Hydrochloric Acid → 5-Ethyl-5,6,7,8-tetrahydropyrido[3,4-b]pyrazine dihydrochloride

HRID 132868Notes

Reaction equation

HRID 132868 reaction equation
[ClH:1].[CH2:2]([CH:4]1[C:9]2=[N:10][CH:11]=[CH:12][N:13]=[C:8]2[CH2:7][CH2:6][N:5]1C(OC(C)(C)C)=O)[CH3:3]>CO>[ClH:1].[ClH:1].[CH2:2]([CH:4]1[C:9]2=[N:10][CH:11]=[CH:12][N:13]=[C:8]2[CH2:7][CH2:6][NH:5]1)[CH3:3]

Participants

4

Reactant 2

HCID 313Hydrochloric AcidHCID 69184558tert-Butyl 5-ethyl-7,8-dihydropyrido[3,4-b]pyrazine-6(5H)-carboxylate

Product 1

HCID 691934695-Ethyl-5,6,7,8-tetrahydropyrido[3,4-b]pyrazine dihydrochloride

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A solution methanolic hydrogen chloride (approx. 1.6M, 1.5 mL) was added to tert-butyl 5-ethyl-7,8-dihydropyrido[3,4-b]pyrazine-6(5H)-carboxylate (29 mg, 0.11 mmol) dissolved in 0.25 mL of methanol. After 3.5 h, the solution was concentrated under a stream of nitrogen. Methanol (two portions) was added, with evaporation of the solvent after each addition, to give the title compound as a hygroscopic foam. 1H NMR (500 MHz, CD3OD) δ 8.57 (d, 1H, J=3 Hz), 8.54 (d, 1, J=3 Hz), 4.57 (dd, 1H, J=8, 5 Hz), 3.77 (ddd, 1H, J=13, 6, 5 Hz), 3.59 (ddd, 1H, J=10, 6 Hz), 3.37 (ddd, 1H, J=18, 10, 7 Hz), 3.35 (dt, 1H, J=18, 5 Hz), 2.51-2.41 (m, 1H), 2.06-1.96 (m, 1H), 1.18 (t, 3H, J=8 Hz). LC/MS 164 (M+1).

Workup

  1. concentrationthe solution was concentrated under a stream of nitrogen
  2. additionMethanol (two portions) was added, with evaporation of the solvent
  3. additionafter each addition

Sources & evidence

ORD record
ord-734cf04e505241c69b7dd6094f0af0c3
Source dataset
uspto-grants-2008_06
Patent number
US07388019B2

Reaction notes

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