Concerning the product of [2 + 2] cyclodimerization of 9-allenylcarbazole

Article abstract of DOI:10.1007/s10593-005-0059-x

The isomerization of 9-propargylcarbazole in alcoholic alkali leads to the product of dimerization of 9-allenylcarbazole, 1,2-bis(9-carbazolylmethylene) cyclobutane, the structure of which was established by X-ray diffraction analysis.

Full text of DOI:10.1007/s10593-005-0059-x

Chemistry of Heterocyclic Compounds, Vol. 40, No. 11, 2004
CONCERNING THE PRODUCT
OF [2 + 2] CYCLODIMERIZATION
OF 9-ALLENYLCARBAZOLE
1
2
2
1
1
O. I. Kharaneko , S. V. Shishkina , O. V. Shishkin , A. V. Kibalnyi , and V. I. Dulenko
The isomerization of 9-propargylcarbazole in alcoholic alkali leads to the product of dimerization of
-allenylcarbazole, 1,2-bis(9-carbazolylmethylene)cyclobutane, the structure of which was established
9
by X-ray diffraction analysis.
Keywords: allenylcarbazole, 1,2-bis(9-carbazolylmethylene)cyclobutane, cyclodimerization.
We have synthesized 9-propargylcarbazole 1 with the aim of studying its properties and application in
synthesis of acetylene derivatives of carbazole. This was achieved by the action of propargyl bromide on
carbazolylsodium, prepared in 80% yield by heating metallic sodium and carbazole in dioxane. This compound
was obtained previously by the action of propargyl bromide on the sodium derivative of carbazole in liquid
ammonia [1,2], in DMF [3], or in acetonitrile [4]. The patented procedure [5] differed in the use of potassium
derivative of carbazole.
1
2
. Na
. BrCH C
CH
2
Dioxane
N
N
H
H
1
Both on carrying out the synthesis and on studying the Favorsky rearrangement of 9-propargylcarbazole
(heating in alcoholic alkali) we noted the formation of a difficultly soluble product, which became
1
predominant on boiling compound 1 in alcoholic KOH solution for 8 h. The formation of difficultly soluble solid
on rearranging compound 1 has been observed previously. For example, the authors of [1], while studying the
isomerization of N-propargyl-substituted heterocycles, assumed it to be a polymer. We have established that
under the conditions indicated above the main product of isomerization of carbazole 1 is an individual compound
having the same elemental composition as the initial carbazole 1. The structures of the isomeric
9
-allenylcarbazole 2 and 9-propynylcarbazole 3 are excluded according to the spectral characteristics, by the
_
_________________________________________________________________________________________
1
L. M. Litvinenko Institute of Physical Organic and Coal Chemistry, National Academy of Sciences of
2
Ukraine, 70 R. Luxemburg St, Donetsk 83114, Ukraine; e-mail: kibalny@infou.donetsk.ua. Department of
Alkali Halide Crystals STC, Institute for Single Crystals, National Academy of Sciences of Ukraine, 60 Lenina
Ave, Kharkov 61001, Ukraine; e-mail: shishkin@xray.isc.kharkov.com. Translated from Khimiya
Geterotsiklicheskikh Soedinenii, No. 11, pp. 1652-1661, November, 2004. Original article submitted April 13,
2
001.
0
009-3122/04/4011-1427©2004 Springer Science+Business Media, Inc.
1427

lack of carbonyl group absorption band, and also of allenic and acetylenic bonds (at 1950-1980 and
-
1
1
2
100-2200 cm ) and by the presence in the H NMR spectrum of a complete set of signals for the aromatic
protons of carbazole nucleus substituted at position 9.
_
_
OH
OH
1
N
N
Dimer
2
4
3
The compound obtained is neither an oxidation product of propargylcarbazole 1, nor the hydrolysis
product of allene 2, nor the cyclization product of the latter into a derivative of pyrrolocarbazole, which might
have been expected on the basis of the results of [6]. The molecular weight measured by the Rast method,
proving to be double the molecular weight of the initial compound 1, enabled the dimeric structure to be
proposed, i.e. bis(9-carbazolylmethylene)cyclobutane (4), the product of [2 + 2] cyclodimerization of
9
-allenylcarbazole 2. The significant predominance of allene 2 in the equilibrium mixture compared with the
other isomers 1 and 3, recorded by the authors of [1] on carrying out the isomerization using alkaline catalysts,
also points in favor of allene dimer. According to the data of the same authors, this special feature is probably
most widely expressed among carbazole derivatives. On isomerizing propargylcarbazole under certain other
conditions (potassium hydroxide in DMSO at room temperature) used by the authors of [3,7], 9-allenylcarbazole
2
was isolated in almost quantitative yield.
We have shown that in the simpler and more convenient way dimer 4 may be obtained from the
available [8] epoxypropylcarbazole 5, as shown in the Scheme.
_
SOCl2
OH
2
4
N
N
Cl
5
O
Cl
6
The dimerization of allenes [8] may lead to 1,2- and 1,3-disubstituted derivatives of cyclobutane, and on
the basis of the data obtained it is not possible to make an unequivocal choice between the structures of 1,2- and
1
,3-bis(9-carbazolylmethylene)cyclobutane (4a and 4b respectively). We therefore carried out an X-ray
diffraction investigation of the dimerization product 4, showing unequivocally that the obtained dimer
corresponds to structure 4a (Fig. 1, Tables 1-3).
N
N
N
N
4b
4a
1
428

Fig. 1. Structure of 1,2-bis(9-carbazolylmethylene)cyclobutane 4a molecule.
4
TABLE 1. Coordinates (×10 ) and Equivalent Isotropic Thermal Parameters
3
(
×10 ) of the Non-hydrogen Atoms in the Structure of Compound 4a
2
Atom
1
x
y
z
Ueq, Å
2
3
4
5
N(1A)
6189(7)
6316(7)
7760(9)
8749(9)
3687(2)
4418(2)
3805(3)
3595(3)
3768(3)
4138(3)
4339(3)
4176(3)
4278(3)
4599(3)
4598(3)
4284(3)
3961(3)
3961(3)
3325(2)
3272(2)
2835(3)
3072(2)
3525(2)
3976(3)
4642(3)
4497(3)
4800(3)
5218(3)
5355(3)
5063(2)
9927(5)
12725(6)
10852(8)
12177(7)
12885(7)
12277(9)
10955(9)
10223(7)
8810(7)
7662(8)
6447(7)
6327(7)
7430(7)
8650(7)
10146(7)
11310(6)
11721(7)
13224(7)
12706(6)
13342(6)
11373(8)
10422(7)
9201(7)
8931(7)
9900(7)
11153(7)
40(1)
39(1)
39(2)
44(2)
60(2)
67(2)
58(2)
44(2)
49(2)
56(2)
61(2)
65(2)
52(2)
42(2)
46(2)
43(2)
58(2)
55(2)
40(2)
48(2)
41(2)
45(2)
53(2)
57(2)
52(2)
42(2)
N(2A)
C(1A)
C(2A)
C(3A)
10327(10)
11011(10)
10005(10)
8438(10)
7153(9)
C(4A)
C(5A)
C(6A)
C(7A)
C(8A)
7005(10)
5602(11)
4294(10)
4405(9)
C(9A)
C(10A)
C(11A)
C(12A)
C(13A)
C(14A)
C(15A)
C(16A)
C(17A)
C(18A)
C(19A)
C(20A)
C(21A)
C(22A)
C(23A)
C(24A)
5794(10)
5171(8)
4883(8)
4068(9)
4669(9)
5336(8)
5936(8)
5285(10)
3762(10)
3017(9)
3846(10)
5355(10)
6140(9)
1
429

TABLE 1 (continued)
1
2
3
4
5
C(25A)
C(26A)
C(27A)
C(28A)
C(29A)
C(30A)
N(1B)
7637(10)
5119(3)
5468(3)
5415(3)
5021(3)
4668(3)
4724(2)
2540(2)
1833(2)
2265(2)
2256(3)
1942(3)
1633(3)
1644(3)
1965(3)
2066(3)
1900(3)
2114(3)
2483(3)
2655(3)
2426(2)
2908(2)
2967(2)
3416(3)
3184(3)
2719(2)
2274(2)
1536(3)
1605(3)
1257(3)
863(3)
12417(7)
12819(7)
14141(9)
15083(8)
14672(8)
13367(7)
9548(6)
6736(5)
10826(6)
12073(8)
13180(7)
13036(8)
11803(8)
10666(7)
9249(8)
8540(8)
7204(8)
6605(8)
7264(7)
8595(7)
9364(6)
8191(6)
7825(7)
6287(7)
6793(6)
6130(6)
6086(8)
4760(8)
4394(8)
5310(9)
6604(9)
7014(7)
8266(7)
9514(8)
10487(9)
10262(7)
9045(7)
8066(7)
46(2)
55(2)
70(3)
71(2)
55(2)
38(2)
41(2)
39(1)
42(2)
53(2)
60(2)
67(2)
58(2)
42(2)
45(2)
55(2)
65(2)
60(2)
51(2)
37(2)
40(2)
41(2)
58(2)
59(2)
44(2)
44(2)
47(2)
51(2)
70(2)
72(2)
61(2)
42(2)
43(2)
56(2)
67(3)
57(2)
45(2)
40(2)
8972(9)
10253(11)
10239(10)
8982(10)
7683(9)
8176(7)
N(2B)
8080(6)
C(1B)
C(2B)
8564(9)
9974(10)
10034(10)
8718(13)
7307(10)
7211(9)
C(3B)
C(4B)
C(5B)
C(6B)
C(7B)
C(8B)
5961(10)
4364(10)
3392(9)
C(9B)
C(10B)
C(11B)
C(12B)
C(13B)
C(14B)
C(15B)
C(16B)
C(17B)
C(18B)
C(19B)
C(20B)
C(21B)
C(22B)
C(23B)
C(24B)
C(25B)
C(26B)
C(27B)
C(28B)
C(29B)
C(30B)
4052(10)
5613(10)
6591(10)
9235(7)
9489(7)
10365(9)
9761(9)
9055(8)
8460(8)
6688(10)
5366(9)
4090(10)
4086(11)
5405(11)
6712(9)
795(3)
1126(2)
1167(3)
877(3)
8216(9)
9014(11)
10547(13)
11397(9)
10620(10)
9090(10)
1010(3)
1437(3)
1736(3)
1609(3)
This variant of the dimerization of 9-allenylcarbazole 2 is effected in our opinion as a result of the
association of the heterocyclic fragments in solution with the formation of eximers (resonance interaction).
There are two molecules (A and B) in the symmetrically independent part of the unit cell. The molecule
of compound 4a has a conformation in which the two π-electron systems are disposed practically parallel one
above the other (the angle between them is 12.9° in molecule A and 12.4° in molecule B). The conjugated cyclic
systems are not entirely planar, the angle between the planes of the benzene rings is 4.2 and 5.1° in A and 5.1
and 3.6° in B. The cyclobutane ring is bent somewhat along the C(15)–C(17) bond (the angle between the planes
of C(14), C(15), C(17) and C(15), C(16), C(17) is 6.7° in conformer A and 7.3° in conformer B). The exocyclic
double bonds C(13)–C(14) and C(18)–C(17) are twisted somewhat relative to one another [torsion angle C(13)–
C(14)–C(17)–C(18) is 19(2) in A and -16(2)° in B]. The conjugation between the tricyclic
1
430

fragments and the double bonds is disturbed to a significant extent as a result of their noncoplanarity [torsion
angle C(1)–N(1)–C(13)–C(14) is 48.1(9) in A, 139.9(7)° in B and C(19)–N(2)–C(18)–C(17) is 47.0(9) in A,
1
36.3(7)° in B].
Such a conformation of the molecule is probably caused by significant steric stress as shown by
shortened intramolecular contacts for H(2A)–C(14A) at 2.84 (sum of van der Waals radii 2.87 [11]),
H(2A)–C(17A) 2.82 (2.87), H(11A)–C(13A) 2.84 (2.87), H(20A)–C(14A) 2.75 (2.87), H(20A)–C(17A) 2.81
(
2.87), C(20A)–C(12A) 3.38 (3.42), C(20A)–C(13A) 3.32 (3.42), C(20A)–C(14A) 3.31 (3.42), C(20A)–C(17A)
3
3
.31 (3.42), N(2A)–C(1A) 3.17 (3.21), C(19A)–N(1A) 3.15 (3.21), C(19A)–C(1A) 3.30 (3.42), C(21A)–C(11A)
.39 (3.42), C(18A)–C(2A) 3.38 (3.42), H(11B)–C(14B) 2.85 (2.87), H(11B)–C(17B) 2.82 (2.87),
H(29B)–C(14B) 2.77 (2.87), H(29B)–C(17B) 2.82 Å (2.87 Å).
TABLE 2. Bond Lengths (l) in the Structure of Compound 4a
Bond
N(1A)−C(1A)
N(1A)−C(12A)
N(2A)−C(18A)
C(1A)−C(2A)
C(2A)−C(3A)
C(4A)−C(5A)
C(6A)−C(7A)
C(7A)−C(12A)
C(9A)−C(10A)
C(11A)−C(12A)
C(14A)−C(17A)
C(15A)−C(16A)
C(17A)−C(18A)
C(19A)−C(24A)
C(21A)−C(22A)
C(23A)−C(24A)
C(25A)−C(30A)
C(26A)−C(27A)
C(28A)−C(29A)
N(1B)−C(12B)
N(1B)−C(13B)
N(2B)−C(18B)
C(1B)−C(2B)
l, Å
1.367(8)
Bond
l, Å
N(1A)−C(13A)
N(2A)−C(30A)
N(2A)−C(19A)
C(1A)−C(6A)
C(3A)−C(4A)
C(5A)−C(6A)
1.390(8)
1.374(8)
1.426(8)
1.427(9)
1.41(1)
1.396(8)
1.411(8)
1.384(9)
1.371(9)
1.38(1)
1.357(9)
1.398(9)
1.352(9)
1.373(9)
1.336(8)
1.495(8)
1.507(8)
1.359(8)
1.385(9)
1.351(9)
1.432(8)
1.42(1)
1.449(9)
1.42(1)
C(7A)−C(8A)
C(8A)−C(9A)
1.39(1)
C(10A)−C(11A)
C(13A)−C(14A)
C(14A)−C(15A)
C(16A)−C(17A)
C(19A)−C(20A)
C(20A)−C(21A)
C(22A)−C(23A)
C(24A)−C(25A)
C(25A)−C(26A)
C(27A)−C(28A)
C(29A)−C(30A)
N(1B)−C(1B)
1.348(8)
1.469(8)
1.530(8)
1.325(8)
1.402(9)
1.401(9)
1.396(9)
1.396(9)
1.369(9)
1.37(1)
1.40(1)
1.365(9)
1.399(8)
1.377(9)
1.407(8)
1.39(1)
1.381(8)
1.413(8)
1.403(8)
1.373(8)
1.38(1)
N(2B)−C(19B)
N(2B)−C(30B)
C(1B)−C(6B)
C(2B)−C(3B)
C(3B)−C(4B)
1.38(1)
C(4B)−C(5B)
C(6B)−C(7B)
1.365(9)
1.439(9)
1.398(9)
1.39(1)
C(5B)−C(6B)
C(7B)−C(8B)
C(8B)−C(9B)
1.403(9)
1.380(9)
1.39(1)
C(7B)−C(12B)
C(9B)−C(10B)
C(11B)−C(12B)
C(14B)−C(17B)
C(15B)−C(16B)
C(17B)−C(18B)
C(19B)−C(24B)
C(21B)−C(22B)
C(23B)−C(24B)
C(25B)−C(26B)
C(26B) −C(27B)
C(28B)−C(29B)
C(10B)−C(11B)
C(13B)−C(14B)
C(14B)−C(15B)
C(16B)−C(17B)
C(19B)−C(20B)
C(20B)−C(21B)
C(22B)−C(23B)
C(24B)−C(25B)
C(25B)−C(30B)
C(27B)−C(28B)
C(29B)−C(30B)
1.353(9)
1.329(8)
1.532(8)
1.544(9)
1.392(9)
1.38(1)
1.405(9)
1.466(8)
1.557(9)
1.320(8)
1.414(9)
1.38(1)
1.37(1)
1.37(1)
1.426(8)
1.443(9)
1.41(1)
1.393(9)
1.36(1)
1.379(9)
1.361(9)
1
431

This leads to a lengthening of bonds N(1)–C(13) 1.390(8) (A), 1.413(8) (B), and N(2)–C(18) 1.411(8)
A), 1.403(68) Å (B) compared with the mean value of 1.355 Å [10].
(
Such a sterically stressed conformation of the molecule is probably stabilized to a significant degree by
fairly strong stacking interactions between the π-systems of the tricyclic fragments. Their close-to-parallel
orientation and the distances between the fragment atoms being in the range 3.15 to 3.8 Å indicates this.
The compound 4a molecules in the crystal form mutually perpendicular stacks along the
crystallographic directions (1 0 0) and (0 0 1). The angle between the planes of the tricyclic fragments of
neighboring molecules (0.7°) and the distance between the spatially adjacent π-systems (3.55 Å) suggests the
presence of intermolecular stacking interactions also. Shortened intermolecular contacts were detected in the
crystal between molecules located in the independent part of the unit cell, H(13A)–C(12B) 2.83 (x, y, z) and
H(13B)–C(1A) 2.85 Å (x, y, z).
The presence in the crystal structure of compound 4a of intra- and intermolecular stacking interactions
creates conditions for carrying out various topochemical reactions, which may lead to both intra- and
intermolecular cyclization involving the tricyclic fragments.
TABLE 3. Bond Angles (ω) in the Structure of Compound 4a
Angle
1
ω, deg.
2
Angle
3
ω, deg.
4
C(1A)−N(1A)−C(13A)
C(13A)−N(1A)−C(12A)
C(30A)−N(2A)−C(19A)
N(1A)−C(1A)−C(2A)
C(2A)−C(1A)−C(6A)
C(2A)−C(3A) −C(4A)
C(6A)−C(5A)−C(4A)
126.7(5)
124.5(6)
108.7(6)
130.3(7)
119.0(7)
122.2(7)
122(1)
C(1A)−N(1A)−C(12A)
C(30A)−N(2A)−C(18A)
C(18A)−N(2A)−C(19A)
N(1A)−C(1A)−C(6A)
C(3A)−C(2A)−C(1A)
C(5A)−C(4A)−C(3A)
C(5A)−C(6A)−C(1A)
C(1A)−C(6A)−C(7A)
C(8A)−C(7A)−C(6A)
108.6(6)
125.7(6)
125.4(6)
110.5(6)
119.2(8)
117.4(8)
120.1(7)
105.1(6)
134.7(8)
119.8(7)
120.9(7)
129.9(7)
108.4(6)
138.8(6)
91.2(5)
C(5A)−C(6A)−C(7A)
134.7(8)
118.0(7)
107.3(6)
120.7(6)
118.9(7)
121.6(6)
127.4(6)
129.5(6)
89.1(5)
C(8A)−C(7A)−C(12A)
C(12A)−C(7A)−C(6A)
C(8A)−C(9A)−C(10A)
C(12A)−C(11A)−C(10A)
C(11A)−C(12A) −C(7A)
C(14A)−C(13A)−N(1A)
C(13A)−C(14A)−C(15A)
C(14A)−C(15A)−C(16A)
C(18A)−C(17A)−C(14A)
C(14A)−C(17A)−C(16A)
C(20A)−C(19A)−C(24A)
C(24A)−C(19A)−N(2A)
C(20A)−C(21A)−C(22A)
C(22A)−C(23A)−C(24A)
C(23A)−C(24A)−C(25A)
C(30A)−C(25A)−C(26A)
C(26A)−C(25A)−C(24A)
C(26A)−C(27A)−C(28A)
C(30A)−C(29A)−C(28A)
C(29A)−C(30A)−C(25A)
C(12B)−N(1B)−C(1B)
C(1B)−N(1B)−C(13B)
C(19B)−N(2B)−C(30B)
C(2B)−C(1B)−C(6B)
C(9A)−C(8A)−C(7A)
C(11A)−C(10A)−C(9A)
C(11A)−C(12A)−N(1A)
N(1A)−C(12A)−C(7A)
C(13A)−C(14A)−C(17A)
C(17A)−C(14A)−C(15A)
C(17A)−C(16A)−C(15A)
C(18A)−C(17A)−C(16A)
C(17A)−C(18A)−N(2A)
C(20A)−C(19A)−N(2A)
C(19A)−C(20A)−C(21A)
C(23A)−C(22A)−C(21A)
C(23A)−C(24A)−C(19A)
C(19A)−C(24A)−C(25A)
C(30A)−C(25A)−C(24A)
C(27A)−C(26A)−C(25A)
C(29A)−C(28A)−C(27A)
C(29A)−C(30A)−N(2A)
N(2A)−C(30A)−C(25A)
C(12B)−N(1B)−C(13B)
C(19B)−N(2B)−C(18B)
C(18B)−N(2B)−C(30B)
C(2B)−C(1B)−N(1B)
88.4(5)
139.0(6)
91.0(5)
129.8(5)
127.2(5)
129.5(7)
117.0(7)
120.7(6)
117.7(7)
107.6(6)
107.5(6)
118.9(7)
120.7(7)
129.5(7)
108.9(6)
127.1(5)
125.1(6)
125.7(6)
130.5(7)
123.6(7)
107.0(6)
120.9(7)
120.0(7)
134.4(7)
119.1(7)
133.4(7)
120.4(7)
119.2(7)
121.5(7)
109.4(6)
123.3(6)
109.2(7)
121.4(6)
1
432

TABLE 3 (continued)
1
2
3
4
C(6B)−C(1B)−N(1B)
C(2B)−C(3B)−C(4B)
C(4B)−C(5B)−C(6B)
C(1B)−C(6B)−C(7B)
108.0(6)
121.1(7)
119.4(7)
107.0(6)
119.8(7)
107.5(6)
119.7(7)
116.4(8)
129.7(7)
125.9(5)
128.0(6)
88.1(5)
C(1B)−C(2B)−C(3B)
C(5B)−C(4B)−C(3B)
C(1B)−C(6B)−C(5B)
C(5B)−C(6B)−C(7B)
C(8B)−C(7B)−C(6B)
C(7B)−C(8B)−C(9B)
118.6(7)
120.6(7)
119.0(7)
134.0(7)
132.5(7)
118.7(8)
123.3(7)
108.0(6)
121.9(7)
139.8(6)
92.1(5)
C(8B)−C(7B)−C(12B)
C(12B)−C(7B)−C(6B)
C(8B)−C(9B)−C(10B)
C(10B)−C(11B)−C(12B)
N(1B)−C(12B)−C(11B)
C(14B)−C(13B)−N(1B)
C(13B)−C(14B)−C(15B)
C(14B)−C(15B)−C(16B)
C(18B)−C(17B)−C(14B)
C(14B)−C(17B)−C(16B)
N(2B)−C(19B)−C(20B)
C(20B)−C(19B)−C(24B)
C(20B)−C(21B)−C(22B)
C(24B)−C(23B)−C(22B)
C(23B)−C(24B)−C(25B)
C(26B)−C(25B)−C(24B)
C(24B)−C(25B)−C(30B)
C(26B)−C(27B)−C(28B)
C(30B)−C(29B)−C(28B)
C(29B)−C(30B)−C(25B)
C(11B)−C(10B)−C(9B)
N(1B)−C(12B)−C(7B)
C(7B)−C(12B)−C(11B)
C(13B)−C(14B)−C(17B)
C(17B)−C(14B)−C(15B)
C(17B)−C(16B)−C(15B)
C(18B)−C(17B) −C(16B)
C(17B)−C(18B)−N(2B)
N(2B)−C(19B)−C(24B)
C(21B)−C(20B)−C(19B)
C(23B)−C(22B)−C(21B)
C(23B)−C(24B)−C(19B)
C(19B)−C(24B)−C(25B)
C(26B)−C(25B)−C(30B)
C(27B)−C(26B)−C(25B)
C(29B)−C(28B)−C(27B)
C(29B)−C(30B)−N(2B)
N(2B)−C(30B)−C(25B)
88.3(5)
139.7(6)
91.0(5)
129.0(5)
126.1(5)
109.5(6)
117.1(7)
120.2(7)
119.3(7)
106.9(6)
116.8(7)
120.7(8)
118.5(8)
131.2(7)
106.9(6)
129.3(7)
121.2(7)
122.0(7)
120.1(8)
133.8(7)
135.7(7)
107.4(6)
121.8(7)
120.3(8)
121.9(6)
EXPERIMENTAL
1
The H NMR spectra were recorded on a Gemini 200 (200 MHz) instrument, internal standard was
TMS. The IR spectra were taken on a Specord IR 75 instrument in KBr disks. The numbering of the carbon
atoms in the compound 4a molecule is given in Fig. 1.
X-Ray Diffraction Investigation of Compound 4a. The crystals of compound 4a are monoclinic,
3
C H N , at 20°C: a = 9.036(2), b = 25,645(7), c = 10.291(2) Å; β = 115.10(2)°; V = 2159.5(9) Å ;
3
0
22
2
3
-1
M = 410.50; Z = 4; space group P2 ; d = 1.263 g/cm ; µ(MoKα) = 0.074 mm ; F(000) = 864. The parameters
r
1
calc
of the unit cell and the intensities of 4034 reflections (3795 independent, Rint = 0.04) were measured on a
Siemens automatic P3/PC four-circle diffractometer (MoK , graphite monochromator, 2θ/θ scanning,
α
2
θmax = 50°).
The structure was solved by the direct method with the SHELX97 [12] set of programs. The positions of
the hydrogen atoms were clarified by an electron density difference synthesis and refined with a rider model
2
with Uiso = 1.2 U . The structure was refined according to F by a full-matrix least-squares method with an
eq
anisotropic approach for the nonhydrogen atoms to wR = 0.134 for 3795 reflections (R = 0.049 for
2
1
1
998 reflections with F > 4σ(F), S = 0.894). The final coordinates of atoms are given in Table 1, and values of
bond lengths and bond angles in Tables 2 and 3.
-Propargylcarbazole (1). Mixture of carbazole (16.7 g, 0.1 mol) and metallic sodium (2.3 g, 0.1 mol)
in anhydrous dioxane (50 ml) was boiled with stirring until complete dissolution of sodium. Propargyl bromide
46.7 g, 0.4 mol) was added with stirring to the boiling mixture. At the end of the intense exothermic reaction the
9
(
mixture was boiled for a further 15 min, and poured into cold water (500 ml). The separated oil was removed,
washed several times with warm water, and left for ~16 h at room temperature. The separated crystals
1
433

were filtered off, washed with water, dried, and recrystallized from cyclohexane. Yield 16.4 g (80%);
mp 101-102°C. After recrystallization from methanol the compound had mp 106-107°C (mp 108°C [1]).
9
-(2,3-Dichloro-1-propyl)carbazole (6). Mixture of 9-epoxypropylcarbazole 5 (22.3 g, 0.1 mol),
benzene (50 ml), DMF (0.5 ml), and SOCl (12 ml) was heated under reflux on a water bath. After the
2
exothermic reaction had passed the solvent was distilled off, and the residue was recrystallized from
1
cyclohexane. Yield 25 g (90%); mp 90-92°C. H NMR spectrum (DMSO-d ), δ, ppm (J, Hz): 4.0 (2H, d, J ~ 3.9,
6
N-CH ); 4.6-4.9 (3H, m, CH and CH ); 7.2 (2H, t, J ~ 7.9, H-2,7); 7.4 (2H, t, J ~ 8.0, H-3,6); 7.6 (2H, d, J ~ 7.9,
2
2
H-1,8); 8.1 (2H, d, J ~ 8.0, H-4,5). Found, %: C 64.5; H 4.9; Cl 25.6; N 5.2. C H Cl N. Calculated, %:
1
5
13
2
C 64.77; H 4.71; Cl 25.49; N 5.04.
,2-Bis(9-carbazolylmethylene)cyclobutane (4a). A. Mixture of 9-propargylcarbazole 1 (1.93 g,
.01 mol), ethanol (5 ml), and KOH (0.1 g) was boiled in nitrogen atmosphere for 8 h. The precipitated solid was
filtered off, washed with acetone, and with water, dried in the air, and crystallized from pyridine. Yield 1.5 g
1
0
-
1
(
1
78%) of pale yellow prisms; mp 224-225°C. IR spectrum (KBr), ν, cm : 3040, 2960, 2910, 1640, 1620, 1590,
1
450, 740, 715. H NMR spectrum (Py-d ), δ, ppm (J, Hz): 2.85 (4H, s, 2H-15, 2H-16); 6.54 (2H, s, H-13,18);
5
6
.85 (4H, t, J ~ 7.5, H-3,10,21,28); 6.9 (4H, d, J ~ 8.1, H-2,11,20,29); 7.1 (4H, t, J ~ 7.5, H-4,9,22,27); 7.35 (4H,
d, J ~ 7.8, H-5,8,23,26). Found, %: C 87.6; H 5.5; N 6.9. C H N . Calculated, %: C 87.77, H 5.40; N 6.82.
3
0
22
2
B. Mixture of compound 6 (27.8 g, 0.1 mol) and KOH (22.4 g, 0.4 mol) in 2-propanol (50 ml) was
boiled with stirring for 24 h. After cooling, the solid was filtered off, washed with acetone, and with water, dried,
and crystallized from pyridine. Product 4a was obtained (9.4 g, 46%); mp 224-225°C. A mixing test with a
sample obtained by method A gave no depression of melting point.
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1
2
3
4
.
.
.
.
A. J. Hubert and H. Reimlinger, J. Chem. Soc. C, 606 (1968).
J-.L. Dumont, Compt. Rend., 261, 1710 (1965).
J-.L. Dumont, W. Chodkievicz, and P. Cadiot, Bull. Soc. Chim. Fr., 1197 (1967).
S. M. Fomin, A. N. Flerova, G. N. Gerasimov, and E. N. Teleshov, USSR Inventor's Certificate
1
384578; Byull. Izobret., No. 12, 78 (1988).
5
6
7
8
.
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.
K. C. Yee, US Patent 4125534; Chem. Abstr., 90, 88046 (1979).
J. Reisch and R. Salchi-Artimani, Monatsh. Chem., 116, 1099 (1985).
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4
86014; Byull. Izobret., No. 36, 62 (1975).
9
.
H. F. Schuster and G. M. Coppola, in Allenes in Organic Synthesis, Wiley, New York (1984), p. 317.
H-.B. Burgi and J. D. Dunitz, in Structure Correlation, Vol. 2, VCH, Weinheim (1994), p. 741.
Yu. V. Zefirov and Yu. V. Zorkii, Usp. Khim., 58, 713 (1989).
G. M. Sheldrick, SHELX97. PC Version. A System of Computer Programs for Crystal Structure Solution
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1
1
1
0.
1.
2.
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434