Hydrazine → 8-Chloro-3-ethyl-[1,2,4]triazolo[4,3-A]pyrazine

HRID 1919495Notes

Reaction equation

HRID 1919495 reaction equation
[Cl:1][C:2]1[C:3]([NH:8][NH2:9])=[N:4][CH:5]=[CH:6][N:7]=1.ClC1C(Cl)=NC=CN=1.NN.[C:20](OCC)(OCC)(OCC)[CH2:21][CH3:22]>>[Cl:1][C:2]1[C:3]2[N:4]([C:20]([CH2:21][CH3:22])=[N:9][N:8]=2)[CH:5]=[CH:6][N:7]=1

Participants

5

Reactant 4

HCID 9321HydrazineHCID 66995Ethyl orthopropionateHCID 785752,3-DichloropyrazineHCID 3214302-Chloro-3-hydrazinopyrazine

Product 1

HCID 299234618-Chloro-3-ethyl-[1,2,4]triazolo[4,3-A]pyrazine

Procedure

To 3-chloro-2-hydrazinopyrazine (3.0 g, 20.75 mmol), prepared from 2,3-dichloropyrazine and hydrazine using a procedure analogous to that described in the literature (Huynh-Dinh et al, J. Org. Chem. 1979, 44, 1028), was added 8 mL of triethyl orthopropionate. After refluxing for 10 h, the reaction was cooled down to ambient temperature and the precipitate was filtered. The solid was purified by flash chromatography (100% ethyl acetate, then 10% methanol in ethyl acetate) to give 2.73 g of the title compound as a solid. 1H NMR (500 MHz, CDCl3) δ 1.54 (t, 3H, J=7.6 Hz), 3.16 (q, 2H, J=7.8 Hz), 7.70 (d, 1H, J=4.5 Hz), 7.83 (d, 1H, J=4.8 Hz).

Workup

  1. temperatureAfter refluxing for 10 h
  2. filtrationthe precipitate was filtered
  3. customThe solid was purified by flash chromatography (100% ethyl acetate

Sources & evidence

ORD record
ord-c52ea26411324087871ab42029ab2fcf
Source dataset
uspto-grants-2012_05
Patent number
US08168637B2

Reaction notes

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