The bromination of isatoic anhydride

Abstract

Bromination of isatoic anhydride in acetic acid gives N-dibromoacetyl-3,5-dibromoanthranilic acid. Three new anthranils a r e described.In connection with another problem we desired a series of anthranils substituted with halogen and nitro groups. Lesser and Weiss reported (1) that bromination of isatoic anhydride (I) in acetic acid gave a "tribromoanthranilic acid" (II), which with acetic anhydride was ' I dehydrated" to a tribromoanthranil" (III). Such a dehydration is unlikely, for the reaction of anthranilic acids with acyl anhydrides gives 4 -0x0 -4H -3 , l -benzoxazines (2) rather than anthranils.W e now show that I1 and III a r e N-dibromoacetyl-3,5-dibromoanthranilic acid and 2-dibromomethyl-6,8-dibromo-4-oxo-4H-3,l-benzoxazine, respectively.Elemental analyses and molecular weight determinations support the C, rather than the C, formulations. Spectral data (Table I) further support these assignments. The infrared spectrum of I1 shows N-R, 0-H, and two C=O absorptions. Both the infrared and ultraviolet spectra are similar to those of C H A R T 3 , 5 -dibromo -Nacetylanthranilic acid (IV). The n.m.r. spectrum of I1 in dimethyl sulfoxide 4 shows two aromatic protons situated meta to each other and one proton a t 6.51 p.p. m. assigned to the single proton of the dibromoacetyl group. Possibly the carboxyl proton is lost by exchange with water in the solvent, and probably the amide NH proton resonance i s so broad and weak a s to be unobservable ( 3 ) . The 6.51 p. p. m. assignment is in reasonable accord with the signals observed for the corresponding proton in cup-dibromoacetanilide (5.96 p.p.m.), ethyl dibromoacetate (5.89 p. p. m. ), and dibromoacetic acid (5.90 p.p.m.). The infrared spectrum of 111 has strong, sharp bands a t 1795 and 1645 cm-' attributable to the O=C-0-C=N grouping, is very simil a r to spectra of several authentic 4-oxo-m-3,1benzoxazines, and is very different from spectra of authentic anthranils (4) which have only moderate absorption near 1650 cm-'. The ultraviolet spectrum IV. R = A C V I V, R = H / / , . i i / / 111 Br Br V I I V l l l I X

Actively Controlling Anticipation of Irregular Events

“…The models proposed by Bertelson (1966) and Welford (1959Welford ( , 1967Welford ( , 1977 suggest that after a subject makes any response his central decision mechanism may be captured by feedback during a fixed refractory period, M . Any new signal must queue for attention until M is over.…”

Polychloroheteroaromatic Compounds

“…trichloroanthranil) (310) may be prepared by reduction of 3,4,5-trichloro-2-nitrobenzaldehyde with tin and acid [666], and that 3,5,7-trichloro-l,2-benzisoxazole (311) is obtained when 5,7dichloro-3-hydroxy-l,2-benzisoxazole is treated with phosphorus oxychloride at 140-150° in the presence of triethylamine [667].…”

Refractoriness in Same-Different Judgments

“…Davis (1964) favoured interpretation in terms of a limited-capacity, "singlechannel" processing system (cf. Broadbent, 1958;Bertelson, 1966). Since the system can generally process only one stimulus at a time, he argued, a second stimulus closely following a first must be held in buffer storage until the processor is free.…”