tert-butyl3-(4-amino-1H-pyrazol-1-yl)azetidine-1-carboxylate

Uses

4-Amino-1-(1-boc-azetidin-3-yl)-1H-pyrazole is a pyrazolamine derivative that can be prepared by alkylation of nitropyrazole with alcohol and subsequent reduction.

Synthesis

The general procedure for the synthesis of tert-butyl 3-(4-amino-1H-pyrazol-1-yl)azetidine-1-carboxylate from tert-butyl 3-(4-nitro-1H-pyrazol-1-yl)azetidine-1-carboxylate was carried out as follows: under an atmosphere of hydrogen gas (1 atmosphere), compound 54-b (1.33 g, 5 mmol) was dissolved in methanol (10 ml), 10% palladium carbon catalyst (0.1 g). The reaction mixture was stirred at 25 °C for 12 hours. Upon completion of the reaction, the catalyst was removed by filtration and the filtrate was concentrated under reduced pressure to afford the crude product compound 65-b (940 mg, 79% yield). The product could be used in subsequent reactions without further purification. Liquid chromatography-mass spectrometry (electrospray ionization) analysis showed: m/z = 261 [M + Na]+.

References

[1] Patent: US2015/336982, 2015, A1. Location in patent: Paragraph 0406; 0407
[2] Tetrahedron Letters, 2008, vol. 49, # 18, p. 2996 - 2998
[3] Patent: EP2832734, 2015, A1. Location in patent: Paragraph 0521