3252
JOHNSON AND HEESCHEN
pure acid XI, m.p. 94-96' dec. A mixture melting point with an authentic sample of X I (lit.2 m.p. 94-96') was not depressed. The infrared spectra of the two samples were identical. Acid X I (2.1 g., 0.01 mole) was heated in an oil bath a t llG 115' until carbon dioxide evolution had ceased, to give 1.6 g. (987,) of benzoylacetone, m.p. 58-60'. Acid X I (2.1 g., 0.01 mole) was heated on the steam bath with 20 g. of polyphosphoric for 1.5 hr. The resulting dark red mixture was poured onto 200 g. of crushed ice to precipitate a solid
VOL. 29
which was collected by filtration and digested with hot absolute ethanol. There was obtained 1.7 g. (90%) of lactone VII, m.p. 258-259" dec., which was identified by mixture melting point and by comparison of infrared spectra with an authentic sample of VII, m.p. 254-256' dec.17 (17) Melting of lactone VI1 was accompanied by considerable decomposition which evidently resulted in the lower melting point (241-244') reported in ref. 2.
A n Unusual Reaction Product from Epichlorohydrin and Sodium Cyanide FRANCIS JOHNSON AND J. P. HEESCHEN The Dow Chemical Company, Eastern Research Laboratory, Framingham, Massachusetts, and the Chemical Physics Laboratory, Midland, Michigan Received M a y 22, 1964 The major product arising from the reaction of epichlorohydrin and unbuffered potassium cyanide solution, aside. from water-soluble polymers, is shown, largely by physical means, to be trans-3,4-dihydro-2-cyano-3hydroxymethyl-4-hydroxyaniline (I). A seven-step mechanism for its formation is proposed.
The reaction of potassiuni cyanide in aqueous solustudy of the spectroscopic properties of the compounds tion with epichlorohydrin was first investigated by I-IV in the hope that this would provide an answer. Pazschke' in 1870, although undoubtedly this same The data, presented below, has permitted the assignsystem was under study indirectly, when Sinipson2 ment of the structure trans-3,4-dihydro-2-cyano-3treated 1,3-dichloropropanol-2 with 2 equiv. of this hydroxymethyl-4-hydroxyaniline to I. salt, exactly a century ago. In the interim other investigators have examined "2 this reaction and have shown that the nature of the products is dependent on the pH a t which the system is maintained. At neutral pH the chief product is 4chlor0-3-hydroxybutyronitrile,~whereas a t pH 9-9.5 acthe major component is 3-hydro~yglutaronitrile~ I companied by sinal1 amounts of 4-chloro-3-hydroxybutyronitrile and 4-hydroxycrotononitrile. With an Infrared Evidence.-The infrared spectrum' of I unbuffered potassium cyanide solution (pH 11.5-12.5) showed bands a t 2.90, 2.99 (sharp), and 3.09 1.1, indicasmall ainounts of the two latter substances were isotive of both hydroxyl and amino groups, while a strong lated3 together with 2,5-biscyanoniethyI-l,4-dio~ane~~~~~ absorption a t 4.56 1.1 characterized a highly unsaturated in yields of 10% or less. nitrile. Bands a t 6.01, 6.11, and 6.34-6.35 CL could be However, under the latter conditions, the mateascribed to double bond and/or imine functions whereas rial (I) which is produced in greatest amount, apart from those a t 9.40, 9.65, and 9.90 1.1were characteristic of C-0 water-soluble polymer, appears to have been missed by stretching vibrations. Lastly a weak absorption a t previous workers. Failure to observe it, can be traced 12.85 p suggested cis ethylenic hydrogens but its unto the fact that it is water soluble and can only be isousual sharpness mitigated against this geometry. lated from the reaction mixture by prolonged continuous In the spectruni of the diacetate (11)a triplet of sharp extraction with ethyl acetate. Obtained in this manner bands a t 2.91, 2.99, and 3.08 p , highly characteristic of I crystallized froin ethanol as cubic, lemon yellow crysan unsaturated amino group in the solid state, contals, 1ii.p. 154", having a niolecular weight of 166 and the firmed the presence of this function. A number of the einpirical forniula, C8HloN2O2. Acetylation was trouble bands already observed for I were apparent in the specfree and gave a pale yellow diacetate (11). Catalytic retruni of I1 but in the latter the appearance of two duction, equally facile, led t o a colorless dihydro derivapeaks a t 5.76 and 5.80 p indicated the presence of two tive (111)and acetylation of this substance or hydrogenadifferent types of acetate groups. tion of I1 led to the same dihydrodiacetate (IV). I n an The spectra of the dihydro derivatives (111 and IV) attempt to deduce the structure of I by chemical means were interesting in that they showed the nitrile group a number of other reactions, including acid hydrolysis, absorption to be unchanged a t 4.55 1.1 despite the fact various oxidations, and diazotization, were tried, but the band for cis-ethylenic hydrogen atoms a t 12.85 quite consistently, if starting material were not re1.1 was now absent. The high position of absorption of covered, irresolvable syrups or tars were obtained. the nitrile group in all these compounds, together with Rather than persist with chemical failure we turned to a the fact that the amine group did not acetylate under the mild conditions used, indicated the presence of a (1) F. 0. Pazschke, J. p r a k t . Chem., [2] 1, 97 (1870). Ziegler-Thorpe system, while the loss of color on hydro(2) M. Simpson, Ann., 188, 74 (1864). (3) C. C. J. Culvenor, W. Davies. and F. G. Haley. J . Chem. Soc., 3123 genation suggested that the latter group in I was con(1950). jugated with a double bond, Taken as a whole then, (4) F. Johnson, J. P. Panella, and A. C. Carlson, J . O w . Chem., 87, 2241 the above information permitted the partial formulas, (1962). ( 5 ) W. Hartenstein, J . p r ~ k t Chem., . [2] 7 , 297 (1873). (6) A . van Dormael. Trav. lab. chim. gen., Uniu. Louuain. 34 (1942-1947).
(7) All infrared spectra were run as Nujol mulls unless otherwise stated.
REACTION PRODUCT FROM EPICHLOROHYDRIN
Kovernber, 1964
-40I
3253
. . . . , . . . -3.0 . I . . . l , . . . -an . I . . . . , . . . -I. 0! . . . .
I
...;
-
Pry
0[
bH+
100
2m
503
100
0
CPS
U - J
f
e
.
I , , , I . , , . . I , , , , I , ,, , , , I . , I I . . . . I . . . -.7 0 I . . . . I . . . -bO . I . . . I . . . .-5 I0 . . . . I . . . .- 1I0 . . . . I . .
-1.0
Fig. 1.-Proton -1a I ' " ' I
-sa
f
.
-10
~
-0
.
I
~ -70
~
.
.
d
I -bO
.
,
. , I . . . . I0
-1.4
-1 0
, ,
.-
UY
0 ??H
' " ~ l " ' '
~
u c
NH2
.
.
-++
Ibb
Lu
e
Fig. 2.-Proton
l
~
.
UULLU
b
~
CSH~(OH)B
ther inforll1ation on this point was forthconling fro111 $he n.1n.r. spectra of I and 11. N.m.r. Evidence.*-The spectrum of I (Fig. 1) was obtained in DzO because of the lack of solubility of this
-40
l
~
~
CPS
0 6CH3
a
.
0
.
~
~
~
I
.
- %a. n.m.r. spectrum of diacetate (11) in deuteriochloroform (60 Me.) -50
seen below, to be written for I. Since all of the hetero a t o m in I now were accounted for, I had to be a carbocycle, but whether this was a five-, six-, or sevenmembered ring remained unanswered. However, fur-
H
-10
503
LLUU
.
,
" l " ' " " " I " " ~ " " I " ' " " " I " ' " " " I " " ' " " I " ' " " " I " "
'
400
I
I
n.m.r. spectrum of dialcohol I in deuterium oxide (60 Mc.).
-Lo
-7n
.
, , . , , I , , , . , . I , , , , , , I . -.3 0I . . . . I . . . -1. 0I . . . . I . . ..- 1 1I . . . . I
-30
~
. -11)
~
l
.
. I .
I . . ,
,
0 PIY
substance in organic solvents. However the spectra of the diacetate proved the clearest and most useful and these were recorded in deuteriochloroforni (Fig. 2), in trifluoroacetic acidg (Fig. 3), and in acetone. I n ( 8 ) T h e n.m.r. spectra were obtained with a Varian Associates A-60 analytical spectrometer. T h e analyses are first order unless otherir ise noted. (9) T h e parameters assigned to the diacetate in trifluoroacetic acid solution are based on the stronger spectrum seen immediately after preparation of the solution.lo When trifluoroacetic acid is added to the deuteriochloroform solution of 11. the spectrum becomes blurred and shows a change toward t h a t in the acid. Tn-o separate species were not apparent. Thus it seems certain t h a t the trifluoroacetic acid solution a t first contains the same molecule as the deuteroichloroform solution and t h a t interconversion
b e ~ ~~c~~ ~ molecule.
:';
~
~
disrtppears n ~ ~ o w i n g~ to decomposition of the
I
,
,
.
JOHNSON AND HEESCHEN
3254
I
'
I
,
.
l
,
-IJ
,
.
,
I
l
,
I . . . .
-70
-&J
Fig. 3.-Proton
,
,
,
, . .. .
I , , I . . , .
,
, . .
,
.
-5 0
Proton
a b
I in DiOb
-2.65 -3.48' -3.62' -4.30 -6.10' -6.330 -4.67
TABLE I Chemical shift (shielding), p.p.m.' 7 Diacetate (II)---I n acetone I n CDCla I n CFsCOOH
-2 -3 -4 -5 -6 -6 -5
87 83C 13c 32 27c 33c 90
- 2 95 -3 22 -3 89' -4 6 -4 I5C C - 5 32 -6 03 d e -6 10' -7 00 -6 25' -7 50 f - 5 08 "(OH) 1 - 2 05 -2 32 CHICO ( - 2 08 - 2 34 Relative to internal TMS; accurate to f 0 . 0 2 p.p.m. * Internal reference is CH3 of (CH3)SiCH2CH2CH2S0JJa. Calculated as AB of ail ABX spectrum (J. A. Pople, W. G . Schneider, and H. J. Bernstein, '.High Resolution Nuclear Magnetic Resonance,'' McGraw-Hill Book Co., Inc., Kew York, Y . Y., 1959).
1
TABLE I1
-Proton coupling
I in D20
.
1.'. .
-4.0
.
i
.I.
, ' .
i
-10
, ' . . .
I.,
,
,
i , ,
.I.
, . .
-11)
,
,
[ . I .
-10
. ' / .
,
. .
I
.'.
I PPM
n.m.r. spectrum of diacetate (11) in trifluoroacetic acid (60 Mc.).
these spectra the individual protons are labeled a, b, c, d, e, and f and their cheniical shifts and nonzero coupling constants are listed in Tables I and 11.
--
l .
VOL. 29
Nonzero coupling constant, c . p . ~ . ~ Diacetate (11) I n acetone I n CDCls I n CFaCOOH
+8 lb 3-4 +6.4 +8.1b +5 9b 4-3 +6.0 +5.9b 3 5 9 J.d 3.8 3.05 J.f 0.5
