Formaldehyde → Tert-butyl 4-[(6-hydroxy-3-oxo-2,3-dihydrobenzofuran-7-yl)methyl]piperazine-1-carboxylate

HRID 1749728Notes

Reaction equation

HRID 1749728 reaction equation
[OH:1][C:2]1[CH:11]=[CH:10][C:5]2[C:6](=[O:9])[CH2:7][O:8][C:4]=2[CH:3]=1.[C:12]([O:16][C:17]([N:19]1[CH2:24][CH2:23][NH:22][CH2:21][CH2:20]1)=[O:18])([CH3:15])([CH3:14])[CH3:13].[CH2:25]=O>C(O)C>[OH:1][C:2]1[CH:11]=[CH:10][C:5]2[C:6](=[O:9])[CH2:7][O:8][C:4]=2[C:3]=1[CH2:25][N:22]1[CH2:23][CH2:24][N:19]([C:17]([O:16][C:12]([CH3:15])([CH3:13])[CH3:14])=[O:18])[CH2:20][CH2:21]1

Participants

5

Reactant 3

HCID 712FormaldehydeHCID 143452tert-Butyl piperazine-1-carboxylateHCID 2357176-Hydroxy-3-coumaranone

Product 1

HCID 60155786Tert-butyl 4-[(6-hydroxy-3-oxo-2,3-dihydrobenzofuran-7-yl)methyl]piperazine-1-carboxylateYield 50.4%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of 6-hydroxybenzofuran-3(2H)-one (3.00 g, 20.0 mmol) in ethanol (20 mL) was added with 1-tert-butoxycarbonylpiperazine (3.73 g, 20.0 mmol), and 37% aqueous formaldehyde (1.62 g, 20.0 mmol) at room temperature. The mixture was stirred overnight at room temperature, and then subjected to suction filtration, and the filtrate was concentrated. Crude product obtained by silica gel column chromatography (hexane/ethyl acetate) was recrystallized from ethyl acetate to obtain the objective tert-butyl 4-[(6-hydroxy-3-oxo-2,3-dihydrobenzofuran-7-yl)methyl]piperazine-1-carboxylate (3.51 g, 50%).

Workup

  1. filtrationsubjected to suction filtration
  2. concentrationthe filtrate was concentrated
  3. customCrude product obtained by silica gel column chromatography (hexane/ethyl acetate)
  4. customwas recrystallized from ethyl acetate

Sources & evidence

ORD record
ord-d47d30ce2e7148ee8811470a4664c4e1
Source dataset
uspto-grants-2015_10
Patent number
US09156827B2

Reaction notes

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