1‐Amino‐2‐phthalimido‐diazen‐1‐oxide: Bildung, Eigenschaften und Fragmentierungen in Imido‐ und Amino‐nitrene

1‐Amino‐2‐phthalimido‐diazene‐1‐oxides: Formation, Properties and Fragmentation Reactions into Imido‐ and Amino‐nitrenes 1 ) Oxidatively generated phthalimido‐nitrene ( 1 ) reacts with the nitrosoamines 2a‐d (see Scheme 1 ) to give the corresponding ( Z )‐1‐amino‐2‐phthalimido‐diazene‐1‐oxides 3a‐d in good yields. With the O ‐nitroso compound 2e , no addition of the nitrene 1 took place. The constitution the adducts 3 (R = NR′ 2 ) is deduced from their spectroscopic properties (UV., IR., 1 H‐NMR. and MS.) as compared to those of ( Z )‐1‐aryl‐ and ( Z )‐1‐alkyl‐2‐phthalimido‐diazene‐1‐oxides 3 (R = aryl and alkyl, resp.). The ( Z )‐configuration of 3 (R = NR′ 2 ) follows from an X‐ray analysis which is reported separately. Compounds 3 (R = NR′ 2 ) are cleaved photolytically as well as by acid to the corresponding nitrosoamines 2 (R = NR′ 2 ) and the nitrene 1 , which could be trapped by cyclohexene to give 40% of 7‐phthalimido‐7‐azabicyclo [4.1.0]heptane ( 8 ) and by dimethylsulfoxide to yield 96% of S, S ‐dimethyl‐ N ‐phthalimido‐sulfoximide ( 13 ). Nucleophilic attack leads to fragmentation of 3 (R = NR′ 2 ) into derivatives of phthalic acid and degradation products of intermediate aminonitrenes 24 corresponding to the respective nitrosoamines 2 (R = NR′ 2 ) with loss of oxygen. A general rationalization for the formation of 24 includes as a key step of N‐ to C‐migration of the O‐atom (see Scheme 6 ). The final fate of 24 is depending on the type of the nucleophile used. Thus, hydrazinolysis of 3b and of 3c generates besides N, N ′‐phthaloylhydrazine ( 15 ), morpholine ( 14 ) from 3b and 1, 3‐dihydroisoindole ( 16 ) together with 6′‐methylidene‐1, 2, 3, 4‐tetrahydronaphthalene‐2‐spiro‐1′‐cyclohexa‐2′, 4′‐diene ( 17 ) from 3c (see Scheme 5 ). Treatment of 3b and of 3c with sodium methylate leads in both reactions to monomethyl phthalate ( 33 ) and, with 3b , to 1, 2‐dimorpholinodiazene ( 31 ) and, with 3c , to 17 (see Scheme 7 ). Finally, the reaction of 3b with diethylamine generates N, N ‐diethylphthalamic acid ( 36 ), morpholine ( 14 ), 1,1,4,4‐tetraethyl‐2‐tetrazene( 34 ) and l,l‐diethyl‐4,4‐(3‐oxapentamethylene)‐2‐tetrazene ( 35 ) (see Scheme 8 ).