3,123,631 United States Patent Office Patented Mar. 3, 1964 raroa 2 ceeds to produce a high yield of an anthranilate. Simi 3,123,631 larly, reaction 1 predominates with reactants having the PRO{CESS FOR PRESPARNG ESERS OF generic formula R-TH, where T is a non-metallic ele ANHRANLECACD ment from the sixth group of the periodic system having Roger P. Staiger, Collegeville, Pa., and George F. an atomic number from 8 through 52, inclusive (i.e., Schaudecker and Enaery B. Miser, Toledo, Ohio, OXygen, sulfur, selenium or tellurium), and R is an or assignors to Maumee Chemical Company, Toledo, ganic group, and preferably, is aryl, or a radical having (Oiaid, a corporation of 60hio the formula -CH-R in which R' is hydrogen, or an No Drawing. Filed Sept. 9, 1957, Ser. No. 682,630 organic group, and preferably is hydrogen, alkyl, aryl, 6 Cairns. (C. 260-471) O alkenyl, alkynyl, or acyl. This invention relates to isatoic anhydride reaction When the reactant other than isatoic anhydride is a products, and to a method for reacting isatoic anhydride tertiary alcohol, reaction 2 proceeds to produce a high with various hydroxyl-containing, thiol-containing, and yield of an alkyl ester of N-carboxyl anthranilic acid similar inorganic and organic compounds. (isatoic acid) in which the carboxyl that is attached di 5 rectly to the benzene ring is not esterified. isatoic anhydride has been known for some time (see it has been found that both reaction 1 and reaction 2 German Patents 110,577 and 112,976), but neither it proceed when the reactants are isatoic anhydride and a nor any compound produced from it has found any com Secondary alcohol, such as isopropanol. merical use. It is convenient to conduct a reaction until all isatoic The present invention is based upon the discovery of 20 anhydride which is only sparingly soluble in most solvents, an improved method for producing certain reaction prod has been consumed. The anhydride, therefore, is prefer lucts from isatoic anhydride, and of useful isatoic anhy ably used in not more than stoichiometric amounts, al dride reaction products. though, if desired, a substantial excess of either reactant It is, therefore, an object of the invention to provide can be employed. It is usually advantageous to warm an improved method for producing certain reaction prod 25 the reaction mix slightly, for example to a temperature ucts of isatoic anhydride. from about 45° C. to the boiling temperature of the mix, It is a further object of the invention to provide use and to maintain a temperature within such range until ful isatoic anhydride reaction products. reaction has proceeded to a desired extent, for example Other objects and advantages will be apparent from for from 30 minutes to several hours. the description which follows, which is intended only 30 A base is employed in only a catalytic quantity in pro to illustrate and disclose, but in no way to limit, the in ducing an anthranilic acid ester according to the method vention. of the invention. For example, as little as about 1 percent According to one aspect of the invention, an improved of a base has been found to be effective, and, in ordinary method for producing an ester, a thioester, a seleno ester practice, it has usually been preferred to use from about or a telluro ester from isatoic anhydride is provided. In 35 2 percent to about 10 percent of a base. Greater amounts some cases the esters may be anthranilates, while in other can be employed, if desired, but there appears to be no instances, the reaction product is an ester of N-carboxy advantage, unless a salt of the final reaction product is anthranilic acid (isatoic acid) in which the carboxyl at desired, in which case the stoichiometric amount of the tached directly to the benzene ring is not esterified. The base for production of such salt, plus a small excess two reactions are represented, respectively, in Equations 40 should be employed. 1 and 2, below, wherein R represents, for example, an The terms "percent' and “parts' are used herein and alkyl radical: in the appended claims to refer to percent and parts by EQUATION 1 weight, unless otherwise indicated. In general, any base can be employed in carrying 45 out a reaction with isatoic anhydride in accordance with the invention. It is usually preferred, however, to use a strong base, usually a strong inorganic base, and, most desirably, an alkali metal hydroxide. Excellent results have been obtained when the base has been sodium hy 50 droxide. The invention has been defined, in Equations 1 and 2, O above, in connection with the reaction of isatoic anhy. -C- dride with various alcohols. It will be appreciated that -- O R other hydroxyl-containing organic materials, as well as N- N-C-OR 55 various thiol-compounds, selenol-compounds, and tellurol II || El O O compounds, can be similarly reacted. Such organic com pounds can be represented by the generic formula RTH, wherein T is a non-metallic element from the sixth group Such reactions proceed between solutions comprising of the periodic system haiving an atomic number from isatoic anhydride and an organic hydroxyl-containing 60 8 through 52, inclusive, and R is an organic radical. In compound in the presence of small amounts of a base. a preferred class of such organic compounds, R is a It has been found that, in many instances, reaction 1 or member of the group consisting of aryl, and those hav reaction 2 proceeds, virtually to the exclusion of the ing the formula -CH2-R' in which R" is a member of other, and that in such instances, the nature of the hy the group consisting of hydrogen, alkyl, aryl, alkenyl, -droxyl-containing compound principally determines which 65 of the two reaction types takes place. When such reactant alkynyl, and acyl. Another preferred class of such is a primary aliphatic alcohol or a phenoi, reaction 1 pro organic compounds can be represented by the generic 3 4. formula reaction product is a modified polyvinyl alcohol or poly R ester containing functional groups which were not pre IO-C-R sent in the starting material. Such additional functional kn groups, or new functional groups, enabie reactions of wherein R' has the meaning previously set fort, R'' and 5 which the original starting materials were incapable. For R' have the same meanings as R' and not more than example, such reaction product from a polyvinyl alcohol one of the symbois R', R'' and R' represents hydrogen. could be reacted with a polyhydroxy organic compound, Most desirably, none of the symbois R', R'' and R' rep for example a glycol, in order further to increase its resents hydrogen. molecular weight at a desired stage in processing. By 0 using glycerol, pentaeryl thritol or other cross-linking agent In addition to the preferred classes of hydroxyl-, thiol-, having three or more hydroxyl groups, the possibility selenol-, and tellurol-organic compounds identitfied in the would exist of producing a modified polyvinyl alcohol preceding paragraph, it will be appreciated that various having a cross-linked molecular structure, which would other thiol or hydroxyl compounds can be so reacted. be expected to be thermosetting. As a specific example of another such reactant, mention It will also be noted from Equation 1, above, that may be made of cellulose, which is believed to have a carbon dioxide can be evolved during the course of a molecular structure made up of an undetermined num reaction in accordance with the invention. In some ber of repeating cellobiose units, hydroxyl-containing instances, the evolved carbon dioxide can be utilized as polyester materials and polyvinyl alcohol, which is chemi a blowing agent in the production of foamed or cellular cally somewhat similar to cellulose. 20 materials. As is indicated above, certain new compositions of The following examples are presented solely for the matter are provided according to the invention. One purpose of further illustrating and disclosing the inven class of such new compounds is characterized by the tion and are in no way to be construed as limitations presence in its molecular structure of the group thereon. O 25 Example 1 -C-T- Isatoic anhydride was reacted with various organic compounds having the generic formula R-TH to pro duce corresponding anthranilates according to the follow wherein T' is a non-metallic element from the sixth group 30 ing procedure. of the periodic system having an atomic number from A large glass test tube was charged with a 3-milliliter 16 thorugh 52, inclusive (i.e., sulfur, selenium or tel portion of absolute methyl alcohol, 2 grams of isatoic lurium). Such new compositions of matter can be acids, anhydride, and one pellet (approximately A0 gram) of acid salts, or esters. The acids can be represented by sodium hydroxide. The resulting reaction mixture was the generic formula then warmed over a steam bath. After a short period O of heating, gas evolution was noted; heating was con --T-H tinued until gas evolution ceased. Most of the sodium hydroxide pellet remained intact in the reaction mixture, and was removed after heating was discontinued. A 30 4th milliliter portion of cold distilled water was added with wherein T' has the meaning previously stated. The salts swirling to dilute the mixture. Methyl anthranilate at can be formed by reaction of any metal hydroxide with this point was present in the test tube below the aqueous any of the acids. The esters have the generic formula phase, and was separated from the water.