Diethyl Oxalate → Ethyl 4-oxo-1,4-dihydrothieno[3,2-d]pyrimidine-2-carboxylate

HRID 1005728Notes

Reaction equation

HRID 1005728 reaction equation
[NH2:1][C:2]1[CH:6]=[CH:5][S:4][C:3]=1[C:7]([NH2:9])=[O:8].CC[O-].[Na+].[CH2:14]([O:16][C:17](=[O:23])[C:18](OCC)=O)[CH3:15]>CCO>[O:8]=[C:7]1[NH:9][C:18]([C:17]([O:16][CH2:14][CH3:15])=[O:23])=[N:1][C:2]2[CH:6]=[CH:5][S:4][C:3]1=2

Participants

5

Reactant 3

HCID 7268Diethyl OxalateHCID 5189933-Aminothiophene-2-carboxamideHCID 2723922Sodium ethoxide

Product 1

HCID 135585885Ethyl 4-oxo-1,4-dihydrothieno[3,2-d]pyrimidine-2-carboxylateYield 74%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of 3-aminothiophene-2-carboxamide (1.23 g, 8.65 mmol) and EtOH (25 mL) was treated with NaOEt (1.2 g, 17.3 mmol) and diethyloxalate (2.3 mL, 17.3 mmol), refluxed for 18 h, cooled, concentrated in vacuo, treated with water, acidified with HOAc and filtered to give the title compound (1.43 g, 74%) as a cream solid: IR νmax Nujol)/cm−1 3180, 3119, 3078, 3006, 2955, 2924, 2854, 1737, 1667, 1651, 1300 and 1176; NMR δH (400 MHz, DMSO) 1.37 (3H, t, J 7.0 Hz), 4.40 (2H, q, J 7.0 Hz), 7.58 (1H, d, J 5.0 Hz), 8.30 (1H, d, J 5.1 Hz), and 12.92 (1H, s).

Workup

  1. temperaturerefluxed for 18 h
  2. temperaturecooled
  3. concentrationconcentrated in vacuo
  4. additiontreated with water
  5. filtrationfiltered

Sources & evidence

ORD record
ord-531967da94d341788861a7a102f57abe
Source dataset
uspto-grants-2004_09
Patent number
US06787541B1

Reaction notes

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