SOLVOLYSIS OF CY-ARYLETHYL CHLORIDES
July 20, 1957
3-(o-Hydroxyphenyl)-5-phenyl-1,2,4triazole (VIa) formed colorless crystals from benzene, m.p. 204', yield ca. 82%. VIa is soluble in aqueous sodium hydroxide solution and gives violet color with alcoholic ferric chloride solution. Anal. Calcd. for ClaH1lNaO: C, 70.88; H, 4.64; N, 17.72. Found: C, 70.61; H , 4.42; N, 17.90. VIa was similarly prepared by the action of hydrazine hydrate on 1 g. of Va, as described above, in an almost quantitative yield. Identification was carried out by m.p. and mixed m .p. determination. 3-(o-Hydroxyphenyl)-5-( P-methoxyphenyl)-l,2,4-triazole (VIb) formed colorless crystals from ethyl alcohol, m.p. I%", yield ca. 79%. I t behaves in a similar manner to VIa toward ferric chloride and sodium hydroxide solutions. Anal. Calcd. for C,bH13Ns02:C, 67.41; H , 4.87; N, 15.73. Found: C, 67.52; H , 4.65; N, 15.80. Action of Grignard Reagents on IC. ( a ) Phenylmagnesium Bromide.-To a solution of phenylmagnesium bromide (prepared from 0.9 g. of magnesium and 9 g. of bromobenzene in 50 ml. of dry ether) was added a solution of 1.5 g. of IC in 50 ml. of dry benzene. The ether was evaporated and the reaction mixture heated for 3 hr. on a steam-bath. After the mixture had stood overnight a t room temperature, it was poured slowly into 100 ml. of saturated aqueous ammonium chloride solution and extracted with ether. The precipitate which separated from the ether-benzene mixture was crystallized from benzene-light petroleum as colorless crystals, m.p. 122', yield ca. 0.89 g. Anal. Calcd. for C21H17N03: C, 76.13; H, 5.13; N, 4.23; activeH, 0.30. Found: C, 75.68; H , 4.96; N , 4.15; active H , 0.27. 2-(p-Methoxyphenyl)-4-phenyl-l,3-benzoxazine (VIIa) is easily soluble in benzene and hot ethyl alcohol, difficultly soluble in light petroleum and insoluble in cold aqueous sodium hydroxide solution. I t gives red color with sulfuric acid. The alcoholic solution of VIIb does not become colored when treated with alcoholic ferric chloride solution. (b) Benzylmagnesium Chloride.-To a Grignard solution of benzylmagnesium chloride (prepared from 0.8 g. of magnesium, 5.5 g. of benzyl chloride and 50 ml. of dry ether) was added a solution of 1 g. of ICin 40 ml. of benzene. The reaction mixture was worked up in the usual manner. The oily product, obtained upon evaporation of the ethereal extract, solidified after working with light petroleum. 2-(9Methoxyphenyl)-4-benzal-l,3-benzoxazine (IXb) was obtained as yellow crystals from petroleum ether, yield 0.68 g., m.p. 126". Anal. Calcd. for CztHl,N02: C, 80.73; H, 5.20; N, 4.28. Found: C,80.62; H,4.91; N, 4.05. I X b is easily soluble in chloroform and benzene, difficultly soluble in cold petroleum ether and insoluble in cold aqueous sodium hydroxide solution; it gives an orange red color with sulfuric acid. Action of Grignard Reagents on X. ( a ) Phenylmagnesium Bromide.-To a solution of phenylmagnesium bromide was added 1 g. of XIJ in 30 ml. of dry benzene. The reaction mixture was worked up as described above. The oily [CONTRIBUTION FROM
THE
3849
residue, obtained on evaporation of the ethereal extract, solidified on scratching and cooling. N-Benzohydrylsalicylamide (XIIa) was crystallized from petroleum ether (b.p. 100-120°)as colorless crystals, m.p. 140', yield 0.64g. Anal. Calcd. for CmH1,NOz: C, 79.21; H, 5.61; N, 4.62. Found: C, 79.20; H, 5.46; N, 4.32. X I I a is easily soluble in benzene and hot alcohol, difficultly soluble in light petroleum and soluble in cold aqueous sodium hydroxide; it gives an orange-red color with alcoholic ferric chloride solution. Acetylation.--A solution of 0.5 g. of X I I a in 30 ml. of acetic anhydride was refluxed for 2 hr. The reaction mixture was poured into cold water, and the solid, so obtained after cooling, was filtered off, washed thoroughly with water and crystallized from alcohol as colorless crystals (ca. 0.39 g.), m.p. 148'. The acetyl derivative X I I c is insoluble in cold aqueous sodium hydroxide solution and gives no color with ferric chloride. It gives an orange-red color with sulfuric acid. Anal. Calcd. for CnHlsNOa: C, 76.52; H, 5.51; N, 4.06. Found: C, 76.50; H, 5.34; N,3.82. Action of Hydrochloric Acid on XI1a.-A solution of 1 g. of X I I a in 40 ml. of glacial acetic acid was treated with 5 ml. of concentrated hydrochloric acid. The reaction mixture was refluxed for 3 hr., cooled, poured into ice-cold water and neutraiized with sodium carbonate. I t was extracted with ether, dried and evaporated. The solicl residue was crystallized from ethyl alcohol as colorless crystals (ca. 0.41 g.), m.p. 136'; identified as salicylamide (n1.p. and mixed m.p.). Anal. Calcd. for C7H7N02: C, 61.31; H, 5 10; N , 10.21. Found: C, 61.42; H, 4.96; N, 10.12. (b) Methylmagnesium Iodide.-A solution of 1 g. of X I I a in 40 ml. of dry benzene was added to methylmagnesium iodide (prepared from 0.9 g. of magnesium, 3.6 g. of methyl iodide and 50 ml. of dry ether); the reaction mixture was refluxed on a steam-bath for 3 hr., allowed to stand overnight a t 25' and worked out as usual. N-(orPheny1ethyl)-salicylamide (XIIb) was crystallized from light petroleum as colorless crystals, m.p. 103",yield 0.51 g Anal. Calcd. for C I ~ H I S N O ~C,: 74.68; H , 6.22; N, 5.81. Found: C, 74.46; H , 5.98; N,5.85. X I I b is easily soluble in benzene and hot alcohol, difficultly soluble in light petroleum and soluble in cold aqueous sodium hydroxide solution; it gives yellow color with sulfuric acid. The alcoholic solution of X I I b gives violet color with alcoholic ferric chloride solution. Acetylation.-The acetyl derivative X I I d was similarly prepared as previously described in the case of XIIc. It was obtained in colorless crystals from chloroform-light petroleum mixture, m.p. 98O,yield 82%. I t was insoluble in aqueous sodium hydroxide solution and gives no color with alcoholic ferric chloride solution. Anal. Calcd. for C17H17N03: C , 72.08; H, 6.00; N, 4.94. Found: C,71.78; H , 5.82; N,5.00. GIZA,CAIRO,EGYPT
MARIONEDWARDS PARK LABORATORY O F BRYNMAWRCOLLEGE]
Relative Reactivities of Polynuclear Aromatic Systems. The Solvolysis of a-Arylethyl Chlorides' B Y ERNSTBERLINERAND NANSHIEH RECEIVED FEBRUARY 18, 1957 The rates of reaction, activation energies and entropies were determined for the SNIsolvolysis of 13 different a-arylethyl chlorides, ArCHClCHs, in 80% or 90% aqueous acetone. The relative reactivities, referred t o 25" and SO% aqueous acetone, correlate satisfactorily with v-xious theoretical parameters, but compounds with an "a-naphthalene-like" structure react slower than predicted.
Although polynuclear aromatic hydrocarbons have played an important part in organic chemical (1) T a k e n from a dissertation submitted by Miss N a n Shieh t o the G r a d u a t e School of Bryn Mawr College in partial fulfillment of the requirements for the P h . D . degree, June, 1957.
theories, an experimental knowledge of the relative reactivities of polycycIic aromatic systems is very scanty. This is in contrast to the theoretical treatment accorded these systems, particul.arly in
TABLE
KINETIC DATAFOR
Temperatcre, 40.00
7 -
Ar- in ArCHClCHs
Solvent, acrtone
2-Phenanthrvl
80
2-Saphthyl
80
9-Pherianthryl
80 80
su 1-Nap11t hyl
2-Chrysenyl
80
80 90 90 $10
2.5 00 k 106 sec. - 1
x
3.31 3.29 4.71 4.81 .5.83 3.85 7.45 7.'ki 8.96 9.31 Y ,211 11.7 11.7 24.8 24.0 2.30 2.31 2.60 2 . BO 5.65
-
I
THE SOLVOLYSIS O F a-a%RYLETHYL CIILORIDES P
32.00
X
---k
0.843
45.00
102, sec.-i-
3.70 3.77 5.28 3.26
1.45 1.42 1.76
2.14 2.18 2,92 2.98 3.85 ::.Ys 4.59
1.85
4.6ii
7,8!J
2.20 2.23
L> i ,
2.75' 2.71 2.74 6.05
6,Y-l."
1.13
1.16
6.05 0 . ,564
0,629 1)
62:1
-
-m
,5.71i
6.81
15.6 15.8 1.40 1.3; 1 .Sf; I . 51
ti.X(j
r;
log .I
22.9
i 0.2
11.3 i 0 . 2
22.6
*
.1
11.3 i-
.I
.1
ll.8i
,1
.1
11 2
.I
11.; i , l
-.ti. 99
.15
11.4 i .1
-8.30
12.1 i .1
-5.0.4
2:3,21
8;$
7.91
22.25
Zk
IU.4 10.3
22.8 =
12.1 12.5 12.4 27.1 27.9 2.41 2.39 2.62 2.61
22.3
.5su
-*
E, kcal.
7
+
28.8 i .1
+
- 0 ,58
.I
*
.2
10.5
*
.I
- 1 0 u . D-
2 1 . 5 i-
.1
10.2 3z
.1
-13.9
22.0
21A
10.4
-12.9
?iI).1 i. . 1
10.2 i: . 1
- 13.'i
47.7 47,(j
20.6 i-
.1
11.8 i .1
-L51
11. ( I
18,s
*
.1
1 0 . 2 i. . 1
-14
3 . t I
$8
31 31.5
6.98
15.9
6.87
16.2
---Temperature, 1).00 12.00
2-Fluorenyl
80
19.7 1'7 6
3-Pyrr1iyl
90
26 .o 25.5 8!).5 87.5
9-Anthryl
90
,
l i 00
9.60 9.67 10.8
10.7
"C.----18.00
20.5 20.1 21 .o 21, ( j 21.4
26.7 26.7 7
3.00
I)
44,:t
33.2 33.0
17.0
Y.57
- lii,7
Temperatiire: -DC.-----------LOCI iIJ.on 70 00
7.23 2.12 5.83 9.47" 22.2 I . 1 1 0 . 1 _i . 1 -11.2 7.99 2.09 5.68 9.39 T = 39.70". T = 32.13". Values of 9.04 (titrimetric) and 10.0 (polarimetric) are reported by 13. D. Hughes, C. K. Ingold and -4.D. Scott, ref. 8. Phenyl
80
Q
the last decades. Various parameters arising out of modern theories, such as free valences, atomand bond-localization energies, charge densities, molecular diagrams and others, have made it possible to predict relative reactivities a t various positions within the same molecule, as well as differences among different molecules.2 Two lines of approach suggest themselves for a collection of data by which relative reactivities of polynuclear aromatic systems can be ascertained. One is a kinetic study of an electrophilic substitution reaction, the other a study of a suitable sidechain reaction. The latter was chosen for a preliminary survey because a definite position in the polynuclear aromatic compound can be studied (2) For general discussions Fee, f o r in4tanre, L. Pauling, "The Tatiire of t h e Chemical Bond." '2nd Ed., Cornell University Press, I t h a c a N . Y . , 1 W i : C . W. Wheland, "Resonance in Organic Chemistry," J o h n Wiley a n d Sons, I n c . , S e w York, S. Y . , 1955; C. A. Couls o n , "Valence," Oxford University Press, London, 1952; B. Pullman and A. P u l l m a n , "Les Theories electroniques d e la Chimie organic," Xlasson and C o . , Paris, 1922; 31. J. S. Dewar, Tnxs J O U R N A L74, , :3341 8. ( l g 5 2 ) : 11. J . S. D e n a r in J . IV. Cook, "Progress in Organic Chcmistry," Vol. 11, Academic Press I n c . , New York, X. ' I , 1953, p 1
without the complicating factor of isomer distribution or polysubstitution. Most of the older quantitative data refer to various side-chain reactions and dissociation constants in the benzene and naphthalene series, but some extend to biphenyl, anthracene and phenn~ithrene.~ In direct electrophilic substitution, there is ,?bundant qualitative information, based usually on preparative ease of substitution, that the reactivity is anthracene > phenanthrene > naphthalene > benzene for the most reactive positions..l Systematic quantitative data were practically completely missing, until Dewar, Mole and \lTarford recently demonstrated an excellent correlation between theoretical parameters and relative rates of nitration for polynuclear aromatic hydr0carbons.j ( 3 ) Some o f t h e older literature h a s liven rc, ,-drocarbons, vliich had been purified by rccimrnendecl procedures. The physical properties of all compounds and the carbon. hydrogen analyses of tlie new conipoiinds are listed in Table 1 1 1 . 2 7 Kinetic Runs .-Purified acetone21 and boiled-out distilled m t e r were thcrmostated a t 25" and the necessary volumes, nieasured it: 2-1. volumetric flasks (for instance 8 1. of acetone .ind 2 1. of \rater), were mixed in a 5 gal. Pyrex bottle. Enough of thc 80 and the 90% aqueous acetone bras prepired to last throughout the entire investigation. Kinetic runs b e l u x 2Z@,and some :it 25", were conducted in a 100nil. volumetric flask, and 10-1d. samples were irithdrawn :Lt sppropriatc time intervals. X o s t runs a t 25O, and all runs above 2 j 3 , were run in sealed tubes, prepared from 15-fiini. Pyrex tubing. For these runs, a n exactly weighed amount of chicride was i ~ i a d eup to volume in a 100-1111. volumetric ilask a t room temperature, the mixture was cooled and eight approximately 18-nil. sainples were pipetted into tlie ampules, sealed a t ice-bath temperature and placed in tlie tliermostat. IVheri tlie tubes had reached the ternperature oE the tliermostat, one iinipule was opened arid a IO-iiil. sainple was withdrawn and titrated for the zero titer. The contents of onc sealed tube were alloxed to react for at least 10 half-life times, in order to get the infinity reading. ;\11 samples, iiicludiiig the one for the iiifinity reading, were \-vith(irawi a t tile reaction teinpcrcltiires, which were inaintniiicd a t 1 0 . 0 2 " . The 13-1111 rriples were alloired to run arid wcre titrated with :I illto 60-50 nil. of ice-cold acet S ~ i C I Hsolutioii cont:iined in :i 5-tii1. inicrobur-et graduated in huiir1:idths; n (1..570 alcoliolic lacinoid solution was used as ;tn indicator. Initial concentrations of chloride !vue usually for thc less soluble 2-anthryl (0.006ny1 (0.0O.i .liin 807, :icetone) cornthe 2-fluorc:iyl compound a t a 0.01 and Ct.OOZ Jf concentration slion.erl that the rates irere not :iffTccteti by the i;iitiiil co~iccntr:itioi~~. Reactions were the ketones a n d t h e known carbinols during her tenure of a fellowship ~t Tir:.n Aloirr College. ( i l R ! J . il C'mi,>ntand IT. It I. Zerhmeister, ibid., 76, 2308 (1954). ( c ) DjphenyloctaTheoretically, the molecules of this unsymmetritetr?encu' L.Zechmeister a n d A . L. t e l l o s e n , ibid., 64, 2755 (194?); I,. Zirhmeister and J. 13. Pinckard, ibid.. 76, 4144 (1954). ( d ) Bically built compound may assume 32 spatial conphenl-lene derivatives. E. F Magoon and L. ZechmeiTter, ihL1 figurations, the a l l - f i ~ ~form . c i n c l u d e c l . l e 11-e find ,
77, . j c i i ? ( 1 3 4 . ? b i (19 ( 2 ' ! I3;ile and
nrticle.: L. Zcchmeister. c ' h F n 1 . , 10, I (1051). ZechmeiqFer. ?'FITS J o ~ : R v : I T , ,75, 237!t (lQ.5:3'1. ey
r.
( 3 ) K . K;lihn anrl R. \%Lllenfel.;, Rp i...70, l,'{,'$l f I 9 3 7 ) : I ) i . Schmitt, : l x z . , 547. 270 (19.411.
