2,2-diethyl-3,4-dihydro-4-oxo-2H-1-benzopyran-6-carbonitrile → 2,2-Diethyl-2h-chromene-6-carbonitrile

HRID 1460622Notes

Reaction equation

HRID 1460622 reaction equation
[CH2:1]([C:3]1([CH2:16][CH3:17])[CH2:8][C:7](=O)[C:6]2[CH:10]=[C:11]([C:14]#[N:15])[CH:12]=[CH:13][C:5]=2[O:4]1)[CH3:2]>C(O)C>[CH2:16]([C:3]1([CH2:1][CH3:2])[CH:8]=[CH:7][C:6]2[CH:10]=[C:11]([C:14]#[N:15])[CH:12]=[CH:13][C:5]=2[O:4]1)[CH3:17]

Participants

3

Reactant 1

HCID 143013512,2-diethyl-3,4-dihydro-4-oxo-2H-1-benzopyran-6-carbonitrile

Product 1

HCID 147211802,2-Diethyl-2h-chromene-6-carbonitrile

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

13,7 g of this 4-chromanone are dissolved in 420 ml ethanol and the obtained solution is mixed with 1,14 g of sodiumborhydride. After 5 hours at room temperature the reaction solution is partitioned between water and dichloromethane, the organic phases are dried over sodiumsulphate and concentrated. 15 g of the obtained residue are taken up in 600 ml of toluene and are refluxed for 5 hours together with 570 mg of p-toluene-sulphonic acid in a Dean Stark apparatus. Washing of the reaction solution with 2N aq. sodium hydroxide solution and water yields after drying over sodiumsulphate and concentration a residue that is purified by flash-chromatography (silica gel/dichloromethane, hexane 1:2). Concentration of the eluate gives 2,2-diethyl-1-benzopyran-6-carbonitrile as colorless oil.

Workup

  1. additionthe obtained solution is mixed with 1,14 g of sodiumborhydride
  2. customAfter 5 hours at room temperature the reaction solution is partitioned between water and dichloromethane
  3. dry with materialthe organic phases are dried over sodiumsulphate
  4. concentrationconcentrated
  5. temperatureare refluxed for 5 hours together with 570 mg of p-toluene-sulphonic acid in a Dean Stark apparatus
  6. washWashing of the reaction solution with 2N aq. sodium hydroxide solution and water
  7. customyields
  8. dry with materialafter drying over sodiumsulphate and concentration a residue
  9. customthat is purified by flash-chromatography (silica gel/dichloromethane, hexane 1:2)

Sources & evidence

ORD record
ord-c3639ba22d034a5586e8194648e6b2fa
Source dataset
uspto-grants-1991_12
Patent number
US05071871

Reaction notes

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