Potassium Hydroxide → 3-(4-Dibutylaminopropoxybenzoyl)-8-methylimidazo[1,2-a]pyridine

HRID 414272

Reaction equation

HRID 414272 reaction equation
[OH:1][C:2]1[CH:19]=[CH:18][C:5]([C:6]([C:8]2[N:12]3[CH:13]=[CH:14][CH:15]=[C:16]([CH3:17])[C:11]3=[N:10][CH:9]=2)=[O:7])=[CH:4][CH:3]=1.[CH2:20]([N:24]([CH2:29][CH2:30][CH2:31]Cl)[CH2:25][CH2:26][CH2:27][CH3:28])[CH2:21][CH2:22][CH3:23].[OH-].[K+]>CO>[CH2:25]([N:24]([CH2:29][CH2:30][CH2:31][O:1][C:2]1[CH:19]=[CH:18][C:5]([C:6]([C:8]2[N:12]3[CH:13]=[CH:14][CH:15]=[C:16]([CH3:17])[C:11]3=[N:10][CH:9]=2)=[O:7])=[CH:4][CH:3]=1)[CH2:20][CH2:21][CH2:22][CH3:23])[CH2:26][CH2:27][CH3:28]

Participants

5

Reactant 3

HCID 14797Potassium HydroxideHCID 96084N-(3-Chloropropyl)dibutylamineHCID 142014553-(4-Hydroxybenzoyl)-8-methylimidazo[1,2-a]pyridine

Product 1

HCID 102737383-(4-Dibutylaminopropoxybenzoyl)-8-methylimidazo[1,2-a]pyridine

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A mixture of 3-(4-hydroxybenzoyl)-8-methylimidazo[1,2-a]pyridine (2.3 g, 9.6 mmol), dibutylaminopropyl chloride (6.8 g, 33 mmol) and potassium hydroxide (1.3 g, 23 mmol) in methanol (60 ml) was stirred at reflux for 96 hours. The mixture was concentrated and the resulting oil was flash chromatographed (silica gel, 2.5% methanol in diethyl ether) to give 1.3 g (31% yield) of the free base of the title compound. The HCl salt was prepared by dropwise addition of concentrated hydrochloric acid to a solution of the free base in methanol, concentrated and recrystallized from acetone-ether to give the HCl salt of the title compound as an off-white solid, mp 105° C. to 107° C. IR(KBr): 3440, 2640, 1645, 1605 cm-1. MS: 421 (M+). 1H NMR (CD3OD): δ9.66 (d, J=8 Hz, 1H), 8.74 (s, 1H), 8.00-7.61 (m, 4H), 7.20 (d, J=7.2 Hz, 2H), 4.29 (t, J=5 Hz, 2H), 3.41-3.15 (m, 6H), 2.75 (s, 3H), 2.31 (m, 2H), 1.80-1.42 (m, 8H), 1.02 (m, 6H).

Workup

  1. temperatureat reflux for 96 hours
  2. concentrationThe mixture was concentrated
  3. customchromatographed (silica gel, 2.5% methanol in diethyl ether)

Sources & evidence

ORD record
ord-04cd127fc1034615817c748a7c7dcfef
Source dataset
uspto-grants-1988_12
Patent number
US04791117

Linked notes

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