Abstract: Based on ursolic acid, 3 compounds with isothiocyanate groups located at different distances from C-17 of the triterpenoid core have been synthesized through ursane-derived primary amines. To obtain terpene hybrids with thioureas and N,S-containing heterocycles, series of amines and ammonia were reacted with novel isothiocyanates. In the reactions with propargylamine, 3 triterpenoid hybrids with 4,5-dihydrothiazol-2-yl-amine have been selectively obtained in 81%–91% yields. Isothiocyanates containing several bonds between the -CNS group and the triterpenoid backbone reacted with (1-aryl-1H-1,2,3-triazole-4-yl)methanamines, as well as with ammonia, to form thiourea derivatives (78%–94%). The nor-compound with a -CNS group at C-17 of the triterpenoid was the least reactive due to deactivation by a donor terpene branched substituent and reacted readily only with sufficiently strong nucleophiles, such as primary and secondary aliphatic amines. The reaction of the nor-derivative of isothiocyanate 7 with ammonia at elevated temperature led to the unexpected formation of 3β-acetoxy-28-norurs-12-en-17-yl-amine, the precursor of isothiocyanate, as the main product (82%).

Cite: Popov S.A. , Qi Z. , Wang C. , Shults E.E.
Synthesis of ursane-derived isothiocyanates and study of their reactions with series of amines and ammonia
Journal of Sulfur Chemistry. 2023. V.44. N5. P.523-541. DOI: 10.1080/17415993.2023.2193669 WOS РИНЦ

Dates:

Submitted:	Jan 2, 2023
Accepted:	Mar 1, 2023
Published online:	Mar 23, 2023

Identifiers:

Web of science	WOS:000951856100001
Elibrary	62489105
OpenAlex	W4360871710

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