Dimethylformamide dimethyl acetal → (E)-6-((dimethylamino)methylene)-2-(methylthio)-7,8-dihydroquinazolin-5(6H)-one

HRID 2383406Notes

Reaction equation

HRID 2383406 reaction equation
[CH3:1][S:2][C:3]1[N:12]=[CH:11][C:10]2[C:9](=[O:13])[CH2:8][CH2:7][CH2:6][C:5]=2[N:4]=1.[CH3:14][N:15]([CH:17](OC)OC)[CH3:16]>C1(C)C=CC=CC=1>[CH3:14][N:15](/[CH:17]=[C:8]1/[C:9](=[O:13])[C:10]2[CH:11]=[N:12][C:3]([S:2][CH3:1])=[N:4][C:5]=2[CH2:6][CH2:7]/1)[CH3:16]

Participants

4

Reactant 2

HCID 78373Dimethylformamide dimethyl acetalHCID 137925232-(Methylthio)-7,8-dihydroquinazolin-5(6H)-one

Product 1

HCID 59490766(E)-6-((dimethylamino)methylene)-2-(methylthio)-7,8-dihydroquinazolin-5(6H)-oneYield 60.2%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

To a solution of 2-(methylthio)-7,8-dihydroquinazolin-5(6H)-one (0.2 g, 1.0 mmol) in toluene (3 mL) was added DMFDMA (0.2 mL, 1.5 mmol). The reaction mixture was then refluxed for 16 hours. The reaction mixture was then cooled to room temperature and concentrated under reduced pressure. The crude compound was purified by flash column chromatography (SiO2, gradient from 100% dichloromethane to 2% methanol in dichloromethane) to give the pure desired product (0.15 g, 60%) as a solid. 1H NMR (CDCl3, 400 MHz): δ 9.0 (s, 1H), 7.72 (s, 1H), 3.18 (s, 6H), 2.98 (t, J=6.0 Hz, 2H), 2.92 (t, J=6.0 Hz, 2H), 2.60 (s, 3H); LCMS [M+H]: 250.

Workup

  1. temperatureThe reaction mixture was then refluxed for 16 hours
  2. concentrationconcentrated under reduced pressure
  3. customThe crude compound was purified by flash column chromatography (SiO2, gradient from 100% dichloromethane to 2% methanol in dichloromethane)

Sources & evidence

ORD record
ord-0532eaaab2e0428589e5c8528796b9f1
Source dataset
uspto-grants-2012_09
Patent number
US08263610B2

Reaction notes

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