Hydrochloric Acid → 6-cyano-2,2-dimethyl-4-(1,2-dihydro-2-oxo-4-(3-hydroxypropyl)-1-pyridinyl}-2H-benzo[b]pyran

HRID 487646Notes

Reaction equation

HRID 487646 reaction equation
[C:1]([C:3]1[CH:28]=[CH:27][C:6]2[O:7][C:8]([CH3:26])([CH3:25])[CH:9]=[C:10]([N:11]3[CH:16]=[CH:15][C:14]([CH2:17][CH2:18][C:19](OCC)=[O:20])=[CH:13][C:12]3=[O:24])[C:5]=2[CH:4]=1)#[N:2].[BH4-].[Na+].Cl>O1CCOCC1>[C:1]([C:3]1[CH:28]=[CH:27][C:6]2[O:7][C:8]([CH3:26])([CH3:25])[CH:9]=[C:10]([N:11]3[CH:16]=[CH:15][C:14]([CH2:17][CH2:18][CH2:19][OH:20])=[CH:13][C:12]3=[O:24])[C:5]=2[CH:4]=1)#[N:2]

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 4311764Sodium borohydrideHCID 190926026-cyano-2,2-dimethyl-4-{1,2-dihydro-2-oxo-4-(2-ethoxycarbonylethyl)-1-pyridinyl}-2H-benzo[b]pyran

Product 1

HCID 190925556-cyano-2,2-dimethyl-4-(1,2-dihydro-2-oxo-4-(3-hydroxypropyl)-1-pyridinyl}-2H-benzo[b]pyranYield 89.9%

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Procedure

In 16 ml of dioxane, is dissolved 617 mg of 6-cyano-2,2-dimethyl-4-{1,2-dihydro-2-oxo-4-(2-ethoxycarbonylethyl)-1-pyridinyl}-2H-benzo[b]pyran obtained in Example 33. Then, 16 ml of an aqueous solution containing 617 m of sodium borohydride is added at room temperature and reacted first at room temperature for 1.5 hours and then at 60° C. for one hour. After stopping the reaction by adding 20 ml of 2M aqueous hydrochloric acid, the reaction mixture is extracted with ethyl acetate. The organic layer is washed with saturated aqueous solution of sodium chloride and dried over anhydrous magnesium sulfate. The inorganic matter is filtered off and the filtrate is concentrated under reduced pressure. The residue is purified by silica gel column chromatography using 1/10 mixture of methanol/methylene chloride as a developing solvent. Thus, 493 mg of 6-cyano-2,2-dimethyl-4-(1,2-dihydro-2-oxo-4-(3-hydroxypropyl)-1-pyridinyl}-2H-benzo[b]pyran is obtained.

Workup

  1. additionis added at room temperature
  2. customreacted first at room temperature for 1.5 hours
  3. customthe reaction
  4. extractionthe reaction mixture is extracted with ethyl acetate
  5. washThe organic layer is washed with saturated aqueous solution of sodium chloride
  6. dry with materialdried over anhydrous magnesium sulfate
  7. filtrationThe inorganic matter is filtered off
  8. concentrationthe filtrate is concentrated under reduced pressure
  9. customThe residue is purified by silica gel column chromatography
  10. addition1/10 mixture of methanol/methylene chloride as a developing solvent

Sources & evidence

ORD record
ord-9adac9846979422ea86d10b4bfdd4757
Source dataset
uspto-grants-1994_03
Patent number
US05296492

Reaction notes

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