Phosphorus oxychloride → 4-Chloro-2-methyl-5,6,7,8-tetrahydroquinazoline

HRID 2254122Notes

Reaction equation

HRID 2254122 reaction equation
P(Cl)(Cl)([Cl:3])=O.[CH3:6][C:7]1[NH:16][C:15](=O)[C:14]2[CH2:13][CH2:12][CH2:11][CH2:10][C:9]=2[N:8]=1.C(OCC)C.O>CN(C)C1C=CC=CC=1.C1(C)C=CC=CC=1>[Cl:3][C:15]1[C:14]2[CH2:13][CH2:12][CH2:11][CH2:10][C:9]=2[N:8]=[C:7]([CH3:6])[N:16]=1

Participants

6

Reactant 3

HCID 24813Phosphorus oxychlorideHCID 21584184Diethylether waterHCID 1354312714(3H)-Quinazolinone, 5,6,7,8-tetrahydro-2-methyl-

Product 1

HCID 197442074-Chloro-2-methyl-5,6,7,8-tetrahydroquinazolineYield 95%

Reagents, catalysts & solvents 2

HCID 949N,N-DimethylanilineCatalystHCID 1140TolueneSolvent

Procedure

To a mixture of 4.5 mL of phosphorus oxychloride and 20 drops of dimethylaniline in 50 mL of toluene was added 4.2 g of 5,6,7,8-tetrahydro-2-methyl-4-quinazolone. The resulting mixture was refluxed for 3 hours and then cooled to room temperature. The reaction mixture was poured into a ice cold aqueous potassium carbonate. After stirring for 5 minutes the mixture was added to diethyl ether/water. The organic layer was recovered washed with brine, dried over anhydrous magnesium sulfate, filtered and evaporated to yield a yellow oil. This oil was purified on silica to yield the desired compound as a light yellow solid (4.45 g, 95%): 1H NMR (DMSO-d6, 300 MHz) δ 2.78 (m, 2H), 2.64 (m, 2H), 2.50 (s, 3H), 1.78 (m, 4H).

Workup

  1. temperatureThe resulting mixture was refluxed for 3 hours
  2. customThe organic layer was recovered
  3. washwashed with brine
  4. dry with materialdried over anhydrous magnesium sulfate
  5. filtrationfiltered
  6. customevaporated
  7. customto yield a yellow oil
  8. customThis oil was purified on silica

Sources & evidence

ORD record
ord-5f538b3607604f5e8de28b139735b8bd
Source dataset
uspto-grants-1993_08
Patent number
US05234936

Reaction notes

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