Synthesis
The general procedure for the synthesis of tert-butyl 1-allylhydrazinecarboxylate from tert-butyl allyl(1,3-dioxoisoindolin-2-yl)carbamate was as follows: to a solution of tert-butyl allyl(1,3-dioxoisoindolin-2-yl)carbamate (15.6 g, 51.5 mmol) in THF (100 mL) cooled in an ice bath was slowly added methyl hydrazine ( 3.40 mL, 64.3 mmol). The reaction mixture was gradually warmed to room temperature and stirred continuously for 18 hours. Upon completion of the reaction, the resulting white suspension was filtered and the filtrate was concentrated under reduced pressure. A solvent mixture of hexane and EtOAc (3:1, v/v) was added to the concentrate and the resulting precipitate was removed by filtration. After this purification process was repeated twice, the final filtrate was concentrated to give tert-butyl 1-allylhydrazinecarboxylate as a light yellow oil (8.47 g, 49.2 mmol, 96% yield). Thin layer chromatography (TLC) analysis showed an Rf value of 0.22 (unfolding agent ratio 4:1 hexane:EtOAc). Infrared spectroscopy (IR) showed characteristic absorption peaks (cm-1) of 3336, 2977, 2932, 1690. nuclear magnetic resonance hydrogen spectroscopy (1H NMR, 400 MHz, DMSO-d6) showed δ 1.40 (9H, s, -C(CH3)3), 3.85 (2H, ddd, J = 5.5, 1.4, 1.4 Hz, N-CH2). 4.46 (2H, s, NH2), 5.06-5.09 (1H, m, allyl C-Htrans), 5.11 (1H, br, allyl C-Hcis), 5.74-5.86 (1H, m, allyl CH). Nuclear magnetic resonance carbon spectrum (13C NMR, 125 MHz, DMSO-d6) showed δ 28.5 (C(CH3)3), 53.6 (N-CH2), 79.4 (C(CH3)3), 116.2 (allyl-CH2), 134.6 (allyl-CH), 156.5 (C=O).
References
[1] ChemMedChem, 2018, vol. 13, # 16, p. 1681 - 1694
[2] Patent: WO2017/75629, 2017, A2. Location in patent: Page/Page column 33
[3] Tetrahedron Letters, 2000, vol. 41, # 2, p. 205 - 207
[4] Journal of Organic Chemistry, 2000, vol. 65, # 14, p. 4370 - 4374
[5] Patent: US2007/254892, 2007, A1. Location in patent: Page/Page column 30
