Ammonium Hydroxide → 7-Methyl-2-propyl-1H-imidazo[4,5-b]pyridine

HRID 2399446Notes

Reaction equation

HRID 2399446 reaction equation
[NH2:1][C:2]1[C:7]([NH2:8])=[C:6]([CH3:9])[CH:5]=[CH:4][N:3]=1.[NH4+].[OH-]>>[CH3:9][C:6]1[CH:5]=[CH:4][N:3]=[C:2]2[N:1]=[C:4]([CH2:5][CH2:6][CH3:7])[NH:8][C:7]=12

Participants

3

Reactant 2

HCID 14923Ammonium HydroxideHCID 3174954-Methylpyridine-2,3-diamine

Product 1

HCID 150208527-Methyl-2-propyl-1H-imidazo[4,5-b]pyridineYield 174.5%

Conditions

Temperature
100 °C

Procedure

A mixture of burytic acid (6.57 mL, 71.9 mmol), 2,3-diamino-4-picoline (8.05 g, 65.4 mmol), and polyphosphoric acid (50 g) was heated to 100° C. with stirring for 3 hours, and monitored by t1c of NH4OH neutralized aliquots. Basification (NH4OH), extraction (CH2Cl2, 4×50 mL), drying (K2CO3), purification (by filtering through 100 g silica gel, EtOAc solution), and concentration gave 10.0 g (87%) of the title compound as an amorphous tan solid which was judged pure by 1H NMR and t1c: mp 110°-112° C. (without recrystallization).

Workup

  1. extractionBasification (NH4OH), extraction (CH2Cl2, 4×50 mL)
  2. customdrying
  3. custom(K2CO3), purification (by filtering through 100 g silica gel, EtOAc solution), and concentration

Sources & evidence

ORD record
ord-c407404207eb41feb2b00ede8b03b4b6
Source dataset
uspto-grants-1995_09
Patent number
US05449682

Reaction notes

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