[CONTRIBUTION FROM THE LABORATORY OF ORQANIC CHEMISTRY OF THE STATE UNIVEBBITY OF IOWA]

PREPARATION AND BEHAVIOR OF MIXED DIACYL DERIVA- TIVES OF O-AMINOPHENOL CONTAINING A CARBO-

ARYLOXY RADICAL AND THE p-TOLYLSULFONYL GROUP

L. CHAS. RAIFORD AND J. REID SHELTON

February 8, 1939

I I When two acyl radicals, R-C== and R’-C=O, are introduced into

an ortho aminophenol only one mixed diacyl derivative can generally be obtained, regardless of the order of introduction of the radicals; and in this product the heavier and more acidic of these acyl radicals is usuelly attached to nitrogen. To meet this requirement the migration of acyl from nitrogen to oxygen1 must occur in one of these reactions. If the

acyls ,are R-C=O and R-0-C=O the latter is most frequently found I I

attached to nitrogen.2

i s Ar-S=O isomeric I

n 0

groups are introduced place.:’

In the cases thus far tested when one of the acyls

mixed diacyl derivatives are obtained when the

in different orders and no rearrangement takes

After the above observations were made it ww desired to prepare a

diacyl derivative containing the radical Ar-0--0, where Ar is an aroma,tic residue. Although it was found possible to obtain N-carboaryloxy derivatives of ortho aminophenols, attempts to introduce a second acyl derived from a carboxylic acid were unsuc~essful.~ When these N- carboaryloxy compounds were mixed with caustic alkali solution or pyridine, for the purpose of further acylation, they were converted into

I

1 RAIFORD AND CO-WORKERS, J . Am. Chem. SOC., 48, 483 (1926). 8 RANSOM AND NELSON, i b id . , 36, 393 (1914). 8 RAIFORD AND LANEELMA, ibid., 47, 1123 (1925); RAIFORD AND GBOSZ, ibid. , 63,

4 RAIFOBD AND INMAN, i b i d . , 68, 1580 (1934). 3420 (1931).

207

208 L. CHAS. RAIFORD AND J. REID SHELTON

the corresponding benzoxazolones with elimination of the required phenol, as shown.

\CO + HO--C> -OH 0 -0

H H

Before trying to prepare a diacyl derivative containing both a carbo- aryloxy and an arylsulfonyl radical the possibility that the latter might migrate in compounds closely related to the previous ones was tested further. To do this 2-aminophenol and 2-amino-4-methyl-6-bromophenol were, in turn, converted into mixed diacyl derivatives in which one of the acyl groups was always the 4-tolylsulfonyl radical. When the N-sulfonyl and 0-sulfonyl derivatives of the specified aminophenols were converted into diacylated compounds by the introduction of the acetyl, benzoyl, and carboethoxy radicals, respectively, isomers were obtained in each case. When these products were hydrolyzed the p-tolylsulfonyl radical was found on nitrogen in every instance in which i t had been attached there in the starting material, while in those cases where it had been bound to oxygen in the starting material i t was lost by hydrolysis and the other acyl group was found on nitrogen. It is evident that no rear- rangement took place either during acylation or hydrolysis6. These relations are shown in Figure 1 for the behavior of one pair of acyl groups with o-aminophenol.

After confirmation of the previous work several experiments were car- ried out in attempts to obtain a mixed diacyl derivative of o-aminophenol in which the carbophenoxy group is attached to oxygen. In one of them an ether solution of 2-p-tolylsulfonylaminophenol was refluxed with phenyl chlorocarbonate while dimethylaniline was slowly added. Nothing but starting material could be isolated from the mixture. When the aminophenol and the acid chloride were brought together in pyridine solution, and likewise when subjected to the Schotten-Baumann method, none of the required diacyl derivative was obtained, but about 70 per cent. of the starting materials was recovered, while there was isolated a small portion of a product that melted a t 141-142'. When the reaction was carried through in a dioxane solution starting material was again recovered and also a somewhat larger portion of the derivative that melted a t 141-

This is a matter of importance because RAIFORD AND COLLABORATORS [ J . Am. Chem. SOC., 46, 2318 (1924); ibid., 47, 1123 (1925); J. ORG. CHEM., 2, 217 (1937)] have shown that in some instances migration does occur during hydrolysis of certain of these diacyl derivatives obtained from carboxylic acids.

PREPARATION AND BEHAVIOR OF MIXED DIACYL DERIVATIVES 209

142’ was secured. This was identified as 2-p-tolylsulfonylbenzoxazolone by comparison with an authentic sample obtained by the action of p- tolylsulfonyl chloride on benxoxazolone. Though none of this required diacyl derivative was isolated it was probably formed but was too unstable to exist under the conditions. The changes are indicated in Figure 2.

When 2-p-tolylsulfonylamino-4-methyl-6-bromophenol was used and the reaction was carried out in pyridine solution, 27 per cent. of the re- quired diacyl derivative, m.p. 154-156’, was obtained. Much starting

FIGURE I

OSO2CgI4CH&)

--NHCOCeHa - Isomers -

1 3--ococgIK --NHSO&6HdCH$ ( p )

I I

material was recovered. In a repetition of the experiment, modified to the extent that dioxane was used as a solvent and dimethylaniline was added to interact with the hydrogen chloride evolved, only starting material and the corresponding p-tolylsulfonylbenzoxazolone were iso- lated.

Experiments were made to introduce the acyls in the opposite order. When a pyridine solution of 2-aminophenyl p-toluenesulfonate was treated with phenyl chlorocarbonate there was obtained a product that melted a t 114’ and which gave a satisfactory analysis for the expected 2-carbo- phenoxyaminophenyl p-toluenesulfonate. Treatment of 2-amino-4-

210 L. CHAS. RAIFORD AND J. REID SHELTON

methyl-6-bromophenyl p-toluenesulfonate with phenyl chlorocarbonate gave a compound that melted a t 129-131") and analysis of this for halogen and sulfur agreed with the requirements of the desired diacyl derivative.

It is of interest here to record that hot alcohol in the presence of de- colorizing carbon* caused the replacement of the carbophenoxy by the carboethoxy group in the diacyl derivative melting a t 129-131°6. The resulting product, 2-carboethoxyamino-4-methyl-6-bromophenyl p -

I 1

I 1

I 1

..........

H

toluenesulfonate, was identified by analysis and also by its behavior toward alcoholic potash. In the latter case hydrolysis caused the loss of the ptolylsulfonyl radical and the formation of 3-methyl-5-bromo-6-hydroxy-

* Norite was used here. * The interaction of esters with alcohols to replace one alkyl group by another

has long been known. Following the observations of DUFFY [ J . Chem. Soc., 6, 303 (1853)], this change has frequently been observed in the aliphatic series but seldom

PREPARATION AND BEHAVIOR OF MIXED DIACYL DERIVATIVES 211

phenylurethane, previously obtained by Upson' by rearrangement of 2- smino-4-me thyl-6-bromophenyl ethyl carbonate . The relations involved in the present work are shown in Figure 3.

In addition to the compound melting at 129-131" there was isolated from the reaction mixture a small portion of a product that melted above 200". By varying the experimental procedure (see below) the high- melting product was secured in 53 per cent. yield, while the diacyl deriva- tive amounted to 27 per cent. When a portion of the diacyl derivative was dissolved by heating it for a few minutes with pyridine, the liquid was

FIQURE 3 Br

CH3-

t Alcoholic KOH

allowed to stand overnight, and the solution was diluted with water, there was deposited the high-melting product mentioned above. The aqueous filtrate contained phenol, which suggested that a benzoxazolone ring

in the aromatic group. In nearly every case reported some alkali was present, and this was regarded as a catalyst. More recently BELLET [Conzpt. rend., 198, 1785 (1934)l has extended the study. He used an alcoholic solution of caustic alkali and in some instances conducted the experiments in sealed tubes a t elevated temper- atures. In general, an ester containing an alkyl group of high molecular weight was found to react to give an ester of low molecular weight and liberate the heavier alcohol. Such a change in the case of urethanes is certainly less common. Thus, the phenyl ester of phenylaminoformic acid first obtained by HOFMANN [Ber., 4, 249 (1871)] was later obtained by several others, who crystallized i t from alcohol, but did not record any interaction with the solvent.

7 UPSON, Am. Chem. J. , 32, 36 (1904).

212 L. CRAB. RAIFORD AND J. REID SHELTON

closure may have occurred and that the product, m.p., 208-209', might be an impure sample of a substituted benzoxazolone. Mixture melting- point determinations of the product in question with 4-methyl-6-bromo- benzoxazolone, m.p., 220-22208, and its N-p-tolylsulfonyl derivative, m.p., 175-176" (see below), respectively, gave pronounced depressions.

Further study of the product melting a t 208-209" indicated that its formation involved two molecular proportions of the diacyl derivative, map., 129-131'. Molecular-weight measurements by two different methods gave values ranging from 666 to 681, while the values for the diacyl derivative and the N-p-tolylsulfonylbenzoxazolone are 476 and 382, respectively. Analytical data for bromine, nitrogen, and sulfur correspond closely to the formula Ca0H24BrzN20&3z, and this, in turn, agrees with that required by a product formed by elimination of phenol from the diacyl der- ivative and combination of two of the remaining residues. Such a residue would represent 3-methyl-5-bromo-6-(p-tolylsulfonyloxy)phenyl isocya- nate, two molecular proportions of which could interact to give a product of the composition and molecular weight found (see below). This inter- pretation agrees in general with the behavior of phenyl isocyanate which, in contact with triethylph~spine~, and also when boiled with pyridine, gives a crystalline product that has been recorded as diphenyl diisocya- natel0. Still more striking is the observation that this product has recently been obtained by a reaction which closely parallels that involved in the present work, for Warren and Wilsonll found that phenylurethane reacts with thionyl chloride to eliminate alcohol and give diphenyl diisocyanate. Staudinger12 regards this product as a four atomic ring derivative,

C@HaN-C=O I I

O=C--N--CaHa , which has more recently been listed as diphenyl~retidone'~. The compound melting a t 208-209' should therefore be 1,3-di-(3-methyl-5-bromo-6-p- tolylsulfonyloxypheny1)uretidone.

In the formation of this product from the diacyl derivative the urethane grouping only was involved. The sulfonyl radical remained attached to oxygen because hydrolysis of the new compound readily caused the loss of p-toluenesulfonic acid, which was isolated from the reaction mixture,

8 RAIFORD AND INMAN, J . Am. Chem. SOC., 66, 1589 (1934). 9 HOFMANN, Ann. Suppl., 1, 57 (1861). lo SNAPE, J . Chem. SOC., 49, 254 (1886). l1 WARREN AND WILSON, Ber., 68, 957 (1935). l e STAUDINGER, "Die Ketene," Enke, Stuttgart, 1912, p. 126. Is Chem. Abstr., S O , 9899 (1936).

PREPARATION AND BEHAVIOR OF MIXED DIACYL DERIVATIVES 213

and left a product that contained no sulfur but showed the correct per- centages of bromine and nitrogen for the structure indicated below. It is proposed to call this substance 1 ,3-di-(3-methyl-5-bromo-6-hydroxy- pheny1)uretidone. The relations are summarized in Figure 4.

FIGURE 4

-0S02CaH4CH3 ---OSO&aHdCH3 Pyridine'

....................

r(

+ 2 HOS02CeHdCHa

HO Br

EXPERIMENTAL

The 2-aminophenol used was obtained by sublimation of the best commercial grade. 2-Amino-4-methyl-6-bromophenol was prepared as directed by Raiford and Grosz,14 and was stored in the form of the hydrochloride.

Many acylations here involved were carried out by Einhorn and Hollandt's method.15 In some cases the Groenvik16 scheme was employed, but this involves the conversion of one-half the aminophenol into the hydrochloride, and may cause the formation of some diacyl derivative." In cases where the above methods did not work well, satisfactory results were obtained by treatment of a 1,4-dioxane solution of the aminophenol and dimethylaniline with the required acid chloride. The third compound listed in Table I was obtained by the last method indicated above, and the

l4 R.AIFORD AND GROSZ, J . Am. Chem. SOC., 63, 3422 (1931). Is EJINHORN AND HOLLANDT, Ann., 301, 95 (1898). 16 C~ROENVIK, Bull. S O C . chim., [2], a6, 177 (1876). l7 RAIFORD AND WOOLFOLK, J . Am. Chem. SOC., 46, 2251 (1924).

214 L. CHAS. RAIFORD AND J. REID SHELTON

.u d d

PREPARATION AND BEHAVIOR OF MIXED DIACYL DERIVATIVXS 215

othet three by following Einhorn and Hollandt's directions. In Table I1 the meth- ods are indicated by footnotes. By these methods 2-aminophenol and 2-amino-4- methyl-6-bromophenol were converted into a number of mixed diacyl derivatives in good yields. Analytical and other data for these compunds are given in the accom- panying tables.

I-C'arbophenoryamdnophenyl p-toluenesu1fonate.-To a pyridine solution of 2-ami- nophenyl p-toluenesulfonate 10% more than the required phenyl chlorocarbonate was added with shaking, this mixture was allowed to stand for several hours and was then poured into dilute acid to precipitate the product. The yield was nearly quant,itative. Crystallization from carbon tetrachloride gave material that was contaminated with a sticky brown oil which was removed in large part by extracting the crystals with small portions of fresh solvent. The remaining solid was recrystal- lized from alcohol and was obtained in small colorless needles that melted a t 114". Though the experiment was repeated several times the yield of purified product was never higher than 50%.

Anal.

Attempts to hydrolyze this product with alcoholic potash gave only a dark oil from which no definite product could be isolated.

Action of phenyl chlorocarbonate on I-p-tolylsulfonylaminophenol.-When the reactrtnts were brought together in pyridine solution and also when the Schotten- Baumann method was tried, some starting material was recovered, and a small portion of a product that melted a t 141-142" was obtained. Refluxing a mixture of the reactants in ether solution caused no change. To a warm dioxane solution of these substances the theoretical quantity of dimethylaniline was added dropwise, the liquid was heated for ten minutes on the steam bath, during which time the mixture became purple. After three hours i t was diluted with water, which pre- cipitated an oil that solidified upon standing. Crystallization from alcohol gave a 31% yield of colorless slender rods that melted a t 141-142", and which were identified as 2-p-tolylsulfonylbenzoxazolone by determination of the melting point of a mixture with :in authentic sample obtained by the action of p-toluenesulfonyl chloride on benzoxaz olone.

Calc'd for CSOHIPNO~S: C, 62.66; H, 4.43; N, 3.65. Found: C, 62.60; H, 4.84; II', 3.60.

Anal. Calc'd for C,dH11NOd3: S, 11.07. Found: S, 11.01. R-p-ToEyEsulfonyEamino-~-methyl-6-bromophenyl phenyl carbonate.-A pyridine

solution of the required acylaminophenol was treated with phenyl chlorocarbonate as described above, and after standing overnight this mixture was poured into water. The sticky oil, which would not solidify, was extracted with ether, the extract was shaken with dilute ammonia water which removed some starting material, the ether was distilled, and the residue was crystallized from alcohol. Evaporation of the mother liquor gave more starting material. The new product was isolated as small nearly colorless needles that melted at 154-156". Analysis indicated that the sub- stance was the required diacyl derivative probably contaminated with the cor- responding 2-p-tolylsulfonylbenzoxazolone. Hydrolysis of the compound gave 2-p-tolylsulfonylarnino-4-methyl-6-bromopheno1, which was used as starting ma- terial for the product just described.

Anal. Calc'd for CZIHlsBrNOaS: Br, 16.80. Found: Br, 17.16. In ;L second experiment a warm 1,4-dioxane solution of 5 g. of the sulfonylamino-

phenol was mixed with phenyl chlorocarbonate, dimethylaniline was slowly added, the mixture was warmed on a steam bath for a few minutes, allowed to stand over- night, and then diluted with water. The oil that separated solidified in a short time. It wae removed, washed with dilute hydrochloric acid, extracted with a small volume

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PREPARATION AND BEHAVIOR OF MIXED DIACYL DERIVATIVES 217

of hot alcohol which removed the blue color and most of the starting material. Crystallization of the residue from a larger volume of alcohol gave nearly colorless needles that melted a t 175-176", and which were identified as 2-p-tolylsulfonyl-4- meth:yl-6-bromobenzoxazolone by determination of the melting point of a mixture with an authentic sample of the latter prepared from 4-methyl-6-bromobenzoxaz- olones and the required acid chloride.

Anal. Calc'd for ClsH12BrNOdS: Br, 20.94. Found: Br, 20.90. Adion of phenyl chlorocarbonate on 8-amino-~-methyl-6-bromophenyl p-toluene

sulfouate.-Five grams of the required toluenesulfonate was dissolved in 15-20 cc. of pyridine, one molecular proportion of phenyl chlorocarbonate was added, the mix- ture was allowed to stand overnight and then diluted with five volumes of water. T!ie viscous solid that separated was washed with dilute acid, then with water, and was crystallized from carbon tetrachloride. The resulting nearly colorless solid, whicl- weighed 3.7 g., was boiled with 175 cc. of alcohol, and the mixture was filtered. On cooling, the filtrate deposited about 1 g. of long, thin, nearly colorless fibers that resembled asbestos and which melted a t 208-209". They were identical with the small portion of solid that had not dissolved. Evaporation of the alcoholic mother liquor to a small volume gave about 2 g. of the desired diacyl derivative that melted a t 129-131".

In a second experiment one molecular proportion of phenyl chlorocarbonate was added with stirring and cooling to 50 cc. of a pyridine solution containing 15 g. of the required amino compound. A gummy solid soon separated. The mixture was then warmed on a hot plate until the solid dissolved, the liquid was allowed to cool slowly and after three hours was diluted with three volumes of water. The tan solid that separated was dried and boiled with 125 cc. of carbon tetrachloride, the mixture was filtered, and the residue was washed with pure solvent. Crystallization of the residue from benzene gave 7.5 g. of the product that melted a t 208-209'. Evapora- tion of the carbon tetrachloride filtrate and washings gave first 0.5 g. of the high- melting compound and finally 5.5 g. of the diacyl derivative melting a t 129-131'. The yield of the latter was 27%, thus accounting for 84% of the starting material.

In a third experiment the Groenvik method was used. Ten per cent. more than the calculated half-molecular proportion of phenyl chlorocarbonate was added slowly to an ether solution of 25 g. of the required amino compound. The mixture soon became turbid, and after a few hours colorless crystals began to separate. The mixture was allowed to stand overnight, the solid was removed and washed with water. Recrystallization from alcohol gave 11.5 g. of colorless rods that melted a t 129-131". Evaporation of the ether filtrate gave4 g. of the same substance in slightly less pure condition. On the basis of a 50% conversion of the starting material the yield was 94%.

The above experiment was repeated with the modification that 5 g. of the amino compound was dissolved in 50 cc. of ether, 10% more than one molecular proportion of phenyl chlorocarbonate was added, an equivalent amount of dimethylaniline was run in slowly with shaking, and the mixture was allowed to stand. A colorless solid began to separate within four hours. After twenty-four hours the liquid was de- canted and the residue washed with water. Crystallization from alcohol gave 2-cartiophenoxyarnino-4-methyl-6-bromophenyl p-toluenesulfonate. A small amount of the same substance was recovered from the ether solution. The total yield of purified material was 81%.

Calc'd for C21HlsBrNOaS: Br, 16.80; S, 6.72. Found: Br, 16.75; S, 6.76.

Anal.

218 L. CHAS. RAIFORD AND J. REID SHELTON

The residues obtained by evaporation of the ether solutions left from the last two preparations indicated above were mixed and crystallized from alcohol. The prod- uct that separated was considerably colored and melted a t 128-130". It was dis- solved in alcohol, the solution was boiled with decolorizing charcoal and filtered. The product then separated in colorless fibrous masses that melted a t 123-124". The same product was obtained when an alcoholic solution of a portion of purified 2-carbophenoxyamino-4-methyl-6-bromophenyl p-toluenesulfonate was boiled for about three minutes with Norite. The new substance did not depress the melting point of the compound obtained by the action of ethyl chlorocarbonate on 2-amino- 4-methyl-6-bromophenyl p-toluenesulfonate. Analyses for bromine and for sulfur showed that treatment with alcohol had replaced the CeHbO- radical by CzHaO-.

Anal.

A 2-g. portion of the product melting at 123-124" was mixed with 20 cc. of 1N alcoholic potash, warmed on a steam bath until solution took place, and the liquid acidified. The precipitated material was removed, dissolved in alkali solution and was re-precipitated unchanged by addition of acid. Crystallization from alcohol gave pale-brown irregular prisms that melted a t 82-83". The same compound was obtained when 2-carbophenoxyamino-4-methyl-6-bromophenyl p-toluenesulfonate was subjected to the action of alcoholic potash. The final compound was identified as 3-methyl-5-bromo-6-hydroxyphenylurethane by comparison with a sample of the latter which was prepared for this purpose.

1 , $-Di-(S-methyl-5-bromo-6-p-tolylsuljonyloxyphenyl)uretidone.-Two grams of the purified diacyl derivative melting a t 129-131" was dissolved in 10 cc. of pyridine by warming, the solution was allowed to stand overnight and was then diluted with five volumes of water. The product separated as an oil that solidified on standing. This material was collected, washed with dilute acid and then with water. The filtrate ( F ) was reserved for further examination. The solid was boiled with 50 cc. of alcohol which dissolved but a portion of it, and the mixture was filtered. On cooling the filtrate deposited about 1 g. of colorless solid. Recrystallization of this from benzene gave colorless, fluffy, fibrous material that melted at 208-209". The melting point of a mixture of this material with the high-melting compound that separated during the preparation of the diacyl derivative showed no depression. The remaining solid that did not dissolve in alcohol was crystallized from benzene and was found to be identical with the portion that was dissolved by alcohol.

Calc'd Cl,Hlg,BrNOsS: Br, 18.69; S, 7.48. Found: Br, 18.73; S, 7.34.

Anal. Calc'd for CsoHz~BrzNzO&3~: Br, 20.94; N, 3.66; S, 8.37; mol. wt., 764. Found: Br, 20.83; N, 3.74; S, 8.39; mol. wt., (Rast camphor method) 681,

(freezing-point method with benzene) 666. Filtrate ( F ) was acidified and extracted with ether, the extract evaporated to

dryness, the residue dissolved in water and the resulting solution treated with bromine water. 2,4,6-Tribromophenol was precipitated.

1, S-Di-(S-naethyl-5-bromo-6-hydroxyphenyl)uretidone.-Three grams of the above sulfonyl derivative was dissolved in 25 cc. of alcoholic potash, containing 2 g. of alkali, by warming on a steam bath. After cooling, the mixture was acidified with 10 cc. of 6N hydrochloric acid and then 150 cc. of water was added. This precipi- tated 1.6 g. of nearly colorless solid which decomposed a t about 168". The filtrate (FI) was reserved. Repeated crystallization of the solid from dilute alcohol, from which i t tended to separate as an oil, gave gray, fluffy fibers tha t melted with de- composition a t 169-170". Analysis of the product obtained as described gave a value for halogen 1.5% higher than that demanded by theory. Hydrolysis of a

PREPARATION AND BEHAVIOR OF MIXED DIACYL DBRIVATIVES 219

second portion of the sulfonyl derivative was carried through, and the reaction mixture was acidified with dilute nitric acid. After one recrystallization of this material from dilute alcohol i t melted with decomposition a t 170".

Anal. Calc'd for C1'HlrBrrN201: Br, 35.08; N, 6.14. Found: Br, 35.83; N, 6.15.

Filtrate ( F J was evaporated to dryness under reduced pressure on a steam bath. The residue was repeatedly extracted with small portions of anhydrous ether and finally with absolute alcohol. The extracts were separately evaporated to dryness, the new residues were dissolved in small portions of water, the liquids were filtered to remove insoluble matter, and the filtrates were evaporated to dryness over sulfuric acid in a desiccator. In each case the final residue melted a t 100-102", and mixtures of each with known samples of p-toluenesulfonic acid, m.p., 103-105", melted a t 100-103".

SUMMARY

1. 2-Aminophenol and 2-amino-4-methy1-6-bromopheno1, respectively, have been converted into a number of mixed diacyl derivatives in which one of the radicals was always the p-tolylsulfonyl group. When the

other one was R-C-O, R - O - L , or A r - - ~ - O , isomers were ob- tained when the acyls were introduced in different orders, and no migra- tion was observed.

2. When the second radical was Ar-O-&=O isomeric mixed com- pounds were again formed, but under the conditions these products may fiuffer further change. Thus, the N-p-tolylsulfonylaminophenol obtained from each base reacts with phenyl chlorocarbonate to give the expected 0-carbsophenoxy derivative. That formed from the first base waa not isolated; it lost phenol immediately to give the corresponding N-p-tolyl- sulfonylbenzoxazolone. With the second base both diacyl derivatives and the substituted benzoxazolone were isolated.

3. Treatment of 2-carbophenoxyamino-4-methyl-6-bromophenyl p-tol- uenesulfonate with hot pyridine caused the loss of phenol and the forma- tion of a ('condensation" product which it is proposed to call 1,3-di- (~3-met~hyl-5-bromo-6-p-tolylsulfonylox~henyl)uretidone.

I