291522-03-7Relevant academic research and scientific papers
Synthesis of fused and spiro heterocyclic compounds derived from 3,5-pyrazolidinedione derivatives
Khodairy
, p. 159 - 180 (2000)
The reaction of compound 1 with triethyl orthoformate afforded 2, which in turn reacted with CS2 and active methlyene compounds or malononitrile to give dithiolane and 4-malononitrile methylene derivatives 3,4, respectively. Treatment of compound 4 with active methylene compounds afforded spiro cyclopentene derivatives 5a-c. Compound 1 was reacted with bromomalononitrile or CS2and halocompounds to afford furo-, thieno- and dithiolano-pyrazole derivatives 6-11, respectively. The reaction of compound 12 with phenacyl bromide or benzylidenemalononitrile furnished oxathiol-2-ylidene and pyridinethione derivatives 13,14, respectively. The dibromo derivative 16 was reacted with CS2 and active methylenes or malononitrile to obtain spiro dithietanes 17a-e and 4-dicyano-methlyene derivative 22, respectively. Compounds 17 underwent a cycloaddition reaction with thioglycolic acid, N-phenylbenzohydrazindoyl bromide, 2,5-dimethylfuran and 1-phenyl-3,5-pyrazolidinedione to give cycloadducts 18-21, respectively. Treatment of 0-aminothiophenol or 0-phenylenediamine with the dicyano compound 22 leads to the formation of spiro thiazepine or spiro diazine derivatives 23a,b. The arylidene derivatives 24 was reacted with S,S-acetals, N,S-acetals or ammonium dithiocarbamate to afford dithiane, oxazine or pyrazolodithiocarbamate derivatives 25-29, respectively, Chemoselective cyclization of compound 29 with H2SO4, NaOH or Mel gave compounds 30-32, respectively. Benzopyrano derivatives 34,36 were obtained through the reaction of compound 1 with a mixture of thiourea, triethyl orthoformate and ethyl cyanoacetate or with cyanokelene S,S diacetals, respectively.
