Girard's P reagent1126-58-5100 % similar Girard-T reagent123-46-642 % similar 1-(Carbamoylmethyl)pyridinium Chloride41220-29-535 % similar Phenacylpyridinium bromide16883-69-532 % similar 1-(2-Oxopropyl)pyridinium bromide17282-41-631 % similar