j. am. chem. soc. 1968 copelaelectrophilic aromatic substitution reactions by

8/8/2019 J. Am. Chem. Soc. 1968 CopelaElectrophilic Aromatic Substitution Reactions By

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909

is more symmetrical than (TMCOT)Cr(C0)3, pos-sessing rigorous, crystallographic mirror symmetry.Aside from this, it is structually very similar. Th edihedral angle between the two planes formed by thering is 130', comp ared to 119' in (TMC OT )Cr(C 0)3.This and some other differences may be a consequenceof changing Cr for Mo, bu t a detailed analysis is elu-sive. It is interesting tha t, in all three comp oun ds, thepattern of OC-metal-CO bon d angles is the same, oneangle being about 80" while the other two are 91-94'.

essentially of olefin-to-metal dona tion. Whether thisbe valid or not, it is interesting that the C6H&r(C0)3,(CH3)6C 6Cr(C0)3, ienCr( CO)3, and (TMC OT)C r (C 0)3molecules are so similar in respect to the Cr-CO bondlengths.

(7 ) Finally, i t is appropriate to comp are the (TM C0 T)-Cr (C 0)3 structure with th e structures of the two closelyrelated compounds (COT)M O(C O)~6 and (cycloocta-1,3,5-triene)Cr(C0)3.z7 Th e (COT)M o(CO), molecule

(27) V. S. Armstrong and C. K. Prout, J . Chem. Soc., 3770 (1962).

Electrophilic Aromatic Substitution Reactions by Platinum (11)

and Palladium(11) Chlorides on N,N-Dimethylbenzylamines

Arthur C. Copela and Edwin C. Friedrichlb

Contribution ro m the Department of Chemistry, Massachusetts Institute ofTechnology, Cambridge, Massachusetts 02139. Received May 26, 1967

Abstract: Potassium tetrachloroplatinate(I1) and lithium tetrachloropalladate(I1) react readily with N,N-dimethyl-benzylamine to give di-~-chloro-bis(N,N-dimethylbenzylamine-2-C,N)diplatinum(II)nd -dipalladium(II), re-spectively. These stable crystalline complexes possess both ortho -attached covalent metal-carbon boilding and co -ordinate metal-nitrogen bonding to the benzylamine. Similar bond form ation by palladium(I1) is observed in itscomplexes with the p-methoxy and 3,s-dimethoxy derivatives of N,N-dimethylbenzylamine. However, no pal-ladium-carbon bonds are present in the palladium(I1) chloride complexes obtained from p-nitro-N,N -dimethy l-benzylamine and the N,N-dimethyl-Zphenyl-1-ethyl- nd 3-phenyl-1-propylamines or from benzylamine andvarious secondary benzylamines.

he observation by C ope and Siekm an2 that azo-T enzene reacts with platinum(I1) chlorides andpalladium(I1) chlorides to give complexes 1 and 2having carbon-to-metal u bonds has led us to search

for similar reactions with other arom atic systems. This

2 , M = P t

work was carried out in an attempt to obtain informa-tion concerning the structu ral requirements for aro-matic substitution by platinum and palladium andwhether the substitution reaction is confined to azo-benzene and its derivatives. The systems investigatedwere limited to benzylamines and other classes ofaromatic compounds containing groups which couldcoordinate to the metal and form structures s imilar to1 an d 2 if ortho substitution into the ring takes place.

Results and Discussion

The reactions of both the simple unsubstituted ben-zylamine and the secondary benzylamine, N-methyl-benzylamine, with potassium tetrachloroplatinate(I1)

(1) (a) Deceased; (b) Department of Chemistry, University of

(2) A. C. Cope and R. W. Siekman, J . Am . Chem. Soc., 87 , 3272California, Davis, Calif. 95616.

(1965).

in aqueous methanol solvent did not meet with anysuccess. Only intractable black products were ob-tained. Reac tion of these amines with lithium tetra-chloropalladate(I1) in methanol did give good yields of

crystalline complexes. Analyses, however, show ed th atthese (3 and 4) were of the usual dichlorobis(amine)-palladium(I1) type 3 in which the two am ines are co-ordinated throu gh nitrogen to the metal, and no metal-carb on bon ding is involved. Atte mp ts to facilitatethe aromatic substitution by palladium with the sec-ondary benzylamines by changing the substituent onnitrogen from methyl to benzyl or phenyl, or by re-action with the highly activated N-phenyl-3,5-dim ethoxy-benzylam ine, were unsuccessful. Again only the usualdichlorobis(amine)palladium(II) type complexes 5, 6,and 7 were obtained.

In contrast to the results obtained with the primaryand secondary benzylamines, N,N-dimethylbenzyla-mine was foun d to react smoothly with the platinum (11)an d palladium(I1) chlorides t o give crystalline prod uctswhose elemental analyses suggested that the desireddi-~-chloro-bis(N,N-dimethylbenzylamine-2-C,N)diplat-inum(I1) and -dipalladium(II) complexes had beenformed. These materials have structures 8 and 9 simi-lar to the type found by Cope and S iekma n2 with azo-benzene. Thus, when a solution of N,N-dimethylben-zylamine and a half-molar quantity of potassium tetra-chloroplatinate(I1) in aqueous methanol was allowed tos tand a t room temperature for 45 hr, a dark brown pre-

(3 ) E. Pietsch, Ed., "Gmelins Handbuch der Anorganischen Chemie-Palladium," Vol. 65, 8th ed, Verlag Chemie, GMBH, Weinheim/Berg-

strasse, 1942, p 391.

Cope, Friedrich I Electrophilic Aromatic Substitution b y Pt( l1) and Pd(1Z) Chlorides



910

K 2 P t C 1 4 +ilPdClar [R4HzGN/*

H&’ ‘CHs 2

8 , M = P t9 , M = P d

QH Z C \ ~ / C H ~

‘CH3

cipitate was formed. This precipitate, after purifica-tion, gave a 28 yield of di-p-chloro-bis(N,N-dimethyl-

benzylamine-2-C,N)diplatinum(II)8) as white needles.Correspondingly, the reaction of 2 moles of N,N-di-methylbenzylamine with lithium tetrachloropalladate(I1)in methanol solution for 20 hr a t room temperaturegave a 95 % yield of di-p-chloro-bis(N,N-dimethylben-zylamine-2-C,N)dipalladium(II) 9) as a yellow crystal-line solid. Both of these complexes are stable to heatand storage and are readily soluble in benzene andchloroform. A competition experiment between azo-benzene and N,N-dimethylbenzylamine with lithiumtetrachloropalladate(I1) showed that the benzylamine-palladium complex 9 is formed at a much faster rate.Non e of the complex 1 from azobenzene was observed.

When N,N-dimethylbenzylamine was allowed to

react with an equimolar quantity of lithium tetrachloro-palladate(II), only a 3 5 x yield of the complex 9 wasisolated. Also, there was obtained a small qua ntity ofa red crystalline product which upon analysis wasshown to be dichlorobis(N,N-dimethylbenzylamine

hydrochloride)palladium(II). The yield of 9 could beincreased either, as mentioned previously, by using anexcess of the benzylamine or by adding another weakbase such as tri-n-butylamine to neutralize the hydrogenchloride formed in the reaction. Complex 9 was alsoprepared in good yield by an inhomogeneous reaction ofthe benzylamine with a half-molar quantity of palladium-(11) dichlo ride in meth anol so lution. These resultsare summarized in Table I.

Table I. Platinum and Palladium Complexes ofN.N-Dimethylbenzylamine

Mole Re-rat io action Isolated

amine: time, yield,

Reagenta reagent hr z MP, “C~ ~

KzPtC14 2 : l 45 28 225-227 decLi2PdC14 2 :l 20 96 185-187 dWLzPdCla 1 :l 16 35 184-186 dWLi2PdC14* 1 : l 1 78 183-185 dWP d C I 2: l 4 68 183-185 d a

a R un in methanol or methanol-water solution at room tempera-ture. In the presence of 2 moles of tri-n-butylamine.

Th e reactions of the p-methoxy- and 3,5-dimethoxy-N,N-dimethylbenzylamines with lithium tetrachloro-palladate(I1) gave good yields of the di-p-chloro-bis-(amine)dipalladium(II) complexes 10 and 11 of thesame type as was obtained from N,N-dimethylbenzyl-amine. On the other hand, the reaction o f p-nitro-N,N-dimethylbenzylamine with lithium tetrachloro-palladate(I1) gave a produ ct 12whose analysis indicatedthat i t has a dichlorobis(arnine)palladium(II) structureof the same type as was obtained from benzylamineand the various secondary benzylamines. Th e failure

for aromatic substitution to take place with the de-activated p-nitro-N,N-dimethylbenzylamine ndicatesthat palladium(I1) must only be a weak electrophile.

Substitution of an arom atic hydrogen ortho to themethylene substituent by palladium in the N,N-benzylamine complexes was demonstrated by lithiumaluminum deuteride reduction of the palladium-N,N-dimethyl-p-methoxybenzylamine complex (10).

T he N,N-dimethyl-p-methoxybenzylamine reductionprodu ct4 was examined by mass spectrometry and found

to contain 90% of dl species and 10% of do species.Also, the nmr spectrum of this material integratedfor only one proton at the 7.27-ppm position for thearomat ic pro tons ortho to the methylene substituent.

Confirmation for the ortho substitution was obtainedby examination of the nmr spectra of the palladium com-plexes, especially those (10 and 11) derived from the p -methoxy- and 3,5-dimethoxybenzylamines. Their spec-tra showed conclusively that one arom atic ring prot onortho to the methylene grou ps was missing in each of thecomplexes. The nmr spectrum of the platinum-N,N-dimethylbenzylamine complex (8) also provided evi-dence that in these materials nitrogen is coordinatedthrough its unshared pair of electrons to the metal.

The methyl proton and methylene proton signals inthe spectrum of this complex were observed as tripletsdue to coupling w ith th e Pt1g6 (spin 1/2) isotope. Asummary of the nmr spectral data is given in Table 11.

To determine whether form ation of the five-memberedring structure is essential for aromatic substitution bypalladium, the reactions of lithium tetrachloropalla-date(I1) with the N,N-dimethyl-2-phenyl-l-ethyl-nd3-phenyl-I-propylamines were examined. If substi-tution by palladium occurred into the ortho positionsof these materials, products containing six- and seven-membered rings would be formed. The prod ucts 13

and 14 obtained from these reactions, however, whichwere quite unstable and difficult to handle, were shown

by analyses to be dichlorobis(amine)palladium(II)complexes in which no palladium-carbon bon ds hadbeen formed.

As a logical extension of the study of the reactionsof the N,N-dimethylbenzylamine with lithium tetra-chloropalladate(II), the commercially available N,N-dimethyl- I-naphthylamine was investigated. This ma -terial w as foun d to give rapid fo rma tion of a palladium-(11) complex 15 whose analysis indicated that it alsomust be of the same carbon-to-palladium a-bondedtype as was obtained with the N,N-dimethylbenzyla-mines. It is felt that in this complex the palladiummust have undergone electrophilic substitution at the8 position o n the naphthalene ring via a five-ring transition state similar to that encountered withth e N,N-dimethylbenzylamine. This, however, hasno t yet been definitely established. Com petition ex-

periments for lithium tetrachloropalladate(I1) with theN,N-dimethyl-I-naphthylamine ndicated that it re-acts much slower than N,N-dimethylbenzylamine, butat least ten times faster than azobenzene.

In summary, the following conclusions may be made.The aromatic substitution reactions by platinum(I1)and palladium(I1) chlorides discovered by Cope andSiekman2 are not limited to the azobenzene system and,

(4) For examples of similar metal hydride reductions of carbon-metal

bonds, see F. G. Bordwell and M. L. Douglas, J . Am. Chem. Soc., 88 ,993 (1966); J . K. Stille and R. A. Morgan, ibid., 88, 5135 (1966).

Journal of the American Chemical Society 1 90:4 / February 14,1968



912

anol was mixed with a solution of 0.53 g (0.0021 mole) of lithiumtetrachloropalladate(I1) in 20 ml of methanol. A precipitate formedimmediately which after standing fo r 4 hr at ro om temperature w asfiltered and washed well with methanol (0.80 g, 93% yield). Re-crystallization from 100 ml of boiling methanol gave 0.35 g (41 %yield) of 4 as fine yellow needles, mp 208-209" dec. Th e nm r spec-trum of this complex possessed multiplets at 2.45 ppm (ar ea 6)and 3.45 ppm (area 4) for the N-methyl and methylene protons,respectively, and a singlet a t 7.39 ppm (area 10) for the aromaticring protons.

Aital. Calcd for C16H22N2PdC12:C, 45.78; H , 5.25; N , 6.68;Pd, 25.37; C1, 16.93. F oun d: C, 45.72; H , 5.28; N , 6.40;

Pd , 25.37 ; C1. 16.87.Dichlorobis(dibenzyla~n~)palladium(II) (5). A solution of

0.75 g (0.0038 mole) of dibenzylamine and 0.50 g (0.0019 mole) oflithium tetrachloropalladate(I1) in 40 ml of methanol was allowedto stand at room tempera ture for 4 hr. The precipitate whichformed (0.92 g, 86% yield) was filtered, dissolved in 30 ml of boilingbenzene, diluted with 20 ml of n-hexane, and cooled to obtain 0.75g (70% yield) of 5 as dull orange crystals, mp 196-197" dec. Thenm r spectrum of this material showed a multiplet at 3.50 ppm (area8) for the methylene protons and a singlet at 7.33 ppm (area 20)for the aromatic protons.

Anal. Calcd for C26H30N 2PdC12: , 58.80; H , 5.25; N ,4.90; Pd, 18.62; C1, 12.43. Fo un d: C, 58.71; H , 5.26; N ,4.83; Pd, 18.54; C1, 12.38.Dichlorobis(N-phenylbenzylamine)palladium(II) (6). To a solu-

tion o f 1.30 g (0.0050 mole) of lithium tetrachloropalladate(I1)in 20 ml of methanol was added 0.92 g (0.0050 mole) of N-phenyl-

benzylamine in 20 ml of methanol. After standing at room tem-perature for 21 hr , the solution was filtered to obtain 1.30 g (95%yield) of 6 as a dark yellow microcrystalline solid, mp 185-187"dec.

Anal. Calcd for CZ6H26N2PdC12:, 57.42; H , 4.78; N, 5.15;Pd, 19.58; CI, 13.07. Fou nd: C, 57.14; H , 4.85; N, 5.16; Pd ,19.66; C1, 13.05.

Dichlorobis(N-phenyl-3,5-dimethoxy enzylamine)palladium(II)(7). The reaction of 0.30 g (0.0012 mole) of N-phenyl-3,5-di-methoxybenzylamine (mp 68-69c)5 and 0.32 g (0.0012 mole) oflithium tetrachloropalladate(I1) in 40 ml of methanol resulted inimmed iate formation of an orange crystalline complex . Afterstanding at room temperature for 18 hr the complex was filtered(0.38 g, 95% yield) and recrystallized from 20 ml of boiling 80:20benzene-hexane (0.25 g, 63% yield), mp 178-180" dec. The nmrspectrum of this complex showed a multiplet at 3.92 ppm (area 4)for the methylene protons, a singlet at 3.62 ppm (area 12) for themethoxy protons, a triplet at 6.32 ppm (area 2), a doublet at 6.45ppm (area 4), and a broadened singlet at 7.29 ppm (area 10) fo rthe aromatic ring protons.

Anal . Calcd for C30H3rN204PdC1,:C, 54.27; H , 5.13; N ,4.22; Pd, 16.04; C1, 10.70. F ou nd : C, 54.32; H , 5.13; N ,4.16; Pd, 15.85; C1, 10.69.

Di-p-chloro-bis(N,N-dimethylbenzylamine-2-~,N)diplatinum(1)(8). To a solution of 4.15 g (0.01 mole) of potassium tetrachloro-platinate(I1) in 50 ml of water was added a solution of 2.70 g (0.02mole) of N,N-dimethylbenzylamine in 20 ml of methanol. Theinitially clear red solution, after 45 hr at room temperature, hadbecome colorless and precipitated 3.15 g of brown solids. Thesesolids were extracted with 2G0 ml of boiling benzene and filteredto remove 1.60 g of brown insoluble material, an d the benzenewas removed on a rotary vacuum evapo rator. Chromatographyof the resulting brown residue through a short silicic acid columnwith chloroform gave 1.0 g (28% yield) of 8 s pale yellow crystals.These crystals were dissolved in 100 ml of boiling benzene, diluted

with 150 ml of rz-hexane, and cooled to obtain 0.85 g of dull whiteneedles, mp 225-227" de c.

Anal . Calcd for ClaHZ4N 2Pt2CI2: , 29.63; H, 3.29; N,3.84; Pt, 53.50; CI, 9.74. Fou nd: C, 29.99; H , 3.28; N , 3.69;Pt, 53.30; C1, 10.01.

Di-p-chloro-bis(N,N-dimethylbenzylamine-2-C,N)dipalladium(II)(9) from Lithium Tetrachloropalladate(I1). A solution of 0.50g (0.0037 mole) of N,N -dimethylbenzylamine in 20 ml of methano lwas mixed with a solution of 0.50 g (0.0019 mole) of lithium tetra-chloropalladate(I1) in 20 ml of methano l. Th e initially clear redmixture very quickly became lighter in color and after about 1 minat room temperature began to precipitate a yellow solid. After

standing for 20 hr, the yellow product was filtered (0.50 g, 96%yield). Recrystallization from 50 ml of boiling 50:SO benzene-n-hexane gave 0.45 g of 9 s yellow crystals, mp 185-187" dec; A ~ ~ ' "

340 mp (e 2520).Anal . Calcd fo r C I S H ~ ~ N ~ P ~ ~ C I , :, 39.14; H , 4.35; N,

5.07; Pd , 38.56; C1, 12.87; mol wt, 552. Fo un d: C, 39.47;H, 4.42; N , 4.77; Pd, 38.24; C1, 12.79; mol wt (osmo meter),495.

In a similar run using equimolar quantities of amine (0.50 g,0.0037 mole) and lithium tetrachloropalladate(I1) (0.97 g, 0.0037mole), after 16 hr there w as obtained 0.80 g of a mixture of red andyellow crystals. Th e yellow port ion of the product, which was

soluble in 20 ml of hot benzene, was filtered from the red material.The filtrate was diluted with 25 ml of n-hexane and cooled to obtain0.35 g (35% yield) of 9,mp 184-186" dec. The benzene-insolublered plates weighed 0.25 g, m p 208-210" dec, and were shown byanalysis to be dichlorobis-(N,N-dimethylbenzylamine ydrochlo-ride)palladium(II).

Anal. Calcd fo r C lsH2sN2PdC14: C, 41.51; H, 5.38; N, 5.38;Pd , 20.45; C1, 27.29. Fo un d: C, 41.22; H , 5.40; N , 5.45; Pd,20.60; C1,27.40.

In a further run in the presence of 1.38 g (0.0075 mole) of tri-n-butylamine, the reaction of 0.50 g (0.0037 mole) of N,N-dimethyl-benzylamine with 0.97 g (0.0037 mole) of lithium tetrachloropalla-date(I1) in 40 ml of methanol a t roo m tem pera ture for 1 hr gave 0.80g (78 % yield) of crude 9. Recrystallization from boiling benzene-n-hexane gave 0.75 g of beautiful bright yellow crystals, mp 183-185" dec.

Di-p-chloro-bis(N,N-dimethylbenzylamine-2-C,N)dipalladium(II)

(9) from Palladium(I1) Dichloride. A heterogeneous mixtureof 5.40 g (0.04 mole) of N,N-dimethylbenzylamine and 3.5 g (0.02mole) of palladium(I1) dichloride in 200 ml of methano l w as stirredat room temperature. After 4 hr, all of the palladium dichloridehad dissolved and was replaced by a yellow-brown crystallinesolid. This was recrystallized from boiling benzene-n-hexane toobta in 3.75 g (68 % yield) of 9, mp 183-185 O dec.

Competition between N,N-Dimethylbenzylamine and Azobenzenefor Lithium Tetrachloropalladate(I1). The reaction of 1.35 g(0.01 mole) of N,N-dimethylbenzylamine and 1.82 g (0.01 mole)of azobenzene with 1.32 g (0.005 mole) of lithium tetrachloro-palladate(I1) in 40 ml of methanol for 10 hr at room temperaturegave 1.23 g of greenish yellow crystals, mp 183-185" dec. Th enmr spectrum of this material showed that it consisted entirelyof the benzylamine-palladium complex (9).

Di-p-chloro-bis(N,N-dimethyI-p-methoxybenzylamine-2-C,N)di-palladium(I1) (10). A solution of 1.25 g (0.007 mole) of N, N-dimethyl-pmethoxybenzylamine6 (bp 67-69" (0.1 mm), n z 5 ~.5104)and 2.0 g (0.0076 mole) of lithium tetrachloropalladate(I1) in 20ml of methanol was allowed to stand a t room tem perature for 22 hr.The solvent was then removed on a rotary vacuum evaporator,and the resulting red-yellow residue was extracted with 50 ml ofboiling benzene. Th e benzene solution was filtered, diluted with70 ml of n-hexane, and cooled to obtain 1.15 g (50z yield) of 10as yellow crystals, An analytical sample was prepared by recrystal-lization from boiling benzene, mp 184-185" dec ; h ~ 2 c 1 *43 mp(e 2960).

Anal . Calcd for C20H28N202Pd2C12: C, 39.23 ; H , 4.58; N,4.58; P d, 34.78; C1, 11.61. F ou nd : C, 39.39; H , 4.76; N,4.33; Pd, 34.52; C1, 11.73.

A portion of the benzene-insoluble dichlorobis(amine hydro-chloride)palladium(II) product was recrystallized from hot water,mp 146-148" dec.

Anal . Calcd for C20H32N202PdC14: C, 41.35; H , 5.51; N,4.82; Pd, 18.33; CI, 24.47. Fou nd: C, 41.42; H, 5.63; N,

5.30; Pd, 17.96; C1, 24.67.Di-p-chloro-bis(N,N-dime hyl-3,5-dimethoxybenzylamine-2-C,N)-

dipalladium(I1) (11). The reaction of 0.98 g (0.005 mole) ofN,N-dimethyl-3,5-dimethoxybenzylaminebp 96-97 O (0.5 mm),n% 1.5184) with 0.66 g (0.0025 mole) of lithium tetrachloropal-ladate(I1) in 100 ml of methanol a t room tem perature for 12 hrgave 0.95 g of orange plates, These were dissolved in 50 ml ofboiling benzene, filtered to remove 0.25 g of insoluble material,diluted with 60 ml of n-hexane. and cooled to obtain 0.55 g (66%. -yield) of 11,mp 138-140" dec.

Anal. Calcd for C22H32N204PdZC12:, 39.30; H , 4.76; N ,4.17; Pd, 31.68. Fo un d: C, 39.72; H , 4.77; N , 3.77; Pd,31.70.

( 5 ) Y.Asahina and T. Matsuzaki, J . Pharm. SOC. apan, 509, 527(1924). ( 6 ) M. Tiffeneau, Bull. SOC.Chim. France, 9, 82 7 (1911).

Journal of the American Chemical Society / 90:4 / February 14,1968



913

on a rotary vacuum evaporator gave an orange crystalline residuewhich was extracted into 100 ml of boiling n-hexane, filtered, andcooled t o obta in 1.50 g(60% ield) of 14, mp 83-85'.

A n d . Calcd for CnnHaaN ~PdCl~: C, 52.44; H, 6.75; N,5.56; Pd , 21.14; C1, 14.10. Fo un d: C, 52.70; H, 6.79; N,5.76; Pd , 21.21; C1, 14.35.

Di-~-chloro-bis(N,N-dimethyl-l-naphthyla~e~-C,N)dipalla-dium(I1) (15). T o a solution of 1.30 g (0.0076 mole) of N,N -dimethyl-1-naphthylamine in 150 ml of methanol w as added 1.0 g(0.0038 mole) of lithium tetrachloropalladate(I1) in 50 ml of meth-anol. After abo ut 3 min of standing at room temperature, a yellowcrystalline precipitate began to form. After 3 hr of standing, the

product was filtered and washed well with methanol (1.15 g, 49%yield). This was extracted with 60 ml of boiling benzene, filtered,diluted with 60 ml of n-hexane, and cooled to obtain 0.50 g (21xyield) of 15, mp >300" (blackens at 220"). The nmr spectrum ofthis material possessed a singlet at 3.55 ppm (area 12) for the N-methyl pro tons an d a multiplet at 7.59 ppm (area 12) for the aromaticring protons.

Anal. Calcd for C21Hz4N 2Pd2C12: , 46.17; H, 3.85; N,4.49; P d, 34.11; C1, 11.38. F ou nd : C, 46.53; H, 3.91; N,4.33; Pd, 34.30; C1, 11.59.

Competition between N,N-Dimethylbenzylamine and N,N-Di-methyl-p-methoxybenzylaminefor Lithium Tetrachloropalladate(I1).The reaction of 1.65 g (0.01 mole) of N,N-dimethyl-p-methoxy-benzylamine and 1.35 g (0.01 mole) of N,N-dimethylbenzylaminewith 1.32 g (0.005 mole) of lithium tetrachloropalladate((I1) in 40ml of methanol at room temperature for 10 hr gave 1.30 g of yellowprecipitate. Exam ination of this material by nmr methods showed

that it consisted of approximately a 50:50 mixture of the palladiumcomplexes 9 and 10 of the two amines.

Competition between N,N-Dimethyl-1-naphthylaminend N,N-Dimethyl-p-methoxybenzylamine for Lithium Tetrachloropalla-date(II). A solution containing 0.85 g (0.005 mole) of N,N-di-methyl-1-naphthylamine, 0.82 g (0.005 mole) of N,N-dimethyl-pmethoxybenzylamine, and 0.66 g (0.0025 mole) of lithium tetra-chloropalladate(I1) in 300 ml of methanol was allowed to stand for3 hr at roo m temperature, Th e 0.65 g of yellow crystals which wasobtained was examined by nmr and found to consist entirely ofthe palladium com plex 15 of the N,N-dime thyl-pmethox ybenzyl-amine.

Competition between N,N-Dimethyl-1-naphthylamine nd Azo-benzene for Lithium Tetrachloropalladate(I1). The reaction of0.85 g (0.005 mole) of N,N-dimethyl-1-naphthylaminend 0.91 g(0.005 mole) of azobenzene with 0.66 g (0.0025 mole) of lithiumtetrachloropalladate(I1) in 250 ml of methanol for 3 hr at room

temperature gave 0.55 g of a mixture of red and yellow crystals.The nmr spectrum of this mixture showed that it consisted of atleast 90% of the palladium complex 15 of N,N-dimethyl-1-naph-thy lamine.

Acknowledgment. The authors wish to thank Dr.R ober t W . Siekman for his assistance in obtaining themass spectra.

Dichlorobis(N,N-dimethyl-p-nitrobenzylamine)palladium(II) (12).Reaction of 1.80 g (0.01 mole) of N,N-dimethyl-pnitrobenzyl-amine' (b p 92-94' (0.1 mm), n n 5 ~.5395) with 1.31 g (0.005mole)of lithium tetrachloropalladate(I1) in 200 ml of methanol for 1 hrat roo m temp erature gave 2.2 g (82x ield) of 12 as yellow crystals.An analytical sample was prepared by recrystallization from toluene,mp 127-128" dec.

Anal . Calcd for C18Hz4N404PdC12:C, 40.19; H , 4.47; N ,10.42; Pd, 19.85; C1, 13.21. Fo un d: C, 40.28; H, 4.57; N,9.91; Pd, 19.83; C1, 13.48.

Lithium Aluminum Deuteride Reduction of Di-1-chloro-bis(N,N-dimethyl-p-methoxybenzylamine-2-C,N)dipalladium(II)10). To a

stirred slurry of 0.50 g (0.012 mole) of lithium aluminum deuteridein 100 ml of ether was a dde d in small po rtions 1.50 g (0.0024 mole)of complex 10. After stirring at room temperature for 1 hr, theresulting black slurry was worked up by the careful addition of 3ml of >99.77, deuterium oxide followed by anh ydr ous sodium sul-fate. The ether solution was filtered through anhyd rous sodiumsulfate and the solids were washed well with ether. Rem oval ofthe ether solvent by distillation through a short Vigreux columngave an oil which was distilled at 0.1 mm (bath 70') under n itrogenthrough a microdistillation apparatus (0.63 g, 80% yield, nZ5D

1.5113). The nmr spectrum of this distilled material showed theexpected singlets a t 2.22 ppm (a rea 6), 3.39 (2), and 3.79 (3) for theN-methyl, methylene, and methoxy protons, respectively, of N ,N-dimethyl-p-methoxybenzylamine. In the aromatic region, thesignal at 6.97 ppm, which was a doublet (Jo ,m = 8.0 cps) in theundeuterated material, was found as a multiplet (area 2.0). Thesignal at 7.27 ppm for the aromatic proton s ortho to the methylene

group, which was a doublet (area 2) in the undeuterated material,was found to be a doublet ( J o , , = 8.0 cps, area 1.1) in the redutionproduct.

Dichlorobis(N,N-dimethyl-2-phenyl-l-ethy~amine)pa~~adium(II)(13). Th e reaction of 1.49 g (0.01 mole) of N,N-dimethyl-2-phenyl-1-ethylamines (bp 65-66" (3.0 mm), n Z 5 ~.5009) with 1.31g (0.005 mole) of lithium tetrachloropalladate(I1) in 40 ml of meth-anol for 20 hr at room temperatu re gave a slight palladium mirrorand 1.50 g (64% yield) of 13as a reddish orange crystalline precipi-tate, mp 93-94".

Anal . Calcd for Cz0H30N2PdC12:C, 50.48; H, 6.31; N,5.89; Pd, 22.38; C1, 14.93. F ou nd: C, 50.28; H, 6.49; N,6.22; Pd, 23.04; C1, 15.23.

Dichlorobis(N,N-dimethyl-3-penyl-1-propylamine)palladium(II)(14). The reaction of 1.63 g (0.01 mole) of N ,N-dimethyl-3-p h e n y l - l - p r ~p y l a m i n e ~bp 74-75' (2.0 mm), n 2 b 1.4971) with 1.30g (0.005 mole) of lithium tetrachloropalladate(I1) in 35 ml of meth-

anol for 14 hr a t room tem perature gave a red solution containinga small amount of a black precipitate. Remo val of the solvent

(7) G. M . Bennett and G. H . Willis, J . Chem. Soc., 264 (1929).(8) E. C. Horning, Ed., "Organic Synthesis," COIL Vol. 111, John

(9) M. Tiffeneau and K. Fuhner, Bull. SOC.Chim. France, 15, 173Wiley an d S ons, Inc., New York, N. Y.,955, pp 723-725.

(1914).

Cop e, Friedrich 1 Electrophilic Aromatic Substitution by Pt( Il) and Pdi ll) Chlorides

j. am. chem. soc. 1968 copelaelectrophilic aromatic substitution reactions by

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