Efficient method for cleavage of aziridines with aromatic amines

Full text of DOI:10.1021/jo981869r

J . Org. Chem. 1999, 64, 2537-2539
2537
Ta ble 1. Sn (II) a n d Cu (II) Tr ifla te Ca ta lyzed Azir id in e
Efficien t Meth od for Clea va ge of Azir id in es
w ith Ar om a tic Am in es
Op en in g w ith Ar om a tic Am in es in Eth er a t Room
Tem p er a tu r e
Govindasamy Sekar and Vinod K. Singh*
Department of Chemistry, Indian Institute of Technology,
Kanpur 208 016, India
Received September 15, 1998
Ring opening of activated aziridines with several
nucleophiles by means of Lewis acids has been studied.1-4
If the nucleophiles are amines, the products become
diamines, which synthetically are an important class of
compounds. Recently, the ring opening reaction of mainly
activated aziridines by amines has been reported in the
presence of ytterbium triflate and other lanthanide
triflates as catalysts.5 Most of the amines used in the
reaction were aliphatic, and there was only one entry
where aniline was used as nucleophile. The reaction
required higher concentration of the catalyst (20 mol %)
and longer reaction time (1-3 d). While working on
epoxide cleavage reactions with amines,6 we discovered
that aziridines were efficiently cleaved with less reactive
aromatic amines and 5 mol % of Sn(OTf)2 or Cu(OTf)2 in
a short time. The unusual feature of the reaction was
that aliphatic amines did not open aziridines with these
catalysts, in sharp contrast to the behavior of Yb(OTf)3
and La(OTf)3.5 This prompted us to look at the reaction,
and we report our results in this paper.
A variety of aziridines were synthesized from the
corresponding amino alcohols in one step, using MsCl (1.1
equiv) and Et3N (2.5 equiv) in pyridine (as solvent) at
room temperature. At the outset, the opening reaction
was done using N-phenylcyclohexeneimine and aniline,
with 5 mol % of Sn(OTf)2 in ether at room temperature
for 10 min, and product 1a was obtained in 91% yield
(Table 1, entry 1). The reaction was studied in several
solvents, such as CH2Cl2 (90% yield), MeCN (88% yield),
and THF (80% yield), and it was found that both ether
and CH2Cl2 were equally good solvents for the above
reaction. Use of Cu(OTf)2 as a catalyst facilitated the
reaction equally well, but the reaction time was a little
longer (1 h). The opening of N-phenylcyclohexeneimine
was tried with a variety of aromatic amines, using both
the catalysts (entries 1-12). In all the cases, a very clean
reaction was observed and the trans stereochemistry of
diamines was deduced from the relevant coupling con-
stants. The aziridine opening reaction tolerated a varying
degree of steric hindrance on aromatic amines such as
R-naphthylamine (entry 9), diphenylamine (entry 10),
and o,o′-diisopropylaniline (entry 11).
To show the scope of the reaction, we extended it to a
variety of cyclic and acyclic aziridines. In almost all cases,
a high yield of the opened product was obtained. In the
case of acyclic terminal aziridines, the reaction was
highly regioselective. Only one product was isolated, and
it was due to the attack of aromatic amines at the less
hindered terminal carbon atoms (entries 20-22).7 In the
case of 2-phenyl aziridines (entries 24 and 25), the
situation was the reverse; the product formed was the
one due to the attack of aromatic amines at the benzylic
carbon atom (internal attack).8 The aziridine opening
* Fax: 91-512-590007. E-mail: vinodks@iitk.ac.in.
(1) (a) For a general review of aziridine chemistry, see: Pearson,
W. H.; Lian, B. W.; Bergmeier, S. C. In Comprehensive Heterocylic
Chemistry II; Katritzky, A. R., Rees, C. W., Scriven, E. F. V., Eds;
Pergamon: New York, 1996; Vol 1a. (b) Dauben, P.; Dubois, L.; Dau,
M. E. T. H.; Dodd, R. H. J . Org. Chem. 1995, 60, 2035. (c) da Zhang,
Z.; Scheffold, R. Helv. Chim. Acta 1993, 76, 2602. (d) Bodenan, J .;
Chanet-Ray, J .; Vessiere, R. Synthesis 1992, 288. (e) Sato, K.;
Kozikowski, A. P. Tetrahedron Lett. 1989, 30, 4073. (f) Nakajima, K.;
Neya, M.; Yamada, S.; Okawa, K. Bull. Chem. Soc. J pn. 1982, 55, 3049.
(2) For Cr complex catalyzed opening of aziridine with TMS azide,
see: Leung, W.-H.; Yu, M.-T.; Wu, M.-C.; Yeung, L.-L. Tetrahedron
Lett. 1996, 37, 891.
(3) For opening of aziridine with TMSCN in the presence of
lanthanoid tricyanide, see: (a) Matsubara, S.; Kodama, T.; Utimoto,
K. Tetrahedron Lett. 1990, 31, 6379. (b) Osborn, H. M. I.; Sweeney, J .
B. Synlett 1994, 145.
(4) While this manuscript was being prepared, a paper appeared
where acylaziridine is rearranged to oxazoline by means of orthogonal
Lewis acids. For reference, see: Ferraris, D.; Drury, W. J ., III; Cox,
C.; Lectka, T. J . Org. Chem. 1998, 63, 4568.
(5) (a) Meguro, M.; Asao, N.; Yamamoto, Y. Tetrahedron Lett. 1994,
35, 7395. (b). Meguro, M.; Yamamoto, Y. Heterocycles 1996, 43, 2473.
(6) .Sekar, G.; Singh, V. K. J . Org. Chem. 1999, 64, 287.
(7) This was ascertained by comparing the δ value of N-Me in
products obtained from the opening of similar epoxide with N-methyl
aniline. For details, see ref 6.
10.1021/jo981869r CCC: $18.00 © 1999 American Chemical Society
Published on Web 03/09/1999

2538 J . Org. Chem., Vol. 64, No. 7, 1999
Notes
2H), 3.56 (bs, NH, 1H), 4.63 (bs, 1H, NH), 6.48 (m, 2H), 6.58
(m, 2H), 6.7 (m, 1H), 7.15 (m, 2H), 8.02 (m, 2H); 13C NMR
(CDCl3, 75 MHz) δ 24.4, 24.6, 32.2, 32.6, 56.9, 57.4, 111.5, 113.4,
118.0, 126.4, 129.5, 138.0, 147.1, 152.9; LCMS (APCI, m/z) 312
(M+ + 1). Anal. Calcd for C18H21N3O2: C, 69.45; H, 6.75; N,
13.50. Found: C, 69.38; H, 6.82; N, 13.42.
reaction was also smooth in a disubstituted acyclic
substrate (entry 23).
The worthy feature of the reaction is that highly
deactivated amines such as p-nitroaniline also opened the
aziridines in high yield. It is remarkable that unactivated
aziridines could be opened with aromatic amines under
very mild conditions. This kind of result is quite unprec-
edented in the literature for aziridine chemistry.
The unusual feature of this reaction is that only
aromatic amines opened the aziridines. Aliphatic amines,
such as diethylamine, n-butylamine, benzylamine, and
pyrrolidine, failed to react with aziridine at room tem-
perature for 1 d in the presence of a catalytic amount of
copper or tin triflate. Although we do not have any proof
for the mechanism, we feel that it is ionic in nature. It
was assumed that a loose complex of an aromatic amine
and the catalyst coordinated with the N of an aziridine
and initiated the opening reaction. Aliphatic amines by
virtue of their higher basicity made stronger complexes
to the copper and tin triflate which failed to activate the
aziridine. This was deduced from an observation that
aniline failed to open N-phenylcyclohexeneimine in the
presence of benzylamine and copper or tin triflate under
the above conditions. Irrespective of the mechanism, the
cleavage of aziridine with aromatic amines in the pres-
ence of tin or copper triflate is unique and unprecedented.
A variety of chiral nonracemic ligands can be complexed
with copper or tin triflate for asymmetric version of the
reaction which is in progress in our laboratory.
tr a n s-N-P h en yl-N′-(2-h ydr oxyph en yl)-1,2-cycloh exan edi-
a m in e (1d ). Semisolid; Rf 0.66 (1:5, EtOAc in petroleum ether);
1
IR (KBr) 3510, 3360, 3280 cm-1; H NMR (CDCl3, 300 MHz) δ
1.25 (m, 4H), 1.68 (m, 2H), 2.21 (m, 2H), 2.93 (m,1H), 3.20 (dt,
J ) 9.9, 3.9 Hz, 1H), 4.40 (bs, 2H, NH), 6.80 (m, 6H), 7.20 (m,
3H); 13C NMR (CDCl3, 75 MHz) δ 24.9, 25.0, 32.5, 32.7, 58.5,
60.6, 114.7 118.8, 120.5, 121.7, 129.6, 135.4, 147.0, 147.5; LCMS
(APCI, m/z) 283 (M+ + 1). Anal. Calcd for C18H22N2O: C, 76.60;
H, 7.80; N, 9.93. Found: C, 76.62; H, 7.90; N, 9.84.
tr a n s-N-P h en yl-N′-(o-m eth ylp h en yl)-1,2-cycloh exa n ed i-
a m in e (1e). Mp 70-71 °C; Rf 0.42 (2% EtOAc in petroleum
1
ether); IR (KBr) 3390 cm-1; H NMR (CDCl3, 300 MHz) δ 1.30
(m, 2H), 1.50 (m, 2H), 1.82 (m, 2H), 2.05 (s, 3H), 2.41 (m, 2H),
3.28 (ddd, J ) 9.6, 9.6, 3.6 Hz, 1H), 3.37 (ddd, J ) 9.9, 9.9, 3.9
Hz, 1H), 3.93 (bs, 2H, NH), 6.71 (m, 5H), 7.1 (d, J ) 7.5 Hz,
1H), 7.23 (m, 3H); 13C NMR (CDCl3, 75 MHz) δ 17.5, 24.6, 24.7,
32.6, 32.7, 57.3, 57.7, 110.2, 113.7, 117.1, 117.7, 122.9, 127.0,
129.3, 130.3, 145.6, 147.5; LCMS (APCI, m/z) 281 (M+ + 1). Anal.
Calcd for C19H24N2: C, 81.43; H, 8.57; N, 10.00. Found: C, 81.46;
H, 8.70; N, 9.88.
tr a n s-N-P h en yl-N′-(m -br om op h en yl)-1,2-cycloh exa n ed i-
a m in e (1f). Semisolid; Rf 0.39 (2% EtOAc in petroleum ether);
IR (KBr) 3390 cm-1; 1H NMR (CDCl3, 300 MHz) δ 1.22 (m, 2H),
1.45 (m, 2H), 1.81 (m, 2H), 2.38 (m, 2H), 3.19 (m, 2H), 3.82 (bs,
2H, NH), 6.52 (m, 1H), 6.65 (d, J ) 8.5 Hz, 2H), 6.75 (m, 2H),
6.84 (m, 1H), 7.02 (m, 1H), 7.21 (m, 2H); 13C NMR (CDCl3, 75
MHz) δ 24.5, 24.6, 32.3, 32.5, 57.0, 57.2, 112.2, 113.5, 115.7,
117.7, 120.1, 123.3, 129.3, 130.5, 147.5, 149.0; LCMS (APCI, m/z)
345 and 347 (1:1; M+ + 1). Anal. Calcd for C18H21N2Br: C, 62.60;
H, 6.09; N, 8.12. Found: C, 62.58; H, 6.08; N, 8.06.
tr a n s-N-P h en yl-N′-(p-m eth oxyph en yl)-1,2-cycloh exan edi-
a m in e (1g). Colorless gel; Rf 0.3 (2% EtOAc in petroleum ether);
IR (neat) 3365 cm-1; 1H NMR (CDCl3, 300 MHz) δ 1.22 (m, 2H),
1.42 (m, 2H), 1.78 (m, 2H), 2.34 (m, 2H), 3.11 (ddd, J ) 9.6, 9.6,
3.3 Hz, 1H), 3.20 (ddd, J ) 9.6, 9.6, 3.3 Hz, 1H), 3.70 (bs, 2H,
NH), 3.76 (s, 3H), 6.63 (m, 4H), 6.71 (m, 1H), 6.79 (m, 2H), 7.19
(m, 2H); 13C NMR (CDCl3, 75 MHz) δ 24.6, 32.6, 55.8, 57.4, 58.4,
113.6, 115.0, 115.3, 117.6, 129.3, 141.8, 147.8, 152.4; LCMS
(APCI, m/z) 297 (M+ + 1). Anal. Calcd for C19H24N2O: C, 77.03;
H, 8.12; N, 9.46. Found: C, 76.78; H, 8.12; N, 9.40.
Exp er im en ta l Section 9
Gen er a l P r oced u r e for Azir id in e Op en in g w ith Ar o-
m a tic Am in es. A solution of an aziridine (1 mmol) and an
aromatic amine (1.2 mmol) in anhydrous ether or CH2Cl2 (5 mL)
was treated with 5 mol % of Cu(OTf)2 or Sn(OTf)2 for the
appropriate period of time (see Table 1) at room temperature.
The solvent was removed on a rotary evaporator, and the crude
product was purified over silica gel by column chromatography
to provide pure trans diamine in high yield.
tr a n s-N,N′-Dip h en yl-1,2-cycloh exa n ed ia m in e (1a ). Col-
orless gel; Rf 0.4 (2% EtOAc in petroleum ether); IR (neat) 3390
t r a n s-N -P h e n y l-N ′-(â-n a p h t h y l)-1,2-c y c lo h e x a n e d i-
a m in e (1h ). Semisolid; Rf 0.42 (2% EtOAc in petroleum ether);
1
cm-1; H NMR (CDCl3, 300 MHz) δ 1.23 (m, 2H), 1.42 (m, 2H),
1
IR (KBr) 3380 cm-1; H NMR (CDCl3, 300 MHz) δ 1.3 (m, 2H),
1.8 (m, 2H), 2.39 (m, 2H), 3.24 (m, 2H), 3.92 (bs, 2H, NH), 6.62
(d, J ) 7 Hz, 4H), 6.75 (t, J ) 7 Hz, 2H), 7.21 (dd, J ) 7 Hz,
4H); 13C NMR (CDCl3, 75 MHz) δ 24.6, 32.5, 57.2, 113.47, 117.54,
129.3, 147.7; LCMS (APCI, m/z) 267 (M+ + 1). Anal. Calcd for
C18H22N2: C, 81.20; H, 8.27; N,10.53. Found: C, 81.02; H, 8.38;
N, 10.60.
1.5 (m, 2H), 1.82 (m, 2H), 2.42 (m, 2H), 3.32 (m, 2H), 3.98 (bs,
2H, NH), 6.62 (m, 2H), 6.78 (m, 1H), 6.82 (m, 2H), 7.20 (m, 3H),
7.40 (m, 1H), 7.64 (m, 3H); 13C NMR (CDCl3, 75 MHz) δ 24.57,
24.60, 32.2, 32.5, 57.15, 57.22, 104.8, 113.5, 117.6, 118.5, 122.0,
125.8, 126.4, 127.5, 127.6, 129.0, 129.3, 135.1, 145.3, 147.6;
LCMS (APCI, m/z) 317 (M+ + 1). Anal. Calcd for C22H24N2: C,
83.54; H, 7.59; N, 8.86. Found: C, 83.38; H, 7.58; N, 8.96.
t r a n s-N -P h e n y l-N ′-(r-n a p h t h y l)-1,2-c yc lo h e xa n e d i-
a m in e (1i). Semisolid; Rf 0.45 (2% EtOAc in petroleum ether);
IR (KBr) 3390 cm-1; 1H NMR (CDCl3, 60 MHz) δ 0.90-1.90 (m,
6H), 2.33 (m, 2H), 3.33 (m, 2H), 3.80 (bs, 2H, NH), 6.5 (m, 4H),
7.2 (m, 8H). Anal. Calcd for C22H24N2: C, 83.54; H, 7.59; N, 8.86.
Found: C, 83.32; H, 7.55.
tr a n s-N-P h en yl-(N′-m eth yl-N′-ph en yl)-1,2-cycloh exan edi-
a m in e (1b). Viscous liquid; Rf 0.5 (2% EtOAc in petroleum
ether); IR (neat) 3400 cm-1; 1H NMR (CDCl3, 300 MHz) δ 1.2-
1.6 (bm, 4H), 1.82 (m, 3H), 2.42 (m, 1H), 2.66 (s, 3H), 3.31 (ddd,
J ) 10.2, 10.2, 3.6 Hz, 1H), 3.64 (m, 1H), 4.0 (bs, NH, 1H), 6.58
(m, 2H), 6.7 (m, 1H), 6.78 (m, 1H), 6.84 (m, 2H), 7.15 (m, 2H),
7.27 (m, 2H); 13C NMR (CDCl3, 75 MHz) δ 24.6, 25.7, 27.8, 30.7,
33.5, 55.2, 62.9, 113.2, 114.0, 117.2, 117.3, 129.18, 129.24, 147.8,
150.8; LCMS (APCI, m/z) 281 (M+ + 1). Anal. Calcd for
t r a n s-N -P h e n yl-N ,N ′-(d ip h e n yl)-1,2-c yc loh e xa n e d i-
a m in e (1j). Mp 106-107 °C; Rf 0.6 (2% EtOAc in petroleum
ether); IR (KBr) 3405 cm-1; 1H NMR (CCl4, 60 MHz) δ 0.95-1.9
(m, 6H), 2.25 (m, 2H), 3.0 (m, 1H), 3.9 (m, 1H), 4.15 (bs, 1H,
NH), 6.8-7.7 (m, 15H).
C
19H24N2: C, 81.42; H, 8.57; N, 10.00. Found: C, 81.28; H, 8.68;
N, 10.14.
tr a n s-N-P h en yl-N′-(p -n it r op h en yl)-1,2-cycloh exa n ed i-
a m in e (1c). Yellow solid; mp 145 °C; Rf 0.8 (1:3, EtOAc in
petroleum ether); IR (KBr) 3350 cm-1 1H NMR (CDCl3, 300
tr a n s-N-P h en yl-[N′-(2,5-d iisop r op ylp h en yl)-1,2-cyclo-
h exa n ed ia m in e (1k ). Viscous liquid; Rf 0.45 (2% EtOAc in
;
MHz) δ 1.22-1.6 (bm, 4H), 1.80 (m, 2H), 2.30 (m, 2H), 3.28 (m,
1
petroleum ether); IR (neat) 3360, 3400 cm-1; H NMR (CDCl3,
60 MHz) δ 1.15 (d, J ) 5.5 Hz, 6H), 1.25 (d, J ) 5.5 Hz, 6H),
1.3-2.4 (m, 8H), 2.93-3.2 (m, 4H), 3.27 (q, J ) 7 Hz, 2H), 6.75
(m, 2H), 7.0-7.4 (m, 6H). Anal. Calcd for C24H34N2: C, 82.29;
H, 9.71; N, 8.00. Found: C, 82.00; H, 9.58; N, 8.38.
(8) This was ascertained by comparing the δ value of N-Me in
products obtained from the opening of styrene oxide with N-methyl
aniline. For reference, see: Chini, M.; Crotti, P.; Macchia, F. J . Org.
Chem. 1991, 56, 5939.
(9) (a) For general methods, see: Sekar, G.; DattaGupta, A.; Singh,
V. K. J . Org. Chem. 1998, 63, 2961. (b) Silica gel coated TLC plates
were used.
2-N-(tr a n s-2′-Am in op h en yl Cycloh exyl)-5-Ch lor o P yr i-
d in e (1l). Mp 89-90 °C; Rf 0.62 (1:10, EtOAc in petroleum
1
ether); IR (KBr) 3400 cm-1; H NMR (CDCl3, 300 MHz) δ 1.25

Notes
J . Org. Chem., Vol. 64, No. 7, 1999 2539
(m, 4H), 1.78 (m, 2H), 2.2 (m, 1H), 2.28 (m, 1H), 3.13 (m, 2H),
3.81 (m, 1H), 4.37 (m, 1H), 6.24 (m, 1H), 6.48 (m, 2H), 6.62 (m,
1H), 7.05 (m, 2H), 7.26 (m, 1H), 8.05 (m, 1H). Anal. Calcd for
C17H20N3Cl: C, 67.66; H, 6.63; N, 13.93. Found: C, 67.37; H,
6.57; N, 13.80.
6.71 (m, 3H), 7.23 (m, 7H); MS (EI, m/z) 394 (M+). Anal. Calcd
for C27H42N2: C, 82.23; H, 10.66; N, 7.11. Found: C, 82.00; H,
10.58; N, 7.32.
N-Met h yl-N-p h en yl[2-(N′-ter t-b u t yl)a m in o]t r id eca n y-
la m in e (7). Viscous liquid; Rf 0.15 (1:10, EtOAc in petroleum
1
ether); IR (neat) 3380 cm-1; H NMR (CDCl3, 300 MHz) δ 0.87
tr a n s-N-P h en yl-N′-ben zyl-1,2-cycloh exa n ed ia m in e (2).
Mp 68-70 °C; Rf 0.58 (1:3, EtOAc in petroleum ether); IR (KBr)
(t, J ) 6.8 Hz, 3H), 1.05 (s, 9H), 1.25 (m, 18H), 1.36 (m, 2H),
2.89 (s, 3H), 2.94 (m, 1H), 3.19 (d, J ) 6.0 Hz, 2H), 6.70 (m,
3H), 7.21 (m, 2H); MS (EI, m/z) 360 (M+). Anal. Calcd for
C24H44N2; C, 80.00; H, 12.22; N, 7.78. Found: C, 79.72; H, 12.21;
N, 7.96.
1
3295 cm-1; H NMR (CDCl3, 300 MHz) δ 1.1 (m, 1H), 1.23 (m,
3H), 1.7 (m, 2H), 2.10 (bs, 1H, NH), 2.18 (m, 2H), 2.33 (ddd, J )
9.9, 9.9, 4.2 Hz, 1H), 3.12 (ddd, J ) 10.2, 10.2, 3.6 Hz, 1H), 3.37
(bs, 1H, NH), 3.80 (ABq, J ) 13.5 Hz, 2H), 6.64 (m, 3H), 7.13
(m, 2H), 7.25 (m, 5H); 13C NMR (CDCl3, 75 MHz) δ 24.6, 25.0,
31.4, 32.5, 50.7, 57.5, 60.8, 114.0, 117.7, 126.9, 128.1, 128.4,
129.2, 140.6, 148.2; LCMS (APCI, m/z) 281 (M+ + 1). Anal. Calcd
for C19H24N2: C, 81.43; H, 8.57; N, 10.00. Found: C, 81.58; H,
8.49; N, 9.96.
N-Meth yl-N-ph en yl[3-ben zylam in o]bu tyl-2-am in e (8). Vis-
cous liquid; Rf 0.32 (1:10, EtOAc in petroleum ether); IR (neat)
3300 cm-1 1H NMR (CDCl3, 300 MHz) δ 1.02 (d, J ) 6.6 Hz,
;
3H), 1.14 (d, J ) 6.6 Hz, 3H), 2.30 (bs, 1H, NH), 2.50 (s, 3H),
2.73 (m, 1H), 3.67 (m, 1H), 3.81 (ABq, J ) 13.5 Hz, 2H), 6.76 (t,
J ) 7.2 Hz, 1H), 6.8 (d, J ) 8.1 Hz, 2H), 7.26 (m, 7H); MS (EI,
m/z) 268 (M+). Anal. Calcd for C18H24N2: C, 80.60; H, 8.95; N,
10.45. Found: C, 80.44; H, 8.89; N, 10.58.
tr a n s-N,N′-Dip h en yl-1,2-cyclop en ta n ed ia m in e (3). Vis-
cous liquid; Rf 0.3 (2% EtOAc in petroleum ether); IR (neat) 3365
cm-1 1H NMR (CDCl3, 300 MHz) δ 1.5 (m, 2H), 1.8 (m, 2H),
;
2.21 (m, 2H), 3.6 (m, 2H), 3.78 (bs, 2H, NH), 6.64 (m, 4H), 6.70
N-Ben zyl-[2-(N′-m eth yl-N′-p h en yl)a m in o]-2-p h en yleth y-
la m in e (9). Viscous liquid; Rf 0.14 (1:20, EtOAc in petroleum
(m, 2H), 7.18 (m, 4H); 13C NMR (CDCl3, 75 MHz) δ 21.4, 31.2,
60.7, 113.4, 117.5, 129.3, 147,7; LCMS (APCI, m/z) 253 (M+
1). Anal. Calcd for C17H20N2: C, 80.95; H, 7.94; N, 11.11.
Found: C, 80.87; H, 7.89; N, 11.20.
+
1
ether); IR (neat) 3400 cm-1; H NMR (CDCl3, 300 MHz) δ 1.72
(bs, 1H, NH), 2.67 (s, 3H), 3.22 (d, J ) 7.8 Hz, 2H), 3.89 (ABq,
J ) 13.5 Hz, 2H), 5.21 (t, J ) 7.2 Hz, 1H), 6.78 (t, J ) 8.1 Hz,
1H), 6.91 (d, J ) 8.1 Hz, 2H), 7.19 (m, 2H), 7.29 (m, 10H); MS
(EI, m/z) 316 (M+). Anal. Calcd for C22H24N2: C, 83.54; H, 7.59;
N, 8.86. Found: C, 83.32; H, 7.48; N, 9.02.
tr a n s-N,N′-Dip h en yl-1,2-cyclooct-5-en ed ia m in e (4). Mp
71-72 °C; Rf 0.34 (2% EtOAc in petroleum ether); IR (KBr) 3400
1
cm-1; H NMR (CDCl3, 300 MHz) δ 1.62 (m, 2H), 2.10 (m, 2H),
2.30 (m, 2H), 2.43 (m, 2H), 3.66 (d, J ) 8.7 Hz, 2H), 3.93 (bs,
2H, NH), 5.78 (t, J ) 5.4 Hz, 2H), 6.54 (m, 4H), 6.7 (m, 2H),
7.18 (m, 4H); 13C NMR (CDCl3, 75 MHz) δ 23.8, 33.1, 56.2, 113.2,
117.3, 129.3, 129.7; LCMS (APCI, m/z) 293 (M+ + 1). Anal. Calcd
for C20H24N2; C, 82.19; H, 8.22; N, 9.59. Found: C, 81.98; H,
8.10; N, 9.86.
N-n -Bu tyl-[2-(N′-m eth yl-N′-p h en yl)a m in o]-2-p h en yleth -
yla m in e (10). Viscous liquid; Rf 0.65 (1:5, EtOAc in petroleum
1
ether); IR (neat) 3300 cm-1; H NMR (CDCl3, 300 MHz) δ 0.89
(t, J ) 7.2 Hz, 3H), 1.33 (m, 2H), 1.47 (m, 2H), 1.55 (bs, 1H,
NH), 2.68 (m, 2H), 2.71 (s, 3H), 3.20 (d, J ) 7.8 Hz, 2H), 5.16 (t,
J ) 6.6 Hz, 1H), 6.75 (t, J ) 7.2 Hz, 1H), 6.89 (d, J ) 8.1 Hz,
2H), 7.27 (m, 7H); MS (EI, m/z) 282 (M+). Anal. Calcd for
N,N′-Dip h en yl-1,2-d od eca n ed ia m in e (5). Viscous liquid;
Rf 0.55 (2% EtOAc in petroleum ether); IR (neat) 3150-3440
cm-1; 1H NMR (CDCl3, 80 MHz) δ 1.00 (t, J ) 4.4 Hz, 3H), 1.25
(m, 18H), 3.5 (m, 5H), 6.7 (m, 5H), 7.5 (m, 5H). Anal. Calcd for
C24H36N2: C, 81.82; H, 10.23; N, 7.95. Found: C, 81.48; H, 10.18.
N -Me t h yl-N -p h e n yl[2-(N ′-b e n zyl)a m in o]t r id e ca n yle -
a m in e (6). Viscous liquid; Rf 0.3 (1:10, EtOAc in petroleum
C
19H26N2: C, 80.85; H, 9.22; N, 9.93. Found: C, 80.58; H, 9.18;
N, 10.00.
Ack n ow led gm en t. V.K.S. thanks DST (Govern-
ment of India) for a Swarnajayanti Fellowship (1998).
We also thank CSIR, New Delhi for a research grant
(to V.K.S.) and a Senior Research Fellowship (to G.S.).
1
ether); IR (neat) 3340 cm-1; H NMR (CDCl3, 300 MHz) δ 0.88
(t, J ) 5.4 Hz, 3H), 1.26 (m, 18H), 1.49 (m, 2H), 1.65 (bs, 1H,
NH), 2.87 (s, 3H), 2.92 (m, 1H), 3.20 (dd, J ) 14.4, 5.4 Hz, 1H),
3.34 (dd, J ) 14.4, 8.4 Hz, 1H), 3.79 (ABq, J ) 13.5 Hz, 2H),
J O981869R