1,6,6aSIV-Trithiapentalenes and Related Structures

TLDR: Arndt, Nachtwey, and Pusch as mentioned in this paper obtained a compound C7H8S3 by reaction of 2,4,6-heptanetrione with phosphorus pentasulfide.

Abstract: Publisher Summary This chapter focuses on 1,6,6aSIV-trithiapentalene, which was described in 1925 by Arndt, Nachtwey, and Pusch, who obtained a compound C7H8S3 by reaction of 2,4,6-heptanetrione with phosphorus pentasulfide. Reaction of phosphorus pentasulfide with β,δ-triketones leads to 1,6,6aSIV-trithiapentalenes. This was the first synthesis of trithiapentalenes known, but its development was delayed until practical methods for preparing β,δ-triketones were available. One of these procedures is the acylation of ketones in the presence of sodium hydride. Another method begins with the diacylation of the enamine derived from a cyclanone. Reaction of phosphorus pentasulfide has been frequently used for preparing trithiapentalenes from the corresponding 1,2-dithiol-3-ylideneketones. Various solvents which have been used include benezene, toluene, xylene, pyridine, and diglyme. α- ( 1, 2-Dithiol- 3-ylidene)malononitriles, when treated with hydrogen sulfide in pyridine and triethylamine give 2-amino-3-cyano-1,6,6aSIV-trithiapentalenes. Methyl or methylene groups at positions 2 and 5 are activated by the partial positive charge in these positions on the trithiapentalene system.