MAY
1961
CHLORALQUINALDINE WITH PYRIDINE AND ALKALI
rated. The chloroform layer was evaporated leaving a red solid, which was recrystallized from 95% ethanol. After sevcrtl recrystallizations 4.45 g. (71 yo) of ,V-benzylidene:tmiiio-5-mcthylisatin was obtained as a red solid, m.p. 1 S5-1-t5.5'. A n a l . Calcd. for CL6H12N202:C, 72.71 ; 11, 4.59; N, 10.00. Found: C, 72.53; H, 4.69; H, 10.53. 3-Phenyl-6-methylcinnoline-4-carbozylic acid ( IVb) . One gram (0.0038 mole) of N-benzylideneamino-5-methylisatin was suspended in a solution of 20 g. of sodium hydroxide dissolved in 100 ml. of water. The solution was refluxed for 5 hr. The reaction mixture was filtered and acidified with O N hydrochloric acid. The yellow precipitate which formed was recrystallized from ethanol, giving 1 g. (10070) of 3phenyl-6-methylcinnoline-4-carboxylic acid, m.p. 220229 5". n n a l . Calcd. for C I ~ H L ~ NC,~ O 72.71; ~ : H, 4.59; N, 10.60. Found: C, 72.45; H, 4.69; N, 10.67.
1539
6-Methyl-3-phenyl cinnoline (Vb). A mixture of 0.5 g. (0.0019 mole) of 3-phenyl-6-methylcinnoline-4-carboxylic acid and 2.5 g. (0.0025 mole) of benzophenone was heated for GO min. a t 260" under an atmospherc of nitrogen. The gas evolved gave a turhidity when bubbled through barium hydroxide, indicating thc gas to be carbon dioxide. After being cooled, the mixture was dissolved in 250 ml. of ether and the ethcrcal solution was extracted with about 300 ml. of O N hydrochloric arid. The yellow acidic solution was cooled in an ice bath, saturated with potassium carbonate, filtered, and extracted with ether. The ethereal solution was concentrated. The yellow solid which separated was recrystallized from Skellysolvc B,l* giving 0.40 g. (95%) of 3-phenyl-6-mcthylcinnolinr, m p. 138.5-139.5". A n a l . Calcd. for C1bHl?NB: C, 81.79; H, 5.49; N, 12.72. Found: C, 82.06; H, 5.48; S , 12.47
LINCOLN 8, NEB.
[CONTRIBUTION FROM AVERY LABORATORY, UNIVERSITY
OF
NEBRASKA]
The Reaction of Chloralquinaldine with Pyridine and Alkali',' HENRY E. BAUMGARTEN, RICHARD BECKERBAUER, A N D MARJORIE R. DEBRUNNER Received August 10, 1.960
Chloralquinaldine rcacts with pyridine and aqueous potassium hydroxide to yicld a. purple-black solid, CI?H1?N&, which is shown to be 2-(3-hydrosy-5,6-benzo)indolizylpyridinium bctninc (XI). Similar sut)stnncrs are obtained from chloral-2picoline and chloral-2-methylbenzothiazole. Several reactions of thrse substanccs arc described and the mechanism of their forrnntion discussed.
Woodward and Kornfeld3 have shown that the the investigation described in this communication reaction of chloralquinaldiiie (I) wit'h aqueous was undertaken to examine an alternative sequence alcoholic sodium hydroxide yields sodium 3- for the initial phases of the reaction of I with alkali. ncetyl-1,2-dihydroquinaldate (11) in addition to All of the previously reported mechanism^^^^^^ thc expected sodium P-(2-quinolyl)acrylate (IIIa). 4 have been based on the premise that one of the hyhlechanisms to explain the formation of I1 have drogens on the carhon atom alpha to the ring is l w n suggested by Woodward and I i ~ r n f e l d , ~removed by base in niic of the early steps of the reaction. However, it would appear equally if not COCH3 more likely that the initial proton exchange would wCR2CHOHCCI3 C02Na involve removal by base of the hydrogen atto the oxygen of the carbinol group. Thus, tached I I1 there have lxcn a number of reports in the literature describing base-cat nlysed reactions of triCH=CHC02R chloromethylcarhiiiols which take place as shown in the following equation.' JIIa. R = N a
aH
0-
IIIb. R = H
I hy Brown, Hammick and R ~ b i i i s o n ,and ~ by RCHOHCCls +RCHCCl, --+ IV V I h u b e n and Vaughan.6 Although the most recent, O B B of these, the mechanism of Dauben and Vaughnn,6 / \ B: I I appears t o be for the most. part quite reasonnble, RCII-CC12 --+ R C H C O - or RCHCOB VI
(1) This work was supported in part I)y grant CY-:drogcwi- cule of cth:iiiol of cryst:tlliz:ilion. tion proc:uct of coriipouiid A. .-lnai. Calcd. for CL8Hl2X2O7.C2Hd): C, G8.5ti; H, 5.18; A 0.185-g. s:tmple of the crude hydrochloride (before re- ?;, 8.00. Found: C, 68.71; H, 5.15; S , 8.23. moval of the piperidine hydrochloride) \vas dissolved in 3 LISCOLN 8 , XEB. nil. of water, and the solution \v:is filtered :uid made slightly nlk:iline \vit.h dilutc sodium hydroxide solutioii. Tlic whitc
-
(2.5)
IY. Koviiigs. h'cw. 33, 218 (1900).
