Hydrochloric Acid → 5-amino-6-chloro-2-ethyl-N-(piperidin-4-ylmethyl)imidazo[1,2-a]pyridine-8-carboxamide

HRID 965801Notes

Reaction equation

HRID 965801 reaction equation
[NH2:1][C:2]1[N:7]2[CH:8]=[C:9]([CH2:11][CH3:12])[N:10]=[C:6]2[C:5]([C:13]([NH:15][CH2:16][CH:17]2[CH2:22][CH2:21][N:20](C(OC(C)(C)C)=O)[CH2:19][CH2:18]2)=[O:14])=[CH:4][C:3]=1[Cl:30].Cl>CO.Cl>[NH2:1][C:2]1[N:7]2[CH:8]=[C:9]([CH2:11][CH3:12])[N:10]=[C:6]2[C:5]([C:13]([NH:15][CH2:16][CH:17]2[CH2:22][CH2:21][NH:20][CH2:19][CH2:18]2)=[O:14])=[CH:4][C:3]=1[Cl:30]

Participants

4

Reactant 2

HCID 313Hydrochloric AcidHCID 22236502Tert-butyl 4-({[(5-amino-6-chloro-2-ethylimidazo[1,2-a]pyridin-8-yl)carbonyl]amino}methyl)piperidine-1-carboxylate

Product 1

HCID 99496125-amino-6-chloro-2-ethyl-N-(piperidin-4-ylmethyl)imidazo[1,2-a]pyridine-8-carboxamideYield 45.4%

Reagents, catalysts & solvents 1

HCID 21893726Hydrochloride methanolSolvent

Procedure

To a stirred solution of tert-butyl 4-({[(5-amino-6-chloro-2-ethylimidazo[1,2-a]-pyridin-8-yl)carbonyl]amino}methyl)piperidine-1-carboxylate (Example 4, Step 3, 13.71 g, 31.44 mmol) in 10% hydrochloric acid methanol solution (314 mL) was added concentrated hydrochloric acid (10 mL). After stirring at room temperature for 26 h, the mixture was concentrated to about 50 mL in vacuo. The residue was basified with an excess of sodium carbonate and then insoluble material was filtered off. The filtrate was concentrated azeotropically with ethanol and diluted with a mixture of dichloromethane and methanol (5:1, 200 mL). The formed inorganic solid was filtered off again. The filtrate was concentrated in vacuo to give a pale yellow amorphous powder, which was crystallized from ethanol to afford 4.79 g (45%) of the title compound as an off-white solid. Furthermore, 5.09 g (48%) of the compound was obtained from the mother liquid.

Workup

  1. concentrationthe mixture was concentrated to about 50 mL in vacuo
  2. filtrationinsoluble material was filtered off
  3. concentrationThe filtrate was concentrated azeotropically with ethanol
  4. additiondiluted with a mixture of dichloromethane and methanol (5:1, 200 mL)
  5. filtrationThe formed inorganic solid was filtered off again
  6. concentrationThe filtrate was concentrated in vacuo
  7. customto give a pale yellow amorphous powder, which
  8. customwas crystallized from ethanol

Sources & evidence

ORD record
ord-b781d839970a4d808a800d6658adfa22
Source dataset
uspto-grants-2005_10
Patent number
US06951867B2

Reaction notes

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