Reactions of 1′-benzyl-1′,4′-dihydro-2,3′-biquinoline with organolithium compounds [5]

Full text of DOI:10.1023/A:1017592221830

Chemistry of Heterocyclic Compounds, Vol. 37, No. 2, 2001
REACTIONS OF 1'-BENZYL-
1',4'-DIHYDRO-2,3'-BIQUINOLINE
WITH ORGANOLITHIUM COMPOUNDS
A. V. Aksenov and A. V. Sarapy
Keywords: 2,3'-biquinoline, 1',2'-dihydro-2,3'-biquinoline, 1',4'-dihydro-2,3'-biquinoline, organolithium
compounds, nucleophilic substitution, alkylation, arylation.
We previously [1] studied the reactions of 1'-methyl-1',4'-dihydro-2,3'-biquinoline with organolithium
compounds. In this paper we report on the reactions of 1'-benzyl-1',4'-dihydro-2,3'-biquinoline (1) with
organolithium compounds.
We have established that, in contrast to 1'-methyl-1',4'-dihydro-2,3'-biquinoline, compound 1 gives with
MeLi (1.4 mol/l in ether) or PhLi (2 mol/l in cyclohexane with ether in a mole ratio of 1:3.5 in absolute THF at
room temperature in 15 min, with isolation analogous to that described elsewhere [2]) a mixture of
2'-R-1',2'-dihydro-2,3'-biquinolines 2a and 2b and 4'-R-1',4'-dihydro-2,3'-biquinolines 3a and 3b, in ratios
analogous to the addition of these reagents to the 2,3'-biquinoline 4 (2a:3a 3:17, 2b:3b 1:1). These experimental
results are in good agreement with the mechanism shown in the scheme which includes the intermediate
formation of the biquinoline 4.
–
RLi
– PhCH2
N
N
– RH
–
N
N
1
Ph
Ph
N
1. RLi
2. H2O
R
N
+
H
2a,b
N
R
N
4
N
N
H
3a,b
2, 3 a R = Me; b R = Ph;
____________________________________________________________________________________________
Stavropol State University, Stavropol 355009, Russia; e-mail: nauka@stavsu.ru. Translated from
Khimiya Geterotsiklicheskikh Soedinenii, No. 2, 283-284, February, 2001. Original article submitted
September 21, 2000.
0009-3122/01/3702-0261$25.00©2001 Plenum Publishing Corporation
261

1
The structures of the substances synthesized were confirmed by their H NMR spectra and by
independent synthesis [2]. For all of the compounds mixed melting points with known samples did not give
depression of the melting point. Their 1H NMR spectra were identical to those cited previously [2-4].
2'-Methyl-1',2'-dihydro-2,3'-biquinoline (2a). Yield 14%; mp 138-139°C (ethanol), lit. [2],
mp 138-139°C.
2'-Phenyl-1',2'-dihydro-2,3'-biquinoline (2b). Yield 46%; mp 207-209°C (ethanol), lit. [2],
mp 207-209°C.
4'-Methyl-1',4'-dihydro-2,3'-biquinoline (3a). Yield 77%; mp 148-149°C (benzene), lit. [3],
mp 148-149°C.
4'-Phenyl-1',4'-dihydro-2,3'-biquinoline (3b). Yield 49%; mp 213-214°C (ethanol), lit. [4],
mp 213-214°C.
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2.
A. V. Aksenov and A. V. Sarapy, Khim. Geterotsikl. Soedin., 1257 (1999).
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(1998).
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4.
A. V. Aksenov, O. N. Nadein, I. V. Borovlev, and Yu. I. Smushkevich, Khim. Geterotsikl. Soedin., 232
(1998).
A. V. Aksenov, I. V. Aksenova, I. V. Borovlev, and Yu. I. Smushkevich, Khim. Geterotsikl. Soedin.,
1094 (1997).
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