Hexamethylenetetramine → 2-Naphthalenecarboxaldehyde, 5,6,7,8-tetrahydro-1-methoxy-3,5,5,8,8-pentamethyl-

HRID 1632452

Reaction equation

HRID 1632452 reaction equation
[CH3:1][O:2][C:3]1[C:12]2[C:11]([CH3:14])([CH3:13])[CH2:10][CH2:9][C:8]([CH3:16])([CH3:15])[C:7]=2[CH:6]=[C:5]([CH3:17])[CH:4]=1.C1N2CN3CN(C2)CN1C3.FC(F)(F)[C:30](O)=[O:31]>>[CH:30]([C:4]1[C:5]([CH3:17])=[CH:6][C:7]2[C:8]([CH3:16])([CH3:15])[CH2:9][CH2:10][C:11]([CH3:13])([CH3:14])[C:12]=2[C:3]=1[O:2][CH3:1])=[O:31]

Participants

4

Reactant 3

HCID 4101HexamethylenetetramineHCID 6422Trifluoroacetic acidHCID 2267025-Methoxy-1,1,4,4,7-pentamethyl-1,2,3,4-tetrahydronaphthalene

Product 1

HCID 1747662-Naphthalenecarboxaldehyde, 5,6,7,8-tetrahydro-1-methoxy-3,5,5,8,8-pentamethyl-

Procedure

Formylation. 1-Methoxy-3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalene (50 g, 0.2155 mol) was added to a stirred mixture of hexamethylenetetramine (31.4 g, 0.224 mol) and trifluoroacetic acid (250 mL) at 35°-40° C., under a nitrogen atmosphere. The stirred reaction mixture was heated to 85°-90° C. and maintained at this temperature for 1.5 h. Trifluoroacetic acid was removed by distillation and the residue was poured onto an ice-water mixture (800 mL). The mixture was then stirred for 0.5 h, neutralized with a 10% sodium carbonate solution, and the product extracted with benzene (2×150 mL). The combined extracts were washed with brine (50 mL) and dried (Na2SO4). The solvent was then removed by distillation and the residue crystallized from hexane to provide 2-formyl-1-methoxy-3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalene (14 g), mp 78° C., GLC purity 100%. 1H-NMR (CDCl3) δ10.39 (1H, s), 6.93 (1H, s), 3.86 (3H, s), 2.49 (3H, s), 1.63 (4H, s), 1.39 (6H, s), 1.37 (6H, s), 13C-NMR (CDCl3) δ192.1 (1C, d), 165.4 (1C, s), 153.5 (1C, s), 138.3 (1C, s), 135.8 (1C, s), 125.8 (2C, s, d), 66.1 (1C, q) 38.1 (1C, t), 35.3 (1C, s), 34.8 (1C, t), 34.3 (1C, s), 31.7 (2C, q), 29.8 (2C, q), 20.8 (1C, q). IR (melt) 1245, 1682 cm-1,MS (m/e) 260 M+, 20.8), 246 (18.7), 245 (100.0), 141 (12.3), 128 (13.2), 115 (13.0).

Workup

  1. customThe stirred reaction mixture
  2. temperaturewas heated to 85°-90° C.
  3. temperaturemaintained at this temperature for 1.5 h
  4. customTrifluoroacetic acid was removed by distillation
  5. additionthe residue was poured onto an ice-water mixture (800 mL)
  6. extractionthe product extracted with benzene (2×150 mL)
  7. washThe combined extracts were washed with brine (50 mL)
  8. dry with materialdried (Na2SO4)
  9. customThe solvent was then removed by distillation
  10. customthe residue crystallized from hexane

Sources & evidence

ORD record
ord-29627f152a06401ca020d3d7ce79e086
Source dataset
uspto-grants-1984_10
Patent number
US04476040

Linked notes

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