Method for synthesizing acyloxycarboxylic acids

A method for synthesizing an acyloxycarboxylic acid by providing a reaction chamber, establishing sources of an .alpha.-hydroxycarboxylic acid and an acid chloride, and repeatedly contacting substantially equal molar amounts of the .alpha.-hydroxycarboxylic acid and the acid chloride within the reaction chamber. The acyloxycarboxylic acid so synthesized is useful as a starting material for conversion to various esters which, when placed in aqueous solution with a source of hydrogen peroxide, result in a peracid and are useful for bleaching applications.

FIELD OF THE INVENTION 
The present invention relates to acyloxycarboxylic acids prepared by an 
alcoholysis reaction, and particularly a method for synthesizing 
acyloxycarboxylic acid in high yields. The synthesized acids are usefully 
converted to derivatives such as esters for bleaching applications. 
BACKGROUND OF THE INVENTION 
Esters of acyloxycarboxylic acids have long been known for a wide variety 
of applications. Thus, for example, U.S. Pat. No. 2,464,992, issued Mar. 
22, 1949, inventors Rehberg et al. teaches several methods for obtaining 
acyloxycarboxylic acid esters from starting materials such as glycolic or 
lactic acid with the esters useful as solvents, plasticizers, 
insecticides, insect repellents and chemical intermediates. An acyloxy 
acetic acid is disclosed as imparting excellent rust preventing 
characteristics to hydrocarbon mineral oils by U.S. Pat. No. 2,659,697, 
issued Nov. 17, 1953, inventor Wayo. 
More recently, U.S. Pat. No. 4,085,277, issued Apr. 18, 1978, inventor 
Harada, discloses preparation of 2-cinnamoyloxyacetic acid as a starting 
compound in the preparation of a cephaloaporanic acid derivative 
possessing antibacterial activity. 
Pending application Ser. No. 928,070, entitled "Glycolate Ester Peracid 
Precursors", filed Nov. 6, 1986, now U.S. Pat. No. 4,778,618 inventors 
Fong et al., of common assignment herewith, discloses compounds termed 
alkanoyloxyperacetic acid which are generated in situ when precursors are 
placed in aqueous solution with a source of hydrogen peroxide. These 
precursors are readily prepared from the acyloxycarboxylic acids 
synthesized by the present invention. 
U.S. Pat. No. 2,503,699, issued Apr. 11, 1950, inventors Adelson et al., 
discloses the reaction of 1.9 equivalents acetyl chloride with 1.0 
equivalent glycolic acid in a single reaction vessel to obtain 
acetylglycolic acid, which was isolated by evaporating excess actyl 
chloride. However, the inventors report that the reaction was violent and 
evolved much hydrochloric acid. Acid chloride removal by evaporation to 
isolate product is not appropriate for longer chain acid chlorides. 
U.S. Pat. No. 4,036,984 discloses adding various chlorides slowly under ice 
cooling into mixtures of various acids or alcohols with the mixtures 
including pyridine. However, when these known techniques are applied to 
the synthesis of acyloxycarboxylic acids such as, for example, 
octanoyloxyacetic acid, isolated yields of only about 40% to about 45% are 
obtained. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a method for 
synthesizing acyloxycarboxylic acids simply and in high yields, which 
acids are usefully converted to alkanoyloxyperacetic acids via ester 
precursors. 
In one aspect of the present invention, a method for synthesizing an 
acyloxycarboxylic acid, useful as a starting material for conversion to 
various esters, comprises providing a reaction chamber, establishing 
sources of an .alpha.-hydroxycarboxylic acid and an acid chloride, and 
repeatedly contacting substantially equimolar amounts of the 
o-hydroxycarboxylic acid and the acid chloride within the reaction 
chamber. The sources of .alpha.-hydroxycarboxylic acid and acid chloride 
are separated from one another, and are preferably repeatedly contacted at 
a predetermined, relatively slow rate within the reaction chamber. 
However, if the mixture within the reaction chamber is sufficiently 
agitated and cooled, then the .alpha.-hydroxycarboxylic acid and acid 
chloride reactants can be contacted at relatively rapid rates. 
The reaction chamber includes a basic component in an effective amount to 
neutralize a hydrogen chloride by-product during formation of the reaction 
product. The reaction product of this method is typically isolatable as at 
least about 65% of theoretical yield and has the structure 
##STR1## 
wherein R.sub.1 is an alkyl group having two to about twelve carbon atoms, 
and R.sub.2 is hydrogen, methyl, ethyl, or propyl and R.sub.3 is hydrogen, 
methyl, ethyl, propyl, and substituted or unsubstituted phenyl or benzyl. 
In another aspect of the present invention, the just described reaction 
product, whether isolated or not, is converted to an ester which, when 
placed in aqueous solution with a source of hydrogen peroxide, results in 
a peracid having the structure (where R.sub.1, R.sub.2 and R.sub.3 are as 
previously described):

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
U.S. Patent application Ser. No. 928,070, entitled "Glycolate Ester Peracid 
Precursors", inventors Fong et al., filed Nov. 6, 1986, and U.S. Ser. No. 
928,065, titled "Acyloxynitrogen Peracid Precursors", inventor Zielske, 
filed November 6, 1986, both assigned to The Clorox Company, are both 
incorporated herein by reference as disclosing ester conversions and 
applications useful with the present invention. The former application, 
for example, discloses preparations of acyloxycarboxylic acids which are 
converted to esters and utilized in bleach compositions to generate 
peracid when placed in aqueous solution with a source of hydrogen 
peroxide. However, the present inventive method provides acyoxycarboxylic 
acid preparations in considerably higher yields than disclosed. 
Thus, Example I of Patent application Ser. No. 928,070 describes a 
synthesis of octanoyloxyacetic acid from glycolic acid and octanoyl 
chloride. The octanoyl chloride was added dropwise by means of an addition 
funnel to a flask charged with glycolic acid in chloroform and 
triethylamine with a minor amount of 4-dimethylaminopyridine. Isolated 
yield of the octanoyloxyacetic acid (with 90% purity) was 40% of 
theoretical yield. By contrast, and as described more fully hereinafter, 
isolated yield of octanoyloxyacetic acid (with greater than 90 wt. % 
purity) from practice of the present invention is at least about 65% of 
theoretical yield, and typically is greater than about 80 mole % crude 
yield. 
Attempts to adapt the previously discussed Adelson et al. method from 
acetyl chloride (at 1.9 equivalents) with glycolic acid (at 1.0 
equivalent) to a longer chain acid chloride, such as octanoyl chloride, 
result in an octanoyloxyacetic acid isolated yield of only 45%, by 
comparison to the above noted at least about 65% isolated yield in 
accordance with the present invention. 
The disappointingly low isolated yields of desired acyloxycarboxylic acids 
by previously known methods are believed due, at least in part, to the 
bifunctional nature of alpha-hydroxycarboxylic acids since the acid 
chloride can react with either (or both) of the hydroxyl moieties. 
Practice of the inventive method is believed substantially to avoid the 
problems incurred with previous methods. That is, the present invention 
avoids the relatively low overall yields of reaction product, avoids the 
use of large excess of expensive starting material and avoids difficulty 
in isolation of the desired reaction product. 
Practice of the inventive method typically provides the desired 
acyloxycarboxylic acid in about 80% to 85% crude yield, substantially 
avoids complicating side reactions such as generation of polygycolic acid, 
and permits the desired reaction product to be readily isolated (if 
desired). 
Practice of the inventive method synthesizes an acyloxycarboxylic acid, or 
reaction product, having the structure illustrated by Formula I below. 
##STR3## 
The R.sub.1 substituent of the Formula 1 structure may be selected from 
alkyl groups (branched and unbranched) having two to about twelve carbon 
atoms, that is from ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, 
nonyl decyl, undecyl, and dodecyl groups. The R.sub.2 substituent of the 
Formula I structure may be hydrogen or a lower alkyl group having one to 
about three atoms. The R.sub.3 substituent may be a lower alkyl, such as 
methyl, ethyl or propyl, an aryl, such as phenyl or benzyl groups, or an 
alkylaryl, such as tolyl or xylyl. 
This acyloxycarboxylic acid reaction product is formed by an alcoholysis 
reaction of an alpha-hydroxycarboxylic acid and an acid chloride in a 
reaction chamber. The total quantity of each reactant to be reacted in the 
reaction chamber is sometimes hereinafter referred to as an 
alpha-hydroxycarboxylic acid source and an acid chloride source. These 
reactant sources are a spaced distance from the reaction chamber and are 
separated from one another. This will be discussed more fully hereinafter. 
Suitable alpha-hydroxycarboxylic acids for use as reactants in the 
inventive method include glycolic acid, lactic acid and the like, with 
some suitable such acids being illustrated by Table I. 
TABLE I 
______________________________________ 
Acid Name Structure 
______________________________________ 
Glycolic 
##STR4## 
Lactic 
##STR5## 
2-hydroxy butyric 
##STR6## 
.alpha.-hydroxy isobutyric 
##STR7## 
Mandelic 
##STR8## 
.beta.-phenyl lactic 
##STR9## 
2-hydroxy-2-methyl-butyric 
##STR10## 
.alpha.-hydroxy isocaproic 
##STR11## 
______________________________________ 
Glycolic acid is particularly preferred due to low cost, ready availability 
and suitable solubilities of the esters. 
Suitable acid chlorides for use as reactants have the structure illustrated 
by Formula II below, where R.sub.1 is an alkyl group (branched or 
unbranched) having 2 to about 12 carbon atoms. 
##STR12## 
Preferred acid chlorides are hexanoyl chloride, octanoyl chloride, 
heptanoyl chloride, nonanoyl chloride decanoyl, undecanoyl, and dodecanoyl 
chloride. Particularly preferred are octanoyl and nonanoyl chlorides. 
It is extremely important that the alpha-hydroxycarboxylic acid and the 
acid chloride reactants be reacted by contacting substantially equimolar 
amounts within the reaction chamber. Excesses of one or the other 
components reduce selectivity of the desired reaction and thus reduce 
yield (illustrated as Reaction I below). For example, an excess of an acid 
reactant such as glycolic acid favors production of polyglycolates. An 
excess of the acid chloride reactant tends to lead to diketene formation. 
The reaction is preferably conducted by contacting relatively small 
portions of the total reactant quantities in the reaction chamber. This 
may be achieved by pumping equimolar, metered quantities of both reactants 
(either neat or in solution) from the respective sources at a 
predetermined rate into the reaction chamber, and thus repeatedly 
contacting substantially equimolar amounts of the alpha-hydroxycarboxylic 
acid and the acid chloride. 
This continuous and controlled reaction has been found substantially to 
prevent formation of a mixed anhydride as reaction product and thus to 
retard formation of undesired esters. For convenience, the reaction in 
which the acyloxycarboxylic acid is formed is illustrated as Reaction I. 
##STR13## 
The contents of the reaction chamber are preferably agitated during the 
repeated contact of reactants, and a predetermined rate of pumped, metered 
quantities of reactants may be from about 0.1 to about 10.0 mole per liter 
per hour, more preferably about one mole per liter per hour for each 
reactant. However, as will be understood, the particular predetermined 
rate will be dependent upon the reaction vessel geometry, the mixing 
efficiency and the heat exchanging capacity of the system being used. 
Means known to the art, such as metering pumps for each reactant source, 
are a convenient way to pump such controlled quantities at the 
predetermined rate. The reaction is exothermic, and thus the reaction 
chamber is preferably cooled during the reaction by means well known to 
the art. 
Where the alpha-hydroxycarboxylic acid is a solid, then a solvent is 
desirable to solubilize the alpha-hydroxycarboxylic acid within the 
reaction chamber during the repeated contact with the acid chloride. 
Suitable solvents are aprotic, polar and vary from water immiscible to 
water miscible, and preferably do not generate much heat from solvation. 
Preferred solvents are acetone, dichloromethane, acetonitrile, methyl 
ethyl ketone, diethyl ether, tetrahydrofuran, glyme, dioxane and ethyl 
acetate, most preferably acetone. The solvent is preferably present within 
the alpha-hydroxycarboxylic acid source, so that solubilized quantities 
can be conveniently flowed to the reaction chamber. Solvents may also be 
present within the reaction chamber to facilitate agitation and cooling of 
the reaction mixture. 
During the reaction, the reaction chamber preferably includes a basic 
component. A suitable base is in an effective amount to neutralize the 
hydrogen chloride by-product that forms as the reaction proceeds. Suitable 
bases are believed to perform a dual function in not only neutralizing the 
hydrogen chloride by-product, but in apparently also acting to promote or 
catalyze the reaction. Preferred bases are tertiary amines such as 
pyridine, dimethylaminopyridine, triethylamine, t-propylamine, 
N-methylpiperidine and polymeric tertiary amines or cross-linked resins, 
such as polyvinylpyridine divinylbenzene, BIO-REX5 intermediate base anion 
exchange resin, AG4-X4 or AG3-X4A weakly basic anion exchange resin (the 
latter three being available from BIO-RAD Laboratories). The base 
preferably is used in about a stoichiometric amount (with respect to the 
reactants illustrated in Reaction I), and must not react with the acid 
chloride reactant. 
The acyloxycarboxylic acid reaction product is contemplated for use as a 
bleach precursor having the general structure illustrated by Formula III. 
##STR14## 
where R.sub.1 and R.sub.2 are as previously described, and L is a leaving 
group. The carbonyl carbon of Formula III adjacent the leaving group is 
preferably esterified, and will have the leaving group bonded through the 
ester linkage. 
Suitable leaving groups include derivatives of substituted or unsubstituted 
phenols, oximes, N-hydroxyimides, and amine oxides. These various suitable 
leaving groups are more fully described in previously noted application 
Ser. No. 928,065 and application Ser. No. 928,070. 
The conversion of reaction product, prepared in accordance with the 
invention, to an ester is preferably via an acid chloride of the reaction 
product, as will be exemplified hereinafter. Such an ester, or bleach 
precursor, is usefully formulated with a solid source of peroxide, such as 
an alkaline peroxide, in amount effective to perhydrolyze the precursor 
and thus to provide effective bleaching. Suitable such sources of peroxide 
include sodium perborate monohydrate, sodium perborate tetrahydrate, 
sodium carbonate peroxyhydrate, sodium pyrophosphate peroxyhydrate, urea 
peroxyhydrate, sodium peroxide, and mixtures thereof. Sodium perborate 
monohydrate and sodium perborate tetrahydrate are particularly preferred 
alkaline peroxides for combination with such precursors as a dry bleach 
composition or, when surfactant is included, as a dry laundering and 
bleaching composition. 
The source of peroxide (that is, compounds yielding hydrogen peroxide in an 
aqueous solution) itself constitutes a peroxygen bleaching compound. 
However, bleach compositions including peroxyacid precursor and peroxide 
source together provide better bleaching, particularly at temperatures 
below about 60.degree. C., than the peroxide source alone. 
Two preferred bleach compositions including glycolate esters prepared in 
accordance with the inventive method are illustrated below. 
______________________________________ 
15.6% sodium perborate tetrahydrate 
19.0% octanoyloxy acetic acid, 
p-phenyl sulfonate ester 
7.0% nonionic surfactant 
15.0% sodium carbonate 
43.4% sodium sulfonate 
100.0% 
15.5% sodium perborate tetrahydrate 
16.8% octanoyloxy acetic acid, 
t-butyl phenol ester 
7.0% nonionic surfactant 
15.0% sodium carbonate 
45.7% sodium sulfate 
100.0% 
______________________________________ 
Of course, a variety of other laundry adjuvants such as brighteners, 
fragrances, stabilizers, colorants, and the like, may be incorporated into 
such compositions. 
Aspects of the invention will now be exemplified. 
EXAMPLE I 
Synthesis of Octanoyloxy Acetic Acid (OOAA) 
15.8 gm (0.20 mole) pyridine and 50 ml. acetone were combined in a 250 ml. 
round bottomed-three necked flask equipped with magnetic stir bar and two 
addition funnels, and cooled in an ice water bath with stirring. One 
addition funnel was charged with 15.5 gm (0.20 mole) glycolic acid 
dissolved in approximately 75 ml. acetone. The other addition funnel was 
charged with 32.5 gm (0.20 mole) octanoyl chloride. The contents of each 
addition funnel were added simultaneously to the cooled, stirred pyridine 
solution so that the complete addition of each component was continuous 
over one hour. The resultant slurry (a precipitation of pyridine 
hydrochloride was noted) was stirred an additional 45 minutes at ice bath 
temperature, and then at room temperature for another 30 minutes. Solvent 
was then removed by rotary evaporation at reduced pressure and 45C. The 
residual oil was dissolved in 200 ml dichloromethane and this was 
extracted with 3.times.150 ml. of 4% aqueous HCl. The dichloromethane 
layer was dried over sodium sulfate, decanted and the solvent removed by 
rotary evaporation. Drying on high vacuum for 4 hours left OOAA and 8.0% 
octanoic acid by weight, giving a crude yield for OOAA of 84%(mole). 
Recrystallization from 200 ml. hexane gave 27 g of a white crystalline 
product melting at 50 to 52.degree. C., which was determined to be 99% wt. 
OOAA, giving a 67% (mole) yield of pure octanoxyloxyacetic acid. 
EXAMPLE II 
Synthesis of Octanoxyloxy Acetyl Chloride 
101.1 gm (0.5 mole) octanoyloxy acetic acid and 83 gm (0.65 mole) oxalyl 
chloride are combined in a 1 liter round bottom flask with a magnetic stir 
bar and a CaSO.sub.4 drying tube (note: a little hexame or petroleum ether 
can be added if the solid does not completely dissolve). The reaction is 
stirred at room temperature while rapid gas evolution is noted, then 
gradually heated to 40-50.degree. C. and held there for 2 hours, then at 
65-70.degree. C. for one hour (note: the reaction can also be run at room 
temperature overnight with the advantage that it remains colorless). The 
slightly yellow solution is then heated to 60-70.degree. C. under 
aspirator pressure for one to 11/2 hours to remove excess oxalyl chloride. 
After cooling to room temperature the oil is diluted with 400 ml petroleum 
ether (bp 30-60.degree. C.) and extracted with 3.times.200 ml ice water 
(caution: gas evolution can be vigorous-). The organic layer is dried over 
MgSO.sub.4, filtered and roto vapped to a clear straw colored oil, weight 
=115.7 gm (110.4 gm theoretical). IR shows no acid-OH stretch and two 
carbonyls at about 1,812 cm.sup.-1 and at about 1,755 cm.sup.-1. 
EXAMPLE III 
Synthesis of Octanoyloxy Acetic Acid, Phenyl Sulfonate Ester 
17.3 gm (.079 mole) octanoyloxy acetyl chloride and 17.0 gm (.087 mole) 
sodium-p-phenol-sulfonate (dried at 120.degree. C. in vacuo for 16 hours) 
were combined in a 250 ml round bottom flask with a magnetic stir bar. 30 
ml of ethylene glycol-dimethyl ether (glyme) was added, and the slurry 
stirred with cooling in an ice-water bath. 7.8 gm (0.077 mole) triethyl 
amine was placed in an additional funnel equipped with a CaSO.sub.4 drying 
tube and this was added dropwise to the above slurry over 1/2 hour. The 
reaction becomes very thick and more glyme (or ethyl ether) can be added 
at this time to enable good stirring. The reaction was stirred for two 
hours at room temperature, diluted with ethyl ether and stirred one hour 
more. The reaction was filtered on a coarse glass frit, washed with 
several portions of ethyl ether, sucked dry for one hour and dried in 
vacuo at room temperature. Weight of product: 39 gm (theoretical wt.=42.1 
gm). 
This material can be recrystallized from 60/40 (vol/vol) IpA/water in an 
approximate 3 to 4:1 (wt./wt.) ratio of solvent to ester reaction mixture 
to give an approximate 40-60% yield of ester (90.sup.+ % in purity). 
EXAMPLE IV 
Synthesis of Hexanoyloxy Acetic Acid 
10.1 gm (0.10 mole) triethyl amine (TEA), 10 drops of pyridine, and 15 ml 
acetone were combined in a 250 ml round bottomed, three-necked flask 
equipped with magnetic stir bar and two addition funnels, and cooled in an 
ice water bath with stirring. One addition funnel was charged with 7.61 gm 
(0.10 mole) glycolic acid dissolved in 30 ml acetone. The other funnel was 
charged with 13.5 gm (0.10 mole) hexanoyl chloride. The contents of each 
addition funnel were added simultaneously to the cooled, stirred 
TEA/pyridine solution so that the complete addition of each component was 
continuous over 20 minutes (note: a heavy white precipitate, presumably 
TEA hydrochloride, formed during the addition). The reaction was stirred 
an additional one hour, filtered and the isolated salts washed with 
acetone, which was combined with the initial filtrate. Solvent was removed 
by rotary evaporation leaving a sweet smelling oil, which was dissolved in 
150 ml di-ethyl ether, and extracted with 2.times.200 ml of 1% aqueous 
HCl. The ether layer was dried over magnesium sulfate, filtered and rotary 
evaporated to an oil weighing 20 gm of 74% wt. purity by GC, for a yield 
of 85% mole. No hexanoic or glycolic acids were found in the product, 
which was used without further purification. 
EXAMPLE V 
Synthesis of Hexanoyloxy Acetic Chloride 
8.7 gm (0.05 mole) of hexanoylacetic acid and 12.7 gm (0.10 mole) of oxalyl 
chloride were mixed together at room temperature. The reaction was heated 
gradually over one hour at 50-60.degree. C. for about two hours. Excess 
oxalyl chloride was removed under reduced pressure to yield an oil that 
exhibits no --OH stretch by IR. Weight was 9.6 gm. 
EXAMPLE VI 
Synthesis of Sodium, n-Hexanoyloxyacetate, p-phenylsulfonate 
9 2 gm (0.04 mole) of n-hexanoyloxyacetyl chloride was added dropwise to an 
ice-cooled slurry of 9.0 gm (0.046 mole) sodium, p-phenolsulfonate (dried 
four hours at 110.degree. C. in vacuo) and 5.5 gm (0.045 mole) 
triethylamine in 45 ml diglyme in a 100 ml round bottom flask fitted with 
a stirrer and low temperature thermometer. The reaction mixture was 
stirred for two hours at 0-4.degree. C., diluted with 100 ml ethyl ether, 
and filtered. The white solid precipitate was triturated with 3.times.100 
ml of warm isopropanol and the solid was vacuum filtered and dried 
overnight under vacuum. 
EXAMPLE VII 
Synthesis of Octanyloxyacetate, T-butyl Phenol Ester 
5.95 gm (.025 mole) octanoyloxyacetyl chloride dissolved in about 15 ml 
anhydrous ethyl ether was added dropwise to a solution containing 21/2 gm 
(0.027 mole) pyridine and 4.70 gm (.031 mole) t-butyl phenol in about 100 
ml pyridine over one-half hour, with the solution being maintained at a 
temperature of 0-4.degree. C. in an ice bath and stirred via a magnetic 
stir bar. The reaction was stirred at 5-10.degree. C. for about 2 hours, 
filtered and then diluted to about 200 ml with ethyl ether. This was 
washed with 3 times 100 ml of 4% hydrochloric acid, 1 times 150 ml water, 
2 times 100 ml of 10% sodium carbonate solution, then dried over sodium 
sulfate. The product was filtered and roto-vapped to yield a yellow oil, 
which was chromatographed on 60 gm of silica gel with 4% ethyl 
ether/petroleum ether distillate, yielding 5.3 gm of ester product 
determined to be 99.9 wt. % in purity by GC, saponification and NMR-13C. 
EXAMPLE VIII 
Synthesis of Mixed Octanoyloxy/Decanoyloxy Acetic Acids 
Reaction 1: 156.5 gm (1.01 equivalents) of C.sub.8 /C.sub.10 mixed 
aliphatic acids (63 mole % C.sub.8 and 37 mole % C.sub.10) and 114 ml 
(approx. 165 gm, 1.3 mole) oxalyl chloride were combined in a 1000 ml 
round bottomed flask equipped with a magnetic stir bar and a calcium 
sulfate drying tube. The resultant solution was stirred for 19 hours 
(note: vigorous gas evolution ensued upon mixing of the two reactants). 
Excess oxalyl chloride was removed by warming of the reaction under 
reduced pressure for one hour. The residue was taken up in 300 ml of 
hexane and this solution was extracted with 5.times.250 ml of ice cold 
water. The hexane layer was dried over sodium sulfate, filtered and the 
solvent removed by rotary evaporation, leaving 184.5 gm of light straw 
colored oil. (No --OH by IR, and a strong v.sub.C.dbd.O at 1,803 cm). 
Reaction 2: A two liter, three-necked round bottom flask, equipped with 
mechanical stirrer and two addition funnels, was flame dried and charged 
with 79.5 gm (1.0 mole) pyridine in 200 ml acetone, which was then chilled 
in an ice water bath. One addition funnel was charged with the product 
from reaction 1 above, and the other charged with 84 gm (1.1 mole) 
glycolic acid in 300 ml acetone. The contents of the two addition funnels 
were added simultaneously and continuously to the stirred, chilled 
pyridine solution over 50 minutes. The reaction was then stirred an 
additional 21/2 hours at ice bath temperature. Solvent was removed by 
rotary evaporation and the oily residue dissolved in 50 ml 
dichloromethane, which solution was then extracted with 5.times.350 ml 5% 
aqueous HCl and 1.times.600 ml saturated NaCL, dried over sodium sulfate, 
filtered and rotary evaporated to a thick oil which soldified upon 
standing. Pumping off the residual solvent under high vacuum left 199 gm 
of solid which was determined to be 54.7% mole octanoyloxy acetic acid and 
34.1% mole decanolyoxy acetic acid by GC. Overall yield of the two step 
reaction was 83.4% mole for the combined acyl oxy acetic acids. 
EXAMPLE IX 
Synthesis of Mixed Octanoyl/Decanoyl-Oxyacetic Acids, Sodium Phenol 
Sulfonate Esters 
198 g of mixed octanoyl/decanoyl oxyacetic acids from Example VIII were 
melted on a warm (50.degree. C.) oil bath in a 1,000 ml round bottom 
flask. 113 ml of oxalyl chloride were added to the liquified acids and the 
reaction stirred by magnetic stir bar overnight at room temperature. The 
reaction was then warmed to 50.degree. C. on an oil bath and excess oxalyl 
chloride removed at water aspirator pressure for 31/2 hours. The oily 
residue was dissolved in 700 ml hexane and washed with 3.times.250 ml of 
ice cold water. The hexane layer was dried over Na.sub.2 SO.sub.4, 
filtered, and rotary evaporated to a light yellow oil weighing 219 
gm.multidot.IR of this material exhibited no --OH stretch and C.dbd.O 
stretch at 1,760 cm.sup.-1 and 1,820 cm.sup.-1. These acid chlorides were 
then esterified as follows: 
219 gm of the acid chlorides, 220 gm of sodium phenol sulfonate (from 
di-hydrate dried in vacuo at 120.degree. C. for 48 hours), and 800 ml of 
anhydrous glyme were combined in a flame dried 21/3 necked Morton flask, 
equipped with a mechanical stirrer and addition funnel, and placed in an 
ice-water bath. The addition funnel was charged with 120 gm of triethyl 
amine, which was added dropwise over one hour to the rapidly stirred, 
cooled acid chloride/phenol slurry. Over the time of addition of the amine 
the reaction mixture became so thick that an additional 500 ml of glyme 
was added to enable efficient stirring to proceed. Upon completion of the 
amine addition the reaction was stirred 1/2 hour longer, by which time it 
had become unstirrable. The reaction was allowed to stand two hours, and 
then filtered on a C-frit Buchner funnel. The filter cake was washed with 
1,000 ml of ethyl ether and sucked dry overnight. The residue was dried in 
vacuo leaving 470 gm of off-white powder, which contained 62% wt. of the 
desired esters, corresponding to a 74% mole conversion based on the 
starting (C.sub.8 /C.sub.10) acid mixture. After two recrystallizations 
from (approximately 1,200 to 1,800 ml each) 194 gm. of 95.7% wt. of the 
desired esters was obtained. Overall yield from the starting acids was 54% 
mole for the four reaction steps (Examples VIII and IX). The product 
contained less than 1.0% each of the C.sub.8 /C.sub.10 acyl-oxy acetate 
benzene sulfonate esters (HPLC). 
EXAMPLE X 
Synthesis of 2-Hexanoyloxy-2-Methyl-Butryic Acid 
11.8 gm (0.10 mole) 2-methyl-2-hydroxy-butyric acid was dissolved in 50 ml 
acetone and placed in one of two 125 ml addition funnels attached to a 250 
ml three-necked round bottom flask charged with 8.0 gm (0.10 mole) 
pyridine in 50 ml acetone cooled in an ice-water bath. The other addition 
funnel was charged with 13.46 gm (0.10 mole) hexanoyl chloride. The 
contents of the two addition funnels were simultaneously added dropwise 
over 20 minutes to the stirred/cooled pyridine solution. The reaction was 
then stirred for two hours at 4-15.degree. C., then the solvent was 
removed by rotary evaporation. The oily residue was dissolved in 200 ml 
dichloromethane and this solution extracted with 5.times.150 ml 3% aqueous 
HCl, then washed with 1.times.200 ml deionized water. The organic layer 
was dried over Na.sub.2 SO.sub.4, filtered and solvent removed by rotary 
evaporation, leaving 20.4 gm of light yellow oil (IR shows V.sub.C.dbd.O 
at 1,745 and 1,728 cm.sup.-1). .sup.13 C NMR saponification and GC 
analysis shows this material to be 99% the desired product, for an overall 
yield of 93%. 
EXAMPLE XI 
Synthesis of 2-Octanoyl-Mandelic Acid 
15.2 gm (0.10 mole) dl-mandelic acid was dissolved in 50 ml acetone and 
placed in one of two 125 ml additional funnels attached to a 250 ml 
three-necked round bottom flask charged with 8.0 gm (0.10 mole) pyridine 
in 50 ml acetone cooled in an ice water bath. The other addition funnel 
was charged with 16.3 gm (0.10 mole) octanoyl chloride. The contents of 
the two addition funnels were simultaneously added dropwise over 20 
minutes to the stirred/cooled pyridine solution. The reaction was removed 
by rotary evaporation. The residue was dissolved in 200 ml diethyl ether 
and this solution was extracted with 5.times.150 ml 5% HCl, and then 
washed with 1.times.200 ml deionized water. The organic layer was dried 
over Na.sub.2 SO.sub.4, filtered and the solvent removed by rotary 
evaporation. After drying in vacuo there remained 28.2 gm of oil. GC and 
.sup.13 C NMR determined this material to be 83.1% of the desired product, 
for an overall 84.2% yield. 
EXAMPLE XII 
Synthesis 2-Hexanoyl Mandelic Acid 
15.2 gm (0.10 mole) dl-mandelic acid was dissolved in 50 ml acetone and 
placed in one of two 125 ml additional funnels attached to a 250 ml 
three-necked round bottom flask charged with 8.0 gm (0.10 mole) pyridine 
in 50 ml acetone cooled in an ice water bath. The other addition funnel 
was charged with 13.46 gm (0.10 mole) hexanoyl chloride. The contents of 
the two addition funnels were simultaneously added dropwise to the 
stirred, cooled pyridine solution. The reaction was then stirred at room 
temperature for two hours, at which time the solvent was removed by rotary 
evaporation. The oily residue was dissolved in 200 ml CH.sub.2 Cl.sub.2, 
and this solution was extracted with 4.times.150 ml 3% aqueous HCl, and 
washed with 1.times.200 ml deionized water. The organic layer was dried 
over Na.sub.2 SO.sub.4, filtered and the solvent removed by rotary 
evaporation, and dried in vacuo leaving 24.9 gm of oil. .sup.13 C NMR and 
GC analysis determined this material to be 89.5% desired product, for an 
overall 89% yield. 
Preparation of an oxime derivative is preferably by obtaining an acid 
chloride (illustrated by Example II and Example V), reacting with acetone 
oxime in a solvent such as THF dropwise with rapid stirring, in a manner 
analogous to Example I of previously noted application Ser. No. 928,065. 
The acyloxycarboxylic acids just exemplified by Examples I, Iv, VIII, X, 
XI and XII are summarized by Table II. 
TABLE II 
______________________________________ 
Crude 
Yield 
Example Acid Prepared (mole %) 
______________________________________ 
##STR15## 84 
IV 
##STR16## 85 
VIII 
##STR17## 83.4 
X 
##STR18## 93.0 
XI 
##STR19## 84.3 
XII 
##STR20## 89.0 
______________________________________ 
As may be seen from Examples I, Iv, VIII, X, XI and XII, yield of crude 
acid products prepared by the inventive method ranged from 83.4% to 93%. 
While these acyloxycarboxylic acids may then be isolated before conversion 
to an ester for use as a bleach precursor, such isolation is often not 
necessary. Example II illustrates use of an isolated acyloxycarboxylic 
acid (prepared as in Example I) to the chloride derivative and Example III 
illustrates conversion of such chloride to the p-phenyl sulfonate ester; 
however, Examples VIII and IX illustrate preparation of ester derivatives 
without an isolation of acyloxycarboxylic acid. Thus, the present 
invention provides a method for synthesizing acyloxycarboxylic acids 
simply and in high yields, which acids are usefully converted (without or 
without isolation) to ester precursors of alkanoyloxy peracetic acids. 
Although the present invention has been described with reference to 
specific examples, it should be understood that various modifications and 
variations can be easily made by those skilled in the art without 
departing from the spirit of the invention. Accordingly, the foregoing 
disclosure should be interpreted as illustrative only and not to be 
interpreted in a limiting sense. The present invention is limited only by 
the scope of the following claims.