Ring-Enlargement and Ring-Opening Reactions of 1,2-Thiazetidin-3-one 1,1-Dioxides with Ammonia and Primary Amines as Nucleophiles

✍ Scribed by Tonya R. Todorova; Anthony Linden; Heinz Heimgartner

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: German
• Weight: 264 KB
• Volume: 82
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/(sici)1522-2675(19990310)82:3<354::aid-hlca354>3.0.co;2-h

✦ Synopsis

The N-benzyl-and N-alkyl-substituted 1,2-thiazetidin-3-one 1,1-dioxides 1b ± d reacted readily with NH 3 and primary amines via ring opening. The reaction with NH 3 proceeded at À 788 3 room temperature yielding ring-opened adducts via nucleophilic attack of NH 3 at the sulfonyl group, whereas the reactions with amines at room temperature yielded products via attack at the carbonyl group. The N-unsubstituted analogue 1a, when reacted with benzylamine in refluxing EtOH, also gave a product of ring opening via nucleophilic attack at the carbonyl group of 1a. The transamidation-like reactions of the 2-(aminoalkyl)-1,2-thiazetidin-3-one 1,1dioxides 19a ± d proceeded via six-, seven-, and eight-membered intermediates, giving the ring-enlarged eight-, nine-, and ten-membered products 21 ± 24 ( Schemes 8 and 9), respectively, in 42 ± 87% yields. The products resulted from the nucleophilic attack of the amino group of the side chain at the carbonyl C-atom. The structure of the eight-membered product 24 with an asymmetrically situated methyl substituent was established by X-ray crystallography.