Ernst Schmitz

Surprising reactions or special azoolefins - self-arylation, indole ring closure, mild chlorine substitution, and “tert. amino effect”

Abstract Azoolefins 2 either decompose or react with aryldiiminea with uptake of an aryl group to give compounds 3 . The latter can undergo ring closure to N -amino-indoles 4 . In the 2,4,6-trichloro compound 3b ortho -chlorines are selectively replaced bymorpholine under very mild conditions giving 5a , which easily fragments to form the benzimidazole 7 .

Ring opening and ring enlargement of a cyclopropene carboxylic acid

Abstract 3,3-Dimethyl-2-phenyl-cyclopropenecarboxylic acid 4 is prepared, starting with chlorophenyldiazirine 1. With acids 4 yields the open chain carboxylic acids 5, 6 and 7. Thionychloride leads to the cyclobutenone 10, DCC to the acid anhydrides 11 and 13.

Aminations with oxaziridine. Syntheses of aryl- and hetaryl-hydrazines

Five acetylaminobenzenes (2) (X = CH), two 3-acetylaminopyridines (2) (X = N) and one 3-acetylaminopyridinel-oxide (2) (X = N(O)) are aminated by 1-oxa-2-azaspiro[2.5]octane (1)/DABCO to cyclohexylidenehydrazino compounds (3), which are characterized as benzaldehyde or 4-nitrobenzalde-hydehydrazones (4). In some cases the acetyl group is removed during the amination