1,4-Dibromo-2,5-difluorobenzene327-51-530 % similar 4-N-Butylbenzenesulfonyl chloride54997-92-130 % similar 1,2-Dibromo-4,5-difluorobenzene64695-78-930 % similar 4-Isopropoxybenzenesulfonyl chloride98995-40-530 % similar