Loro, Camilla published the artcileNon-Decarboxylative Ruthenium-Catalyzed Rearrangement of 4-Alkylidene-isoxazol-5-ones to Pyrazole- and Isoxazole-4-carboxylic Acids, Quality Control of 1076-59-1, the publication is Organic Letters (2022), 24(16), 3092-3096, database is CAplus and MEDLINE.
Non-decarboxylative ruthenium-catalyzed rearrangement of 4-(2-hydroaminoalkylidenyl)- and 4-(2-hydroxyalkylidenyl)-substituted isoxazol-5(4H)-ones with catalytic amounts of [RuCl2(p-cymene)]2, without any additive, afforded pyrazole-4-carboxylic acids I [R1 = Me, Pr, Ph, etc.; R2 = H, Me, Et, etc.; R3 = Ph, CH2Bn, etc.] and isoxazole-4-carboxylic acids I [R1 = Me, Pr, Ph, etc.; R2 = H, Me, Ph, etc.] resp. The presence of an intramol. H-bond in these substrates was the key to divert the classical mechanism toward a ring-opening non-decarboxylative path that was expected to generate a vinyl Ru-nitrenoid intermediate, the cyclization of which afforded the rearranged products I and II. A gram scale protocol demonstrated the synthetic applicability of this transformation.
Organic Letters published new progress about 1076-59-1. 1076-59-1 belongs to isoxazole, auxiliary class Oxazoline,Benzene,Ester, name is 3-Phenylisoxazol-5(2H)-one, and the molecular formula is C9H7NO2, Quality Control of 1076-59-1.
Referemce:
https://en.wikipedia.org/wiki/Isoxazole,
Isoxazole | C3H3NO – PubChem