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ACYL DERIVATIVES OF 0-AMINOPHENOL. 
R. E. NELSON AND H. L. DAVIs. 
When o-aminophenol, (HOC,H:NH:), is acylated with two differ- 
ent acyl groups, one group attaches itself to the nitrogen and the other 
to the oxygen, forming a stable diacyl compound. In attempting to 
prepare the isomer of the above compound, the isomer rearranges spon- 
taneously forming the same diacyl compound. A molecular rearrange- 
ment takes place and the group finally found attached to the nitrogen 
depends on the two acyl groups used. 
Saponification of the diacyl compound removes the acyl group at- 
tached to the oxygen first. 
If the remaining hydrogen of the acylated amino group be replaced 
by an alkyl group no rearrangement takes place. 
A typical example of this rearrangement is found in Ransom’s’ 
work. He acylated oxyphenylurethane, (HOC;H:NHCO.C:H;), with ben- 
zoyl chloride in alkaline solution. The attempt to prepare the isomer 
of benzoyloxyphenylurethane, (C;H;CO.OC;H:NHCO-.C.H;), by acylating 
benzoyl-o-aminophenol, (HOC;H:NHCOC,H;), with ethyl chlorformate 
in alkaline solution, resulted in the formation of benzoyloxyphenylure- 
thane, the carbethoxy group,—CO.C:H;, occupying the position formerly 
held by the benzoyl group. 
Ransom and Nelson’ observed similar rearrangement in attempting 
to prepare the isomer of carbamyl o-oxyphenylethylurethane, (C;Hi:CO:. 
OC;H:NHCO.C:H;) . 
If an acyl group is attached to the oxygen of o-nitrophenol and 
the acylated nitrophenol is reduced the resulting free base rearranges. 
The acyl group exchanges position with one hydrogen of the amino 
group. 
Stieglitz and Upson’® investigated the time of arrangement of a 
number of substituted monoacyl derivatives of o-aminophenol, substitut- 
ing chlorine, bromine and the methyl group about the ring, and con- 
cluded that, “the more or less positive character of the amino group, 
as shown by the affinity constants, does not seem to have any para- 
mount influence in determining the tendency of the base to undergo 
rearrangement, as measured by the rate of rearrangement’, but that, 
“the velocity constant depends more on changes affecting the neighbor- 
ing carbalkoxyl groups”. 
Raiford* did not find the rearrangement of diacyl derivatives af- 
fected by the substitution of negative groups about the ring. 
From the previous work done it seems that the diacyl derivatives 
of o-aminophenol tend to undergo rearrangement regardless of the 
1 Amer. Chem. Journ. Vol. 23, No. 1, 1. 
2 Jour. Amer. Chem. Soc. Vol. 36, N 2, 390. 
3 Amer. Chem. Journ. Vol. 31, No. 1, 497. 
4 Journ. Amer. Chem. Soc. Vol. 41, No. 12, 2068. 
