Chloroacetaldehyde → Methyl 5-amino-6-chloroimidazo[1,2-a]pyridine-8-carboxylate

HRID 1168245Notes

Reaction equation

HRID 1168245 reaction equation
[NH2:1][C:2]1[N:11]=[C:10]([NH2:12])[C:9]([Cl:13])=[CH:8][C:3]=1[C:4]([O:6][CH3:7])=[O:5].Cl[CH2:15][CH:16]=O>CO>[NH2:12][C:10]1[N:11]2[CH:15]=[CH:16][N:1]=[C:2]2[C:3]([C:4]([O:6][CH3:7])=[O:5])=[CH:8][C:9]=1[Cl:13]

Participants

4

Reactant 2

HCID 33Chloroacetaldehyde2×HCID 12088100Methyl 2,6-Diamino-5-chloronicotinate

Product 1

HCID 22313263Methyl 5-amino-6-chloroimidazo[1,2-a]pyridine-8-carboxylateYield 68%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A mixture of methyl 2,6-diamino-5-chloronicotinate (EXAMPLE 1, METHOD B, Step 1, 2.0 g, 9.92 mmol) and chloroacetaldehyde (1.2 mL, 10.91 mmol) in methanol (100 mL) was refluxed for 135 min. A further chloroacetaldehyde (1.2 mL, 10.91 mmol) was added and refluxing continued over 21 hours. The solvent was evaporated and the resulting solid co-evaporated with methanol (75 mL×2) prior to drying under vacuum, giving 2.62 g of crude material. The residue was chromatographed on a column of silica gel eluting with dichloromethane/methanol/25% aqueous ammonia (96.5:3.5:0.5 to 93:7:1) to give 1.52 g (68%) of the title compound as an off white powder.

Workup

  1. temperaturewas refluxed for 135 min
  2. temperaturerefluxing
  3. customThe solvent was evaporated
  4. dry with materialthe resulting solid co-evaporated with methanol (75 mL×2) prior to drying under vacuum
  5. customgiving 2.62 g of crude material
  6. customThe residue was chromatographed on a column of silica gel eluting with dichloromethane/methanol/25% aqueous ammonia (96.5:3.5:0.5 to 93:7:1)

Sources & evidence

ORD record
ord-13eb329a157a4478b99fa7fd6c561e2a
Source dataset
uspto-grants-2003_09
Patent number
US06624162B2

Reaction notes

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