BOSTON. Prosecutors argued yesterday that a NortheasternUniversity chemistry graduate student accused of selling an illegal drugto an FBI informant in a Philadelphia parking lot poses a danger to thecommunity and should be held in jail pending his open drug andthreatening cases. Dennis Szymanski is facing drug charges for allegedly driving toPhiladelphia to sell drugs and then creating fake Facebook and e-mailaddresses to threaten that informant and his girlfriend. He allegedlyarranged to meet at a Best Buy parking lot in South Philadelphia inApril to provide him with 2 kilograms of MDA, also known as the “lovedrug,” in exchange for $36,000.