1,2,3-Thiadiazole mit ungesättigten Seitenketten - Monomerbausteine für Photoresist-Materialien / 1,2,3-Thiadiazoles with Unsaturated Side Chains - Monomeric Building Blocks for Photoresists

The phosphonium salts 4 are versatile reagents for the synthesis of 1,2,3-thiadiazoles 6 with unsaturated side chains. The preparation starts with the α-chloroketones 1 which are transformed in a stepwise process to the phosphonium salts 2 and 3. The reaction with SOCl leads to a regioselective ring closure 3 → 4 . Subsequent Wittig reactions yield the monomers 6, which exhibit with the exception of 6ac a high tendency for a thermal polymerization. Cleavage of the ester groups in 6ca and 6 cd generates the carboxylic acids 7ca and 7 cd which possess a higher stability.