Hexamethylenetetramine → HCID 12938336, compound

To a solution of hexamethylenetetramine (HMTA)(6.75 g, 48.1 mmol) in trifluoroacetic acid (TFA)(40 ml) heated at reflux was added a solution of 4-ethoxy-1,3-dimethoxybenzene, (4.0 g, 24.1 mmol) in TFA (40 ml) dropwise over 90 min. The reaction mixture was heated at reflux for 2 h. The dark solution was concentrated in vacuo with mild heating leaving a dark red syrup. Ice water was added to the syrup until it became cloudy, then stirred at room temperature for 20 min. The mixture was basified with solid K2CO3, then stirred at room temperature for 20 min, and extracted with CH2Cl2 (200 ml×4). The combined CH2Cl2 solution was washed with water and brine, dried over MgSO4, and concentrated in vacuo to give a crude title compound (4.46 g) as a orange solid. The crude product was recrystallized from hexane-ethyl acetate to give title compound (2.51 g, 53.7%) as a pale yellow solid. 1H-NMR δ: 10.30 (s, 1H), 7.63 (s, 1H), 6.40 (s, 1H), 3.93 (s, 3H), 3.92 (s, 3H), 2.56 (q, J=7.3 Hz, 2H), 1.16 (t, J=7.3 Hz, 3H) IR(KBr, cm-1): 1662, 1610, 1578, 1505, 1488, 1477, 1457, 1437, 1408, 1354, 1320, 1279, 1261, 1216, 1189, 1111, 1025, 908, 825, 697.

1. temperatureat reflux
2. temperatureThe reaction mixture was heated
3. temperatureat reflux for 2 h
4. concentrationThe dark solution was concentrated in vacuo
5. temperaturewith mild heating
6. customleaving a dark red syrup
7. stirringstirred at room temperature for 20 min
8. extractionextracted with CH2Cl2 (200 ml×4)
9. washThe combined CH2Cl2 solution was washed with water and brine
10. dry with materialdried over MgSO4
11. concentrationconcentrated in vacuo
12. customto give a crude title compound (4.46 g) as a orange solid
13. customThe crude product was recrystallized from hexane-ethyl acetate

ORD record

ord-6281f73b558349888360d2ea1327fe63

Source dataset

uspto-grants-1997_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05604241