Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Synthetic route of the intermediates. Reagents and conditions: (a) secondary amine, K2CO3, DMF, 90 °C, 10–15 h; (b) malonic acid, piperidine in pyridine, reflux, 3 h; (c) (i) HCl, NaNO2, H2O, 0–5 °C, 30 min; (ii) NaN3, H2O, 0–5 °C, 2–4 h; (d) propiolic acid, l-ascorbic acid sodium salt, CuSO4·5H2O, n-BuOH/H2O, r.t., 24 h; (e) NH3·H2O, reflux, 5 h; (f) diethyl phosphite, 70–75 °C, 2–5 h; (g) p-TsOH, THF, 0 °C, 2 h; (h) NH3·H2O, r.t., 30 min; (j) chloroacetyl chloride, TEA, r.t., 3 h.
