Acetic Anhydride → 6-Bromopteridin-4-ol

HRID 2201571Notes

Reaction equation

HRID 2201571 reaction equation
[NH2:1][C:2]1[C:3]([C:9]([NH2:11])=[O:10])=[N:4][C:5]([Br:8])=[CH:6][N:7]=1.[CH3:12]C(OC(C)=O)=O>C(OC(OCC)OCC)C>[Br:8][C:5]1[N:4]=[C:3]2[C:2](=[N:7][CH:6]=1)[N:1]=[CH:12][NH:11][C:9]2=[O:10]

Participants

4

Reactant 2

HCID 7918Acetic AnhydrideHCID 4708993-Amino-6-bromopyrazine-2-carboxamide

Product 1

HCID 1357426076-Bromopteridin-4-olYield 48%

Reagents, catalysts & solvents 1

HCID 31214Ethyl orthoformateSolvent

Conditions

Temperature
90 °C

Procedure

To a solution of 3-amino-6-bromopyrazine-2-carboxamide (200 mg, 0.92 mmol) in triethoxymethane (10 mL) was added Ac2O (2 mL). The mixture was stirred at 130° C. for 1 h and 90° C. for 3 h. After being cooled to RT and extracted with EtOAc, the combined organic phases were basified to pH=8 with a.q. NaHCO3, washed with brine, dried over Na2SO4, filtered and evaporated. The crude product was purified by prep-TLC (DCM:MeOH=50:1) to give the product of 6-bromopteridin-4(3H)-one (100 mg, yield: 48%). 1H-NMR (DMSO-d6, 400 MHz) δ 8.59 (s, 1H), 7.89 (s, 1H). MS (M+H)+: 227/229.

Workup

  1. temperatureAfter being cooled to RT
  2. extractionextracted with EtOAc
  3. washNaHCO3, washed with brine
  4. dry with materialdried over Na2SO4
  5. filtrationfiltered
  6. customevaporated
  7. customThe crude product was purified by prep-TLC (DCM:MeOH=50:1)

Sources & evidence

ORD record
ord-b64d26cde8f84634b71736906d0aaf57
Source dataset
uspto-grants-2016_06
Patent number
US09364482B2

Reaction notes

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