Acetic Acid → Ethyl 4,5-dihydro-5-methyl-4-oxo-imidazo(1,5-a)pyrido(2,3-e)pyrazine-3-carboxylate

HRID 2351324Notes

Reaction equation

HRID 2351324 reaction equation
[CH3:1][N:2]1[C:7](=[O:8])[C:6](=O)[NH:5][C:4]2[CH:10]=[CH:11][CH:12]=[N:13][C:3]1=2.P(Cl)(OCC)(OCC)=O.[N+:23]([CH2:25][C:26]([O:28][CH2:29][CH3:30])=[O:27])#[C-:24].C(O)(=O)C>CN(C)C=O>[CH3:1][N:2]1[C:3]2[N:13]=[CH:12][CH:11]=[CH:10][C:4]=2[N:5]2[CH:24]=[N:23][C:25]([C:26]([O:28][CH2:29][CH3:30])=[O:27])=[C:6]2[C:7]1=[O:8]

Participants

6

Reactant 4

HCID 176Acetic AcidHCID 13139Diethyl chlorophosphateHCID 533707Ethyl isocyanoacetateHCID 131929424-Methyl-1,4-dihydropyrido[2,3-b]pyrazine-2,3-dione

Product 1

HCID 14460551Ethyl 4,5-dihydro-5-methyl-4-oxo-imidazo(1,5-a)pyrido(2,3-e)pyrazine-3-carboxylate

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent2×

Procedure

To a stirred solution of 1,2,3,4-tetrahydro-4-methyl-2,3-dioxo-pyrido(2,3-b)-pyrazine (5g) in 50 ml of dry dimethyl formamide (DMF) was added potassium-t-butylate (4 g). The mixture was allowed to stir at room temperature for 15 min whereafter it was cooled to -25° C. and charged with diethyl chlorophosphate (5ml). Stirring continued at 0° C. for 15 min, then it was cooled to -20° C. whereafter a preformed -30° C. cold solution of ethyl isocyanoacetate (3.9ml) and pottasium-t-butylate (4 g) in 30ml of dry DMF was added. The resulting solution was allowed to obtain room temperature before acetic acid was added (1,5 ml). The DMF was removed by evaporation in vacuo, whereafter the residue was treated with water to give the crude title compound as pale crystals. Recryst in 96% ETOH M.p. 233°-234° C.

Workup

  1. temperaturewas cooled to -25° C.
  2. stirringStirring
  3. waitcontinued at 0° C. for 15 min
  4. additionwas added
  5. additionwas added (1,5 ml)
  6. customThe DMF was removed by evaporation in vacuo, whereafter the residue
  7. additionwas treated with water

Sources & evidence

ORD record
ord-6c1095962aec4a8786f3d0036df5a095
Source dataset
uspto-grants-1989_10
Patent number
US04873244

Reaction notes

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