1230
NORMAN H. CROMWELL, HAROLDH . EBYAND DAVIDB. CAPPS
VOl. 73
[CONTRIBUTION PROM AVERYLABORATORY, UNIVERSITY OF NEBRASKA]
Endocyclic +Unsaturated Ketones. 111. Reaction of Z-Brom0-4,4-dimethyl-lketo- 1,4-dihydronaphthalene with Amines2 BY NORMAN H. CROMWELL, HAROLD H. EBYAND DAVIDB. CAPPS The purpose of this investigation was to extend our knowledge of the behavior of endocyclic a-bromo-a,p-unsaturated ketones with amines. 2-Bromo-4,4-dimethyl-l-keto-l,4-dihydronaphthalene has been found to react with morpholine and piperidine to produce a-amino-a,B-unsaturated ketones. These reactions are contrasted with those previously reported in the perinaphthenone-7 series and for the open chain a-bromo-a,p-unsaturated ketones. It was surprising to find that the same a-amino-a,@-unsaturatedketones also resulted in low yields from the reactions of the amines with the corresponding saturated ketone, 2-bromo-4,4-dimethyltetralone-1.The unsaturated bromide reacted with cyclohexylamine to produce an ethylene imine ketone which was converted to the corresponding a-chloro-,%amino ketone hydrochloride.
In the previous paper' in this series the reactions study of their absorption spectra. The hydrolysis of the endocyclic a-bromo-4-unsaturated ketone, produced a new 1,2-diketone (111) which readily 8-bromoperinaphthenone-7 with amines were discussed. Recently Arnold and his co-workers3 have reported the synthesis of another interesting bromide of this type, namely, 2-bromo-4,4-dimethyl-l-keto-1,4-dihydronaphthalene. This a-bromo-cr,P- unsaturated ketone has been found to react readily a t room temperature in the presence of an excess of morpholine or piperidine to give excellent yields of 2-morpholino (I) and 2-piperidino (11) 4,4-dimethyl-lketo-l,4-dihydronaphthalene, respectively. With two or three equivalents of the amine to one equivalent of the bromide, the reactions were quite slow especially in b enzene. These results are somewhat in line with the previous findings with 8-bromoperinaphthenone-7l and vary sharply with the behavior of the open chain a-bromo-a,Bunsaturated ketones. With the present a-bromo-a,p-unsaturated ketone, no tendency to form p-amino-a,p-unsaturated ketones was observed. This is in contrast to the behavior of 8-bromoperinaphthenone-7 which produced both a-amino- and pamino-a, 8-unsaturated ketones in such reactions. The steric effect of the two methyl groups in the 4-position of the present a-bromo-a,P-unsaturated ketone promotes the rearrangement of the primary product, 2-bromo-3-amino4,4-dimethyltetra1onee1 (A), to the intermediate quaternary ethyleneimmonium salt (E). The salt (B) preferentially loses hydrogen bromide to forin the a-amino ketones. The mechanisms of such reactions have been discussed 1V VI in more detail meviouslv.lp+ The structur& of the k i n o ketones (I) and (11) gave the expected acetoxy derivative (IV), and owere established by acid hydrolysis and from a phenylenediamine produced the phenazine deriva( I ) For paper I1 in this series, see Cromwell, Capps and Palmer. THIS tive (V). The maxima of the ultraviolet absorption JOURNAL IS, , 1226 (1951). spectra curves shown in Fig. 1 point to an a-amino(2) A part of this material is abstracted from the Ph.D. thesis of a,B-unsaturated ketone structure for (I) and (11). IIarold H. Eby, Eastman Kodak Fellow, University of Nebraska, 1947The low, broad band nearest the red end of the 1948. spectrum is the most characteristic feature of the (3) Amold, Buckley arid Richter, T H IJ~O U R N A L69, , 2322 (1947). (4) For example the reactions of a-bromobenzalacetone and aspectra of such compound^.'^^ bromobeuzalacetopheuone with only one equivalent of morpholine or Cyclohexylamine reacted with 2-bromo-4,4-di' in ether solution is quite rapid; see Cromwell. C h o n . piperidine a t 0 Rws., 38, 83 (1846), and origirral papers rcferrrd l o therein.
( 5 ) CrouiwL-11and Watson, J . Org. Chcm., 14, 411 (1944).
2-BROMO-4,4-DIMETHYL-l-I(ETO-1,4-DIHYDRONAPHTHALENE WITH AMINES
March, 1951
1231
methyl-l-keto-l,4-dihydronaphthalene apparently to produce an ethylene imine ketone (C) which was an oil and could not be identified as such. This product (C), however, reacted with hydrogen chloride in a manner characteristic of ethylene imine ketones6 t o produce 2-chloro-3~cyclohexylamino-4,4dimethyltetralone-1-hydrochloride (VI) in an excellent yield. The structure of this product (VI) is indicated by its analysis and by the fact that i t readily releases iodine from an acidified potassium iodide solution a t 65" .I It was surprising to find that the saturated ketone, 2-bromo-4,4-dimethyltetralone-l, reacted slowly with morpholine or piperidine under various conditions to produce the a-amino-a,p-unsaturated ketones (I) and (11) along with large amounts of the dehydrobrominated product, 4,4-dimethyl-1keto-l,4-dihydronaphthalene. Although the dehydrobromination is not too unexpected3 the formation of the a-amino-a,p-unsaturated ketones (I) and (11) instead of the expected a-amino saturated ketones (D) is unique. The dehydrogenation of the expected product (D), which must have taken place to produce (I) and (11),is unusual. HzC
280 300 320 340 360 1,mp. Fig. 1.-Ultraviolet absorption spectra of a-amino-a,@-unsaturated ketones ( I ) and (11) in heptane solutions.
CH,
220
240
260
mides. The excess starting amine was washed away with water and the ether solutions extracted with dilute hydrochloric acid. Nearly pure solid products resulted on neu0 0 0 tralization of the acid solutions with sodium carbonate. The reaction with morpholine gave a 98y0 yield of colorless crystals (I) ; recrystallized from aqueous ethanol or petroleum ether, m.p. 124-125'. Anal. Calcd. for C16Hd02: C, 74.69; H, 7.44; N , I and I1 5.44. Found: C, 74.38; H, 7.04; N, 5.62. We were unable to isolate any of the saturated The reaction with piperidine produced a 99% yield of pale ketone, 4,4-dimethyltetralone-1. Had this sub- yellow crystals (11); recrystallized as for (I), map. 69-70'. Anal. Calcd. for C17H21NO: C, 79.96; H, 8.29; IC, stance been found in quantity it would have indicated that the dehydrobrominated product 4,4-di- 5.49. Found: C, 79.81; H , 8.36: N, 5.57. reaction between 2.9 g. (0.0115 mole) of the bromide methyl-l-keto-l,4-dihydronaphthalenehad func- andA 3.1 ml. (0.0356 mole) of morpholine in 25 ml. of methtioned as a dehydrogenation agent during the reac- anol after refluxing for eight hours gave only a 5370 yield of (I). Using three molar equivalents of morpholine and tion. Numerous attempts, using the usual conditions piperidine, respectively, to one equivalent of the bromide benzene solution, reflux times of 71 and 48 hours were reand such amines as piperidine, morpholine and tet- in quired to obtain a 68.5Yc yield of (I) and a 67% yield of (11). rahydroisoquinoline, were made to add amines to Acid Hydrolysis of (I) and (11) to 4,4-Dimethyl-l,2-di4,4 - dimethyl - 1 keto - 1,4 - dihydr~naphthalene.~ketotetralin (III).-A 2.15-g. sample of (I) and (11) were There was no evidence of any reaction having taken each heated on the steam-bath with 25 ml. of 30% sulfuric acid for 1.5 hours. The oil which separated was recrysplace. Such addition reactions go readily with tallized from petroleum ether. Compound (I) gave a various open chain a,P-unsaturated ketones8 but 95.5YCyield while (112 gave an 80% yield of (111); colorless have failed with another endocyclic a,p-unsatu- crystals, m.p. 70-71 . rated ketone, perinaphthenone-7.l Anal. Calcd. for Cl2HI2O2:C, 76.57; H, 6.43. Found: C, 76.49; H , 6.23. Experimentalg This diketone (111) gave muddy, violet-brown color with Reaction of 2-Bromo-4,4-dimethyl-l-keto-l,4-dihydroferric chloride and readily dissolved in dilute sodium hynaphthalene with Morpholine and Piperidine .-Four-gram droxide to give a yellow solution. Acidification of the alsamples of the unsaturated bromoketone3 were dissolved kaline solution precipitated (111). 2 -Acetoxy-4,4-dimethyl-l -keto-l,4-dihydronaphthalene in 14 ml. each of morpholine and piperidine a t room tem(IV) .-A mixture of 0.30 g. of (III), 0.15 g. of sodium aceperature and allowed to stand for two days. The addition of 250 ml. of dry ether t o the reaction mixtures precipitated tate and 3.0 ml. of acetic anhydride was heated on the near theoretical amounts of the starting amine hydrobro- steam-bath for two hours. An 81% yield of (IV), ocolorless crystals from aqueous ethanol, resulted, m.p. 66-67 . (6) See, for example, Cromwell and Wankel, THISJOURNAL, 71, 711 Anal. Calcd. for C14H1403:C, 73.02; H, 6.13. Found: (1949). . C, 72.88; H, 6.01.
-
(7) Cromwell and Wankel, i b i d . , 70, 1320 (1948). (8) (a) Cromwell, Wiles and Schroeder, ;bid., 64, 2432 (1942); (b) Cromwell and Burch, ibid., 66, 872 (1944).
(9) Most of the micro analyses for carbon, hydrogen and nitrogen are by the Clark Microanalytical Laboratory, Urbana, Illinois, arranged for through the courtesy of the Smith, Kline and French Lahoratories, Philadelphia, Pa.
2,2-Dimethy1-3,4-benzo-l,Z-dihydrophenazine (V) .-
The diketone (111) reacted with o-phenylenediamine in 95YC ethanol in five minutes to give a 71oj, yield of (V); colorless crystals from aqueous ethanol, m.p. 114.5-116'. Anal. Calcd. for CliH~eNz: C, 83.04; H, 6.21; N , 10.75. Found: C, 83.14; H, 6.64; N , 10.45.
1232
JOHN
E'. AMBROSE,G. I3. KISTIAKOWSKY AND ANDREWG. KRIDL
VOl. 73
Reaction of 2-Bromo4,4-dimethyltetralone-lwith MorUsing piperidine in place of morpholine, experiment (d) pholine and Piperidine.-The reaction of this saturated (Ywas repeated giving the theoretical yield of piperidine hydrobromoketonea with morpholine was carried out under four bromide, a 35% yield of (11), and a 477, yield of 4,4-didifferent sets of conditions. (a) A 1.27-g. (0.005 mole) methyl-1 -keto-I ,4-dihydronaphthalene. sample of bromide and 1.3 g. (0.015 mole) of morpholine Reaction of 2-Bromo-4,4-dimethyl-l-keto-1,4-dihydrowere allowed to stand for 11 days in 13 ml. of methanol in naphthalene with Cyclohexylamine.-A mixture of 1.26 g. the dark at room temperature. Only 27y0 of the bromide (0.005 mole) of the unsaturated a-bromoketone, 1.15 ml. had reacted after this time. Based upon the amount of (0.01 mole) of'cyclohexylamine and 0.5 ml. of absolute ethbromide reacting, a 557, yield of the cr-amino-cu,@-unsat- anol was allowed to stand a t room temperature in the dark for urated ketone (I) resulted. The unreacted bromide was three days. The colorless oily product which could not be largely recovered. (b) Using the same amounts of reagents induced to crystallize was treated with dry hydrogen chloride a t 65' for 28 hours, 807, of the starting bromide reacted. gas in dry ether to produce 1.62 g. (95%) of a colorless solid; An 18% yield of (I) and a 207, yield of 4,4-dimethyl 1- recrystallized from methanol and ether, m.p. 176-177' (VI). keto-l,44ihydronaphthalenewere isolated from the reacAnaE. Calcd. for C L ~ H ~ S S O CCI ,~ :63.16; 1 1 , 7.36; tion mixture. (c) A 1.26-g. sample of the saturated a- 5 , 4 0 9 . Found: C,63.12; H,7.15; N,3.96. hromoketone was allowed to stand in the ice-chest for 27 Using the technique described previously7 the aminodays in 4 ml. of morpholine. The calculated amount of mor- chloroketone hydrochloride (VI) reacted with acidic potaspholine hydrobromide was obtained along with a 2270 sium iodide solution a t 65' to release 32.8% of one equivayield of (I) and a 72r& yield of 4,4-dimethyl-l-keto-1,4-di- lent of iodine in 15 minutes, 74.4% in 30 minutes and 85% in hydronaphthalene from the reaction mixture. (d) Experi- 45 minutes. Under these conditions 2-bromo-4,4-dimethylment (c) was repeated except that the reaction mixture tetralone-1 released 1 0 0 y in five minutes while 2-bromostood for three days a t room temperature. The calculated 4,4-dimethyl-l-keto-1,4-dihydronaphthalene released n o amount of morpholine hydrobromide, as well as a 31y0 iodine in 30 minutes. yield of (I) and a 2070 yield 4,4-dimethyl-l-keto-1,4-diLINCOLN,NEBRASKA RECEIVED AUGUST25, 1930 hydronaphthalene were isolated.
\CONTRIBUTION FROM THE
GIBBSCHEMICAL LABORATORY, HARV.4RD
UNIVERSITY]
Inhibition of Urease by Silver Ions BY JOHN F. AMBROSE,~" G. B. KISTIAKOWSKY AND ANDREWG, K R I D L ~ ~ The inhibition of urease by silver ions has bcen studied in a citrate buffer a t pH 5.G and 20". The results indicate that the inhibition is produced by a reversible rcaction of one silver ion with an active site in the enzyme molecule. Silver ions react also with inactive protein which was prescnt in the repeatedly recrystallized samples of urease. The affinity for silver and the specific binding capacity of active urease and of the inactive protein were found to be the same, which suggests that the inactive protein was urease deactivated in the process of purification. Extrapolation to pure active enzyme shows that one mole of it is totally inhibited by reaction with three to four moles of silver ions. The significance of these findings is discussed.
&larked inhibitory effects of metal ions on the activity of urease have been r e ~ o r t e d . " , ~The ~ ~ action of silver ions has been the subject of a detailed study by Sumner and M y r b a ~ k . They ~ concluded that seven ions suffice to inactivate one molecule of urease, from their measurements of the total concentration of silver ions required for half inactivation of the enzyme. The reversible nature of the inhibition as well as the uncertainty in the extrapolation of the half inactivation concentration to total inactivation was realized and emphasized by these writers. Sumner and lfyrback have shown dlso that the quantity of silver which is bound by the enzyme a t higher concentrations of sihcr ions exceeds by a t least a factor of ten the miniinal amount necessary for total inhibition. 'The inhibition of urease by p-chloroniercurihenmate has been studied by Hellerrnari and co-worke r ~ . Their ~ conclusions were not presented on a 1) (a) Bell Telephone Laboratories Murray HI!^ N J (b) Monsanto Predoctoral Fellow Shell Development Co , Emerybille Calif (2) (a) J I3 Sumner, Pioc Soc Exptl Rrol Med 84, 287 (1927) l b I R Sumner a n d D I3 Hand J Btol Chcm 76, 149 (1938) ( 3 ) J B Surnner and G F S o m e n ' Chemistrv a n d Methods of es '' Academic P r r w Inc Neu York, N I' 1917. p 117 J R Siirnner i i i , l k b I y r h ~ c 1 / p h ) c i i I 1 hein , 189, ?I$ t i ) I Hcllerniari I $ 1 ; (191-)
I' Cliirinrti -ind 1 K 1 ) r r t l 1 Hiol Chctr
147
molecular basis, but using the data of Sumner6 it may be calculated that twenty-two equivalents of the sulfhydryl reagent must be added per mole of enzyme before any effect is noted upon the enzymatic activity and twenty-two more equivalents are required before inhibition is complete. This disparity between the numbers of ions or molecules of the inhibitor required for full inactivation of urease indicated that a more thorough examination of the inhibition by silver ions is desirable. Both of the previous studies evaluated only the total concentration of the inhibiting substance in the enqnie solutions. This left open the possibility that the reaction with the enzyme was not complete. In the present experiments both the total concentration of silver and the concentration of free silver ions were determined, making possible an application of the mass action law.
Experimental Details Preparation of Pure Enzyme.-The crystalline enzyme was prepared from jackbean meal obtained from the Arlington Chemical Company, Yonkers, New York, batch numbers 490,428 and 490,208. The preparative procedure finally adopted involved repeated crystallizations from acetone -water mixture according to the general method developed by Sumner,? although in details some changes were madc. I n particular, no preservatives of any kind were introdiircd into the enzyme solutions. ( 0 ) J . F',. Siiiniier, ?; (:ralcn :md I. W Eriksaon-Qucnscl. ihid 37 (1!143) ( 7 ) Scr klso 4 I-. Dourice, ibid., 140, 307 (1941).
,
126,
