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Azimine. II . Synthese und thermische Fragmentierung von cis ‐ und trans ‐2,3‐Diphenyl‐1‐phthalimido‐2,3‐di[ 15 N]‐azimin
Author(s) -
Leuenberger Christian,
Karpf Martin,
Hoesch Lienhard,
Dreiding André S.
Publication year - 1977
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19770600313
Subject(s) - chemistry , fragmentation (computing) , thermal decomposition , mass spectrum , medicinal chemistry , stereochemistry , organic chemistry , ion , computer science , operating system
Azimines. II Teil I, siehe [1]. . Preparation and Thermal Fragmentation of cis ‐ and trans ‐2,3‐Diphenyl‐1‐phthalimido‐2,3‐di[ 15 N]‐azimine Teilweise vorgetragen in der Versammlung der Schweizerischen Chemischen Gesellschaft am 8./9. Oktober 1976 in Genf und als Autoreferat veröffentlicht [2].cis ‐ and trans ‐2,3‐Diphenyl‐1‐phthalimido‐2,3‐di[ 15 N]‐azimine ( 11 and 12 ) wer synthesized from cis ‐di[ 15 N]‐azobenzene (10) and phthalimido‐nitrene (2) , the latter generated by lead tetraacetate oxidation of N‐aminophthalimide (1). Useful information was obtained from the comparison of several data of 11 and 12 with those of the unmarked diphenyl‐azimines 5 and 6 (R = C 6 H 5 ). The 15 N‐ and 13 C‐NMR. spectra of 11 and 12 were interpreted to furnish additional evidence for the azimine structure and for the indicated configurations. The IR. spectra permitted identification of two bands in the 1200 to 1450 cm −1 region, probably characteristic for the functionality of diaryl‐phthalimido‐azimines. Comparison of the mass spectrum of 11/12 with that of the unmarked analogues 5/6 (R = C 6 H 5 ) permitted the interpretation of the fragmentation path of 1‐phthalimidoazimines. The major path may be the purely thermal decomposition to 13 and 7 (R = C 6 H 5 ), respectively. Two other competing fragmentation paths are discussed. Prolonged thermolysis of 11 at 61° in solution gave 83% of N,N′‐diphenyl‐N N′‐phthaloyl‐di[ 15 N]‐hydrazine (13) of 98% isotope purity, which means that the imide nitrogen atom and N(1) of the azimine function are removed in this reaction. A mechanism passing through an intermediate cyclic tetrazene 16 is considered. Benzocyclobutenedione (14) added to trans ‐azobenzene ( 4 , R = C 6 H 5 ) under the influence of a high pressure lamp in a quarz apparatus to give N,N′‐diphenyl‐N,N′‐phthaloyl‐hydrazine ( 7 , R = C 6 H 5 ). This reaction was found not to take place in the dark, even after prolonged heating in trichloromethane.