Diketene → 2-[4-(Pyridin-2-yl)piperazin-1-yl]ethyl 3-oxobutanoate

HRID 329889Notes

Reaction equation

HRID 329889 reaction equation
[N:1]1[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=1[N:7]1[CH2:12][CH2:11][N:10]([CH2:13][CH2:14][OH:15])[CH2:9][CH2:8]1.[CH2:16]=[C:17]1[O:21][C:19](=[O:20])[CH2:18]1>C1(C)C=CC=CC=1>[C:19]([O:15][CH2:14][CH2:13][N:10]1[CH2:9][CH2:8][N:7]([C:2]2[CH:3]=[CH:4][CH:5]=[CH:6][N:1]=2)[CH2:12][CH2:11]1)(=[O:20])[CH2:18][C:17]([CH3:16])=[O:21]

Participants

4

Reactant 2

HCID 12661DiketeneHCID 105125282-[4-(Pyridin-2-yl)piperazin-1-yl]ethan-1-ol

Product 1

HCID 198712182-[4-(Pyridin-2-yl)piperazin-1-yl]ethyl 3-oxobutanoateYield 78.3%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

To a solution of 4-(2-pyridyl)-1-piperazineethanol (4.65 g) in toluene (3 ml) was added dropwise diketene (2.26 g) under stirring at 70°-80° C. The mixture was further stirred at room temperature for an hour and purified by silica gel chromatography [eluent: dichloromethanemethanol (95:5)] to give 2-[4-(2-pyridyl)-1-piperazinyl]ethyl acetoacetate as an oil (5.12 g, 78.3%). IR(Neat): 1740, 1715 cm-1. NMR(CDCl3)δ: 2.26(3H, s), 2.47-2.79(6H, m), 3.40-3.64(6H, m), 4.27(2H, t, J=6), 6.43-6.69(2H, m), 7.24-7.56(1H, m), 8.02-8.18(1H, m).

Workup

  1. stirringThe mixture was further stirred at room temperature for an hour
  2. custompurified by silica gel chromatography [eluent: dichloromethanemethanol (95:5)]

Sources & evidence

ORD record
ord-cd675c384da24f409dc2939a77d2eb61
Source dataset
uspto-grants-1990_01
Patent number
US04892875

Reaction notes

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