Zur Photolyse von 1‐Acyl‐benzotriazolen

Abstract

Die Photolyse von 1-Acyl-benzotriazolen wird in Abhangigkeit von Solvens, Konzentration und eingestrahlter Wellenlange untersucht. Im photochemischen Primarschritt spaltet sich Stickstoff ab; die Diradikale stabilisieren sich durch Wasserstoff-Abstraktion, Addition von Losungsmittel-Molekulen, RingschluO-Reaktionen unter Wasserstoff-Verschiebung und Polymerisation. Die Konkurrenz dieser Prozesse llBt sich an Hand der Ausbeuten der gebildeten N-Acyl-aniline, 2-Acylamino-biphenyle und des Phenanthridons verfolgen. Photolysis of I-AcylbenzotriazolesThe photochemical decomposition of I-acylbenzotriazoles is investigated by variation of solvent, concentration and used frequencies. After elimination of nitrogen the diradicals formed are stabilized by abstraction of hydrogen, addition of solvent molecules, ring closure (accompanied with a hydrogen shift) and polymerisation. The competition of these reactions is studied by evaluating the yields of formed N-acylaniline, N-acyl-2-biphenylamine and phenanthridone. 1.2.3-Triazole mit

Flash Vacuum Pyrolysis of Azides, Triazoles, and Tetrazoles

“…It has previously been asserted that only benzoxazoles are formed on pyrolysis, phenanthridinones on photolysis, and both on electron-impact-induced fragmentation of 1-benzoylbenzotriazoles. , …”

“…It has previously been asserted that only benzoxazoles are formed on pyrolysis, phenanthridinones on photolysis, and both on electron-impact-induced fragmentation of 1-benzoylbenzotriazoles. 406,407 The group of Moyano has employed the technique of catalytic flash vacuum pyrolysis over mixed oxides in a one-pot synthesis of 7H-dibenzo[b,d]azepin-7-one from phenacyl benzotriazole (eq 103). 408,409 The reaction can be considered a homologous version of the Graebe−Ullmann carbazole synthesis.…”

Reaction between 6-azidoazolopyridazines or 2-azidopyrido[1,2-a]pyrimid-4-one and some secondary aliphatic amines

“…Compound 24 is a 1-substituted triazole and is apparently photostable, although it has been observed that only 2-substituted 1,2,3-triazoles are photostable and others easily eliminate nitrogen. [19][20][21][22][23] This is probably not the case with compound 18, since in a photochemical reaction of compound 16 with diethylamine only 17d was isolated and no 18 could be detected, which contrasts with the corresponding thermal transformation. 6-Azidoazolopyridazines with Secondary Aliphatic Amines…”

Elektronenstoß‐induzierte Fragmentierung von 1,2,3,‐Thiadiazolen

“…thiadiazolcarbonsaure-(4)-athylester, (111) : 172(3,5), 145(1,5), 144(16), 127(10), 116(3,5), 102(3), 101(5), 100(6), 99(10), 98(1), 88(21), 85(14),8 4 ( 3 ) , 83(5), 73(7), 72(36), 71(70), 70(7), 69(12), 67(1 l), 60(2), 59(21), 58(5), 47(4), 46(6), 45(56), 44(1 I), 43(15), 4 1 ( 9 ) , 40(4), 39(25), 3 8 ( 8 ) , 3 7 ( 4 ) , 3 0 ( 3 ) , 29(100). 4-Acetyl-5-methyl-1,2,3-thiadiazol, (IV) : 142(1), 115(3), 114(30), 99(3), 76(4), 73(4), 72(33), 71(26), 70(3), 69(7), 67(14), 59(7), 45(16), 44(1,5), 43(100), 39(15), 38(5), 3 7 ( 4 ) .…”