Hydrochloric Acid → 2-Oximino-4-methyltetrahydro-1,4-oxazin-3-one

HRID 225121Notes

Reaction equation

HRID 225121 reaction equation
[CH3:1][N:2]1[CH2:7][CH2:6][O:5][CH2:4][C:3]1=[O:8].CC(C)([O-])C.[K+].[N:15](OCC(C)C)=[O:16].Cl>O1CCCC1.C(O)C>[N:15](=[C:4]1[C:3](=[O:8])[N:2]([CH3:1])[CH2:7][CH2:6][O:5]1)[OH:16]

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 10958Isobutyl nitriteHCID 110078674-Methylmorpholin-3-oneHCID 23665647Potassium tert-butoxide

Product 1

HCID 867373532-Oximino-4-methyltetrahydro-1,4-oxazin-3-one

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 8028TetrahydrofuranSolvent3×

Procedure

While maintaining the temperature near -55°, a solution of 11.5 grams of 4-methyltetrahydro-1,4-oxazin-3-one dissolved in 100 ml of anhydrous tetrahydrofuran was added over a period of twenty minutes to a slurry of 14.6 grams of potassium t-butoxide in 100 ml of tetrahydrofuran vigorously stirring under a nitrogen atmosphere. After equilibrating the resultant mixture for 30 minutes at -60°, a solution of 11.4 grams of isobutyl nitrite in 50 ml of tetrahydrofuran was added over 15 minutes while maintaining the temperature at -60° with external cooling. After a 15-minute equilibration at -60°, the reaction mixture was brought to 25° and stirred for 3 hours. The solution was then cooled to 0° and neutralized to pH 5 with 65 ml of a solution of 18 ml of conc. hydrochloric acid diluted to 100 mls. with absolute ethanol. After a 15-minute equilibration, potassium chloride was filtered off and the solvent removed in vacuuo. The resulting oil was triturated with 50 ml of ethyl acetate and the resulting solid was collected and then recrystallized from 150 ml. of acetonitrile yielding 5.07 g of the oxime product, mp. 199°-201°.

Workup

  1. temperatureWhile maintaining the temperature near -55°
  2. customfor 30 minutes
  3. customat -60°
  4. temperaturewhile maintaining the temperature at -60° with external cooling
  5. waitAfter a 15-minute equilibration at -60°
  6. customwas brought to 25°
  7. stirringstirred for 3 hours
  8. additiondiluted to 100 mls
  9. filtrationAfter a 15-minute equilibration, potassium chloride was filtered off
  10. customthe solvent removed in vacuuo
  11. customThe resulting oil was triturated with 50 ml of ethyl acetate
  12. customthe resulting solid was collected
  13. customrecrystallized from 150 ml

Sources & evidence

ORD record
ord-2d6c36652e924e40ba78384408f7dd2d
Source dataset
uspto-grants-1980_11
Patent number
US04235902

Reaction notes

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