Dimethylformamide → 3,4-Dimethoxynaphthalene-1-carbaldehyde

HRID 393877Notes

Reaction equation

HRID 393877 reaction equation
[CH3:1][O:2][C:3]1[C:12]2[C:7](=[CH:8][CH:9]=[CH:10][CH:11]=2)[CH:6]=[CH:5][C:4]=1[O:13][CH3:14].CN([CH:18]=[O:19])C.O=P(Cl)(Cl)Cl>C1C(Cl)=CC=C(Cl)C=1>[CH3:14][O:13][C:4]1[CH:5]=[C:6]([CH:18]=[O:19])[C:7]2[C:12]([C:3]=1[O:2][CH3:1])=[CH:11][CH:10]=[CH:9][CH:8]=2

Participants

5

Reactant 3

HCID 6228DimethylformamideHCID 24813Phosphorus oxychlorideHCID 2992571,2-dimethoxynaphthalene

Product 1

HCID 134955543,4-Dimethoxynaphthalene-1-carbaldehydeYield 68.9%

Reagents, catalysts & solvents 1

HCID 46851,4-DichlorobenzeneSolvent

Conditions

Temperature
0 °C

Procedure

A mixture of 1,2-dimethoxynaphthalene (0.74 g, 4 mmol) and DMF (0.8 mL, 10 mmol) in dichlorobenzene (0.8 mL) was stirred with POCl3 at 100° C. for 2 h. The reaction mixture was cooled to 0° C., quenched with a cold aqueous solution of NaOAc, diluted with H2O and extracted with benzene. The extracts were dried (MgSO4), concentrated and in vacuo and dichlorobenzene was removed by kugelrohr distillation at 110° C./0.5 mm Hg. Column chromatography (20%EtOAc in hexane) gave the product 18 (596 mg, 68%), which was used in the following step without further purification. 1H NMR (CDCl3) 10.42 (s, 1H), 9.00-9.15 (m, 1H), 8.15-8.30 (m, 1H), 7.61 (s, 1H), 7.50-7.65 (m, 2H), 4.12 (s, 3H), 4.07 (s, 3H).

Workup

  1. customquenched with a cold aqueous solution of NaOAc
  2. additiondiluted with H2O
  3. extractionextracted with benzene
  4. dry with materialThe extracts were dried (MgSO4)
  5. concentrationconcentrated and in vacuo and dichlorobenzene
  6. customwas removed by kugelrohr distillation at 110° C./0.5 mm Hg

Sources & evidence

ORD record
ord-ca5e6166279145b6b6043871e22970f8
Source dataset
uspto-grants-2004_10
Patent number
US06809176B2

Reaction notes

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