Pyrazolo-1,5-diazocines

A solution of 1-phenyl-1//-pyrazolo[3,4-rf]pyridazinc-7-carbonitrilc (150 mg. 0.68 mmol) and A,A-diethyl-prop-l-ynamine(151 mg, 1.36 mmol) in l,4-dioxane(2 mL) was refluxed for 5 h. After cooling, the reaction mixture was poured onto excess ice, and extracted with CHC13. The extract was washed with H20, dried (Na2S04) and concentrated under reduced pressure. Purification by chromatography (silica gel, benzene then bcnzene/EtOAc 20 1) gave, from the benzene eluate, 6-diethylamino-1 -phenyl-1 //-indazole-7-carbo-nitrile [yield 81 mg (39 %) mp 104-105 C (benzene/petroleum ether)] as slightly yellow prisms and, from the second eluate, the diazocine 5 as yellow needles yield 90 mg (40 %) mp 121-122 C (benzene/ petroleum ether). 

Regarding the 1,3-diazocines, it was reported that the synthesis of the left domain of haplophytine, a hetero-dimeric alkaloid endowed with insecticidal activity, contained a pyrrolo-fused carbonyl bridged 1,3-benzodiazocine moiety <2007AG(E)4715>. It was also reported that the synthesis of a pyrazolo-fused 1,3-benzodiazocine and its activity as inhibitor of lymphocyte-specific protein tyrosine kinase (Lck) <2007W0026720>, and the thermal decomposition of a polynitro substituted 1,3-diazocine <2006RJGC499>. 

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