Abstract The synthesis of azoacetylenes (= dialkynyldiazenes) 1 and 2 has been investigated. They represent a still elusive class of chromophores with potentially very interesting applications as novel bistable photochemical molecular switches or as antitumor agents (Fig. 1). Our synthetic efforts have led us alongside three different approaches (Scheme 1). In a first route, it was envisioned to generate the azo (= diazene) bond by ...
![ethyl 2-[4-oxo-5-(pyridin-3-ylmethylidene)-2-sulfanylidene-1,3-thiazolidin-3-yl]acetate Structure](https://image.chemsrc.com/caspic/229/6141-96-4.png)
