Photoresist Chemicals Pyrazolo[1,5-a]pyrazine-6-carboxylic acid, 3-(2-fluorophenyl)-4,5-dihydro-4-oxo-2-(1-piperazinyl)-, ethyl ester, monohydrochloride Cas:880254-29-5 Molecular Formula:C19H20FN5O3.ClH