Water → HCID 58501747, compound

Participants

Reaction Steps

A water (5 mL) solution of LiOH (0.146 g, 6.09 mmol) was added to a methanol (5 mL) solution of (S)-1-tert-butyl 5-methyl 1H-pyrazole-1,5(4H,5H)-dicarboxylate (0.76 g, 3.11 mmol), and stirred at ambient conditions for ˜7 h. The reaction mixture was cooled with an ice-water bath, and HCl/H2O (3 mL of 1.00 N; 3.0 mmol) was added dropwise and stirred for a few minutes. Then, the volatile component was removed in vacuo and the resultant viscous oil was exposed to high vacuum to afford lithium (S)-2-(tert-butoxycarbonyl)pyrazolidine-3-carboxylate as a white foam, which was used without further purification. 1H NMR (DMSO-d6, δ=2.50 ppm, 400 MHz) for crude sample: 3.98 (dd, J=8.5, 6.3, 1H), 2.86-2.74 (m, 2H), 2.45 (s, 3H), 2.25-2.17 (m, 1H), 2.10-2.02 (m, 1H), 1.35 (s, 9H). LC-MS: Anal. Calcd. for [M+H]+ C10H19N2O4: 231.13. found 231.21.

Provenance & Evidence