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

HRID 487638Notes

Reaction equation

HRID 487638 reaction equation
[C:1]([C:3]1[CH:26]=[CH:25][C:6]2[O:7][C:8]([CH3:24])([CH3:23])[CH:9]=[C:10]([N:11]3[CH:16]=[CH:15][C:14]([C:17](OCC)=[O:18])=[CH:13][C:12]3=[O:22])[C:5]=2[CH:4]=1)#[N:2].[BH4-].[Li+].P([O-])([O-])([O-])=O.Cl>O1CCCC1>[C:1]([C:3]1[CH:26]=[CH:25][C:6]2[O:7][C:8]([CH3:23])([CH3:24])[CH:9]=[C:10]([N:11]3[CH:16]=[CH:15][C:14]([CH2:17][OH:18])=[CH:13][C:12]3=[O:22])[C:5]=2[CH:4]=1)#[N:2]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 1061PhosphateHCID 4148881Lithium borohydrideHCID 190925696-cyano-2,2-dimethyl-4-(4-ethoxycarbonyl-1,2-dihydro-2-oxo-1-pyridinyl)-2H-benzo[b]pyran

Product 1

HCID 190925956-cyano-2,2-dimethyl-4-(1,2-dihydro-2-oxo-4-hydroxymethyl-1-pyridinyl)-2H-benzo[b]pyranYield 52.9%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

In 4 ml of anhydrous tetrahydrofuran, is dissolved 350 mg of 6-cyano-2,2-dimethyl-4-(4-ethoxycarbonyl-1,2-dihydro-2-oxo-1-pyridinyl)-2H-benzo[b]pyran obtained in Example 21. Then, 0.50 ml of 2.0M solution of lithium borohydride in tetrahydrofuran is added to the solution at room temperature and reacted at room temperature for 1.5 hours. After stopping the reaction by adding 0.2M phosphate buffer, the insoluble matter is solubilized by adding 2N aqueous hydrochloric acid. Then, the reaction mixture is extracted with ethyl acetate. The organic layer is washed with saturated aqueous solution of sodium chloride and dried over anhydrous sodium sulfate. The inorganic matter is filtered off, and the filtrate is concentrated under reduced pressure. The residue thus obtained is purified by silica gel column chromatography using 1/20 mixture of methanol/methylene chloride as a developing solvent to obtain 163 mg of 6-cyano-2,2-dimethyl-4-(1,2-dihydro-2-oxo-4-hydroxymethyl-1-pyridinyl)-2H-benzo[b]pyran.

Workup

  1. customreacted at room temperature for 1.5 hours
  2. customthe reaction
  3. extractionThen, the reaction mixture is extracted with ethyl acetate
  4. washThe organic layer is washed with saturated aqueous solution of sodium chloride
  5. dry with materialdried over anhydrous sodium sulfate
  6. filtrationThe inorganic matter is filtered off
  7. concentrationthe filtrate is concentrated under reduced pressure
  8. customThe residue thus obtained
  9. customis purified by silica gel column chromatography
  10. addition1/20 mixture of methanol/methylene chloride as a developing solvent

Sources & evidence

ORD record
ord-a8cbc7317cdc4704b58f418254b37e03
Source dataset
uspto-grants-1994_03
Patent number
US05296492

Reaction notes

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