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

HRID 487647Notes

Reaction equation

HRID 487647 reaction equation
[C:1]([C:3]1[CH:29]=[CH:28][C:6]2[O:7][C:8]([CH3:27])([CH3:26])[CH:9]=[C:10]([N:11]3[CH:16]=[CH:15][C:14]([CH:17]([OH:24])[CH2:18][C:19](OCC)=[O:20])=[CH:13][C:12]3=[O:25])[C:5]=2[CH:4]=1)#[N:2].[BH4-].[Na+].Cl>O1CCOCC1>[C:1]([C:3]1[CH:29]=[CH:28][C:6]2[O:7][C:8]([CH3:26])([CH3:27])[CH:9]=[C:10]([N:11]3[CH:16]=[CH:15][C:14]([CH:17]([OH:24])[CH2:18][CH2:19][OH:20])=[CH:13][C:12]3=[O:25])[C:5]=2[CH:4]=1)#[N:2]

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 4311764Sodium borohydrideHCID 190925286-cyano-2,2-dimethyl-4-{1,2-dihydro-2-oxo-4-(1-hydroxy-2-ethoxycarbonylethyl)-1-pyridinyl}-2H-benzo[b]pyran

Product 1

HCID 190925486-cyano-2,2-dimethyl-4-{1,2-dihydro-2-oxo-4-(1,3-dihydroxypropyl)-1-pyridinyl}-2H-benzo[b]pyranYield 67.1%

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Procedure

In 50 ml of dioxane, is dissolved 3.87 g of 6-cyano-2,2-dimethyl-4-{1,2-dihydro-2-oxo-4-(1-hydroxy-2-ethoxycarbonylethyl)-1-pyridinyl}-2H-benzo[b]pyran obtained in Example 31. Then, 50 ml of an aqueous solution containing 3.71 g of sodium borohydride is added at room temperature and reacted at room temperature for one hour. After stopping the reaction by adding 100 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, 2.32 g of 6-cyano-2,2-dimethyl-4-{1,2-dihydro-2-oxo-4-(1,3-dihydroxypropyl)-1-pyridinyl}-2H-benzo[b]pyran is obtained.

Workup

  1. additionis added at room temperature
  2. customreacted at room temperature for one hour
  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-377c586b1fa0422ea810e99baf9b20ba
Source dataset
uspto-grants-1994_03
Patent number
US05296492

Reaction notes

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