Carbamimidic acid, methyl ester, sulfate (1:1) → 1,4-Dihydro-2-methoxy-6-methyl-4-(3-nitrophenyl)-5-pyrimidinecarboxylic acid, ethyl ester

HRID 622273Notes

Reaction equation

HRID 622273 reaction equation
[N+:1]([C:4]1[CH:5]=[C:6]([CH:10]=[C:11]([C:17](=O)[CH3:18])[C:12]([O:14][CH2:15][CH3:16])=[O:13])[CH:7]=[CH:8][CH:9]=1)([O-:3])=[O:2].S(O)(O)(=O)=O.[CH3:25][O:26][C:27](=[NH:29])[NH2:28].C([O-])(=O)C.[Na+]>O1CCCC1.C(OCC)(=O)C>[CH3:25][O:26][C:27]1[NH:29][C:17]([CH3:18])=[C:11]([C:12]([O:14][CH2:15][CH3:16])=[O:13])[CH:10]([C:6]2[CH:7]=[CH:8][CH:9]=[C:4]([N+:1]([O-:3])=[O:2])[CH:5]=2)[N:28]=1

Participants

6

Reactant 3

HCID 169039Carbamimidic acid, methyl ester, sulfate (1:1)HCID 367507Ethyl 2-(3-nitrobenzylidene)-3-oxobutanoateHCID 517045Sodium Acetate

Product 1

HCID 139125831,4-Dihydro-2-methoxy-6-methyl-4-(3-nitrophenyl)-5-pyrimidinecarboxylic acid, ethyl esterYield 47.9%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 8857Ethyl AcetateSolvent

Procedure

A reaction mixture containing 2-[(3-nitrophenyl)methylene]-3-oxobutanoic acid, ethyl ester (2.62 g, 10.0 mmole), 2-methylpseudourea sulfate (1.72 g, 10.0 mmole), and sodium acetate (1.8 g, 22.0 mmole) in tetrahydrofuran (10 ml) is heated under reflux for 4 hours. The reaction mixture is allowed to cool to room temperature, diluted with ethyl acetate, and filtered. The filtrate is washed with sodium bicarbonate and brine, and then dried over anhydrous magnesium sulfate. Evaporation of the solvent gives a yellow oil which is purified by flash chromatography (5% ethyl acetate in dichloromethane). The resulting foam is crystallized from isopropyl ether-hexanes to provide 1.53 g of 1,4-dihydro-2-methoxy-6-methyl-4-(3-nitrophenyl)-5-pyrimidinecarboxylic acid, ethyl ester as a colorless crystalline product; m.p. 103.5°-105°. TLC (silica gel; ethyl acetate:hexanes, 50:50) Rf =0.31.

Workup

  1. temperatureis heated
  2. temperatureunder reflux for 4 hours
  3. filtrationfiltered
  4. washThe filtrate is washed with sodium bicarbonate and brine
  5. dry with materialdried over anhydrous magnesium sulfate
  6. customEvaporation of the solvent
  7. customgives a yellow oil which
  8. customis purified by flash chromatography (5% ethyl acetate in dichloromethane)
  9. customThe resulting foam is crystallized from isopropyl ether-hexanes

Sources & evidence

ORD record
ord-fbd683a5f27c4fd48584519624a7d755
Source dataset
uspto-grants-1988_09
Patent number
US04769371

Reaction notes

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