3,658,836 United States Patent Office Patented Apr. 25, 1972 1. 2 the mol ratio of boric acid to amine and therefore if a 3,658,836 . mol ratio of less than 5:1, respectively, is used unreacted HYDROXYBOROXN-AMNE SALTS . amine will remain. Billy Dale Vineyard, St. Louis, Mo. assignor to Conveniently the preparation of the above-described Monsanto Company, St. Louis, Mo. - salts is conducted using a reaction medium which may No Drawing. Filed Apr. 16, 1964, Ser. No. 360,411 form a homogeneous or heterogeneous reaction mass. Int, C. C07d 49/34 Suitable reaction media are aromatic hydrocarbons such U.S. C. 260-309.7 6 Claims as benzene, toluene and xylene, alone or with water. Also an excess of the amine reactant will suffice as a reaction ABSTRACT OF THE DISCLOSURE O medium. The use of benzene is preferred since its use allows removal of water by azeotropic distillation at a This invention relates to hydroxyboroxin-amine Salts relatively low temperature after completing the reaction. which are prepared by reacting boric acid with an amine Typical materials which can be used to form the salts as described hereinafter. The compounds are useful inter of this invention are the mono-, di- and trialkyl amines alia as fungicides and additives for lubricating oils. 15 in which each alkyl group has from 1 to 20 carbons, such as methylamine, ethylamine, n-propylamine, isopropyl amine, n-butylamine, isobutylamine, sec-butylamine, amyl This invention relates to new hydroxyboroxin-amine amine, n-heptylamine, n-hexylamine, 1,1,3,3-tetramethyl salts which can be represented by the structure butylamine, n-octylamine, 2-ethylhexylamine, isooctyl C 20 amine, nonylamine, 2,2,4,4-tetramethylpentylamine, n-dec g EO - YB - Ois Y4 ylamine, isodecylamine, dodecylamine, 1,1,3,3,5,5-hexa Ba. e On 1. (Zy4. methylhexylamine, tridecylamine, pentadecylamine, ste N-ye and -Bag s arylamine, and the like; dimethylamine, diethylamine, 0 a So in OH Yy f Ye methylethylamine, diisopropylamine, di-n-butylamine, di 3. to - BN1 - ot 25 isoamylamine, dioctylamine, didecylamine, methyldecyl (I) (II) amine, distearylamine and the like; and trimethylamine, where Y is selected from hydrogen, alkyl, cycloalkyl and triethylamine, methyldiethylamine, tri-n-propylamine, di aralkyl and Y and Y are hydrogen, except that Y1, Y2 methylbutylamine, methyl-di-tert-butylamine, tri-n-hexyl and Y can, together with the nitrogen atom, form a amine, tri-2-ethylhexylamine, n-propyldioctylamine, tri group having a quinuclidine-type structure, that is, a 30 laurylamine, dimethyldodecylamine, dimethylstearyl quinuclidine compound, pyridine or a picoline; and Y4, amine, tristearylamine and the like. There can also be Ys and Ys are each selected from hydrogen, alkyl, cyclo used cycloalkyl amines of 3 to 10 carbon atoms, such alkyl and aralkyl, except that when Y is hydrogen Ys as cyclopropylamine, cyclohexylamine, dicyclohexylamine, and Y can, together with the nitrogen atom, form a methylcyclohexylamine, tricyclohexylamine, cyclooctyl heterocyclic ring selected from (i) 6-membered carbon 35 amine and cyclodecylamine. Also alkylenediamines such and nitrogen-containing rings, (ii) 6-membered carbon-ni as ethylenediamine, propylenediamine, trimethylenedi trogen- and oxygen-containing rings and (iii) 5-membered amine, tetramethylenediamine, hexamethylenediamine and rings selected from pyrrolidine, pyrroline, imidazole and the like can be used. Furthermore aralkyl amines can be thiazolidine, and further excepted that Y4, Ys and Ys can, used such as amines containing only aralkyl groups such together with the nitrogen atom, form a group having a 40 as benzylamines, phenethylamine, dibenzylamine and tri quinuclidine-type structure, that is, a quinuclidine com benzylamine, but there can also be used mixed alkyl pound. ' ' - aralkyl amines such as methylbenzylamine, dibenzyl In preparing the compounds of this invention, boric methylamine, methylpropylbenzylamine, decylbenzyl acid is reacted with a suitable amine, that is, an amine amine, stearylbenzylamine and the like. which will form a hydroxyboroxin-amine salt as de 45 The heterocyclic secondary amines which can be used scribed above, by heating a mixture of boric acid and to form the monoammonium pentaborates (II) are, for amine at temperatures of the order of 25-100° C. How example, piperidine, piperazine, pyrrolidine, the oxazines ever, steric requirements of the amine and mol ratio of (such as morpholine and 1,4-isoxazine), pyrroline, imid reactants dictates which product is formed as more fully azole, and thiazolidine, and their alkyl-substituted deriva explained below. 50 tives such as 2-methylpyrrolidine, and the like. Thus, the compounds represented by (I) which are The tertiary amines having a quinuclidine-type struc monoammonium salts of 1,3,5-trihydroxyboroxin (meta ture suitable for preparing the compounds of this inven boric acid), can be formed by reacting an amine YNH2 tion include, in addition to quinuclidine itself, triethylene and boric acid in a mol ratio of three or less mols of diamine, and alkyl-substituted derivatives thereof, such as boric acid per mol of amine. In the case of the com 55 3 - methylquinuclidine, 4-ethylcquinuclidine, 5-methyltri pounds containing a quinuclidine group, or pyridine or ethylenediamine, N-ethyltriethylenediamine and the like. a picoline, the mol ratio of boric acid to amine, as with Tertiary amines such as pyridine and the picolines can the primary amines, YNH2, is three or less to one, respec also be used. tively. - The preparation of typical examples of the salts The compounds represented by (II), which are mono 60 described above are given below in which parts are parts ammonium salts of spiro (3,5-dihydroxyboroxin) - 1,1'- by weight unless otherwise stated. (3',5' - dihydroxyboroxin)), but which can also be de scribed as monoammonium pentaborates, can be formed EXAMPLE 1. (1) from primary amines, YaNH2, and amines having a Triethylenediamine (16.8 parts-0.15 mol) in 50 ml. quinuclidine structure, by reacting boric acid with such 65 of benzene was added to a slurry of 18.6 parts of boric amines in mol ratios of three to five mols of boric acid acid (0.3 mol), 10 ml. of water, and 150 ml. of benzene. per mol of amine; (2) from secondary amines, YYNH, The mixture was then stirred for 5 minutes at room tem and the heterocyclic secondary amines, and tertiary perature. A sample of the reaction mixture was removed; amines, YYYsN, provided such amines have a dissocia the solid removed by filtration, washed with diethyl ether tion constant greater than about 1x10, by reacting such 70 and dried. The remaining reaction mixture was refluxed amines with boric acid. When using such secondary, and (70-80°. C.) until theory water (15-16 ml.) had been tertiary amines, the spiro compounds form regardless of . removed. The benzene insoluble product was then col 8,658,836 3 4. lected on a filter, washed with diethyl ether and dried. In the manner of the foregoing examples additional Infrared spectrum and elemental analysis of the final monoammonium salts of 1,3,5-trihydroxyboroxin, meet product was identical to the product obtained from the ing the above definition, can be prepared. Examples of sample removed after 5 minutes. The product, obtained in such salts are the following: 98% yield, was the monotriethylenediamine salt of 1,3,5- monomethylammonium salt of 1,3,5-trihydroxyboroxin. trihydroxyboroxin. Analysis of this product showed the monoethylammonium salt of 1,3,5-trihydroxyboroxin presence of 13.02% boron and 11.20% nitrogen. mono-n-butylammonium sait of 1,3,5-trihydroxyboroxin. EXAMPLE 2. mono-n-pentylammonium salt of 1,3,5-trihydroxyboroxin mono-n-hexylammonium salt of 1,3,5-trihydroxyboroxin. n-Octylamine (25.8 parts-0.2 mol) was added rapidly O mono-n-decylammonium salt of 1,3,5-trihydroxyboroxin to a mixture of 12.4 parts of boric acid (0.2 mol), 7 ml. monododecylammonium salt of 1,3,5-trihydroxyboroxin. of water and 100 ml. of benzene. The mixture was then monotridecylammonium salt of 1,3,5-trihydroxyboroxin refluxed (70-80 C.) until theory water (10.6 ml.) was monopentadecylammonium salt of 1,3,5-trihydroxy removed by azeotropic distillation. The solid product, the boroxin mono-n-octylammonium salt of 1,3,5-trihydroxyboroxin, 5 monostearylammonium salt of 1,3,5-trihydroxyboroxin was filtered from the cooled reaction mixture, washed with mono-a-picolinium salt of 1,3,5-trihydroxyboroxin diethyl ether and dried. The yield was 90%. The infrared monothiazolidinium salt of 1,3,5-trihydroxyboroxin spectrum showed bands at 714 cm.-1 and 1640 cm. 1 monoquinuclidinium salt of 1,3,5-trihydroxyboroxin (boroxin ring and amine salt, respectively). Analysis of monobenzylammonium salt of 1,3,5-trihydroxyboroxin the product showed the presence of 12.26% boron and 20 5.25% nitrogen. monophenethylammonium salt of 1,3,5-trihydroxy EXAMPLE 3 boroxin Four parts of 1,3,5-trihydroxyboroxin (metaboric acid) The preparation of monoammonium salt of spiro (3,5- (0.031 mol) was added to 11.4 parts of n-octylamine dihydroxyboroxin)-1,1-(3',5'-dihydroxyboroxin) (II) is (0.088 mol). The mixture was stirred at 40-60° C. for 25 illustrated in the following examples. 40 minutes, and then at 80 C. for 20 minutes. Diethyl EXAMPLE 8 ether (50 ml.) was added to the thick mass, and the in soluble solid isolated by filtration. The prdouct was n-Octylamine (10.3 parts, 0.08 mol) was added to a obtained in essentially quantitative yield. Infrared and slurry of 24.8 parts (0.4 mol) of boric acid, 15 ml. of elemental analyses as well as X-ray powder diffraction 30 water and 100 ml. of benzene. The mixture was stirred showed that this material was identical to the boric acid at 25-30 C. for 0.5 hour and then heated to reflux (70 n-octylamine reaction product obtained in Example 2.