p-Toluenesulfonic acid → 3,4-Dihydro-2,6-naphthyridin-1(2H)-one

HRID 1844018Notes

Reaction equation

HRID 1844018 reaction equation
COC1C=CC(C[N:8]2[CH2:17][CH2:16][C:15]3[C:10](=[CH:11][CH:12]=[N:13][CH:14]=3)[C:9]2=[O:18])=CC=1.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[C:9]1(=[O:18])[C:10]2[C:15](=[CH:14][N:13]=[CH:12][CH:11]=2)[CH2:16][CH2:17][NH:8]1

Participants

4

Reactant 2

HCID 6101p-Toluenesulfonic acidHCID 735546032-(4-Methoxybenzyl)-3,4-dihydro-2,6-naphthyridin-1(2H)-one

Product 1

HCID 122519733,4-Dihydro-2,6-naphthyridin-1(2H)-oneYield 27.1%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

2-(4-Methoxybenzyl)-3,4-dihydro-2,6-naphthyridin-1(2H)-one (I-67g: 300 mg, 1.119 mmol) was reacted with p-toluene sulfonic acid (851 mg, 4.476 mmol) and toluene (10 mL) at 110° C. for 4 hours. The reaction mass was concentrated under reduced pressure, neutralized with 1N HCl solution to pH 7 and extracted using DCM. The organic layer was dried over anhydrous Na2SO4 and concentrated under reduced pressure to afford the crude product. Purification by column chromatography on silica gel (2% methanol in CHCl3) afforded 45 mg of the product (27.10% yield).

Workup

  1. concentrationThe reaction mass was concentrated under reduced pressure
  2. extractionextracted
  3. dry with materialThe organic layer was dried over anhydrous Na2SO4
  4. concentrationconcentrated under reduced pressure
  5. customto afford the crude product
  6. customPurification by column chromatography on silica gel (2% methanol in CHCl3)

Sources & evidence

ORD record
ord-d0826c698e6b4762a8d24aef6c4ca50c
Source dataset
uspto-grants-2015_02
Patent number
US08946260B2

Reaction notes

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