DIRECT SYNTHESIS OF 8-(~-BROMOMERCURIETHYL)-

QUINOLINE, A CONVENIENT MODEL FOR STUDYING

REACTION MECHANISMS

O. A . R e u t o v , V . V. B a s h i l o v , and V. [. S o k o l o v

UDC 542.91:547.254.9:547.831:541.124

In o rder to study the s t e r e o c h e m i s t r y of the reac t ions of o r g a n o m e r c u r y compounds it is n e c e s s a r y to have opt ical ly act ive models in which the m e r c u r y a tom is found in the ch i ra l cen te r . Recent ly , we used the d i a s t e r e o m e r i c L-menthy l e s t e r s of ~ - m e r c u r i - ~ - p h e n y l a c e t i c acid [1], the d i rec t synthes is of which has been known for a long t ime [2], in the reac t ion with t r is( t r iphenylphosphine)plat inum(0) .

Now we have found that 8- (~-bromoethyl )quinol ine r e a c t s when shaken with meta l l ic m e r c u r y to give the ch i ra l 8 - (~ -b romomercur ie thy l )qu ino l ine (D. The compound is new. At tempts to obtain it by o ther methods , in p a r t i c u l a r via the organol i th ium and - m a g n e s i u m compounds, we re unsuccessful . The m e r c u r y der iva t ive f r o m 8-bromomethylquinol ine was obtained in s i m i l a r m a n n e r , but in lower yield.

Since ~ -b romoe thy lbenzene under analogous conditions does not fo rm the m e r c u r y der iva t ive , the de te rmin ing fac tor in the case of 8-haloalkyl quinolines is apparent ly the poss ib i l i ty of having i n t r amo lecu l a r coopera t ion of the reac t ion via the donor n i t rogen a tom. The favorab le effect of an ex terna inucleophi le was obse rved p rev ious ly [3].

T e s t r eac t ions between 8 - (~-bromomercur ie thy l )qu ino l ine and Pb(0) complexes led to meta l locyc les of known chela te type [4].

EXPERIMENTAL

8-(~-Bromomercuriethyl)qulnoline (1). A mixture of 5.0 g of 8-(~-bromoethyl)quinoline and 5 ml of Hg was shaken in a thick-walled flask for 3 h. The formation of a colorless crystalline substance was observed during shaking. The mixture was extracted with benzene and CH2CI 2. The combined extracts were filtered from the Hg, the CH2CI 2 was evaporated in vacuo, and the substance was precipitated from benzene solution with pentane. We obtained 2.8 g (30%) of (I), mp 156-157~ Rf 0.45 (Silufol, benzene). Infrared spectrum (KBr, 9, cm-l): 2945, 2864 (CH~; 2893 (CH); 3099, 3080, 3061, 3037, 3013 (quinoline). Found: C 30.24; H 2.24;

Br 18.89; Hg 45.48%. CliHi0BrHgN. Calculated: C 30.25; H 2.31; Br 18.30; Hg 45.93%.

8-Bromomercurimethylquinoline (If). A mixture of 2.5 g of 8-bromomethylquinoline, 5.0 ml of Hg, and 5.0 g of NaBr in 20 ml of abs. ethanol was shaken for 5 h. The mixture was extracted with 75 rnl of CH2CI 2. The solution was filtered from the Hg and NaBr, evaporated in vaeuo to small volume, and the substance was precipitated with hexane. We obtained 0.6 g (12%) of (II), mp 157 ~ (decompn.) (from EtOH). Found: C 28.62; H 1.84; Br 19.75; Hg 46.68%. CIoHsBrHgN. Calculated: C 28.42; H 1.91; Br 18.91; Hg 47.46%.

CONCLUSIONS

The preparation of the previously unknown chiral 8-(~-bromomercuriethyl)quinoline and 8-bromomercuri- methylquinoline by direct synthesis from the corresponding bromides and mercury was described.

LITERATURE CITED

I. O.A. Reutov, V. I. Sokolov, G. Z. Suleimanov, and V. V. Bashilov, J. Organomet. Chem., 160, 7 (1978). 2. A.N. Nesmeyanov, O. A. Reutov, and S. S. Poddubnaya, Dokl. Akad. Nauk SSSR, 88_, 479 (i953). 3. M.E. Vol'pin, E. A. Tvdoradze, and K. P. Butin, Zh. Obshch. Khim., 40, 315 (1970). 4. L.L. Troitskaya, A. I. Grandberg, V. I. Sokolov, and O. A. Reutov, Dokl. Akad. Nauk SSSR, 228,367

(1976).

A. N. Nesmeyanov Institute of Heteroorganic Compounds, Academy of Sciences of the USSR, Moscow. Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1169-1170, May, 1981. Original article submitted October I0, 1980.

928 0568-5230/81/3005-0928 $07.50 �9 1981 Plenum Publishing Corpora t ion