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Eli Kennerly Marshall.

On the reactions of diazoalkyls with urazoles and their salts .. online

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ON THE PXACTIOKS OF LIASOALI{YLE
VaTH URAZOLES AND THEIR SALTS.



DISSERTATION

Subiiiittea to the Board of University Studies of
the Johns Hopkins Uriiversit3'- in Gonforraity
with the Requirements for the
Dearee of Doctor of
Philosophy.



3Y
ELI I{EKi^lERLY ],IAR?HALL, JR.

Baitiiaore

1911.



CONTENTS .

A kn o w le dgn i e nt

Theoretical - - - - - -

Experiiuentdl ___-_ - - - «^

Proparauion of coiapounds used - - - -^

Alkylations of l-plienyl-2-n;ethylura:iole ^

with ciiazoEiethane - - - - ^

Alky lat ions of l-r.henyl-3-i;.ethylurazole
liberated froi-. its sodiimi salt by
alooholio hydrochloric acid, with
diazon-iethane - - - - 11

Alky lat ions of l-phenyl-3-r.ethylurazole
liberated fror. its sodiUTi salt "oy
alcohol, with aiazor.ethane - - - - 17

Alkx'lationa of l-phenyl-x;-i::ethylurazols
liberated from its zinc salt by
alcoholic hydrochloric acid, with



diazoiuethane ___ - -

Alkylatioiis of l-phenyl-2-r;.ethylurazole
liberated fron its silver salt by
alcoholic hydrochloric acia, with
aiaiioi ethane - - - -



diazoethane



18



19



Alky lat ions of l^phenyl-2-r-.3thylurazole ,
liberated fror. its double silver-
sodiura salt by alcoholic hydro-
chloric acid, with diazor.e thane - - 22

Alky lat ions of l-phenyl-2-r:.ethylurazole

with diazoethane - - - - 22

Alkylations of l-phenyl^:^r.,ethyliirazole ,
liberated fron its sodiun; salt by
alcoholic hydrochloric acid, with



23



Alkylations of phenylurazole with diazo-

methane - - - - - 34

Alkvlations of l-r^henyl-li-othylurazole ,
and l-phenyl-3-ethylurazole liber-
atea froj.: its sodi-um salt by alcohol-
ic hydrochloric aci.,.., with diazo-
£,'.ethane - - - - - 25



Alky lat ion of l-phenyl-S-thioliuethyl-
urazole, and 1- phenyl- 3-th io 1-
r-ethylura^ole liberateu. from its
sodiuci salt by alcoholic hydro-
chloric acid, with diazoi!:ethano - - 26

Alkylutions of l-phonyl-4-nethyl-

urazole with diaaoListhune _ _ _ - 27

Alky lat ions of l-phenyl-4-D:ethyl"urazole,
liberrited froL; its sodiur.: salt toy
alooholio hydrochloric acid, with
diaaoir.ethuiie ________ 28



Aiky lat i onB o f 1- phe ny 1- 4-r;!e t hy 1 uraii o le

v.ith cliaiioethane -___ - _ 29

Alkylations oT silver salt of 1-phenyl-

£-iiethyiu.rai:ole _______ 30

Alky lat ions of the sodixiir. salt of

1-phe nj l-2_]iie t hy lurazo le vi it h

L.ethyi nitrate - __-__- 52



Conciueions ______-_ - - 34

Biography ____________ 35



A oknov;le accent .

The author wishes to take this opportxmity
to express his gratitude to Presiaent Remsen, Professor
Horse, Professor Jones, Professor Ames, and Associate
Professor Aoree for the valuable instruction reoeiveci
in lecture room and laboratory.

This work '.vas undertaken at the suggestion of
Associate Professor Aoree and carried out under his
direction. The author is glad of this opportixnity to
thank hiii; for his constant encoura^enent and inspiration
throughout the v;ork.



ON Tin: REACTIONS OF DIAZOALPCYLS
TJ^ITE URAZOLES AKE TKEIR RALTF .

VariouB theories have been proposed to ac-
count for the phenorj.ena of tciuton.erisru. Ariorig these
shoulu te zi.entioned those of Gor-stock"^, V'heeler , Nef ,
and Miohael'*. One necessary- fact which all these
theories have attempted to explain is how t;vo or more
stable, isoi:.erio products can be obtained by the action
of a reagent on the tautoir.eric substance. The various
explanations given are ver:^ helpful and suggestive, al-
though not necessarily in their final state of usvelop-
liient if cor-sidered in the light of the large aruount of
quantitative data accumulated in this laboratory in con-
nection v;ith the tautomeric urazoles and their deriva-
tives. It appears that ir. all cases in which these
urazoles or their salts give two or s.ore stable, isor.eric
products as the result of a reaction, they do so because
they exist, (A) in one tautor..erij fori;, alone which yields
two or luore derivatives through inu-epencient side reactions ;
or (B) in two or iiiors foruiS in eciuilibriui"::, each of vrhich
gives its own dsrivative through an indepencient reaction.

The follo'.ving ".-ork was started v,'ith the idea of



1. Ber. d. chec Gtes . , 23, 2;:i74:j Amer. Che:.,. J., lo, 493 j

IZ 514 535 .

2. Aai.er. CHer... j!, 21,' 187; 23, 135; 30, 28.

3. Ann. Chen;., 231 , 52; 276 , SOG; 277 , oS, 83.

4. J. prakt. Cher;., 57, ¥69; 45, 580; 4S, 189;

/•ricr. Cheiu. J., 43, 322.

5. For iLatheLiutioal discussion of the theory in detail

see Acree, Ainer. Chen.. J . , 3S, 1.



Ui



dstem-ininr, if possible, whether such substances as
l-phen^^lurazole , l-phenyl-.2-r;:eth3'-luraiiole , l-phen^^l-
r3-etliylurai:ole, l-phen3'-l-d— r.eth3^1ura2:ole , and 1-phenyl-
5-thiorr:ethyl-5-ox3mrazole exist in only one fomi, or
are really mixtures of two or v.oxe tautoir.eric foiT.:s
whioli establish the equilibrivji: so v^uickiy ut oruiuary
temperature that this rapia change is net ohovm by the
reaotioi:is ox :..ethod3 used previous iy.

The faot''' that the sodiur:., potassium, ziixC,
cobalt, nickel, anu. i..aiiganese salts of the l-phen^ri-
4-i;nethylura5iole give, v.hen treated vvith alk^^l halides,
about the saL.e ratio of ?'I-ester:0-GSter, .yhils the
silver, lead, anu. :..croury salts give a hi{];her proportion
cf 0-GSter, very properly su::^eBt3 the question v:hether
(a) each salt e-xists in only one foni. which yields, when
trsatea 'vVith alkyl halides, the t-^^o esters by indepenoent
siae reactions, the velocity constants of v.-hich vary with
the salt and alkyl halia.e; ox (B) each Salt is really a
mi:-:ture of two or Kore forras, the equilibrivjii conditions
of -.vhich r.:.ay or i-ay net vary i/ith different salts, and
may or may not i..if fer fror.. those of the corresponding
acivuP; such differences would perhaps necessarily cause
the different rc.tiot" of esters actually obtainea.

The slcv: alk3^1c^tion reactions ana the con-
ductivity^ ::.ethcds used up to this tii-js sheu. no light on
this viuestion, as the differences in esjiilibri-uiii cor.di-
tions may be too small ana the change too rapiu to be



Bsr. d. chem. Ges., 41, 51S9; /.zer. Chei.' . J., 42, 571



(3)



E-.ecvSured. If, hov/ever, the c.cid be liber:ited fror:. its
sdlt and alkylate..^ at onoe; and the ratio of estero
obtained in this way be couipured with that obtained from
the acid ^lone, evictenoe should be obtained concerning
the probability of (A) or (B), provided a sufficiently
lev; teuperature and a preset ioally instantuneo-u3 alkyl-
atinr; a:jent be employe:.. Tho viiazoalkylc react very
rapidly with theee uraaole c^cids, and ^ive a iiixture of
N- and 0- esters which can be isolated and analyzed.
Nirdlin^er has shov.'n that l-phenyl-2-E;ethylurazole
yields a constant ratio of esters even ivhen varying
noleoular concentrations of diazoalk^'-l are used. Then
l-phenyl-^-Kethylurazole is liberated fror. its salts by
the action of alcohol or h3'-dro chloric acid in the pres-
ence of a diazoalkyl, hov:ev9r, a ratio of ?!-ester:0-ester
is obtained, vrhich is, in fact, different fror. that
forr.ied when the urazcle acid alor.e is alkylated under
the Bar.e conditions of ter.iperature and solvent. But if
this sarae liberated urasole acid is alloYired to stand
about 15 seconds, and is then treated ?;'ith diazoir.ethane^
the ratio of esters obt:^ined is the sar.e as that forr.ed
froia the acid alone ■'onder the sar.ie conditions. Chan.^e
of concentration of the ur:-.2ole acid or diazoalkyl does
not change the ratio apprecicibl3'-; the hydrochloric acid,
furtherraore , effects no change as is sho"m in the ex-
peTir.:ental portion. These facts, in connection v/ith
those already published , seer; to excluds the possibility

1. Eer. d. Cher;.. G«s . , 41, 5199.



(O



(A) tlic*t tlis uraiiole aci.^ ^nu. G:..lt have onl^^ one

tu-utoinerio f orr.. . ?he only other -.-iucstion to be con-

Bi^ereu in this ccnriOotion is whether both the ior^

:>ii^-.oii>, or sore oc:..pla:c salt^ Lay reuot .vith the

dic^^oius thane .

R IIK + CH;.lT.j > R i:CI~l5 + N^

_ +
n II + H + CH .i'lp — > H I'CI^z + Wo

E ICI-n + OH^II^ ¥ K 11011^+ 11;^ f S

7.e n.ust consiucr the poBtiibility that, at the very nioiuont
ox the liosriaticn of the nra^ole uoio. f roin the Sti.lt, the
few rr.olecules of auiv^ present may yield one ratio of
esters, ana the ions of the aoiu., ivhioh are in great
r;-.a;^ority, r_ay yielu. another ru-tio of esters; vrhile the
iorxS of the ura^ols aoia are joi-ibinir.^ to forr;; the un-
ionizeu. uraiiole ajij we should, therefore, obtain u
ohaxi^in^ Xc^tio of esters. It .vouii... Beeiii probable, ho'.v-
ever, that vvhen the hy'droohlorio aoiu is ad^eu to the
ura^ole salt, the ior.s of the ura-:.ole auid '.voulu. oo. .-
bine praotiualiy instantaneoiioly, ana hen oe ^^ive the
n.oleoular fcrii: whioh woulu vie la the 6a2;:e ratio of
esters vthioh we cbtainsa from the aois* alone. But n.y
experii:.ents uo not ij>iv6 absolute evidence on this point,
and until I can oonplete certain ?;ork nov/ planned we
must leccvs this poesibilit]'- open to '^puestion.

In general, ho^.evsr, all the eviosnce at hand
shovvs such ionic chanties to be practically instantaneous ,



1. Seit. f. Eleic, 14,



un^ -this coi.oepticn CA) £eei..i3 less likely tHan the
UU3S (B) '■.■hid'i I shdll nov; .disc-ass.

Althoush the ri^tio of isoi-.erio esters obtc^inSv.
by the t.otion of diaiiousthane does not repxeBent the
xcitio of the t;;o tautouers in the original aubstunoe,
the 3ca..e rcitio should oe obtdineu. f ror. the uoius or
scilts if the eLi..ilibxivuv v;ere the s^i..e in eaoh. The
dcia liberatea f roru the salt ana allcweu. to btan^^ ^ives
the saLS ratio IT-ester :0-ester as the aoia alone. Yaaen
the acici^liberatea and the diazoEethane adusa CiUioiiiy,
vje get w. rc.tio inten^eaiate bet.veen that obtained f roi;:
the aci^ liberateu f ror. the salt in the presenoe of the
dia^ioiae thane, an^ that cbtainsa fro^: the uraiiole aoiu
alone. YJe L.ust oonclaae, therefore, that the salts of
l-.phsnyl-3-r:iethylurai;ole have an equilibriuru constant
v/hioh ..infers fro:., that of the l^-.-hsnyl-S-ii-ethyrarazols

itself.

The l-phsnyl-'i-ii.ethylara2ole and diazoruethane
give about e^iual ai^oants of II- an.. 0-osters. Its salts
saeni to have the sai^e or very ne;.rly the Sc.i..e eciUilibriLa.
constar^ts as the free aoia. The tv;o tautoi-.Gric for^^ in
this case are c.uch ir.ore sensitive to changes in solvent^
or concentration and teinrjerature than the 1^3)henyl-
^nethylaraiiole . l-phenyl-S-ethyiurak:ole and 1-phenyl-
o-thioL'-sthyluraaole, Tvhen alkylated with diazonethans,
give ratios of rl-est6r:0-eater v/nioh are practically
the saiue us those obtuineu. when the acids are liberatea
froL. their souiuu salts in the presence of v.ia2or..ethane .



io)



All tlie suits of l^phenyl-;c;-i!:etliyluru^ole
invey-tioutevi (the eov-liui:, ziinc, ana silver) ^ive pxact-
ioclly the sacs ratio of :T-c3ter:0-ester v/hen trecxte^
with hyurochloric iioid in the presence of diazoi-iSthand .
ThiB shows the eiiuilibri-u:^ oo/-£t^i-.ts to be approxiu.ately
the Bui^ie for ull of these Salts, ^.s previously states.
The silver, leau on., nercjury salts, hov;ever, \vhen traatea
with Liethyl ioaiue ^ive a r^uch higher psroenta^^e of
O-ester thiinUhe other salts. Thess salts, hov/ever, are
onlv Glii^tly soluble in the aloohol-water ruixture useu.
It tiight be possible that this^^vjia^\ uue to the f^ot thut
in one case the salts are usea in hetero^enaou*^ iidxture,
while in the other in hoi^o£,6neous ri.i:d:ure . But I huve
novv foun^L that the silver salt t,ivcs appro:ii:^atsly the
BoJ..e ratio "-estsriO-ester v/hether sus-penosd or dissolved .
This n.ay be aue to the fact that the ions ana luols ^rc
concernsa in the reactions to different eictents for the
^f fersnt Salts, -*/« eviaence for v:hich/na5 been obtainea
by ITirdlinger, Ho^^ers, Robertson anu L^yself with other
coi^pounaf:^ .

If there are tv;o tautoiueric forr..s in eiiUilibriun



c a



R OH


1 3

Online LibraryEli Kennerly MarshallOn the reactions of diazoalkyls with urazoles and their salts .. → online text (page 1 of 3)