Classical benzotriazole-mediated α-aminoalkylations of alkynes: Synthesis and characterization of alk-2-yn-1-amines as amphiphilic materials

Article abstract of DOI:10.1002/hlca.200790173

Reactions of readily available and stable benzotriazolemethanamines 1a-1, obtained from aldehydes and secondary amines (Scheme 2), gave the expected alk-2-yn-1-amines 3a-t (Scheme 3). The amphiphilic character of the synthesized products was responsible f

Full text of DOI:10.1002/hlca.200790173

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Classical Benzotriazole-Mediated a-Aminoalkylations of Alkynes:
Synthesis and Characterization of Alk-2-yn-1-amines as Amphiphilic
Materials
by Krzysztof R. Idzika), Joanna Cabaja), Jadwiga Sołoducho*a), and Ashraf A. A. Abdel-Fattahb)
a) Wroclaw University of Technology, Department of Chemistry, Faculty of Medicinal Chemistry and
Microbiology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland
(e-mail: jadwiga.soloducho@pwr.wroc.pl)
b) Department of Chemistry, Faculty of Science, Benha University, Benha, Egypt
Reactions of readily available and stable benzotriazolemethanamines 1a – l, obtained from
aldehydes and secondary amines (Scheme 2), gave the expected alk-2-yn-1-amines 3a – t (Scheme 3).
The amphiphilic character of the synthesized products was responsible for physicochemical measure-
ments. Specific aggregation properties of the obtained compounds make them useful as electroactive
materials in the Langmuir– Blodgett technique.
Introduction. – The formation of CꢀC bonds is of fundamental importance in
organic chemistry. The Mannich reaction is a prominent method for forming CꢀC
bonds and provides a key step for the synthesis of numerous N-containing
pharmaceuticals, natural products, polymers, dyes, and cross-linking agents [1 – 5].
However, the classical Mannich reaction is confined to aminomethylation and is
frequently accompanied by deamination [6]. On the other hand, the use of preformed
iminium salts has some basic advantages, e.g., the reactions require milder conditions
and allow the aminoalkylation of structurally diverse nucleophiles [7][8]. As the
intermediates are frequently thermally unstable and hygroscopic and often undergo
deprotonation with basic nucleophiles in preference to normal addition [1], novel
advantageous aminoalkylating reagents are still highly desirable.
Benzotriazolemethanamines 1 have a high potential in organic synthesis [9][10].
The methine C-atom in 1 possesses a high degree of electrophilicity due to the existence
of the equilibrium of both isomers 1 and 1’ with the iminium benzotriazolide ion pair 2
[11] (Scheme 1). Studies from Katritzkyꢀs group have successfully applied this concept
in their reactions with suitable reagents to provide an easy access to secondary and
tertiary amines [12 – 14].
The high synthetic potential of alkanamine derivatives is connected also with many
electronic applications like photon funnels or energy-transfer controllers [15], the
concentration of conducting units being essential as well as the knowledge of the
Langmuir – Blodgett film architecture. We undertookthe study of the formation of
single and two-component Langmuir and Langmuir – Blodgett films of synthesized
heterocyclic molecules. Particular attention was paid to the films containing alkylhe-
teroaromatic compounds mixed with docosanoic acid (DA), tricos-22-enoic acid (TA),
ꢁ 2007 Verlag Helvetica Chimica Acta AG, Zürich

Helvetica Chimica Acta – Vol. 90 (2007)
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Scheme 1
11-mercaptoundecanoic acid (MUA), and gramicidine A (GrA) which are amphiphilic
molecules facilitating the deposition.
Since the Langmuir – Blodgett technique allows the controlled, layer-by-layer
deposition of ordered molecular films on solid substrates, the films constructed by
means of this method are expected to be components for potential applications in
sensorics, photonics, or photoelectronics [16].
Results and Discussion. – Synthesis of 1H-Benzotriazole-1-methanamines 1a – l.
Benzotriazoles (Bt) are precursors in the synthesis of complex organic compounds
including classes which are difficult to prepare [17][18]. This fact motivated us to
synthesize by this way compounds 1a – l (Scheme 2). One of the basic procedures
connected with the synthesis of alkanamine derivatives is the reaction in which a
benzotriazole (Bt) derivative is used as intermediate. Thus, the 1H-benzotriazole-1-
methanamines 1a – l were easily synthesized by the well-established condensation of
1H-benzotriazole, an aliphatic aldehyde, and a secondary amine, either in CH2Cl2 in the
presence of anhydrous MgSO4 at room temperature (1d – g,i,j,l) [18] or, in the case of
aromatic aldehydes, in toluene under Dean – Stark conditions (for 1a – c,h,k) [18]. The
reaction under Dean – Stark conditions catalyzed by p-toluenesulfonic acid (TsOH)
resulted in much better yield.
Synthesis of Alk-2-yn-1-amines. A group of alk-2-yn-1-amines 3 were obtained
according to the standard procedure of lithiation of organic compounds [19] (Table,
Scheme 3). The key step of this methodology was the deprotonation of the alkynes and
formation of unstable lithio compounds, which at ꢀ 788 in THF reacted with the 1H-
benzotriazole-1-methanamines 1a – l and finally gave alk-2-yn-1-amines 3a – t. The
reaction occurred with very good yield at ꢀ 788 in THF with BuLi or lithium
diisopropylamide (LDA), both bases giving similar results.
The 1H- and 13C-NMR spectra and the elemental analyses of all synthesized
compounds fully supported the structures.
Biological interest of the prepared derivatives is connected with the potential
inhibition character of 3a – t as squalene-epoxidase inhibitors [20]. The amphiphilic
character of the obtained compounds causes interest in aggregation and electro-
conductivity measurements.
Physicochemical Effects of Langmuir– Blodgett Films Build from Synthesized
Materials. To obtain Langmuir films, the synthesized amphiphilic compounds 4-(1-
phenylhept-2-yn-1-yl)morpholine (¼ MF 6; 3s) and a-(oct-1-yn-1-yl)-N,N-bis(phenyl-

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Scheme 2
Scheme 3 a)
a) For R1, R2, and R3, see Table.
methyl)benzenemethanamine FDF 8; 3t) (Table) were dissolved in CHCl3 (Aldrich;
HPLC grade) and spread onto the H2O surface of a Langmuir trough. Concentrations
of solutions were maintained at ca. 1 mg/ml. All measurements were carried out
according to our previous reports [19][21]. The films of desired composition were
formed by dropwise spreading of the alkynamine derivative solution, with or without
docosanoic acid (DA), tricos-22-enoic acid (TA), 11-mercaptoundecanoic acid
(MUA), or gramicidine A (GrA), respectively, on high purity H2O at 293 K. The
binary systems were mixed to obtain molar compositions of the deposition mixture of
1:1, 1:2, and 10 :1.
From the measured p – A isotherms of the synthesized derivatives MF 6 (3s) and
FDF 8 (3t), it was clear that these unsymmetric structures form stable Langmuir and
Langmuir – Blodgett films. The pressure – area isotherms for representative binary

Helvetica Chimica Acta – Vol. 90 (2007)
Table. Synthesized Compounds 3
1675
R
NR1R2
R3
Yield [%]
3a
3b
3c
3d
3e
3f
3g
3h
3i
3j
3k
3l
3m
3n
3o
3p
3q
3r
Me3CCH2
4-MeC6H4
iPr
N(CH2CH2)2O
N(CH2CH2)2O
N(CH2CH2)2O
N(CH2CH2)2O
N(CH2CH2)2S
Bn2N
Me(CH2)5
Ph
Me(CH2)5
Ph
Me(CH2)5
Me(CH2)5
4-MeC6H4
4-MeC6H4
4-MeC6H4
4-MeC6H4
Bu
Bu
Bu
Bu
Me(CH2)4
Me(CH2)4
Me(CH2)4
Me(CH2)4
Bu
86
89
92
93
95
90
92
94
90
95
87
88
94
83
89
87
98
91
97
90
iPr
Me3CCH2
iPr
Me3CCH2
4-ClC6H4
Me3CCH2
Ph
N(CH2)4
N(CH2CH2)2O
N(CH2CH2)2O
Bn2N
Ph
Bn2N
4-ClC6H4
Me3CCH2
naphthalen-1-yl
Ph
naphthalen-1-yl
4-MeC6H4
iPr
N(CH2CH2)2O
N(CH2CH2)2S
N(CH2)5
Bn2N
N(CH2)5
N(CH2CH2)2O
PhNMe
N(CH2CH2)2O
Bn2N
3s
3t
Ph
Ph
Me(CH2)5
complexes of MF 6 (3s) and FDF 8 (3t) are shown on Figs. 1 and 2. The compression
proceeds smoothly until the film collapses. Although pure MF 6 and FDF 8 form good
Langmuir films, their Langmuir – Blodgett films are not stable because the transfer
procedure occurs under a relatively low surface pressure.
Comparison of the p – A isotherms of Figs. 1 and 2 shows also that when using
binary films, it is possible to obtain much higher surface pressures and, therefore, closer
Fig. 1. p – A Isotherms of binary MF 6 (3s) complexes with TA (tricos-22-enoic acid), MUA (11-
mercaptoundecanoic acid), and GrA (gramicidine A)

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Fig. 2. p – A Isotherms of binary FDF 8 (3t) complexes with DA (docosanoic acid) and MUA (11-
mercaptoundecanoic acid)
packing, and MUA, TA, and gramicidine A facilitate this process in the most
prosperous way. This is caused by an almost planar structure of the alkynamine moiety
of the derivatives MF 6 and FDF 8, by the alkyl chain being almost vertical to the
hydrophilic part of MF 6 and FDF 8, and by the very favorable properties of the used
acids MUA or TA or of GrA which improve packing and Langmuir – Blodgett-film
architecture. We observed also similar results (besides unfavorable results) with long-
chain acids (tricos-22-enoic acid, docosanoic acid) as model amphiphile in the case of
another, previously synthesized heterocyclic compound [19].
In Fig. 3, a computer-generated model of the MF 6 (3s) molecule is presented
(structure optimization in Gaussian03 at the AM1 theory level; the surface was
generated by the Molekel 4.3 program under command fast surface [22]). If the
average plane of all aromatic rings was laid almost flat on the water, the aliphatic chain
would be elevated by nearly 908. In our case, i.e., of an amphiphilic (hydrophilic –
hydrophobic) molecule, aromatic rings are the more hydrophilic part of it. In such
an arrangement, the calculated area per molecule equals ca. 30 Š2, which is also
confirmed by the p – A isotherm (in the binary system).
Transfer of the Langmuir films of MF 6 or FDF 8 from the air/H2O interface onto a
substrate under a constant surface pressure of 10 mN/m allowed to achieve complete
and good-quality Langmuir – Blodgett films, as confirmed by the UV/VIS spectrum of
FDF 8 (3t) on a quartz substrate (75 mm ꢁ 19 mm ꢁ 1.08 mm) (Fig. 4). The usefulness
of the obtained films in electrical experiments was established by the stability of the
deposited layers.
Conclusions. – We successfully synthesized a series of alkynamine derivatives by a
typical, straightforward and convenient methodology starting from an aldehyde and an
amine via a 1H-benzotriazole derivative. The obtained alkynamines could find
applications, for example, in promising electro-active materials. The alkynamines 3s
and 3t, mixed with substances facilitating film building, gave stable and good-quality

Helvetica Chimica Acta – Vol. 90 (2007)
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Fig. 3. Computer-generated models of MF 6 (3s)
Fig. 4. UV/VIS Absorption spectra of a CHCl3 solution and of a Langmuir– Blodgett film of FDF 8 (3t)
Langmuir – Blodgett films. The electrical properties of a thin Langmuir – Blodgett film
obtained with a synthesized alkynamine are in the course of evaluation.
We would like to thank Prof. Alan R. Katritzky from the Center for Heterocyclic Compounds,
Department of Chemistry, University of Florida, Gainesville, for valuable suggestions. This workwas
supported by a Wrocław University of Technology Grant (No. 332093).
Experimental Part
General. THF was used immediately after distillation from a soln. containing benzophenone/Na.
Other starting materials, reagents, and solvents were used as received from suppliers. Column
chromatography (CC): Merck silica gel 60 (5386). M.p.: capillary melting point apparatus equipped with
a digital thermometer. NMR Spectra: Varian-VXR-300 spectrometer; at 300 (1H) and 75 MHz (13C) in
CDCl3 unless otherwise specified; d in ppm, J in Hz.

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General Procedure. To a soln. of an alkyne (2 mmol) in dry THF (10 ml), 1.6m BuLi in hexane
(1.5 ml, 2.2 mmol) was added at ꢀ 788. The soln. was stirred at ꢀ 788 for 1 h, and a soln. of the Bt
derivative 1a – l (2 mmol) in THF (10 ml) was added. The mixture was stirred for 12 h, while the temp.
was allowed to rise to 208. After quenching with H2O (20 ml) and extraction with AcOEt (3 ꢁ 25 ml), the
combined org. layer was washed with H2O (25 ml) and dried (MgSO4) and the solvent evaporated. The
oily residue was subjected to CC (hexane/AcOEt 10 :1 then 6 :1): product 3a – t.
4-[1-(2,2-Dimethylpropyl)non-2-yn-1-yl]morpholine (3a): 480.69 mg (86%). Colorless oil.
1H-NMR: 3.77 – 3.67 (m, 4 H); 3.35 – 3.31 (m, 1 H); 2.66 – 2.60 (m, 2 H); 2.50 – 2.43 (m, 2 H); 2.19 (td,
J ¼ 7.0, 1.9, 2 H); 1.55 (d, J ¼ 6.6, 2 H); 1.53 – 1.28 (m, 8 H); 0.98 (s, 9 H); 0.89 (t, J ¼ 6.8, 3 H). 13C-NMR:
86.1; 78.1; 67.1; 54.2; 49.3; 46.9; 31.3; 30.3; 29.9; 28.5; 22.5; 18.6; 14.0. Anal. calc. for C18H33NO (279.47): C
77.36, H 11.90, N 5.01; found: C 77.12, H 12.32, N 5.16.
4-[1-(4-Methylphenyl)-3-phenylprop-2-yn-1-yl]morpholine (3b): 518.69 mg (89%). Colorless micro-
crystals. M.p. 78.5 – 79.58. 1H-NMR: 7.52 – 7.49 (m, 4 H); 7.33 – 7.29 (m, 3 H); 7.17 (d, J ¼ 7.8, 2 H); 4.74 (s,
1 H); 3.77 – 3.68 (m, 4 H); 2.67 – 2.58 (m, 4 H); 2.35 (s, 3 H). 13C-NMR: 137.4; 134.7; 131.7; 128.9; 128.5;
128.2; 128.1; 122.9; 88.2; 85.2; 67.1; 61.7; 49.8; 21.1. Anal. calc. for C20H21NO (291.40): C 82.44, H 7.26, N
4.81; found: C 82.17, H 7.47, N 4.84.
4-(1-Isopropylnon-2-yn-1-yl)morpholine (3c): 462.61 mg (92%). Colorless oil. 1H-NMR: 3.77 – 3.66
(m, 4 H); 2.76 (dt, J ¼ 9.3, 1.9, 1 H); 2.64 – 2.57 (m, 2 H); 2.45 – 2.38 (m, 2 H); 2.22 (td, J ¼ 7.0, 2.1, 2 H);
1.81 – 1.72 (m, 1 H); 1.56 – 1.28 (m, 8 H); 1.02 (d, J ¼ 6.6, 3 H); 0.96 (d, J ¼ 6.6, 3 H); 0.89 (t, J ¼ 6.8, 3 H).
13C-NMR: 86.4; 67.1; 64.6; 49.8; 31.2; 29.7; 28.9; 28.4; 22.4; 19.9; 19.6; 18.5; 13.9. Anal. calc. for C16H29NO
(251.42): C 76.44, H 11.63, N 5.57; found: C 76.12, H 12.02, N 5.68.
4-(1-Isopropyl-3-phenylprop-2-yn-1-yl)morpholine (3d): 452.63 mg (93%). Colorless microcrystals.
M.p. 68.5 – 69.58. 1H-NMR: 7.46 – 7.41 (m, 2 H); 7.31 – 7.25 (m, 3 H); 3.80 – 3.69 (m, 4 H); 3.01 (d, J ¼ 9.62,
1 H); 2.74 – 2.67 (m, 2 H); 2.51 – 2.48 (m, 2 H); 1.95 – 1.85 (m, 1 H); 1.11 (d, J ¼ 6.6, 3 H); 1.03 (d, J ¼ 6.6,
3 H). 13C-NMR: 131.6; 128.2; 127.8; 123.3; 86.7; 86.5; 67.2; 65.1; 49.9; 29.8; 20.3; 19.7. Anal. calc. for
C16H21NO (243.35): C 78.97, H 8.70, N 5.76; found: C 79.31, H 8.86, N 5.81.
4-[1-(2,2-Dimethylpropyl)non-2-yn-1-yl]thiomorpholine (3e): 561.51 mg (95%). Colorless oil.
1H-NMR: 3.31 – 3.26 (m, 1 H); 2.90 – 2.84 (m, 2 H); 2.74 – 2.63 (m, 6 H); 2.19 (td, J ¼ 7.0, 1.9, 2 H);
1.53 (d, J ¼ 6.6, 2 H); 1.50 – 1.28 (m, 8 H); 0.96 (s, 9 H); 0.89 (t, J ¼ 6.7, 3 H). 13C-NMR: 85.7; 78.4; 55.3;
51.6; 47.0; 31.3; 30.3; 29.9; 28.9; 28.5; 28.2; 22.5; 18.6; 14.0. Anal. calc. for C18H33NS (295.53): C 73.16, H
11.26, N 4.74; found: C 72.79, H 11.65, N 4.89.
N-(1-Isopropylnon-2-yn-1-yl)-N-(phenylmethyl)benzenemethanamine (3f): 650.84 mg (90%). Col-
orless oil. 1H-NMR: 7.44 – 7.38 (m, 4 H); 7.33 – 7.27 (m, 4 H); 7.24 – 7.18 (m, 2 H); 3.79 (dd, J ¼ 13.9, 2.5,
2 H); 3.36 (dd, J ¼ 13.7, 3.7, 2 H); 2.86 (dd, J ¼ 8.4, 2.0, 1 H); 2.31 – 2.28 (m, 2 H); 1.89 – 1.83 (m, 1 H);
1.59 – 1.52 (m, 4 H); 1.36 – 1.34 (m, 4 H); 1.01 – 0.91 (m, 9 H). 13C-NMR: 140.1; 128.8; 128.1; 126.7; 85.8;
59.2; 54.9; 31.4; 30.9; 29.3; 28.6; 22.7; 21.0; 19.9; 18.7; 14.1. Anal. calc. for C26H35N (361.58): C 86.37, H
9.76, N 3.87; found: C 86.14, H 10.14, N 4.06.
1-{3,3-Dimethyl-1-[(4-methylphenyl)ethynyl]butyl}pyrrolidine (3g): 495.75 mg (92%). Orange oil.
1H-NMR: 7.30 (d, J ¼ 8.0, 2 H); 7.09 (d, J ¼ 8.1, 2 H); 3.80 (dd, J ¼ 9.2, 4.1, 1 H); 2.77 – 2.66 (m, 4 H); 2.33
(s, 3 H); 1.80 – 1.76 (m, 4 H); 1.74 – 1.64 (m, 2 H); 1.03 (s, 9 H). 13C-NMR: 137.6; 131.3; 128.9; 120.6; 88.4;
85.5; 51.0; 49.0; 48.9; 30.3; 30.0; 23.4; 21.4. Anal. calc. for C19H27N (269.43): C 84.70, H 10.10, N 5.20;
found: C 84.49, H 10.52, N 5.49.
4-[1-(4-Chlorophenyl)-3-(4-methylphenyl)prop-2-yn-1-yl]morpholine (3h): 612.58 mg (94%). Yel-
1
low microcrystals. M.p. 95 – 968. H-NMR: 7.57 (d, J ¼ 8.4, 2 H); 7.40 (d, J ¼ 8.0, 2 H); 7.32 (d, J ¼ 8.4,
2 H); 7.13 (d, J ¼ 8.0, 2 H); 4.74 (s, 1 H); 3.76 – 3.67 (m, 4 H); 2.61 – 2.58 (m, 4 H); 2.35 (s, 3 H).
13C-NMR: 138.5; 136.5; 133.4; 131.6; 129.8; 129.0; 128.3; 119.6; 88.9; 83.5; 67.1; 61.3; 49.7; 21.4. Anal. calc.
for C20H20ClNO (325.84): C 73.72, H 6.19, N 4.30; found: C 73.47, H 6.41, N 4.28.
4-{3,3-Dimethyl-1-[(4-methylphenyl)ethynyl]butyl}morpholine (3i): 513.77 mg (90%). Colorless
microcrystals. M.p. 42.5 – 43.58. 1H-NMR: 7.31 (d, J ¼ 8.1, 2 H); 7.09 (d, J ¼ 7.8, 2 H); 3.79 – 3.69 (m,
4 H); 3.56 (dd, J ¼ 7.9, 5.3, 1 H); 2.76 – 2.69 (m, 2 H); 2.59 – 2.52 (m, 2 H); 2.32 (s, 3 H); 1.70 – 1.65 (m,
2 H); 1.03 (s, 9 H). 13C-NMR: 137.7; 131.3; 128.9; 120.2; 87.2; 86.2; 67.0; 54.6; 49.4; 46.8; 30.3; 29.9; 21.3.
Anal. calc. for C19H27NO (285.43): C 79.95, H 9.53, N 4.91; found: C 79.91, H 9.81, N 4.86.

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a-[(4-Methylphenyl)ethynyl]-N,N-bis(phenylmethyl)benzenemethanamine (3j): 762.96 mg (95%).
Colorless microcrystals. M.p. 106.5 – 107.58. 1H-NMR: 7.30 (d, J ¼ 7.7, 2 H); 7.52 (d, J ¼ 8.0, 2 H); 4.93 (s,
1 H); 3.79 (AB, J ¼ 13.5, 2 H); 3.54 (AB, J ¼ 13.5, 2 H); 2.36 (s, 3 H). 13C-NMR: 139.6; 139.3; 138.3;
131.8; 129.1; 128.9; 128.2; 128.1; 127.4; 127.0; 120.2; 88.7; 83.9; 56.0; 54.6; 21.5. Anal. calc. for C30H27N
(401.56): C 89.73, H 6.78, N 3.49; found: C 89.49, H 6.93, N 3.46.
a-(Hex-1-yn-1-yl)-N,N-bis(phenylmethyl)benzenemethanamine (3k): 639.52 mg (87%). Colorless oil.
1H-NMR: 7.68 (d, J¼ 7. 8, 2 H ) ; 7. 41 – 7. 39 ( m, 4 H); 7.30 –7.25 (m, 6 H); 7.20–7.18 (m, 3 H); 4.69 (s, 1 H);
3.70 (AB, J ¼ 13.5, 2 H); 3.44 (AB, J¼ 13.5, 2 H); 2.42 (td, J¼ 6.8, 1.9, 2 H); 1.68–1.52 (m, 4 H); 1.00 (t, J¼
7. 2, 3 H ) . 13C-NMR: 139.8; 139.7; 128.8; 128.3; 128.2; 127.9; 127.2; 126.9; 88.7; 74.6; 55.6; 54.5; 31.3; 22.1;
18.5; 13.7. Anal. calc. for C15H22NO2S (367.54): C 88.23, H 7.95, N 3.81; found: C 88.10, H 7.86, N 3.61.
1
4-[1-(4-Chlorophenyl)hept-2-yn-1-yl]morpholine (3l): 513.60 mg (88%). Yellow oil. H-NMR: 7.50
(d, J ¼ 8.4, 2 H); 7.30 (d, J ¼ 8.4, 2 H); 4.49 (s, 1 H); 3.71 – 3.67 (m, 4 H); 2.51 – 2.48 (m, 4 H); 2.32 (td, J ¼
7.0, 2.1, 2 H); 1.59 – 1.42 (m, 4 H); 0.94 (t, J ¼ 7.1, 3 H ) . 13C-NMR: 137.1; 133.2; 129.8; 128.1; 89.1; 74.6;
67.0; 60.9; 49.6; 31.0; 22.0; 18.4; 13.6. Anal. calc. for C17H22ClNO (291.82): C 69.97, H 7.60, N 4.80; found:
C 69.66, H 7.79, N 4.95.
4-[1-(2,2-Dimethylpropyl)hept-2-yn-1-yl]thiomorpholine (3m): 502.86 mg (94%). Colorless oil.
1H-NMR: 3.24 – 3.18 (m, 1 H); 2.84 – 2.74 (m, 2 H); 2.66 – 2.63 (m, 6 H); 2.13 (td, J ¼ 6.7, 1.9, 2 H);
1.46 (d, J ¼ 6.7, 2 H); 1.43 – 1.31 (m, 4 H); 0.89 (s, 9 H); 0.85 (t, J ¼ 7.1, 3 H ) . 13C-NMR: 85.3; 78.1; 55.2;
51.4; 46.9; 30.9; 30.1; 29.7; 28.0; 21.7; 18.1; 13.4. Anal. calc. for C16H29NS (267.48): C 71.85, H 10.93, N
5.24; found: C 71.47, H 11.37, N 5.39.
1-[1-(Naphthalen-1-yl)hept-2-yn-1-yl]piperidine (3n): 507.08 mg (83%). Yellow oil. 1H- NMR: 8.36
(d, J ¼ 8.1, 1 H); 7.85 (d, J ¼ 7.3, 1 H); 7.80 (d, J ¼ 7.7, 1 H); 7.74 (d, J ¼ 8.2, 1 H); 7.50 – 7.38 (m, 3 H); 5.17
(s, 1 H); 2.60 – 2.45 (m, 4 H); 2.35 (td, J ¼ 6.8, 1.6, 2 H); 1.63 – 1.40 (m, 10 H); 0.94 (t, J ¼ 7.1 Hz, 3 H).
13C-NMR: 134.9; 133.9; 131.9; 128.2; 128.1; 126.6; 125.5; 125.3; 125.1; 124.6; 88.5; 75.8; 60.0; 50.5; 31.2;
26.2; 24.6; 22.0; 18.5; 13.6. Anal. calc. for C22H27N (305.47): C 86.50, H 8.91, N 4.59; found: C 86.42, H
9.20, N 4.78.
a-(Hept-1-yn-1-yl)-N,N-bis(phenylmethyl)benzenemethanamine (3o): 679.19 mg (89%). Colorless oil.
1H-NMR: 7.70 (d, J¼ 7.7, 2 H ) ; 7.41 –7.39 ( m, 4 H); 7.33–7.26 (m, 6 H); 7.23–7.17 (m, 3 H); 4.69 (s, 1 H); 3.70
(AB, J¼ 13.5, 2 H); 3.44 (AB, J¼ 13.5, 2 H); 2.42 (td, J¼ 6.9, 2.1, 2 H); 1.70–1.63 (m, 2 H); 1.58–1.47 (m,
2 H); 1.45–1.37 (m, 2 H); 0.96 (t, J¼ 7.2, 3 H ) . 13C-NMR: 139.9; 139.8; 128.8; 128.3; 128.2; 127.9; 127.2; 126.9;
88.8; 74.7; 55.6; 54.5; 31.2; 28.9; 22.2; 18.8; 14.1. Anal. calc. for C28H31N (381.57): C 88.14, H 8.19, N 3.67;
found: C 87.89, H 8.51, N 3.62.
1-[1-(Naphthalen-1-yl)oct-2-yn-1-yl]piperidine (3p): 555.91 mg (87%). Yellow oil. 1H-NMR: 8.35
(d, J ¼ 8.1, 1 H); 7.84 (d, J ¼ 7.1, 1 H); 7.80 (d, J ¼ 8.5, 1 H); 7.74 (d, J ¼ 8.2, 1 H); 7.49 – 7.38 (m, 3 H); 5.16
(s, 1 H); 2.53 – 2.52 (m, 4 H); 2.35 – 2.30 (m, 2 H); 1.64 – 1.31 (m, 12 H); 0.91 (t, J ¼ 7.1, 3 H ) . 13C-NMR:
135.0; 133.9; 131.9; 128.2; 128.2; 126.7; 125.5; 125.3; 125.1; 124.7; 88.5; 75.9; 60.0; 50.5; 31.1; 28.8; 26.2;
24.6; 22.2; 18.8; 14.0. Anal. calc. for C23H29N (319.49): C 86.47, H 9.15, N 4.38; found: C 86.62, H 9.43, N
4.62.
4-[1-(4-Methylphenyl)oct-2-yn-1-yl]morpholine (3q): 559.44 mg (98%). Colorless oil. 1H-NMR: 7.42
(d, J ¼ 8.0, 2 H); 7.13 (d, J ¼ 8.0, 2 H); 4.47 (s, 1 H); 3.70 – 3.67 (m, 4 H); 2.53 – 2.49 (m, 4 H); 2.33 (s,
3 H); 2.29 (td, J ¼ 7.0, 2.1, 2 H); 1.60 – 1.53 (m, 2 H); 1.45 – 1.30 (m, 4 H); 0.91 (t, J ¼ 7.1, 3 H ) . 13C-NMR:
137.0; 135.4; 128.6; 128.3; 88.3; 75.5; 67.0; 61.3; 49.6; 31.0; 28.6; 22.1; 21.0; 18.6; 13.9. Anal. calc. for
C19H27NO (285.43): C 79.95, H 9.53, N 4.91; found: C 79.58, H 9.92, N 5.17.
N-(1-Isopropyloct-2-yn-1-yl)-N-methylbenzenamine (3r): 468.50 mg (91%). Yellow oil. 1H-NMR:
7.25 – 7.20 (m, 2 H); 6.82 (d, J ¼ 8.0, 2 H); 6.75 – 6.70 (m, 1 H); 4.04 – 4.01 (m, 1 H); 2.84 (s, 3 H); 2.17 (td,
J ¼ 6.9, 2.1, 2 H); 2.04 – 1.97 (m, 1 H); 1.50 – 1.44 (m, 2 H); 1.40 – 1.26 (m, 4 H); 1.09 (d, J ¼ 6.6, 3 H); 0.93
(d, J ¼ 6.6, 3 H); 0.88 (t, J ¼ 7.1, 3 H ) . 13C-NMR: 150.5; 129.0; 117.2; 114.0; 85.2; 77.6; 59.2; 33.2; 32.2;
31.0; 28.6; 22.1; 20.0; 19.6; 18.6; 14.0. Anal. calc. for C18H27N (257.42): C 83.99; H 10.57, N 5.44; found: C
83.71, H 10.98, N 5.79.
4-(1-Phenylhept-2-yn-1-yl)morpholine (¼ MF6; 3s): 499.32 mg (97%). Colorless oil. 1H-NMR:
7.58 – 7.55 (m, 2 H); 7.37 – 7.26 (m, 3 H); 4.54 (s, 1 H); 3.73 – 3.69 (m, 4 H); 2.55 – 2.52 (m, 4 H); 2.33 (td,
J ¼ 7.0, 2.1, 2 H); 1.60 – 1.44 (m, 4 H); 0.95 (t, J ¼ 7.2, 3 H). 13C-NMR: 138.5; 128.6; 128.1; 127.6; 88.7; 75.3;

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Helvetica Chimica Acta – Vol. 90 (2007)
67.2; 61.7; 49.8; 31.2; 22.1; 18.5; 13.7. Anal. calc. for C17H23NO (257.38): C 79.33, H 9.01, N 5.44; found: C
79.23, H 8.91, N 5.32.
a-(Oct-1-yn-1-yl)-N,N-bis(phenylmethyl)benzenemethanamine (¼ FDF8; 3t): 712.06 mg (90%).
Colorless oil. 1H-NMR: 7.79 – 7.76 (m, 2 H); 7.52 – 7.50 (m, 4 H); 7.44 – 7.37 (m, 6 H); 7.33 – 7.30 (m,
3 H); 4.79 (s, 1 H); 3.80 (AB, J ¼ 13.5, 2 H); 3.54 (AB, J ¼ 13.5, 2 H); 2.53 (td, J ¼ 6.8, 2.0, 2 H); 1.80 – 1.75
(m, 2 H); 1.68 – 1.66 (m, 2 H); 1.50 – 1.45 (m, 4 H); 1.04 (t, J ¼ 7.0, 3 H). 13C-NMR: 139.8; 139.7; 128.8;
128.3; 128.2; 127.9; 127.2; 126.8; 88.8; 74.7; 55.6; 54.5; 31.4; 29.2; 28.6; 22.6; 18.9, 14.1. Anal. calc. for
C29H33N (395.59): C 88.05, H 8.41, N 3.54; found: C 87.95, H 8.30, N 3.45.
General Procedure for Langmuir– Blodgett Deposition. The binary systems were mixed to achieve
1:1, 1:2, and 10 :1 molar compositions of the deposition mixture. The p – A isotherms were measured by
means of a commercial Langmuir – Blodgett trough (KSV, system 5000) by using a Pt hydrophilic
Wilhelmy plate, on high-purity water at 295 K. The compression rates in our experiments ranged from 25
to 100 mm/min, depending on the rigidity of the films. Langmuir – Blodgett films were prepared by means
of vertical emerging and dipping of the substrate at the surface pressure of ca. 10 mN/m.
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Received March 27, 2007