Isoxazoles. XVI. Reaction of nitrous acid and 5-amino-3,4-dialkylisoxazoles was written by Kano, Hideo;Adachi, Ikuo;Yamazaki, Eiko. And the article was included in Chemical & Pharmaceutical Bulletin in 1964.Reference of 14678-05-8 This article mentions the following:
5-Amino-3,4-dialkylisoxazoles (I) treated with HNO2 gave 4-[(3,4-dialkylisoxazol-5-yl)azo]-2-isoxazolin-5-ones (II). Thus, an aqueous solution of 7 g. NaNO2 added to 20 g. I [R = R1 = Me, R2 = H (III)] in 70 ml. 20% HCl at <5° and the precipitate washed (H2O) and dried gave 78% II [R = R1 = Me (IV)], m. 85° (dilute EtOH). Similarly, I (R = Me, R1 = Et, R2 = H) and I [R = Et, R1 = Me, R2 = H (V)] with HNO2 gave liquid II [R = Me, R1 = Et (VI)] and II [R = Et, R1 = Me (VII)], m. 63.5°, resp. IV, VI, and VII warmed 5 min. on a water bath with 10% NH4OH were hydrolyzed to 85% I [R = R1 = Me, R2 = MeC(:NOH)C(:N)Me (VIII)], m. 202° (EtOH), 62% I [R = Me, R1 = Et, R2 = MeC(:NOH)C(:N)Et (IX)],m. 203.5°, and 100% I [R = Et, R1 = Me, R2 = EtC(:NOH)C(:N)Me (X)], m. 149°, resp. VIII, IX, and X were further hydrolyzed by dissolving in 30-40% H2SO4 to I [R = R1 = Me, R2 = MeC(:O)(:N)Me, m. 113°, I [R = Me, R1 = Et, R2 = MeC(:O)C(:N)Et, m. 95-7° (ligroine), and I [R = Et, R1 = Me, R2 = EtC(:O)C(:N)Me], m. 102-4°, resp. III in 10% HCl coupled with the appropriate diazonium chloride afforded liquid XI [R = o-NO2 (XII)], XI [R = m-NO2 (XIII)], m. 72°, and XI [R = p-NO2 (XIV)], m. 91°. XII, XIII, and XIV were hydrolyzed in alc. 10% NH4OH to MeC(:NOH)Ac (XV) o-nitrophenylhydrazone, m. 221° (decomposition), XV m-nitrophenylhydrazone, m. 257°, and XV p-nitrophenylhydrazone, m. 251°, resp. These results showed that Hanriot’s structure (Bull. Soc. Chim. France [3],5 776(1891)) for the product obtained from diazotizing V was incorrect. In the experiment, the researchers used many compounds, for example, Isoxazol-5-amine (cas: 14678-05-8Reference of 14678-05-8).
Isoxazol-5-amine (cas: 14678-05-8) belongs to isoxazole derivatives. Isoxazoles are aromatic heterocycles containing an N–O bond. The weakness of this bond allows the ring opening of these heterocycles under reductive conditions. Isoxazole can be synthesised via a variety of methods. Examples include via a 1,3-dipolar cycloaddition of nitrile oxides with alkynes.Reference of 14678-05-8
Referemce:
Isoxazole – Wikipedia,
Isoxazole | C3H3NO – PubChem