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

HRID 1509965

Reaction equation

HRID 1509965 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-00783bfa219d4e86af466a30724da64d
Source dataset
uspto-grants-2012_07
Patent number
US08211898B2

Linked notes

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