Urea → Thieno(3,2-d)pyrimidine-2,4(1H,3H)-dione

HRID 41887

Reaction equation

HRID 41887 reaction equation
[NH2:1][C:2]1[CH:6]=[CH:5][S:4][C:3]=1[C:7]([O:9]C)=O.[NH2:11][C:12](N)=[O:13]>>[NH:1]1[C:2]2[CH:6]=[CH:5][S:4][C:3]=2[C:7](=[O:9])[NH:11][C:12]1=[O:13]

Participants

3

Reactant 2

HCID 1176UreaHCID 89652Methyl 3-amino-2-thiophenecarboxylate

Product 1

HCID 7059273Thieno(3,2-d)pyrimidine-2,4(1H,3H)-dione

Conditions

Temperature
190 °C

Procedure

A mixture of methyl 3-amino-2-thiophenecarboxylate 1 (13.48 g, 85.85 mmol) and urea (29.75 g, 5 eq.) was heated at 190° C. for 2 hours. The hot reaction mixture was poured onto sodium hydroxide solution and any insoluble material was removed by filtration. The mixture was then acidified (HCl, 2N) to yield 1H-thieno[3,2-d]pyrimidine-2,4-dione 2 as a white precipitate, which was collected by filtration and air dried (9.49 g, 66%). 1H NMR 400 MHz, d6-DMSO) 6.90 (1H, d, J=5.2 Hz), 8.10 (1H, d, J=5.2 Hz), 11.60-11.10 (2H, br s).

Workup

  1. additionThe hot reaction mixture was poured onto sodium hydroxide solution
  2. customany insoluble material was removed by filtration

Sources & evidence

ORD record
ord-02a3a77379f2477288045e7e2bef1df5
Source dataset
uspto-grants-2013_09
Patent number
US08536161B2

Linked notes

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