
US07135478B2

Reaction notes

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