Isopropanol → 3-Amino-5,8-dimethoxy[1,2,4]triazolo[4,3-c]pyrimidine

HRID 279388Notes

Reaction equation

HRID 279388 reaction equation
[NH:1]([C:3]1[C:8]([O:9][CH3:10])=[CH:7][N:6]=[C:5]([O:11][CH3:12])[N:4]=1)[NH2:2].CC(O)C.[N:17]#[C:18]Br>C(#N)C>[NH2:17][C:18]1[N:4]2[C:5]([O:11][CH3:12])=[N:6][CH:7]=[C:8]([O:9][CH3:10])[C:3]2=[N:1][N:2]=1

Participants

5

Reactant 3

HCID 3776IsopropanolHCID 10476Cyanogen BromideHCID 155449972,5-Dimethoxy-4-hydrazinopyrimidine

Product 1

HCID 226248743-Amino-5,8-dimethoxy[1,2,4]triazolo[4,3-c]pyrimidineYield 87.3%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Conditions

Temperature
42 °C

Procedure

4-Hydrazino-2, 5-dimethoxypyrimidine (8.522 g, 0.050 mole) was loaded into a 500 mL three necked flask equipped with an overhead stirrer, condenser, and thermocouple temperature probe. IPA (100 mL) was added and the mixture was stirred to form a slurry. A solution of cyanogen bromide (8.546 g, 0.081 mole) in acetonitrile (15 mL) was added, resulting in a 3° C. endotherm, followed by a 6° C. exotherm. The mixture wash heated to 42° C. for 3.5 h, then cooled to room temperature. A solution of sodium carbonate (5.92 g) in water (100 mL) was added, and the resulting mixture was stirred for 3.3 h. The product precipitated from the solution an d was recovered by filtration through Whatman #54 paper using a Buchner funnel and aspirator vacuum. The solids w ere dried overnight in vacuo at room temperature to give 8.516 g of 3-amino-5,8-dimethoxy[1,2,4]triazolo[4,3-c]pyrimidine (yield=87.1%): mp=232-235° C. 1H NMR (300 MHz, DMSO-d6) 3.83 (s, 3H), 3.97 (s, 3H), 6.45 (br s, 2H), 6.84 (s, 1H); 13C NMR (75.47 MHz, DMSO-d6) 55.4, 56.4, 115.5, 139.7, 142.0, 142.5, 148.3.

Workup

  1. customequipped with an overhead stirrer, condenser
  2. customto form a slurry
  3. customresulting in a 3° C. endotherm
  4. customfollowed by a 6° C.
  5. washThe mixture wash
  6. temperaturecooled to room temperature
  7. additionA solution of sodium carbonate (5.92 g) in water (100 mL) was added
  8. stirringthe resulting mixture was stirred for 3.3 h
  9. customThe product precipitated from the solution an d
  10. filtrationwas recovered by filtration through Whatman #54 paper
  11. customdried overnight in vacuo at room temperature

Sources & evidence

ORD record
ord-cf1d50fb5b98460ba65402a63720e704
Source dataset
uspto-grants-2002_03
Patent number
US06362335B1

Reaction notes

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