Synthetic and spectroscopic study of 5-amino-2-acyl-1,2,4-thiadiazolin-3-ones

✍ Scribed by Do Young Ra; Nam Sook Cho; Jung Hyun Moon; Sung Kwon Kang

• Publisher: Journal of Heterocyclic Chemistry
• Year: 1998
• Tongue: English
• Weight: 380 KB
• Volume: 35
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570350636

✦ Synopsis

Abstract

5‐Amino‐2‐acyl‐1,2,4‐thiadiazolin‐3‐ones 2–1 can be synthesized from 5‐amino‐2__H__‐1,2,4‐thiadiazolin‐3‐one (1–1) via a selective acylation with an acid anhydride in pyridine. The ^1^H nmr spectral characteristics of 5‐amino‐2‐acyl‐1,2,4‐thiadiazolin‐3‐ones 2–1 is in particular, compared with 5‐amino‐2__H__‐1,2,4‐thiadiazolin‐3‐one (1–1) and 5‐amino‐2‐alkyl‐1,2,4‐thiadiazolin‐3‐ones 1–2, 1–3. The 5‐amino group of 2–1 appeared as two peaks in its ^1^H nmr spectrum, which merged to a single peak at a higher temperature, while those of compound 1–1, 1–2 and 1–3 appear only as a single peak. The restricted rotation of the C(5)‐N(5) (at amino) bond of 5‐amino‐2‐acetyl‐1,2,4‐thiadiazolin‐3‐one (2a‐1) is about 14.5 Kcal/mol.