ethyl 2-(N-methyleneamino)-2-methylpropanoate → ethyl 2-(6-cyclopropyl-2,3-dihydro-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropanoate

HRID 377578Notes

Reaction equation

HRID 377578 reaction equation
[CH:1]1([C:4](=[O:16])[CH:5]([C:10]2[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=2)[C:6]([O:8]C)=O)[CH2:3][CH2:2]1.[CH2:17]=[N:18][C:19]([CH3:26])([CH3:25])[C:20]([O:22][CH2:23][CH3:24])=[O:21]>C1(C)C(C)=CC=CC=1>[CH:1]1([C:4]2[O:16][CH2:17][N:18]([C:19]([CH3:26])([CH3:25])[C:20]([O:22][CH2:23][CH3:24])=[O:21])[C:6](=[O:8])[C:5]=2[C:10]2[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=2)[CH2:2][CH2:3]1

Participants

4

Reactant 2

HCID 10855576ethyl 2-(N-methyleneamino)-2-methylpropanoateHCID 19354569Methyl 3-cyclopropyl-3-oxo-2-phenylpropanoate

Product 1

HCID 19354597ethyl 2-(6-cyclopropyl-2,3-dihydro-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropanoate

Reagents, catalysts & solvents 1

HCID 7237O-XyleneSolvent

Procedure

A mixture of methyl 3-cyclopropyl-3-oxo-2-phenylpropanoate (6.54 g) and ethyl 2-(N-methyleneamino)-2-methylpropanoate was heated under reflux in xylene in the presence of 5A molecular sieve (33 g) for 7 hours. The mixture was evaporated and purified by chromatography on silica gel, eluting with hexane/ethyl acetate (7:3) to give ethyl 2-(6-cyclopropyl-2,3-dihydro-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropanoate (7.56 g), as an oil, NMR (CDCl3)δ 0.7-0.78(m,2H), 0.95-1.01(m,2H), 1.22(t,3H), 1.54(s,6H), 1.52-1.61(m,1H), 4.14(q,2H), 5.17(s,2H), 7.21-7.42(m,5H).

Workup

  1. temperaturewas heated
  2. customThe mixture was evaporated
  3. custompurified by chromatography on silica gel
  4. washeluting with hexane/ethyl acetate (7:3)

Sources & evidence

ORD record
ord-14964323c9314af8852bbed45bbe878e
Source dataset
uspto-grants-2000_02
Patent number
US06028032

Reaction notes

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