H O M O L Y T I C A L K Y L A T I O N OF S U C C I N I C A N H Y D R I D E
W I T H 1-A L K E N E S
Y u . N. O g t b i n , M . N. E l i n s o n ,
and G. I. N i k i s h i n
UDC 541.124:66.095.253:547.461.4-312
Free radicals initiate the addition of alkanoic acids [1], esters [2], nitriles [3], acetic anhydride [4], and
other carbofunctional compounds to 1-alkenes, which ties at the base of efftcie-t methods for the homotytic
alkylatton of t h e s e compounds [5]. The reaction of C8-Ct8 1-atkenes (1-octene and do-, t e t r a - , hexa-, and 1-
octadecene) with succinic anhydride was studied in the present paper, tert-Butyt peroxide was used as the
initiator. The study problem was to create a one-step method for the preparation of the higher n-alkylsuc-
cinic anhydrides. The known syntheses usually include at least three to four stepe [6, 7].
The reaction was run at 140-145°C in the presence of chlorobenzene, which was used to homogenize the
reaction mixture and also to prevent the sublimation of the succinic anhydride. The main reaction products
with all of the investigated oleflns were the corresponding n-alkylsuccinic anhydrides (I).
Ctlt--C0
RCHtCHtCH--CO
]
0 PTB
"- - - /
RCH=CH,+[
"o (1)
CHt--CO
CHt--CO /
The structure and compoeitton of the (I) adducts were confirmed by the IR and NMR spectra, the elemental
analysis data, determination of the anhydride equivalent," and also by the melting points of the adducts, which
proved to be identical with the known melting points of the corresponding compounds (Table 1).
The yield of the alkylsuccinic anhydrides is quite dependent on the ratio of the reactat~m, the amount of
employed chlorobenzene, and the scale of the experiment. Thus, a decrease in the succinic anhydride- ole-
fin ratio from 10 to 5, with the other conditions kept constant, causes the yield of dodecylsuccinic anhydride
to decrease from 60 to 44~ (see Table 1, Expts. 3 and 7), and that of octadecylsuectnic anhydride to decrease
from 48 to 32% (Expts. 11 and 12). The optimum amount of ehtorobenzene is 20-40 ml per mole of succinic
anhydride. A decrease inthe yield, caused by a deficiency of chlorobenzene (<20 ml/mote, Expts. 4, 5, 10,
11), is due to the fact that the homogeneity of the reaction medium is destroyed because of the poor mutual
solubility of the oteflns and succinic anhydride. When the amount of employed chlorobenzene exceeds 40 ml/
mote it noticeably inhibits the reaction, probably because it acts as a trap for the radicals.
The yield of the addltlonproducts Increases with increase in the scale of reaction. Thus, with a 10-fold
increase i n t h e amount of reactants the yield of dodecylsuccinic anhydride increases by more than 20% (cf.
Expts. 2 and 4). The molecular weight ofthe 1-alkene has hardly any effect on the course of the alkylation
of succinic anhydride.
Under the optimum conditions the n-alkylsucctnlc anhydrides are formed in 60-75% yield (Expts. 1-3,
9), and here the oleflns react completely. The telomeric anhydrides are always formed along with the addi-
tion products. The amount of the f o r m e r is given in the "Residue" column in Table 1. T h e i r structure and
composition was not studied. The selective extraction method, which is based on the different solubility of
succlnic anhydride, the n-atkylsuccinic anhydrides, and the telomeric anhydrides in chlorobenzene and petro-
leum ether, was used to isolate the atkylsucctnic anhydrides and purify them (Table 2).
In contrast to succinic anhydride, glutaric anhydride does not react with the oleflns under analogous
conditions. This difference in the behavior of the two compounds is apparently the consequence of the great
N. D. Zelinskii Institute of Organic Chemistry, Academy of Sciences of the USSR, Moscow. Translated
from Izvestiya Akademii Nauk SSSR, Seriya Khlmicheskaya, No. 10, pp. 2389-2392, October, 1976. Original
article submitted May 4, 1976.
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