function in acetic acid, but with Soyce and I'r\*or9

4324

VOl. hU

observed by Paul a n d Haniiiiett" that the rxte oi halogenation of iiitroacetophenoiie parallels the measured acidit!. function in acetic acid, but with 3 slope of 1 A. S o y c e and I'r\*or9 obser\.etl that the iiiwsured rates of condensatioii of benzaldehyde alltl acetophenone parallel t.he iiieasured acidity function i i i acetic acid, and (kbhart ant1 A4dairis h:i\-e obsen-ed similar results 011 the rearrangenient beiizopinacol. Experimental ( l r

' ' I

1 I i v proceilures uaecl l1;~seb2eii d e ~ c i - i l l~i lr e \ i ~ i u ~. :l,> J Most rate iiie;isureniei~tswere carried past 50' react i o i i . \\%ere L \ V ( I coiiipeting reactions ha\-c been ii~e:isui-ccl, i i i finity rratliiigs l w v e also I ~ e r iused in calcu1:ttiiig r.itc w i i r

.

st:iIlt,?.

Discussion 'I'lic. reactioii sc.(Iutwc*e outlined i i i t h e 1)r paper is used here for the followiiig tliscussioii. -

CII

0

\

CONDENSATION OF ANISALDEHYDE A N D METHYL ETHYLKETONE

Aug. 20, 1958

anisyl)-3-methyl-3-butene-2-one(111) from the intermediate ester. I n anhydrous acetic acid the elimination reaction can involve only the ester, and proceeds to completion; in wet acetic acid incursion of the cleavage reaction (k2) becomes important. The measured rates of elimination are summarized in Table I.

RATE

OF

HzO,

70

.1 I

VI1 X 102 M

ly,

ka X sec. -

Ho 6

log

/