Methyl 3-amino-4-methylthiophene-2-carboxylate → 7-Methylthieno[3,2-d]pyrimidine-2,4(1H,3H)-dione

HRID 2188995

Reaction equation

HRID 2188995 reaction equation
CO[C:3]([C:5]1[S:6][CH:7]=[C:8]([CH3:11])[C:9]=1[NH2:10])=[O:4].[O-:12][C:13]#[N:14].[K+]>C(O)(=O)C.O>[CH3:11][C:8]1[C:9]2[NH:10][C:13](=[O:12])[NH:14][C:3](=[O:4])[C:5]=2[S:6][CH:7]=1

Participants

5

Reactant 2

HCID 123584Methyl 3-amino-4-methylthiophene-2-carboxylateHCID 11378442Potassium cyanate

Product 1

HCID 103523177-Methylthieno[3,2-d]pyrimidine-2,4(1H,3H)-dioneYield 71.4%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 962WaterSolvent2×

Procedure

To a stirred solution of methyl-3-amino-4-methylthiophene-2-carboxylate (530 mg, 3.1 mmol) in acetic acid (15.5 mL) and water (1.6 mL) was added a solution of potassium cyanate (754 mg, 9.3 mmol) dissolved in water (2.5 mL) dropwise via syringe. The reaction was stirred at room temperature for 15 h, upon completion of the reaction; the reaction mixture was concentrated to 75% and filtered off white solid. To the solid was added 6% aqueous sodium hydroxide (16 mL) and refluxed for 2 h. After cooling to room temperature, the solution was acidified using 12N HCl to pH=6. The resultant precipitate was filtered, washed with water and dried in vacuum oven overnight to give 403 mg (71%) of the title compound as a white solid which was used without any further purification:

Workup

  1. concentrationthe reaction mixture was concentrated to 75%
  2. filtrationfiltered off white solid
  3. additionTo the solid was added 6% aqueous sodium hydroxide (16 mL)
  4. temperaturerefluxed for 2 h
  5. temperatureAfter cooling to room temperature
  6. filtrationThe resultant precipitate was filtered
  7. washwashed with water
  8. customdried in vacuum oven overnight

Sources & evidence

ORD record
ord-abbbeb3e0c6f4732b684c60c02fd22b8
Source dataset
uspto-grants-2012_12
Patent number
US08324223B2

Linked notes

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