Methanol → 5-(2,3-Dihydro-6-methyl-4-oxo-5-phenyl-1,3-oxazin-3-yl)-5-methyl-2,4-hexanedione

HRID 1274857Notes

Reaction equation

HRID 1274857 reaction equation
[Mg].[CH3:2][C:3]1[O:8][CH2:7][N:6]([C:9]([CH3:17])([CH3:16])[C:10](=[O:15])[CH2:11][C:12]([O-:14])=O)[C:5](=[O:18])[C:4]=1[C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1.[CH3:25]O>>[CH3:2][C:3]1[O:8][CH2:7][N:6]([C:9]([CH3:17])([CH3:16])[C:10](=[O:15])[CH2:11][C:12](=[O:14])[CH3:25])[C:5](=[O:18])[C:4]=1[C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1

Participants

4

Reactant 3

HCID 887Methanol2×HCID 5462224MagnesiumHCID 22118320HCID 22118320, compound

Product 1

HCID 221183275-(2,3-Dihydro-6-methyl-4-oxo-5-phenyl-1,3-oxazin-3-yl)-5-methyl-2,4-hexanedione

Conditions

Temperature
60 °C

Procedure

A suspension of magnesium turnings (100 mg) in methanol was stirred whilst a solution of t-butyl [4-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-1,3-oxazin-3-yl)-4-methyl-3-oxo-pentanoate (1.40 g) in methanol was added. The mixture was heated at 60° C. for 1 hour, cooled and evaporated. Toluene was added and the mixture re-evaporated. The residue was redissolved in toluene and a solution of acetyl chloride (300 mg) added. The mixture was stirred at 20° C. for 1 day, then hydrochloric acid (2M) added and the stirring continued for another 1 hour. The organic phase was washed with hydrochloric acid (2M) then with water and dried (magnesium sulphate) 4-Toluene-sulphonic acid (50 mg) was added and the mixture stirred at 80° C. for 1 hour, cooled and washed in turn with saturated sodium bicarbonate solution and water, dried (magnesium sulphate) and evaporated to give 5-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-1,3-oxazin-3-yl)-5-methyl-2,4-hexanedione (Compound 193, 0.15 g) as a brown gum, NMR 1.56(s,6H), 1.91(s,3H), 2.15(s,3H), 3.66 and 3.70(s,1H), 5.25(t,2H), 7.20-7.44(m,5H).

Workup

  1. additionwas added
  2. temperaturecooled
  3. customevaporated
  4. additionToluene was added
  5. customthe mixture re-evaporated
  6. dissolutionThe residue was redissolved in toluene
  7. additiona solution of acetyl chloride (300 mg) added
  8. additionhydrochloric acid (2M) added
  9. waitthe stirring continued for another 1 hour
  10. washThe organic phase was washed with hydrochloric acid (2M)
  11. dry with materialwith water and dried (magnesium sulphate) 4-Toluene-sulphonic acid (50 mg)
  12. additionwas added
  13. stirringthe mixture stirred at 80° C. for 1 hour
  14. temperaturecooled
  15. washwashed in turn with saturated sodium bicarbonate solution and water
  16. dry with materialdried (magnesium sulphate)
  17. customevaporated

Sources & evidence

ORD record
ord-ad027ef2a5a54f46ba9959900db6dc3a
Source dataset
uspto-grants-2000_12
Patent number
US06159902

Reaction notes

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