4490
NOTES
Anal. Calcd. for CIsHI1BrO: C, 62.29; H,4.52. Found: C, 62.89; H , 4.39. Distillation of the liquid residue revealed that it consisted of a complex mixture of by-products. RESEARCH DIVISION ABBOT^ LABORATORIES ILLINOIS YORTHCHICAGO, - _ _ ~ ~ _ _ _
p-Nitroacetophenone in the Mannich Reaction BY IT'rr LIAM B WHEATLEY, WILLIAME FITZGIBBOY, JR , A N D LEE C CHENEY RECEIVED MAY6, 1954
Of the three nuclear nitroacetophenones, only the ortho' and metal2 have been reported as participants in the Mannich reaction. Investigation of the chemistry of p-nitroacetophenone has shown that the Mannich reaction proceeds quite satisfactorily, giving the expected P-(di)-alkylamino-pnitropropiophenones, generally in fair yields.
VOl. 76
secondary Mannich base as the only isolable product. A few reactions of these Mannich bases suggest normal reactivity for this type of compound. Catalytic reduction over palladium-on-carbon gave the 9-aminoketones; over platinum an amount of hydrogen corresponding to reduction of nitro to amino and ketone to alcohol was absorbed, although no crystalline products could be isolated. In the latter case the absorption of the first three moles of hydrogen was approximately ten times as fast as that of the fourth mole. I n the one example tried, the expected pyrazoline formed on treatment of the Mannich base with phenylhydrazine. Experimental
p-(Di)-alkylamino-p-nitropropiophenone Hydrochlorides (See Table I).-Mannich reactions with p-nitroacetophenone were carried out in a manner similar to that describctl for acetophenone.3 Method A refers to experiments in which the amine hydrochloride was used, method B to those i i i
TABLE I 0
O ~ N - ~ - C - C H/I ~ - C H ~ - N R Z . H C ~
-
Analyses, %--Carbon Hydrogen Calcd. P o u n i l Calcd. Found
7 -
Yield,
Method&
M.P., OC.
Recryst. solvent
(cor.)
64 60 37 62 51 53 58 8
A .4 B R A B B B
187.5-188.5 147-152 182.5-185 198-200 207-209.5 150-210 dec. 138-140 138-140.5
EtOH EtOH n-BuOH i-PrOH-Me&O EtOH-H20 i-PrOH-H%O EtOH i-PrOH-HtO
51.1 54.4 54.8 56.3 52.1 59.5 49.0 60.2
51.2 54.8 55.1 56.4 52.4 59.5 49.1 60.7
5.8 6.7 6.0 6.4 5.7 7.9 fi.O 6.6
6.2 6.5 5,8 7.9 5.9 6.8
70
A
186-187
MeOH
61.0
61.1
5.7
6.0
5.9 6.8
6.3 6.7 51.6 51.8 28 B 124.5-127 MeOH 5.3 5.6 59.9 6 0 . 2 68 A 219.5-221 dec. EtOH-MezCO 6.3 6.5 52.8 53.1 MeOH-Met CO 10 B 207-209 dec. 6.8 6.8 57.6 58.0 hleOH-i-PrOH 52 B 191-195dec. 7.9 7.9 59.7 59 6 MeOH 57 A 208-209 5.4 5.7 49.3 49.9 i-PrOH -Hz 0 177-179 33 A a NC4H8 = 1-pyrrolidyl; XC5Hlo= 1-piperidyl; ?iC4HaO = 4-morpholinyl; C6Hil = cyclohexyl; C8Hll-t = 1,1,3,3tetramethylbutyl. * See Experimental.
In Table I are recorded the results of a number of reactions involving primary and secondary amines with formaldehyde and p-nitroacetophenone. The general procedure was that described by Maxwell3 ofor acetophenone. In some cases the amine hydrochloride was employed, in others the amine hydrochloride was prepared in situ by addition of one equivalent of concentrated hydrochloric acid to the amine. The method of choice appears to be dictated by the availability of the amine or its hydrochloride. Under the conditions used, diisopropylamine and p,P'-iminodipropionitrile failed to react, and isopropylamine and dimethallylamine gave only poor yields. Methylamine yielded the tertiary amine by reaction of two moles of ketone and two moles of formaldehyde; the other primary amines yielded the (1) C hlannich and M. Dannehl, Arch. Pharm., 176, 206 (1938). ( 2 ) H. B. Wright and M . Freifelder, THIS J O U R N A L , 71, 1513 (1919). (3) C.B. Moxnell, Ora. Spnlhrses, 9S, 80 (1943),
which the amine plus one equivalent of concentrated hy drochloric acid was used. @,@'-Methyliminodi-( p-nitropropiophen0ne)-Hydrochloride.-A solution of 165 g. (1.0 mole) of p-nitroacetophenone, 30 g. (1.0 mole) of paraformaldehyde and 33.9 g. (0.5 mole) of methylamine hydrochloride in 160 ml. of 9570 ethanol mas refluxed for three hours. The clear hot solution was poured into 800 ml. of acetone; crystals formed otl cooling. Filtration gave 38 g. of solid, m.p. 195-200". Evaporation of the filtrate and crystallization of the residue from methanol gave an additional 66 g. of solid, m.p. 195-200' (total yield, 49%). Recrystallization from dirnethylformamide entailed a large loss, but with little improvement in melting point; an analytical sample thus prepared melted at 198-201' dec. Anal. Calcd. for C19H19N306.HC1:C, 54.1; H , 1.8. Found: C, 54.2; H , 5.4. Unreacted P-nitroacetophenone (42 g., 2,50/,) was recovered from the methanol mother liquors. p-Amino-p-dimethylaminopropiophenoneHydrochloride. -p-Dimethylamino-p-nitropropiophenone hydrochloride (19.4 g., 0.075 mole) was hydrogenated in 200 ml. of rnethanol over 0.5 g. of 5y0 palladium-on-carbon. At three atmospheres, hydrogen absorption was 89% complete (for rcduction of the nitro group only) in two hours. The reduc-
COMMUNICATIONS TO
Sept. 5, 1954
tion mixture was filtered hot, concentrated and cooled. The precipitated solid was collected by filtration; 15.0 g. (87% yielf) was obtained, which decomposed unsharply a t about 200 . Anal. Calcd. for C11HIBNZO.HCl: C, 57.8; H, 7.5. Found: C, 58.1; H , 7.4. p-Amino-p-diethylaminopropiophenoneHydrochloride.Reduction of p-diethylamino-p-nitropropiophenonehydrochloride exactly as described above was rapid and exothermic, being complete in 15 minutes. The product was isolated by diluting the filtered reaction mixture with ether. Recrystallization of the precipitated solid from isopropyl alcohol gave material melting a t 134.5-136.0' dec. Anal. Calcd. for C13H20N20,HC1: C, 60.8; H, 8.3. Found: C, 60.5; H , 8.5. Hydrogenation over Platinum Oxide.-Both p-dimethylamino- and p-diethylamino-p-nitropropiophenone hydrochlorides were hydrogenated under similar conditions except that the catalyst was platinum oxide. Four moles of hy-
~~
~
4491
THE EDITOR
drogen were absorbed, the first three within 15 minutes, the fourth in about two hours. The products were obtained as orange gums, which resisted all attempts to crystallize them. Reaction of p-Diethylamino-p-nitropropiophenone and Phenylhydrazine.-A mixture of 5 g. of p-diethylamino-pnitropropiophenone hydrochloride, 5 g. of phenylhydrazine and 2 g. of anhydrous sodium acetate in 50 ml. of ethanol was heated on the steam-bath for two hours. A dark gummy solid was collected by filtration and washed on the filter with water. After several recrystallizations from pyridinemethanol, 2.2 g. of dark red crystals was obtained, m.p. 152.0-152.5". Analytical data are in agreement with those calculated for 3-(p-nitrophenyl)-l-phenylpyrazoline. Anal. Calcd. for C1SHl3N30z: C, 67.4; H, 4.9. Found: C, 67.6; H , 5.0. RESEARCH DIVISION BRISTOLLABORATORIES, INC. NEWYORK SYRACUSE,
~
COMMUNICATIONS T O T H E EDITOR A LINK BETWEEN FATTY ACYL COA DEHYDROGENASE AND CYTOCHROME c: A NEW FLAVIN ENZYME'
of 0.45yG; (4) the released flavin was identified as FAD by its spectrum and by paper chromatography; it replaces FAD quantitatively with dSir : amino acid apooxidase; ( 5 ) the flavin is not reduciA green (G)' and yellow (Y)z flavoprotein cata- ble by a fatty acyl CoA except in presence of catalyze the dehydrogenation of fatty acyl derivatives lytic mounts of Y (25yGof E44Ompremaining). The of C O A . ~A preparation of 'I!from pig liver showed purest CRF fractions are likewise the most active four peaks on electroph~resis.~ The proteins con- D R F preparations, the ratio of C R F to D R F activstituting two of these peaks were identified as G5 ity being about 1. Such preparations lose C R F and Y , respectively. Although these sampled activity within a few days without decline of D R F components were immediately reducible by sub- activity or perceptible change in the spectrum. strate, the reduced forms were not oxidizable by This relationship of CRF to D R F is reminiscent of electron acceptors. Catalytic activity with indo- that between Cyt reductase and diaphorase.' C R F phenol3 could be restored when G or Y was supple- seems to be a more complex form of DRF, which mented with the additional protein components sep- retains only D R F activity after some degradative arated during electrophoresis. These latter com- process. So far a metal could not be implicated in ponents were not reducible by substrate nor did this phenomenon. they catalyze the oxidation of substrate by indoNo metal has been found in Y in an amount phenol. Only certain fractions of this factor comparable to that of copper in G1. Nonetheless, (DRF)6 which mediates the reoxidation of reduced G requires C R F for optimal interaction with Cyt. G and Y by indophenol are able to catalyze the in- The following scheme illustrates the path of electeraction with Cyt as well. This Cyt reducing fac- trons, indicated by the arrows, as it appears now in tor (CRF) was isolated from pig liver and was found view of the reported work : to be a flavoprotein with the following characterisindophenol, 0 2 tics: (1) extinction maxima a t 270, 375 and 440 mp, minima a t 310 and 400 mp (E270:fsl~:E~6:: E440 = 6.5 :0.3 : 0.9: 1.O) ; ( 2 ) a characteristic shoulder a t 450460 mp; (3) a riboflavin content fatty acyl CoA +Y (or G) --+ D R F + X
t
-.--
L_
( 1 ) D. E. Green, S . Mii, H. R . Mahler and R . M. Bock, J . B i d . Chcm., 206, 1 (1954); H. R . Mahler, ibid., 206, 13 (1954).
(2) H. Beinert and F. L. Crane, F e d . PYOC., 13, 181 (1954); D. E. Green, B i d . Reus., 29, 330 (1954). The relationship of G or Y to a similar enzyme reported by W. Seubert and F. Lynen, THISJOURNAL, 75, 2787 (1953). cannot be evaluated on the basis of available data. (3) CoA = coenzyme A: indophenol = 2,6-dichlorophenolindophenol: Cyt = cytochrome c. (4) Kindly carried out for us by Dr. R. M . Bock. (5) The amount of G present was about 5% of that of Y. (6) D R F = dye reducing factor: CRF = cytochrome c reducing factor. D R F and C R F also catalyze the auto-oxidation of G or Y ; D R F and C R F are heat labile.
I
j. cytochrome c (DRF X = CRF) INSTITUTE FOR ENZYME RESEARCH OF WISCONSIN FREDERICK L. CRANE^ UNIVERSITY MADISON, WISCONSIN HELMUT BEINERT RECEIVED JULY 30, 1954
+
(7) H. R. Mahler and D. G. Elowe, THISJOURNAL, 75, 5769 (1953). (8) Postdoctoral trainee of the National Heart Institute. National Institutes of Health.
