Ethyl 4-aminocinnamate

Synthesis

General procedure for the synthesis of ethyl 4-aminocinnamate from ethyl (E)-3-(4-nitrophenyl)acrylate: to an 8 mL glass vial (14 mm diameter, 50 mm height) equipped with a PTFE-coated oval magnetic stirring bar (8.5 mm) and a plastic screw cap was added ethyl (E)-3-(4-nitrophenyl)acrylate (0.5 mmol, 1.0 equivalents), Fe2O3/NGr(at)C catalyst (50 mg, 4.0 mol% Fe), triethylamine (Et3N, 70 μL, 0.5 mmol, 1.0 equivalents), tetrahydrofuran (THF, 2 mL) and deionized water (H2O, 0.2 mL). The silicone septum was punctured with a 26-gauge syringe needle (0.45 × 12 mm), and the vial was placed in an aluminum plate and transferred to a 300-mL autoclave. After sealing the autoclave, it was placed in an aluminum block and purged with carbon monoxide (CO, 5-10 bar) three times. This was followed by pressurization with CO to 30 bar and addition of nitrogen (N2) at 20 bar. The aluminum block was heated to 125°C with sufficient stirring (700 rpm). After 24 hours of reaction, the autoclave was removed from the aluminum block and cooled to room temperature. After releasing the remaining gas in a water bath, the vial containing the reaction mixture was removed. The reaction mixture was filtered through a diatomaceous earth pad (about 1 cm thick), the filtrate was concentrated and finally analyzed by gas chromatography (GC) and nuclear magnetic resonance (NMR) spectroscopy (Table 2).

References

[1] Advanced Synthesis and Catalysis, 2012, vol. 354, # 2-3, p. 321 - 327
[2] Synthesis (Germany), 2018, vol. 50, # 22, p. 4369 - 4376
[3] Journal of Organic Chemistry, 1999, vol. 64, # 7, p. 2301 - 2303
[4] Organic Letters, 2017, vol. 19, # 24, p. 6518 - 6521
[5] Journal of Medicinal Chemistry, 2016, vol. 59, # 19, p. 8967 - 9004