THE CHEMISTRY OF ORGANO HALOGENIC MOLECULES .155. THE ROLE OF REAGENTSTRUCTURE IN HALOGENATION OF 9-SUBSTITUTED PHENANTHRENES

9-Substituted phenanthrenes were used as target molecules in investiga tions of the effect of the reagent structure and reaction conditions o n halogenation with bromine (1), CsSO4F (2) and F-TEDA omethyl-4-fluor o-1,4-diazoniabicycloe[2,2,2]octane bis(tetrafluoroborate), (3). 9-Met hoxyphenanthrene (4) was converted to 9-bromo-10-methoxyphenanthrene ( 6a) and 9-bromo-10-hydroxyphenanthrene (7a), while the amount of dealk ylation depended on the solvent and was more pronounced in methanol th an in acetonitrile, but no adduct was observed. Addition reaction beca me a major process in fluorination with CsSO4F (2) in methanol and 88% of 9-fluoro-10,10-dimethoxy-9,10- dihydrophenanthrene (8b) was formed , while dealkylation occurred in acetonitrile. The course of fluorinat ion of 9-methoxyphenanthrene with F-TEDA (3) could be completely manip ulated by the choice of solvent and 9,9-difluoro-10-oxo-9,10-dihydroph enanthrene (9b) was formed in acetonitrile, 9-fluoro-10-methoxyphenant hrene (6b) in trifluoroacetic acid and 9-fluoro-10,10-dimethoxy-9,10-d ihydrophen (8b) in methanol. Bromination of 9-hydroxyphenanthrene (5) in acetonitrile resulted only in the substitution process, while 9-flu oro-10-hydroxyphenanthrene (7b) formed in the reaction with CsSO4F and F-TEDA was more reactive than the starting hydroxy derivative and, us ing a 2 molar ratio of F-TEDA, only 9,9-difluoro-10-oxo-9,10-dihydroph enanthrene (9b) was formed.