Acetic Acid → 2-dimethylamino-6,8-dihydrothieno[3,4-d]-1,2,4-triazolo-[1,5-a]pyrimidine-5(9H)-one

HRID 973540Notes

Reaction equation

HRID 973540 reaction equation
[NH2:1][C:2]1[NH:6][N:5]=[C:4]([N:7]([CH3:9])[CH3:8])[N:3]=1.[C:10]([OH:13])(=O)[CH3:11].O=[C:15]1C[S:18][CH2:17][CH:16]1C(OC)=O>>[CH3:8][N:7]([CH3:9])[C:4]1[N:3]=[C:2]2[N:1]=[C:11]3[C:10](=[O:13])[S:18][CH:17]=[C:16]3[CH2:15][N:6]2[N:5]=1

Participants

4

Reactant 3

HCID 176Acetic AcidHCID 984243-Thiophenecarboxylic acid, tetrahydro-4-oxo-, methyl esterHCID 3079781H-1,2,4-Triazole-3,5-diamine, N,N-dimethyl-

Product 1

HCID 199886132-dimethylamino-6,8-dihydrothieno[3,4-d]-1,2,4-triazolo-[1,5-a]pyrimidine-5(9H)-oneYield 73.3%

Procedure

To 19.1 g (0.15 mole) of 5-amino-3-dimethylamino-1H-1,2,4-triazole dissolved in 15 ml of acetic acid 24.3 g (0.15 moles) of methyl 4-oxo-tetrahydrothiophene-3-carboxylate are added and the reaction mixture is boiled for 15 minutes. The product precipitated from the reaction mixture is filtered off from the hot solution, then washed with i-propanol and recrystallized from dimethylformamide. Thus 26.1 g (73.3%) of 2-dimethylamino-6,8-dihydrothieno[3,4-d]-1,2,4-triazolo-[1,5-a]pyrimidine-5(9H)-one are obtained. Melting point: 355°-360° C.

Workup

  1. additionare added
  2. customThe product precipitated from the reaction mixture
  3. filtrationis filtered off from the hot solution
  4. washwashed with i-propanol
  5. customrecrystallized from dimethylformamide

Sources & evidence

ORD record
ord-34380065e2d5408c9a312fd65f41c850
Source dataset
uspto-grants-1991_11
Patent number
US05064826

Reaction notes

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