Hexamethylenetetramine → 3-Cyclopentylmethyl-4-methoxybenzaldeyde

HRID 2210539Notes

Reaction equation

[CH:1]1([CH2:6][C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][C:8]=2[O:13][CH3:14])[CH2:5][CH2:4][CH2:3][CH2:2]1.FC(F)(F)[C:17](O)=[O:18].C1N2CN3CN(C2)CN1C3.[OH-].[Na+]>C(Cl)Cl>[CH:1]1([CH2:6][C:7]2[CH:12]=[C:11]([CH:10]=[CH:9][C:8]=2[O:13][CH3:14])[CH:17]=[O:18])[CH2:2][CH2:3][CH2:4][CH2:5]1

Participants

Conditions

Temperature: 100 °C

Procedure

To a stirred mixture of 1-cyclopentylmethyl-2-methoxybenzene (383 mmol, 72.7 g) in trifluoroacetic acid (3.83 mol, 435 g; 294 mL) was added hexamine (766 mmol, 107 g) in one portion at room temperature, resulting in an exothermic reaction. After the exotherm had subsided, the reaction mixture was heated to 100° C. for 18 hours and cooled to room temperature. The heterogenous mixture was diluted with CH2Cl2 (800 mL) and the resulting homogenous solution was cooled to 0° C. and neutralized to pH 7 by the dropwise addition of 2.5N NaOH (~1L). The layers were separated, the aqueous phase extracted with CH2Cl2 (1×600 mL), dried (Na2SO4), and concentrated in vacuo to afford a viscous oil. Purification by filtration through a plug of SiO2 (gradient elution: 1) hexane, 2) 36:1 hexane/EtOAc, 3) 18:1 hexane/EtOAc, 4) 12:1 hexane/EtOAc, 5) 8:1 hexane/EtOAc) afforded the title compound as a light yellow oil (46.6 g, 56%).

Workup

customresulting in an exothermic reaction
temperaturecooled to room temperature
customThe layers were separated
extractionthe aqueous phase extracted with CH2Cl2 (1×600 mL)
dry with materialdried (Na2SO4)
concentrationconcentrated in vacuo
customto afford a viscous oil
customPurification
filtrationby filtration through a plug of SiO2 (gradient elution: 1) hexane, 2) 36:1 hexane/EtOAc, 3) 18:1 hexane/EtOAc, 4) 12:1 hexane/EtOAc, 5) 8:1 hexane/EtOAc)

Sources & evidence

ORD record: ord-68793066666c495db9dac9c78c8b5a56
Source dataset: uspto-grants-1995_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05459151

Reaction notes

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