Notes - Reactions of N-Bromoamides and N-Bromoimides with

Notes - Reactions of N-Bromoamides and N-Bromoimides with Styrene. Robert Buckles, William Probst. J. Org. Chem. , 1957, 22 (12), pp 1728–1729...
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NOTES

Preparation D: Anhydrous D-glucose (30 g., 0.17 mole), and p-toluidine (24 g., 0.22 mole) were refluxed 180 min. in 200 ml. methanol. After 2 days at room temperature, the brownish solution was concentrated under reduced pressure between 35-50' to a thick sirup, approximately 25 ml. Crystallization occurred at once and after 2 days a t room temperature, a crop was collected, washed, and dried in the usual manner. The crop (28 g., 62%) had the following physical constants: m.p. 126-128" (dec.): [a]? 14.0" (6 min.) -.c -44.7' (constant) (c 0.35).

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DEPARTXENT OF BIOCHEMISTRY UNIVERSITY OF ALABAMA MEDICAL CENTER BIRMINGHAM 3, ALA.

Reactions of N-Bromoamides and N-Bromoimides with Styrene' ROBERT E. BUCKLES AND WILLIAM J. PROBST Received Mag 13, 1957

N-Bromoacetamide has been reported213to react rapidly with styrene to give the dibromide. N Bromosuccinimide, however, gave little or no reaction with ~ t y r e n e I. ~ n all reactions including decomposition N-bromosuccinimide was found qualitatively to be less reactive than N-bromoacetamide. This type of result has been related to the tendency of N-bromosuccinimide to brominate the allyl position so successfully.3For this reason a number of Nbromoamides and N-bromoimides have been tested as to their reactivity with styrene. The results are summarized in Table I.

VOL.

22

hydantoin the N,N'-dibromodiamides were of intermediate reactivity except for N,N'-dibromomalonamide which was very unreactive. N-Rromoglutarimide appeared to be consumed by a slow reaction, but only a small yield of the dibromide was obtained after an extended reaction period. Of the N-bromo compounds which were relatively unreactive to styrene l-bromo-5,5-dimethylhydantoin4 and 1,3-dibrom0-5,5-dimethylhydantoin6 have been reported as successful brominating agents for allyl and benzyl positions. N-Bromophthalimide was reporteda as brominating the allyl position but giving dibromide and a 1:1 adduct as by-products. N-bromoglutarimide was found in the present investigation to react with cyclohexene to give 3-bromocyclohexene in 66% yield in contrast to its reporteda unreactivity. The reaction of styrene with N,N-dibromobenzenesulfonamide evidently gave rise to a 1:1adduct analogous to that reported' for N,N-dibromo-p-toluenesulfonamide. The products isolated, however, were N-benzenesulfonylstyreneimide, when the rea,ction mixture was treated with base, and N-(2bromo-1-phenylethy1)-N-(1-bromo-2-phenyl -ethyl) benzenesulfonamide when excess styrene was present. The structures of these compounds were assigned on the basis of analogous derivatives described7 for N,N-dibromo-p-toluenesulfonamide. EXPERIMENTAL

N-Bromo compounds. Samples of the N-bromo compounds used were kindly supplied by Dr. Thomas D. Waugh,

TABLE I STYRENE I N BOILING CHLOROEORM

ItEACl'IONS 01", ~ T - B R O M OCOMPOUNDS WITH

_.

N - l h m o Compound Namr

i\'-Bromophenylacetamide E-Bromo-a-toluamide N-Bromobenzamide N,X '-Di bromosuccinamide N,N'-Dibromoterephthalamide N,N'-Dibromooxamide 1-Bromo-5 5-dimethylhydantoin N,N'-Dibromomalonamide N-Bromophthalimide .V-Bromoglutarimide 1,3-Dibromobarbituric acid 1,3-Dibromo-5,5-dimethylhyd3ntoin a

Mole

Reaction Time, hrs.

0.025 0.01 0.025 0.018 0.018 0.025

0.04 0.025 0.025 0.025 0.01 0.025

0.5 1 .o 1.25 4.5 10 24 34 25 24 60

24 24

-Amide or imide

% Yield N-Bromo comDd.

91 59 50 86 0 0 53 0 0 29 0

0

0 0 0 0 67 42 0

97 92 0 95 97

Dibromidea

53 23 52 30 31 32 30 0 0 6 0 0

Yield of dibromidp based on the amount of N-bromo compound consumed during the reaction.

The -V bromoimides were the least reactive in general uhile the simple N-bromoamides were the

(4) 0. 0. Orazi and J. Mcscri, Anales asoc. quim. argentina, 37,192,263(1949). (5) 0. 0. Orasi and J. Meseri, Anales asoc. quim. argen_-_ -. (1) Taken from part of the Ph.D. dissertation of William tina, 38,5 (1950). (6) I