3,8-Dimethyl-6-nitro-[1,2,4]triazolo[4,3-A]pyridine → 3,8-Dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-amine

HRID 873920Notes

Reaction equation

HRID 873920 reaction equation
[CH3:1][C:2]1[N:6]2[CH:7]=[C:8]([N+:12]([O-])=O)[CH:9]=[C:10]([CH3:11])[C:5]2=[N:4][N:3]=1.[H][H]>CO.[Pd]>[CH3:1][C:2]1[N:6]2[CH:7]=[C:8]([NH2:12])[CH:9]=[C:10]([CH3:11])[C:5]2=[N:4][N:3]=1

Participants

5

Reactant 2

HCID 748891423,8-Dimethyl-6-nitro-[1,2,4]triazolo[4,3-A]pyridineHCID 178418361HCID 178418361, compound

Product 1

HCID 753574493,8-Dimethyl-[1,2,4]triazolo[4,3-a]pyridin-6-amine

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalyst2×HCID 887MethanolSolvent

Procedure

A suspension of 3,8-dimethyl-6-nitro-[1,2,4]triazolo[4,3-a]pyridine (Step 67.3) (14.1 g, 71.9 mmol) and 10% Pd/C (2.75 g, 25.9 mmol) in MeOH (300 mL) was shaken for 5 h under 4 bar hydrogen atmosphere at RT. Further 10% Pd/C was added and the reaction mixture was shaken another 1 hh under hydrogen atmosphere. The mixture was filtered through Celite. The pad of Celite was washed with MeOH and the resulting filtrate was concentrated under reduced pressure. The crude product was purified by silica gel column chromatography (hexane/(CH2Cl2-MeOH 19:1) 50-100% (CH2Cl2-MeOH 19:1)) to afford the title product as yellow solid. tR: 0.29 min (LC-MS 2); ESI-MS: 163 [M+H]+ (LC-MS 2); TLC (CH2Cl2-MeOH 9:1) Rf=0.26; 1H NMR (400 MHz, DMSO-d6) δ ppm 2.43 (s, 3H) 2.54 (s, 3H) 5.05 (br. s, 2H) 6.75 (br. s, 1H) 7.18 (br. s, 1H).

Workup

  1. filtrationThe mixture was filtered through Celite
  2. washThe pad of Celite was washed with MeOH
  3. concentrationthe resulting filtrate was concentrated under reduced pressure
  4. customThe crude product was purified by silica gel column chromatography (hexane/(CH2Cl2-MeOH 19:1) 50-100% (CH2Cl2-MeOH 19:1))

Sources & evidence

ORD record
ord-7ab2eb257cf4424ea04967591e94b48c
Source dataset
uspto-grants-2015_03
Patent number
US08975417B2

Reaction notes

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