Trifluoroacetic acid → 3-(pyrazin-2-yl)-6,7-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-8(5H)-one

HRID 576692Notes

Reaction equation

HRID 576692 reaction equation
[O:1]=[C:2]1[N:7](C(OCC[Si](C)(C)C)=O)[CH2:6][CH2:5][N:4]2[C:17]([C:20]3[CH:25]=[N:24][CH:23]=[CH:22][N:21]=3)=[N:18][N:19]=[C:3]12.C(O)(C(F)(F)F)=O>C(Cl)Cl>[N:21]1[CH:22]=[CH:23][N:24]=[CH:25][C:20]=1[C:17]1[N:4]2[CH2:5][CH2:6][NH:7][C:2](=[O:1])[C:3]2=[N:19][N:18]=1

Participants

4

Reactant 2

HCID 6422Trifluoroacetic acidHCID 904025312-(trimethylsilyl)ethyl 8-oxo-3-(pyrazin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazine-7(8H)-carboxylate

Product 1

HCID 904025243-(pyrazin-2-yl)-6,7-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-8(5H)-oneYield 191.4%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of 2-(trimethylsilyl)ethyl 8-oxo-3-(pyrazin-2-yl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazine-7(8H)-carboxylate (1.0 g, 2.9 mmol) in DCM (29 mL) was added TFA (5.7 mL, 75 mmol). After 1 h, the reaction mixture was concentrated. The crude residue was diluted with EtOAc, sonicated, and filtered to provide the desired product as a white solid (1.2 g, 95%). MS (ESI): mass calcd. for C9H8N6O, 216.1; m/z found, 217.1 [M+H]+. 1H NMR (500 MHz, DMSO-d6) δ 9.39 (d, J=1.1 Hz, 1H), 8.77 (q, J=2.6 Hz, 2H), 8.56 (s, 1H), 4.73-4.60 (m, 2H), 3.67-3.55 (m, 2H).

Workup

  1. concentrationthe reaction mixture was concentrated
  2. additionThe crude residue was diluted with EtOAc
  3. customsonicated
  4. filtrationfiltered

Sources & evidence

ORD record
ord-417250bc361f498a90ecdf44fb03262c
Source dataset
uspto-grants-2015_05
Patent number
US09040534B2

Reaction notes

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