( a) 4-A .oetoxy-2,5-di-t-butyl-N -nitrosoaoetanilide (0*8346#, 2.50 mmoles) decomposed slov/ly in suspension in cyolohexane (lO*5g#, 0*125 mole) at 42°. A fter l6 hr. the red solution was b o iled under reflu x fo r 1 hr, and a sample was examined by g .l .o . (Table 6 , p. 177 ) with bibenzyl as in tern a l standard,
(b) From a sim ilar reaction of the nitrosamide (5 .8 6 6 ., 1 7 .5 mmoles) in cyolohexane (7 3 .5 6 ., 0.877 mole) there were obtained by d is tilla tio n ; ( i) a liq u id , b .p , 77-81°,
( i i ) an orange s o lid ( 0 ,8 l5 g .), b .p . 65-140° /0 ,05 mm., ( i i i ) a red so lid (0.764g#), b .p , 140-60°/0,05 mm., and
(iv ) a brown residue (2,83g.)# Preparative g . l . c . (7 f t , x
0,375 in , o.d, g la ss column containing 10% NPGS on o e lite at 205°) of fra ctio n ( i i i ) y ield ed samples of 2,5- d i- t - butylphenyl a ceta te, m.p, and mixed m.p, 51-2°; 2,5- d i - t -
butylphenol, m.p, and mixed m.p. 120-21°; and 2,5-di-t-b utyl*
hydroquinone d ia o eta te, m.p, and mixed m.p, 175-6°. The id e n titie s of these components were confirmed by th eir i . r .
TABES 6
Réactions o f A.-Aoetoxy-2.5-ai-t-Eutvl-N-nxtro3oaoetan.llide
Product Y ield (n/lOOm of nitrosamide) by g .l .o .
Reaction K*1 K^2(a) A cetic anhydride 70-90 50-70 2 ,5-Pi-t-butyl-£-benzoquinon0 5.8 2,4 2 ,5-D i-t-butylphenyl acetate 2.5 8,3 2 ,5-D i-t-butylphenol 5 .1 5 .9 2 ,5 -D i-t-butylhydr0quinone diaoetate 2.2 7.7 Biphenyl 2,7
2,5 -Di -t-b u ty lr e s ore in o l diaoetate jo,02ir/lOOm would have been detected in reaction K .l, 0 ,2 in reaction K,2(a) ] and £-di-t-butylbenzene (0,2) were absent.
Q uantitative measurements were made on 10% PBGA, 159 and 199°, and NPGS ca p illa ry , 190°, A cetic anhydride was measured approximately on 2% GAR, 45° vd.th o-bromotoluene as in tern a l standard. The i , r , spectra of the nitrosamide used in these experiments contained no absorption at
—1
L Réactions of p-A oetoxy-N -nitrosoaoetanilide 1, Decomposition in Benzene
£-A oetoxy-N -nitrosoacetanilide ( l.4 4 g ,, 6,495 mmoles) vras allowed to decompose in benzene (20.3s*> 0,260 mole) at 38° fo r l6 hr, and at the reflu x temperature for 1 hr, A
sample of the reaction mixture was examined by g ,l ,c ,
{0 0 NPGS, 172 and 202 ; 8% BDS, 227°) v/ith tran s-s t ilb e ne
as in tern al standard, and was found to contain 4-acetoxy- biphonyl (39,4n/l00m) and 4-hydroxybiphenyl ( 2 ,0 ). Hydro quinone monoacetate (0,ln/l00m vfould have been d etected ),
hydroquinone diaoetate (O.O7) , 3-aoetoxybiphenyl (0,07) and
£-aoetoxyaoetanilide (0,7) were absent, A further sample
v/as seen by g ,l,o , examination ( ^ NPGS, 106°; 8% BDS, 160°)
with naphthalene as in tern a l standard to contain phenyl acetate (2 ,ln /l0 0 m ), Phenol (0,3n/l00m would have been
d etected ), £-benzoquinone (0,2) and biphenyl (0.3) were
absent.
A niline (l,3 0 mmoles) was added to a portion (l,2 2 mmoles nitrosamide) of the reaction mixture, which was then stirred
at 40° fo r 30 ndn, G .l.o , examination (2% NPGS, 172°)
indicated th at acetan ilid e (67m/lOOm), absent from the
origin al reaction mixture, v/as nov/ present. The i . r . spectrum of the nitrosamide used in th is experiment did
M Reactions of Diphenyl ro-(N-nitrosoaoetamido)phenyllphosphine Oxide
1, Decomposition in Benzene
£-Acetamidophenyldiphenylphosphine oxide (5 .4 0 g ,, 15.1 mmoles) was n itrosated and the reaction mixture poured in to
iced water (15O m l,). The yellow o i l which separated vfas
extracted with benzene (25^10 m l,) and the extracts were
washed with water (40 m l.), 3% potassium hydrogen carbonate
solu tion (40 m l,), and water (40 m l,), and stirred with
magnesium sulphate fo r 45 min, and calcium sulphate fo r 45 m in,, the temperature being kept below 5 °. F iltr a tio n gave a solution of the impure nitrosamide (see Section V II)
in benzene (37 S* 9 0,48 m ole), which darkened slovfly. When
the reaction vfas complete, a portion (from 11,2 mmoles amide) of the reaction mixture was chromatographed repeatedly on s ilic a g e l, giving only o ils and ta r s. One such fra ctio n ,
c r y sta llise d from ether and from light-petroleum (b ,p , 6 0 -6 0 °)- benzene (4 :l) yielded o-acetamidophenyldiphenylphosphine oxide, m,p, 128-9° , mixed m.p, 1 2 7 .5 -8 °, The i . r , and n.m .r, spectra were in distingu ish able from those o f the authentic amide,
T .l .c , examination on s ilic a g el with ether-methanol (19:l) suggested that the amide was a major component of most of
the chromatography fr a c tio n s. Diphenyl(o-hydroxyphenyl)phosphine oxide and o-acetoxyphenyldiphenylphosphine oxide could not,
vfith certa in ty , be detected, A portion of the orig in a l
reaction mixture was b o iled with 10% sodium hydroxide solu tion and the aqueous phase separated, washed with benzene and
ether, a c id ifie d , and extracted with chloroform. The ex tra ct, on evaporation, gave a red tar which could not be cry sta llised * T .l.c # examination revealed three p rin cip al components, one
of which had the same value as diphenyl ( o-hydroxyphenyl)-
phosphine oxide.
2, Reaction with Anthracene in Benzene
Anthracene (4 ,2 6 g ,, 24.0 mmoles) was added to a dry benzene so lu tio n (47 m l.) of the product from the n itro sa tio n
of £-acetamidophenyldiphenylphosphine oxide (4#01g,, 12.0 mmoles), and the mixture stirred at 45° fo r 12 hr# and b o iled . Part (from 11.6 mmoles amide) of the reaction mixture was chromatographed on s ilic a g el (2 9 0 g ,). Anthracene (3 .0 7 s.) was removed in benzene, and the column was then eluted with ether containing an increasing proportion o f methanol (0-100%), y ield in g
52x 200 ml, fra ctio n s which were examined by t . l . c . on s ilic a g e l with ether-methanol ( l 9 : l ) . Fractions 1-13 contained tvfo fluorescent components (R^ 0.55 and 0 .6 8 );
fraction s 14-45 contained the slower-moving of th ese, and
also a substance with the same R^ value as £-aoetamido- phenyldiphenylphosphine oxide. Later fraction s were very complex. Fractions 14-23 formed a yellow tar (0,698g.)
which was b o iled with ether to give a powder (O .iy S g .),
C ry sta llisa tio n from oarbon tetrachloride afforded strongly fluorescen t pale yellow needles (0 .1 2 4 g .), m.p. 228-9°*
(Found; 0,83.2; P ,7 .6 ; residuo, 1.15^. A54-).