Liu, Haidong published the artcileα-Iminyl Cation-Involved Indole Construction via Bronsted Acid Promoted Reaction of Isoxazol-5-ones, Application of 3-Phenylisoxazol-5(2H)-one, the publication is Journal of Organic Chemistry (2022), 87(16), 11226-11230, database is CAplus and MEDLINE.
Herein, a strategically novel method for the efficient construction of indole skeletons I (R1 = Ph, furan-2-yl, cyclohexyl, etc.; R2 = H, Me, C(O)OH; R1R2 = -((CH2)4)-; R3 = 5-Me, 7-Cl, 4-Br, etc.) using 2-phenylisoxazol-5-ones as the starting material was reported. This reaction proceeds via Bronsted acid promoted α-iminyl cation generation by N-O bond cleavage and a subsequent intramol. cyclization to obtain 1H-indole-3-carboxylic acids, which further undergoes decarboxylation to afford the final product. Control experiments show that the N-O bond cleavage and intramol. cyclization proceeds so fast that the 1H-indole-3-carboxylic acids, could be isolated in high yields even after 5-10 min. The substrate scope of this transformation is broad and the desired products are obtained in moderate to good yields. The transition-metal-free reaction condition, CO2 as the sole byproduct, and good practicability adds synthetic potential of this transformation in pharmaceuticals and flavors industry.
Journal of Organic Chemistry 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, Application of 3-Phenylisoxazol-5(2H)-one.
Referemce:
https://en.wikipedia.org/wiki/Isoxazole,
Isoxazole | C3H3NO – PubChem