Synthesis of 1,2,3-triazoles containing an allomaltol moiety from substituted pyrano[2,3-d]isoxazolones via base-promoted Boulton–Katritzky rearrangement

• Constantine V. Milyutin,
• Andrey N. Komogortsev and
• Boris V. Lichitsky

Beilstein J. Org. Chem. 2024, 20, 1334–1340, doi:10.3762/bjoc.20.117

• types of aforementioned structures were proved by X-ray analysis. Keywords: allomaltol; Boulton–Katritzky rearrangement; hydrazones; pyrano[2,3-d]isoxazolones; recyclization; 1,2,3-triazoles; Introduction The Boulton–Katritzky rearrangement (BKR) also known as mononuclear heterocyclic rearrangement is

• terarylenes containing an allomaltol fragment were developed in our group [21][22][23][24][25][26]. Ongoing the research in this area, herein, we studied the reaction of aroyl containing substituted pyrano[2,3-d]isoxazolones 1 with various hydrazine hydrochlorides 2. It was shown that formed hydrazones 3

• in the presence of K2CO3 in DMF allowed us to prepare 3-methoxypyran-4-one derivative 7 (Scheme 9). Conclusion In summary, we investigated the reaction of substituted pyrano[2,3-d]isoxazolones with diverse hydrazines. We have demonstrated that initially the studied process leads to appropriate