ethyl 2-(N-methyleneamino)-2-methylpropanoate → ethyl 2-[2,3-dihydro-5-(2-methoxyphenyl)-6-methyl-4-oxo-4H-1,3-oxazin-3-yl]-2-methylpropanoate

HRID 1274879Notes

Reaction equation

HRID 1274879 reaction equation
[CH2:1]=[N:2][C:3]([CH3:10])([CH3:9])[C:4]([O:6][CH2:7][CH3:8])=[O:5].[CH3:11][O:12][C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][C:14]=1[CH:19]([C:25]([CH3:27])=[O:26])[C:20]([O:22]CC)=O>C1(C)C(C)=CC=CC=1>[CH3:11][O:12][C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][C:14]=1[C:19]1[C:20](=[O:22])[N:2]([C:3]([CH3:10])([CH3:9])[C:4]([O:6][CH2:7][CH3:8])=[O:5])[CH2:1][O:26][C:25]=1[CH3:27]

Participants

4

Reactant 2

HCID 10855576ethyl 2-(N-methyleneamino)-2-methylpropanoateHCID 22118306Ethyl 2-(2-methoxyphenyl)acetoacetate

Product 1

HCID 22118261ethyl 2-[2,3-dihydro-5-(2-methoxyphenyl)-6-methyl-4-oxo-4H-1,3-oxazin-3-yl]-2-methylpropanoateYield 117.4%

Reagents, catalysts & solvents 1

HCID 7237O-XyleneSolvent2×

Procedure

A solution of ethyl 2-(N-methyleneamino)-2-methylpropionate (10.3 g) in xylene was added during 1 hour to a solution of ethyl 2-(2-methoxyphenyl)acetoacetate (8.51 g) in xylene whilst heating under reflux. The rate of addition was controlled so as to equal the rate of azeotropic distillation (via a Dean and Stark separator). Additional xylene was then added and distillation continued for 3 hours. The mixture was evaporated in vacuo to give ethyl 2-[2,3-dihydro-5-(2-methoxyphenyl)-6-methyl-4-oxo-4H-1,3-oxazin-3-yl]-2-methylpropanoate (14.1 g), NMR 1.25(t,3H), 1.55(s,6H), 1.8(s,3H), 3.75(s,3H), 4.1 5(m,2H), 5.3(s,2H), 6.9-7.3(m,4H).

Workup

  1. temperaturewhilst heating
  2. temperatureunder reflux
  3. additionThe rate of addition
  4. distillationthe rate of azeotropic distillation (via a Dean and Stark separator)
  5. additionAdditional xylene was then added
  6. distillationdistillation
  7. customThe mixture was evaporated in vacuo

Sources & evidence

ORD record
ord-114cbdb38a204f1e81f54d33ccd4ce04
Source dataset
uspto-grants-2000_12
Patent number
US06159902

Reaction notes

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