Synthesis of new plant growth regulators, isomeric 1-(dimethyloctyl)- and 1-alkylpiperidinium and -morpholinium halides by telomerization of isoprene with secondary amines

Article abstract of DOI:10.1023/B:RUGC.0000016041.29564.e9

The known plant growth regulator, Al'den [1-(3,7-dimethyloctyl)-1- allylpiperidinium bromide], and also 1-(3,7-dimethyloctyl)-1-methylpiperidinium iodide were synthesized by treatment with allyl bromide and methyl iodide, respectively, of exhaustively hydrogenated 1-nerylpiperidine which was obtained by anionic telomerization of isoprene with piperidine. Various quaternary ammonium salts having a terpene substituent with unnatural dimethyloctane skeleton, which effectively stimulate florification of Aster Chinensis L., were prepared by the action of alkyl halides on telomerization products derived from isoprene and piperidine or morpholine in the presence of palladium complexes.

Full text of DOI:10.1023/B:RUGC.0000016041.29564.e9

Russian Journal of General Chemistry, Vol. 73, No. 10, 2003, pp. 1653 1657. Translated from Zhurnal Obshchei Khimii, Vol. 73, No. 10, 2003,
pp. 1747 1752.
Original Russian Text Copyright
2003 by Petrushkina, Zakharkin.
Synthesis of New Plant Growth Regulators, Isomeric
-(Dimethyloctyl)- and 1-Alkylpiperidinium and -morpholinium
1
Halides by Telomerization of Isoprene with Secondary Amines
E. A. Petrushkina and L. I. Zakharkin
Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow, Russia
Received March 12, 2002
Abstract The known plant growth regulator, Al’den [1-(3,7-dimethyloctyl)-1-allylpiperidinium bromide],
and also 1-(3,7-dimethyloctyl)-1-methylpiperidinium iodide were synthesized by treatment with allyl bromide
and methyl iodide, respectively, of exhaustively hydrogenated 1-nerylpiperidine which was obtained by
anionic telomerization of isoprene with piperidine. Various quaternary ammonium salts having a terpene sub-
stituent with unnatural dimethyloctane skeleton, which effectively stimulate florification of Aster Chinensis L.,
were prepared by the action of alkyl halides on telomerization products derived from isoprene and piperidine
or morpholine in the presence of palladium complexes.
Search for new synthetic growth regulators attracts
persistent interest arising from the plant productivity
regulation problem. Plant growth regulators induce
changes in metabolism, which depend on the nature
of both regulator and plant species. Several decades
ago, effective plant growth regulators were found
among quaternary ammonium ssalts; examples are
chlorocholine chloride (I), 1,1-dimethylpiperidinium
chloride (II), and 1,1-dimethylmorpholinium chloride
chloride] in tests on rice and cucumber acrospires [9].
N-Allyl-N-(6,6-dimethylbicyclo[3.1.1]hept-2-en-2-yl)-
methylpiperidinium bromide and other ammonium
salts on the basis of - and -pinenes showed a better
activity than salt I in biological tests on watercress,
tomato, wheat, and barley acrospires [10].
+
N
R1X
R2
(III). Compounds I III were shown to be active
IV
retardants. Their effect was explained by both inhibi-
tion of phytohormone biosynthesis and influence on
enzymes responsible for nitrogen metabolism. The
latter process determines mainly vital activity and
fertility of plants [1]. A considerable number of pub-
lications are concerned with the effect of salts I III
on biosynthesis of various terpenoids, such as gib-
berellins, abscisic acid [2 5], carotinoids, polyiso-
prenoids [6,7], as well as on enzymatic systems
involved in early biosynthesis of terpenoids [8]. Also,
the influence of salts I III on biosynthesis of such
nonterpenoid phytohormones as auxins, cytokinins,
and ethylene was studied. Quite efficient retardants
were found among quaternary ammonium salts con-
taining terpenoid substituents. For example, N,N,N,1-
tetramethyl-3-(2,6,6-trimethyl-2-cyclohexenyl)-2-
propenylammonium iodide derived from -ionone, is
superior in the retardant effect to the known plant
growth regulator AMO-1618 [5-isopropyl-2-methyl-4-
1
2
1
2
R = O, R = All, X = Br (a); R = CH , R = All, X =
2
1
2
1
2
Br (b); R = CH , R = All, X = Cl (c); R = CH , R =
Pr, X = I (d); R = CH , R = Et, X = Br (e).
2
2
1
2
2
Quaternary ammonium salts IV containing a tetra-
hydroneryl group were found to be effective plant
growth regulators [11, 12]. Compound IVb (which
was named Al’den) showed the strongest retardant
effect on Chrysanthemum morifolium species [12]: It
retards florification but has no effect on the develop-
ment of flowers and buds [12, 13]. No retardant effect
was observed in tests with Brassica napus and Ficus
elastica. Although the retardant effect of Al’den (IVb)
in Spirodela oligorrhiza was greater by a factor of 5
than that of compound I, the former (in contrast to I)
did not inhibit biosynthesis chlorophyll even at high
concentrations [14]. The mechanism of action of IVb
was interpreted in terms of its influence on biosyn-
thesis of gibberellins or their bioreceptors.
(
piperidinocarbonyloxy)phenyl(trimethyl)ammonium
The excellent growth-regulating parameters of
Al’den in combination with the absence of damaging
Deceased.
1
070-3632/03/7310-1653$25.00 2003 MAIK Nauka/Interperiodica

1654
PETRUSHKINA, ZAKHARKIN
Table 1. Anionic telomerization of isoprene with piperidine in the presence of lithium catalysts
Isoprene, Piperidine,
Catalyst,
mol/ml (g)
Molar ratio
isoprene amine catalyst
Solvent,
ml
Temperature, Yield of VI,
mol
mol
C (time, h)
%
0
0
.6
.6
0.2
BuLi, 0.0228/20 ml
of 1.14 N benzene
solution
BuLi, 0.0227/20 ml
of 1.36 N benzene
solution
BuLi, 0.0114/10 ml
of 1.14 N benzene
solution
26.3: 8.7: 1
22.2: 7.4: 1
13.2: 4.4: 1
C H , 80
65 (7)
41
6
6
0.2
C H , 60
72 (7)
65 (7)
44
78
6
6
0
.15
0.05
C H , 50
6 6
0
0
.3
.3
0.1
0.1
Metallic Li,
20.8: 6.9: 1
13.9: 4.6: 1
Toluene, 40
C H , 40
70 (4)
23
27
0
.0144/0.1
LiC , 0.0216/1.69 g
20 (48)
6
6
6
LiC6,
0
.15 g of Li
effects prompted us to synthesize this compound and
its analogs by a considerably simpler procedure
Scheme 1.
[
Li]
(starting from isoprene) and examine their effect on
+
HN
the morphogenesis of Aster Chinensis L. species.
The latter were selected as subjects for biological
testing taking into account their neutral photoperiodic
and vernalization responsiveness, which ensures
a relatively stable level of endogenous gibberellin
during florification. The results of biological tests
were reported in [15].
N
VI
H /Raney Ni
2
N
1
00 atm, 60 C
VII
Prior to our studies, Al’den was usually prepared
on the basis of geraniol which was brominated to
geranyl bromide. The latter was treated with piperi-
dine to obtain 1-geranylpiperidine (V). Compound V
was hydrogenated over palladium (under hetero-
geneous conditions), and the subsequent treatment
with allyl bromide afforded salt IVb [11]. It is known
that practical application of terpene derivatives is
limited by high expenses in their large-scale manu-
facture. For example, initial geraniol is either isolated
from rose oil or synthesized via a complex multistep
procedure. We have synthesized Al’den in three steps
from isoprene which is a large-scale petrochemical
product (Scheme 1).
+
RX
N
Br
2
0 C
R
IVb, IVf
IV, R = CH CH CH , X = Br (b), R = CH , X = I (f).
2
2
3
effect of the reactant-to-catalyst ratio was examined.
In the presence of butyllithium, by reducing the above
ratio we succeeded in obtaining amine VI in quantita-
tive yield. The data in Table 1 show that BuLi is the
most efficient catalyst for anionic telomerization of
isoprene with piperidine, as compared to metallic
A number of publications deal with the synthesis
of N,N-diethylnerylamine by anionic telomerization
lithium and LiC . Exhaustive hydrogenation of amine
6
VI over Raney nickel under a hydrogen pressure of
100 atm at 60 C smoothly afforded 95 96% of tetra-
hydronerylpiperidine (VII). Treatment of the latter
with allyl bromide at 20 C gave Al’den (IVb) in 97%
yield, while the reaction with methyl iodide leads to
compound IVf (94%). Amine VII was also syn-
thesized by hydrogenation of -geranylpiperidine,
which was formed by telomerization of isoprene with
of isoprene with Et NH. The most efficient procedure
2
was described in [16]. However, the synthesis of
N-nerylpiperidine in a low yield was reported only in
17]. We have obtained N-nerylpiperidine in 23 78%
yield (Table 1) using butyllithium, metallic lithium,
[
and a layered lithium graphite compound LiC as
6
anionic telomerization catalysts (see also [18]). The
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 73 No. 10 2003

SYNTHESIS OF NEW PLANT GROWTH REGULATORS
1655
piperidine in the presence of palladium complexes
with a selectivity of 40% [19] and was isolated by
rectification.
terpenoids). Among a variety of mixtures of isomeric
N-(dimethyloctadienyl)piperidines described in
[19, 20], for the preparation of Al’den analogs we
selected those containing in total 50% of isomers
and and 50% of isomers and . We planned to
examine whether Al’den analogs XIa XIf having
unnatural - and -carbon skeletons will exhibit
a damaging effect on plants. Isomeric N-(dimethyl-
2,7-octadienyl)piperidines (VIIIa) for the synthesis of
salt IXa were obtained by telomerization of isoprene
with piperidine according to the procedure described
in [19], namely in acetonitrile at 100 C in the pres-
ence of the catalytic system Pd(acac) (EtO) P. For
Anionic telomerization of isoprene with amines
involves toxic and hazardous metallic lithium or
butyllithium. Work with these reagents requires
a specific explosion-proof equipment. Unlike anionic
the telomerization catalyzed by alkali metals and their
derivatives, telomerization of isoprene with amines
in the presence of metal complexes is a much less
expensive process. We previously [19, 20] described
telomerization of isoprene with piperidine, catalyzed
by palladium complexes, which leads to formation of
a mixture of terpene derivatives with all possible
combinations of isoprene units: tail-to-head ( ), tail-
to-tail ( ), head-to-head ( ), and head-to-tail ( ).
2
3
the synthesis of salts XIa XIf, the telomerization
process was performed according to [20]: in ethanol
at 30 C in the presence of the catalytic system
Pd(OAc) Ph P. Isomeric N-(dimethyl-2,7-octadi-
2
3
Isomers
and are monoterpenoids whose carbon
enyl)morpholines (VIIIb) were prepared from
isoprene and morpholine in acetonitrile at 100 C in
the presence of Pd(acac) (EtO) P. Salts IXa and IXb
were synthesized by treatment of VIIIa and VIIIb
with methyl iodide (Scheme 2). Hydrogenation of
skeleton is the same as in a number of naturally
occurring compounds. On the other hand, only a few
natural terpenes have carbon skeleton like or (such
compounds will further be referred to as unnatural
2
3
Scheme 2.
R1
+
HN
a
N
N
N
R1
R1
R1
N
R1
VIIIa, VIIIb
b
c
N
R1
+
N
R1
R2
1
IXa, IXb
2
+
N
N
R1
R1
R2
Xa, Xb
XIa XIg
1
1
2
1
2
VIII, X, R = CH (a), O (b); IX, R = CH , R = CH , X = I, : : : = 6: 76: 4: 14 (a), R = O, R = CH , : : : =
2
2
3
3
1
2
1
2
1
0: 74: 4: 14 (b); XI, R = CH , R = CH CH CH , X = Br, : : : = 43: 27: 5: 25 (a); R = CH , R = CH , X = I,
2 2 2 2 3
1
2
1
2
:
:
:
: : = 43: 27: 5: 25 (b); R = CH , R = C H , X = I, : : : = 43: 27: 5: 25 (c); R = CH , R = C H , X = I,
2 2 5 2 3 7
: : = 43: 27: 5: 25 (d); R = CH , R = C H , X = Br, : : : = 43: 27: 5: 25 (e); R = CH , R = C H , X = Cl,
: : = 43: 27: 5: 25 (f); R = O, R = CH , X = I, : : : = 10: 74: 4: 14 (g). a: Pd(OAc) Ph P, EtOH, 30 C or
1
2
1
2
2
3
7
2
3 7
1
2
3
2
3
2
Pd(acac) P(OEt) , MeCN, 100 C, 91 96%; b: (1) H /Raney nickel, EtOH, 100 atm, 60 C, 90 95%; (2) R X, C H ,
2
3
2
6 6
2
20 C, 65 88%; c : R X, C H , 20 C, 86 91%.
6 6
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 73 No. 10 2003

1656
PETRUSHKINA, ZAKHARKIN
Table 2. Yields, melting points, and elemental analyses of compounds IVf, IXa, IXb, and XIa XIg
Found, %
Calculated, %
Comp.
no.
Yield, %
mp,
C
Formula
C
H
N
Hlg
C
H
N
Hlg
IVf
IXa
IXb
XIa
XIb
XIc
XId
XIe
XIf
XIg
94
84
86
94
92
96
93
91
89
92
142
103 106
52.10
52.96
49.21
8.93
8.40
7.45
34.70 C H IN
52.31
52.89
49.32
9.32
8.32
7.72
34.54
34.92
1
6 34
34.68 C H IN
16 30
110 111
C H INO
15 28
a
62.30 10.05
C H BrN
62.41 10.47
1
8 36
132 133
108 111
51.93
53.60
54.38
58.56 10.57
67.08 12.10
9.23
9.21
9.60
C H IN
52.31
53.53
54.67
59.00 11.00
67.13 12.52
9.32
9.51
9.68
1
6 34
3.47
3.43
C H IN
3.67
3.54
1
7 36
83 84
32.31 C H IN
32.09
34.35
1
8 38
a
C H BrN H O
1
8
38
2
a
C H ClN H O
1
8
38
2
176 177
49.27
8.44
34.10 C H INO
48.78
8.73
1
5 32
a
Viscous or oily substance.
isomer mixtures VIIIa and VIIIb over Raney nickel
under the conditions described above for hydrogena-
tion of amine VI, followed by quaternization of the
resulting N-(dimethyloctyl)piperidines and -morpho-
lines Xa and Xb with alkyl halides, afforded ammo-
nium salts XIa XIe and XIg (Scheme 2; cf. [21]).
The reaction of amine Xa with propyl chloride gave
compound XIf in a poor yield (10 15%); therefore,
the latter was prepared by the action of AgCl on com-
pound XId.
on the biosynthesis of endogenous phytohirmones of
the terpene origin, as compared to the corresponding
tetrahydroneryl derivatives.
EXPERIMENTAL
Monomers containing no less than 99% of the main
substance were used. Isoprene, piperidine, and mor-
pholine were distilled over KOH prior to use; aceto-
nitrile was distilled over P O ; benzene was dried and
2
5
purified; alkyl halides were distilled over CaCl ; and
2
Biological testing [15] of the prepared compounds
showed that they effectively stimulate florification and
budding of Aster Chinensis L. species with no distinct
retardant effect. The most efficient were compounds
XIb and XIe which turned out to be superior to IVb
and IVf having a natural tetrahydroneryl group. Mor-
pholine derivatives, as well as salts IXa and IXb with
unsaturated substituents did not stimulate florification
of Aster Chinensis L.. It is known that treatment with
gibberellins induces efflorescence of some plant
species in the juvenile period, as well as under non-
inductive conditions, and that abscisic acid eliminates
this effect. Therefore, a balance between endogenous
gibberellins and abscisic acid plays an important role
in plant florification. The lack of retardant effect and
stimulation of florification of Aster Chinensis L. (the
latter process should not be influenced by variation of
gibberellin concentration) suggest reduction of
the concentration of endogenous abscisic acid by the
action of Al’den and its analogs, though increase in
the concentration of endogenous gibberellins cannot
be ruled out completely. Thus, the real mechanism of
action of the above compounds requires for further
study. Here, it should be noted that Al’den analogs
with unnatural terpene skeleton exert a stronger effect
lithium graphite compound LiC was prepared by
6
the procedure described in [22]. GLC analysis was
performed on an LKhM-8MD(3) chromatograph
equipped with a 50-m steel capillary column;
stationary phase PEG-20000.
Anionic telomerization of isoprene with piperi-
dine (general procedure). N-(3,7-Dimethyl-2,6-octa-
dienyl)piperidine (VI). To a solution of piperidine
in dry benzene or toluene (Table 1) we added under
argon metallic lithium (cut in small pieces), lithium
graphite compound LiC , or a solution of butyl-
6
lithium, and the mixture was stirred for 2 h at 20 C
(
or until dissolution of metallic lithium). A required
amount of isoprene was added, and the mixture was
heated as indicated in Table 1. After cooling, the
mixture was poured into 50 ml of water (in the reac-
tion with LiC , the mixture was filtered first), and
6
the organic phase was separated and dried over
Na SO . Distillation gave compound VI with bp 114
2
4
20
1
15 C (4 mm), nD = 1.4858 (cf. [17]).
Telomerization of isoprene with morpholine in
the presence of Pd(acac) (EtO) P. N-(Dimethyl-
2
3
2,7-octadienyl)morpholine (VIIIb). To a solution of
0.5 mmol of Pd(acac) and 2 mmol of (EtO) P in
2
3
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 73 No. 10 2003

SYNTHESIS OF NEW PLANT GROWTH REGULATORS
1657
2
5 ml of anhydrous acetonitrile we added under argon
00 mmol of isoprene and 100 mmol of morpholine.
2. Prusakova, L.D. and Chizhova, S.I., Khimicheskaya
regulyatsiya protsessov zhiznedeyatel’nosti rastenii
(Chemical Regulation of Vital Activity of Plants),
Yaroslavl: Yarosl. Gos. Univ., 1985, p. 60.
3. Kur’yata, V.G., Berestetskii, V.A., and Negrets-
kii, V.A., Fiziol. Biokhim. Kul’t. Rast., 1991, vol. 23,
no. 6, p. 563.
2
The solution was heated for 28 h at 100 C in a high-
pressure reactor, the solvent was removed under
reduced pressure (10 mm), and the residue was dis-
tilled, a fraction with bp 113 116 C (1 mm) being
collected (cf. [23]). Yield 19.5 g (87%). According
to the GLC data, the isomer ratio in VIIIb : : :
was 10:74:4:14.
4
. Kur’yata, V.G., Dabizhuk, T.M., Remenyuk, G.L.,
Berestetskii, V.A., and Negretskii, V.A., Fiziol.
Biokhim. Kul’t. Rast., 1995, vol. 27, nos. 5 6, p. 374.
. Zayed, E.A., El-Zawily, A.I., and Ibrahim, S.A.,
Angew. Botanic, 1985, vol. 59, p. 199.
. Muromtsev, G.S., Pavlova, Z.N., Krasnopol’-
skaya, L.M., and Nagubnova, L.I., Izv. Akad. Nauk
SSSR, Ser. Biol., 1989, no. 1, p. 116.
N-(Dimethyloctyl)piperidines and -morpholines
VII, Xa, and Xb (general procedure). Compound VI,
VIIIa, or VIIIb, 68 mmol, in 50 ml of heptane was
hydrogenated in a high-pressure reactor over 2 g of
Raney nickel for 12 h at 60 C and a hydrogen pres-
sure of 100 atm. The catalyst was filtered off, the
solvent was distilled off from the filtrate, and the
residu was distilled under reduced pressure to isolate
5
6
7
8
. Muromtsev, G.S., Krasnopol’skaya, L.M., and
Nagubnova, L.I., Dokl. Ross. Akad. Nauk, 1994,
vol. 335, no. 3, p. 385.
. Foerster, W. and Becker, H., Z. Naturforsch., Teil C,
1987, vol. 42, nos. 1 2, p. 33.
1
(
4.7 g (96%) of compound VII with bp 102 103 C
1 mm), n2 = 1.4635. Found, %: C 79.85, H 13.92;
0
D
N 6.14. C H N. Calculated, %: C 79.92; H 13.86;
1
5
31
9. Haruta, H., Yagi, H., Iwata, T., and Tamura, S.,
Agric. Biol. Chem., 1974, vol. 38, no. 1, p. 141.
0. Reinbol’d, A.M., Morar’, G.V., Pasechnik, G.S.,
and Popa, D.P., Khim. Prirodn. Soedin., 1990, no. 3,
p. 338.
N 6.21. Compound Xa: yield 13.8 g (90%), bp 105
11 C (3 mm) (cf. [20]); compound Xb: yield 14.05 g
91%), bp 101 102 C (1 mm). Found, %: C 73.67;
H 12.84. C H NO. Calculated, %: C 73.94; H 12.85.
1
(
1
1
4
29
N-(Dimethyl-2,7-octadienyl)-N-methylpiperidi-
nium and N-(dimethyl-2,7-octadienyl)-N-methyl-
morpholinium iodides IXa and IXb and N-(di-
methyloctyl)-N-alkylpiperidinium and N-(dimethyl-
octyl)-N-alkylmorpholinium halides IVb, IVf,
XIa XIe, and XIg (general procedure). Alkyl halide,
11. FRG Patent no. 2459129, 1975; Chem. Abstr., 1975,
vol. 83, no. 114228z.
1
1
2. Hueppi, G.F., Bocion, P.F., and De Silva, W.H.,
Experientia, 1976, vol. 32, no. 1, p. 37.
3. Menhenett, R., Ann. Bot., 1979, vol. 43, no. 3,
p. 305.
1
1
4. Knypl, J.S., Experientia, 1977, vol. 33, no. 6, p. 725.
5. Zakharkin, L.I., Petrushkina, E.A., Aksenova, N.P.,
Konstantinova, T.N., and Bavrina, T.V., Dokl. Ross.
Akad. Nauk, 2001, vol. 379, no. 3, p. 402.
6. Takabe, K., Yamada, T., Katagiri, T., and Tanaka, J.,
Org. Synth., 1989, vol. 67, p. 48.
7. Takabe, K., Katagiri, T., and Tanaka, J., Bull. Chem.
Soc. Jpn., 1973, vol. 46, p. 222.
8. Zakharkin, L.I., Guseva, V.V., and Petrushkina, E.A.,
USSR Inventor’s Certificate no. 1027161, 1982;
Byull. Izobret., 1983, no. 25, p. 87.
3
9 mmol, was added to 31 mmol of compound VII,
VIIIa, VIIIb, Xa, or Xb in 25 ml of dry benzene.
The mixture was stirred for 3 days, and the precipitate
was filtered off and washed with two portions of
hexane. If a viscous crystalline material was formed,
the solvent was separated by decanting, and the
residue was washed with two portions of hexane, each
time the washings being separated by decanting. After
drying under reduced pressure (1 mm), salts IVb, IVf,
XIa XIe, and XIg were obtained (Table 2).
1
1
1
N-(Dimethyloctyl)-N-propylpiperidinium
chloride (XIf). To a solution of 0.25 mmol of salt
XId in 7 ml of ethanol we added 0.75 mmol of
freshly prepared AgCl. The mixture was stirred for
1
9. Petrushkina, E.A. and Bregadze, V.I., Metalloorg.
Khim., 1992, vol. 5, no. 5, p. 1161.
20. Zakharkin, L.I., Petrushkina, E.A., and Podvisots-
kaya, L.S., Izv. Akad. Nauk SSSR, Ser. Khim., 1983,
no. 4, p. 886.
3
days, and X-ray diffraction analysis of a sample
withdrawn from the solution showed the absence of
iodine. The precipitate of silver salt was filtered off,
the filtrate was evaporated at 20 C, and the residue
was dried under a residual pressure of 1 mm (Table 2).
21. Zakharkin,
L.I.,
Petrushkina,
E.A.,
Chaila-
khyan, M.Kh., Aksenova, N.P., Konstantinova, T.N.,
and Bavrina, T.V., USSR Inventor’s Certificate
no. 1415709, 1984; Byull. Izobret., 2000, no. 8.
2
2. Postnikov, V.A., Kakuliya, Ts.V., Khananashvi-
li, L.M., Isaev, Yu.V., and Novikov, Yu.N., Izv.
Akad. Nauk SSSR, Ser. Khim., 1979, no. 3, p. 671.
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RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 73 No. 10 2003