Butyric Acid → 7-methyl-2-propyl-6-[(1-oxobutyl)amino]3H-imidazo[4,5-b]pyridine

HRID 36114

Reaction equation

[NH2:1][C:2]1[C:7]([N+:8]([O-])=O)=[C:6]([CH3:11])[C:5]([N+:12]([O-])=O)=[CH:4][N:3]=1.[CH2:15]1[CH2:19][O:18][CH2:17][CH2:16]1.[C:20](O)(=O)[CH2:21][CH2:22][CH3:23].[NH4+].[OH-]>O.[Ni].CO>[O:18]=[C:17]([NH:12][C:5]1[C:6]([CH3:11])=[C:7]2[NH:8][C:20]([CH2:21][CH2:22][CH3:23])=[N:1][C:2]2=[N:3][CH:4]=1)[CH2:16][CH2:15][CH3:19]

Participants

Conditions

Temperature: 85 °C

Procedure

A mixture of 2-amino-3,5-dinitro-4-methylpyridine (3.1 g, 15.6 mmol), THF (100 mL), methanol (100 mL) and Raney-nickel (6 mL of a 1:1 suspension in H2O) was stirred under H2 (1 atm.) for 6 h. The mixture was quickly filtered into a receiving flask containing 3 mL of conc. aqueous HCl, and the solvent was removed in vacuo at r.t. To the resulting crude 2,3,5-triamino-3-methylpyridine.HCl complex was added butyric acid (4.3 mL, 46.9 mmol) and polyphosphoric acid (100 mL) and this mixture was heated to 85° C. for 10 h. The warmed mixture was poured into stirred ice-H2O (200 mL) and this mixture was cooled and neutralized (to pH 3) by the addition of conc. NH4OH. Extraction with CH2Cl2 (3×50 mL), drying (Na2SO4), and concentration gave the title compound as a solid.

Workup

filtrationThe mixture was quickly filtered into a receiving flask
additioncontaining 3 mL of conc. aqueous HCl
customthe solvent was removed in vacuo at r.t
additionThe warmed mixture was poured
temperaturethis mixture was cooled
extractionExtraction with CH2Cl2 (3×50 mL)
customdrying
concentration(Na2SO4), and concentration

Sources & evidence

ORD record: ord-fc41fdc5d05c49e9b0278ac7ee56e708
Source dataset: uspto-grants-1995_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05412097

Linked notes

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