Aldoxime → 3-[2-(3-Methyl-isoxazol-5-yl)-pyridin-4-yl]-3-oxo-propionic acid tert.-butyl ester

Participants

Reaction Steps

The title compound was prepared from 2-(3-methyl-isoxazol-5-yl)-isonicotinic acid methyl ester [prepared by i.) reaction of 2-iodo-isonicotinic acid methyl ester [CAS-No. 134579-47-8] with trimethylsilylacetylene according to general procedure H; ii.) desilylation by reaction with cat. K2CO3 in MeOH at 0° C. for 4 h; iii.) cycloadditon with a mixture of NCS, acetaldoxime, Et3N and cat. amount of pyridine in CHCl3 at 50° C. according to Tetrahedron 1984, 40, 2985-2988] by treatment with lithium tert.-butyl acetate according to general procedure K (method b). Obtained as a brown solid (5.17 g). MS (EI) 302 (M+); mp 59-67° C.

Provenance & Evidence