Compound 5
2-(1-((4-ethoxyphenyl)amino)ethylidene)-5,5-dimethylcyclohexane-1,3-dione
From: Closed-loop recycling of plastics enabled by dynamic covalent diketoenamine bonds
View in PubChem | MDL Molfile | Chemdraw file
Compound data: 1H NMR
Compound data: 13C NMR
Compound data: Crystallographic data
Synthetic procedure: See article for the definitive version of this procedure and for full experimental details.
1 (1 mmol) and para-ethoxyaniline (1 mmol) were dissolved in 500 μL CHCl3 and stirred at 50 ˚C. The reaction was monitored using TLC (silica, 1:1 Hex:EtOAc) and was determined to be complete after 2 h. The reaction mixture solidified at room temperature and was recrystallized in Hex/EtOAc to yield colorless crystals (47% yield). Analytically pure samples were prepared by column chromatography with n-hexane/EtOAc as eluent (SiO2, 0–30% EtOAc gradient). Characterization Data: 1H NMR (500 MHz, CDCl3): δ 14.08 (s, 1H), 7.03 (d, J = 8.8 Hz, 2H), 6.90 (d, J = 8.9 Hz, 2H), 4.03 (q, J = 7 Hz, 2H), 2.48 (s, 3H), 2.42 (s, 4H), 1.42 (t, J = 7 Hz, 2H), 1.07 (s, 6H) ppm; 13C NMR (125 MHz, CDCl3): δ 199.59, 197.04, 172.81, 158.35, 129.15, 126.98, 115.16, 108.49, 63.85, 53.70, 52.34, 30.22, 28.40, 20.28, 14.84 ppm; FT-IR (neat) 3265, 3074, 3046, 2976, 2955, 2936, 2867, 2543, 2488, 2356, 2224, 2075, 2030, 1968, 1901, 1687, 1637, 1609, 1575, 1510, 1455, 1420, 1408, 1394, 1387, 1367, 1342, 1298, 1287, 1248, 1228, 1173, 1141, 1118, 1090, 1049, 1006, 979, 948, 939, 925, 897, 890, 859, 846, 826, 811, 792, 764, 739, 707, 666 cm–1; HRMS (ESI) m/z for C18H24NO3+ (MH)+ calculated 302.1678, found 302.1754; analysis (calculated, found for C18H23NO3): C (71.73, 71.74), H (7.69, 7.60), N (4.65, 4.63). Crystallographic data for compound 5 is available free of charge from the Cambridge Crystallographic Date Centre (www.ccdc.cam.ac.uk) under reference number 1891132. The crystal structure indicates a 50:50 disorder associated with the ethoxy substituent on the arene. This has been modeled as C18A and C18B, and the corresponding hydrogens on C17 were modeled accordingly as well. In the associated cif report, A- and B-level alerts pertain to close contacts between H17A and the 3 hydrogens on C18B (H18D, H18E, H18F). These close contacts are the result of modeling the disorder in the molecule.
