- Email: [email protected]
Synthesis and analytical applications of sodium N-bromo-p-nitrobenzenesulfonamide
Analytzca Chzmica Acta, 147 (1983) 429-433 Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
Short Communication
SYNTHESIS AND ANALYTICAL APPLICATIONS N-BROMO-p-NITROBENZENESULFONAMIDE”
NETKAL M. MADE GOWDA, NORMAN M. TRIEFF* V. M. SADAGOPA RAMANUJAM
OF SODIUM
and
Dzvision of Environmental Toxzcology, Department of Preventive Medicine and Communzty Health, University of Texas Medical Branch, Galveston, TX 77550 (U.S.A.) TADEUSZ MALINSKI, KARL M. KADISH and D. S. MAHADEVAPPAb Department
of Chemistry,
University of Houston, Houston,
TX 77004 (U.S A.)
(Received 20th April 1982) Summary. Sodium N-bromo-p-nitrobenzenesulfonamide (bromamine-N) is useful as an oxidizing titrant. The synthesis, composition and structure are reported. Direct titrations of ascorbic acid, glutathione, thioglycolic acid, methionine, sulfite and arsenite are described. The procedures are simple and rapid; errors are within f 0.5%. The compound is a somewhat better titrant for those species than the chlorine analogs such as chloramine-T and chloramine-N.
Recent papers have described the synthesis of chloramine-N and dichloramine-N and evaluation of these reagents as redox titrants [ 1, 21. The present communication reports the synthesis and evaluation as a titrant of bromamine-N, the sodium salt of N-bromo-p-nitrobenzenesulfonamide. The compound is characterized by its ultraviolet, infrared, and Fourier-Transform ‘H- and ‘3C-nuclear magnetic resonance spectral data. Results are reported for titrations of glutathione, thioglycolic acid, methionine, ascorbic acid, sodium sulfite and sodium arsenite. Experimental Synthesis of bromamine N. Of several synthetic approaches analogous to those for bromamine-T [ 31, the bromination of p-nitrobenzenesulfonamide in alkaline medium was the only successful route to bromamine-N. Bromine (about 4.5 ml) was added dropwise from a microburet to a previously filtered solution of p-nitrobenzenesulfonamide (10 g) in 10 ml of 4 M sodium hydroxide at 65°C with constant stirring for 30 min. The resultant yellow solution was cooled overnight at about 4°C. The yellow product was filtered under suction, washed carefully with two lo-ml portions of ice-cold aThis work was presented in part at the 183rd ACS National Meeting, Las Vegas, NV, U.S.A., March 1982. bPresent address: Department of Chemistry, University of Mysore, Manasa Gangotri, Mysore 570006, India. 0003-2670/83/0000-0000/$03.00
o 1983 Elsevier Scientific Publishing Company
430
water and three 20-ml portions of carbon tetrachloride, and dried. This solid was further purified by recrystallization from hot water (m.p. 207-218°C (dec.), yield 88%). The bromamine-N sample was stored in amber-colored bottles. Characterization. Elemental content was consistent with the formula OzN-C6H4-SO,NBrNa-1.5H,O (calcd. 21.8% C, 2.1% H, 8.5% N, 9.7% S, 24.2% Br, 7.1% Na; found 21.9% C, 2.1% H, 8.4% N, 9.7% S, 24.3% Br, 7.1% Na). The ultraviolet spectrum of the sample in water (20 ,ug ml-‘) had maximum absorption at 258 nm with E,,, = 10413 1 mol-’ cm-‘. The infrared spectrum (in KBr) showed absorption bands (in cm-‘) at 3500-3020 (broad, O-H stretching), 1600 (weak, phenyl ring), 1527 (strong, vWm-NBr,vasyrnNO,), 1350 (strong, vsvm-NO*), 1247 (strong, v,sYm-SOz), 1136 (broad, vsym-SOZ), 1087 (strong, aromatic CH in plane, bending), 943 (strong, broad, v S-N), 855 (strong, v C-N), 740 (medium broad, C-N-O bending and out of plane CH bending of two adjacent aromatic H atoms) and 656 (broad, ring plane deformation). Nuclear magnetic resonance (n.m.r.) spectra were recorded in DzO solvent with sodium 2,2-dimethyl-2-silapentane-5-sulfonate (DSS) as the internal standard. The ’ H-n.m.r. spectrum showed a quadruplet centered around 8.2 6 with coupling constant J, m = 9.00 Hz, indicating the presence of protons in the ortho and metu positions of the benzene ring. However, the Fourier-transform spectrum (80 MHz FT-80A n.m.r. spectrometer) showed a fine structure indicating an AzBz pattern. The 13C F.t.n.m.r. spectrum showed signals (ppm) at 150.67 (C-l carbon atom attached to S atom), 148.34 (C-4 attached to N atom of the NOz group), 129.38 (C-2, 6), and 125.65 (C-3, 5). Formal potential. Polarography was used to determine the formal potential of the reagent in deaerated solutions. Measurements were made with an EG & G Princeton Applied Research (PAR) Model 174A polarographic system and a dropping mercury electrode (DME), a platinum wire counter electrode and saturated calomel reference electrode (SCE). All potentials are reported vs. the SCE and have a maximum associated uncertainty of ?O.OOl V; voltages were checked with other equipment. Reagents. A 5 mM solution of bromamine-N was prepared by dissolving 1.65 g of the solid in 1 1 of deionized water; the solution was stable for one month when stored in an amber-colored bottle. This solution was standardized by the iodimetric method of Bishop and Jennings [4] . Solutions (about 4 mg ml-‘) of reduced glutathione (>98.0%, Aldrich Chemical), isoascorbic acid (D-araboascorbic acid;>98.0%; Eastman Kodak), and DL-methionine (Pfaltz and Bauer) were prepared in deionized water; similar concentrations of sodium sulfite (lOO.O%, Baker Chemical), and sodium arsenite (99.9%, Fisher Scientific) were prepared in deaerated, deionized water. These solutions were standardized titrimetrically [ 1, 23 . Thioglycolic acid (>95.0%; Eastman Kodak) concentration (4 mg ml-‘) was
431
checked as described earlier [ 51. Aqueous solution of other compounds were prepared from reagents of acceptable grades of purity. Titration conditions. Known volumes (l-25 ml) of ascorbic acid or glutathione solutions were mixed in lOO-ml Erlenmeyer flasks with 5-10 ml of 1 M sulfuric acid, 0.1 ml of 1% potassium iodide solution, and 1 ml of 1% starch solution. After dilution to 50 ml with deionized water, the solution was titrated with 5 mM bromamine-N to the appearance of a stable blue. Similar procedures were used for other species except that sulfite was titrated under an atmosphere of nitrogen, arsenite was titrated after addition of 50 ml of 1 M NaHC03 solution instead of sulfuric acid, and thioglycolic acid was titrated after addition of 0.6-1.00 g of potassium iodide but no sulfuric acid. For methionine, the starch method failed but indigo carmine was found to be a suitable indicator. To an aliquot (l-25 ml) of methionine solution, 5-10 ml of 1 M sulfuric acid or 5 ml of anhydrous acetic acid, and O.l0.2 ml of 0.05% (w/v) indigo carmine indicator were added and the solution was diluted with distilled water to 50 ml. The resultant blue solution was titrated carefully with 5 mM bromamine-N solution to the pale yellow endpoint. The indicator correction was determined by a blank titration. The reaction products of the bromamine-N titration of ascorbic acid were identified by thin-layer chromatography to be p-nitrobenzenesulfonamide and dehydroascorbic acid. Oxidized glutathione and methionine sulfoxide were identified by paper chromatography in the relevant titrated solutions. Sulfate and arsenate were detected with spot tests [6]. Results and discussion
The structure of bromamine-iV is considered, from the characterization study, to be -
0I.
.Br
It was concluded from titrations of thiosulfate that the reduction halfreactions of bromamine-l\r in acidic and alkaline media can be represented as follows RNBr- + 2H’ + 2e- + RNH, + Br-
(acidic medium)
(1)
RNBf + 2Hz0 + 2e- + RNHz + Br- + 2 OH-
(alkaline medium)
(2)
where R = p-02NC6H4S02- and RNHz is p-nitrobenzenesulfonamide. Under polarographic conditions in 0.3 M KzS04, bromamine-N exhibits a single, well defined, cathodic wave. The slope, E,,, - E,,4 = 40 mV, of this wave indicates a quasi-reversible two-electron transfer. Coulometric measurements confirmed a value of n = 1.99 * 0.02. Similar results were obtained for
432 TABLE 1 Performance data for titration of some compounds with bromamine-N Compound
Amount taken (mmol)
Titration consumeda (mmol)
Amount founda (mmol)
Standard deviationa (pmol)
Glutathione Thioglycolic acid Methionine Ascorbic acid Sodium sulfite Sodium arsenite
0.1334 0.2177 0.1414 0.1144 0.1588 0.1540
0.0670 0.1093 0.1415 0.1147 0.1588 0.1542
0.1340 0.2187 0.1415 0.1147 0.1589 0.1543
0.46 0.38 0.28 0.35 0.45 0.25
aAverage of five determinations.
chloramine-T. The formal potentials of bromamine-N and chloramine-T were calculated using procedures described for quasi-reversible polarographic waves [7, 81. The values found were 0.012 + 0.005 and 0.000 + 0.005 V for bromamine-N and chloramine-T, respectively. The formal potential for chloramine-T is similar to that reported previously (-0.09 V in 0.5 M K,SO,) [9]. The values of the formal potential indicate that the oxidizing strengths of bromamine-N and chloramine-T differ only slightly. Some typical titration data are presented in Table 1. The observed stoichiometries of oxidation of all species are in agreement with those obtained in titrations with other oxidizing titrants. For methionine, the direct titrations with chlorine derivatives such as chloramine-T are, only successful in the presence of bromide [ 1, 21 whereas those with bromamine-N do not require bromide. Errors for titrations of 4 to 100 mg of all species were between 0 and 0.54%, with an average value of 0.33 f 0.11% for 48 titrations. As part of another program of investigating possible alternatives to chlorine as disinfectants in drinking water and wastewater treatment, the viricidal efficacy of bromamine-N was compared with that of chlorine, chloramine-T [lo], or chloramine-N. These studies suggested that bromamine-N should be considered as a possible alternative to chlorine in drinking and wastewater disinfection. We gratefully acknowledge support by the James W. McLaughlin Fellowship Fund (to N.M.M.G. and N.M.T.), the University of Texas Medical Branch, Galveston, and the Robert A. Welch Foundation (Grant No. H-416 to N.M.T.). We also thank Dr. D. J. Leggett, Department of Chemistry, University of Houston, for the n.m.r. spectra. One of us (N.M.M.G.) thanks the University of Mysore, India for leave of absence. REFERENCES 1 N. M. Made Gowda, N. M. Trieff, D. S Mahadevappa, V. M. S. Ramanujam and R. S Trieff, Microchem. J., 27 (1982) 87. 2 N. M. Made Gowda, V. M. S. Ramanujam, N. M. Trieff, G. J. Stanton and D. S. Mahadevappa, Microchem. J., 26 (1981) 95.
433 3 C. G. R. Nair, R. Lalitha Kumari and P. I. Senan, Talanta, 25 (1978) 525. 4 E. Bishop and V. J. Jennings, Talanta, 8 (1961) 697. 5 D. S. Mahadevappa, Cm-r. Sci., 34 (1965) 530. 6 F. Feigl, Spot Tests m Inorganic Analysis, Elsevier, Amsterdam, 1958. 7 J. Koryta, Electrochim. Acta., 6 (1962) 67. 8 J. M. Hale and R. Parsons, Collect. Czech. Chem. Commun., 27 (1962) 2474. 9 J. Heyrovsky and J. Kuta, Principles of Polarography, Academic Press, New York, 1966, p. 555. .O N. M. Made Gowda, N. M. Trieff and G. J. Stanton, Appl. Environ. Microbial., 42 (1981) 469.
Short Communication
SYNTHESIS AND ANALYTICAL APPLICATIONS N-BROMO-p-NITROBENZENESULFONAMIDE”
NETKAL M. MADE GOWDA, NORMAN M. TRIEFF* V. M. SADAGOPA RAMANUJAM
OF SODIUM
and
Dzvision of Environmental Toxzcology, Department of Preventive Medicine and Communzty Health, University of Texas Medical Branch, Galveston, TX 77550 (U.S.A.) TADEUSZ MALINSKI, KARL M. KADISH and D. S. MAHADEVAPPAb Department
of Chemistry,
University of Houston, Houston,
TX 77004 (U.S A.)
(Received 20th April 1982) Summary. Sodium N-bromo-p-nitrobenzenesulfonamide (bromamine-N) is useful as an oxidizing titrant. The synthesis, composition and structure are reported. Direct titrations of ascorbic acid, glutathione, thioglycolic acid, methionine, sulfite and arsenite are described. The procedures are simple and rapid; errors are within f 0.5%. The compound is a somewhat better titrant for those species than the chlorine analogs such as chloramine-T and chloramine-N.
Recent papers have described the synthesis of chloramine-N and dichloramine-N and evaluation of these reagents as redox titrants [ 1, 21. The present communication reports the synthesis and evaluation as a titrant of bromamine-N, the sodium salt of N-bromo-p-nitrobenzenesulfonamide. The compound is characterized by its ultraviolet, infrared, and Fourier-Transform ‘H- and ‘3C-nuclear magnetic resonance spectral data. Results are reported for titrations of glutathione, thioglycolic acid, methionine, ascorbic acid, sodium sulfite and sodium arsenite. Experimental Synthesis of bromamine N. Of several synthetic approaches analogous to those for bromamine-T [ 31, the bromination of p-nitrobenzenesulfonamide in alkaline medium was the only successful route to bromamine-N. Bromine (about 4.5 ml) was added dropwise from a microburet to a previously filtered solution of p-nitrobenzenesulfonamide (10 g) in 10 ml of 4 M sodium hydroxide at 65°C with constant stirring for 30 min. The resultant yellow solution was cooled overnight at about 4°C. The yellow product was filtered under suction, washed carefully with two lo-ml portions of ice-cold aThis work was presented in part at the 183rd ACS National Meeting, Las Vegas, NV, U.S.A., March 1982. bPresent address: Department of Chemistry, University of Mysore, Manasa Gangotri, Mysore 570006, India. 0003-2670/83/0000-0000/$03.00
o 1983 Elsevier Scientific Publishing Company
430
water and three 20-ml portions of carbon tetrachloride, and dried. This solid was further purified by recrystallization from hot water (m.p. 207-218°C (dec.), yield 88%). The bromamine-N sample was stored in amber-colored bottles. Characterization. Elemental content was consistent with the formula OzN-C6H4-SO,NBrNa-1.5H,O (calcd. 21.8% C, 2.1% H, 8.5% N, 9.7% S, 24.2% Br, 7.1% Na; found 21.9% C, 2.1% H, 8.4% N, 9.7% S, 24.3% Br, 7.1% Na). The ultraviolet spectrum of the sample in water (20 ,ug ml-‘) had maximum absorption at 258 nm with E,,, = 10413 1 mol-’ cm-‘. The infrared spectrum (in KBr) showed absorption bands (in cm-‘) at 3500-3020 (broad, O-H stretching), 1600 (weak, phenyl ring), 1527 (strong, vWm-NBr,vasyrnNO,), 1350 (strong, vsvm-NO*), 1247 (strong, v,sYm-SOz), 1136 (broad, vsym-SOZ), 1087 (strong, aromatic CH in plane, bending), 943 (strong, broad, v S-N), 855 (strong, v C-N), 740 (medium broad, C-N-O bending and out of plane CH bending of two adjacent aromatic H atoms) and 656 (broad, ring plane deformation). Nuclear magnetic resonance (n.m.r.) spectra were recorded in DzO solvent with sodium 2,2-dimethyl-2-silapentane-5-sulfonate (DSS) as the internal standard. The ’ H-n.m.r. spectrum showed a quadruplet centered around 8.2 6 with coupling constant J, m = 9.00 Hz, indicating the presence of protons in the ortho and metu positions of the benzene ring. However, the Fourier-transform spectrum (80 MHz FT-80A n.m.r. spectrometer) showed a fine structure indicating an AzBz pattern. The 13C F.t.n.m.r. spectrum showed signals (ppm) at 150.67 (C-l carbon atom attached to S atom), 148.34 (C-4 attached to N atom of the NOz group), 129.38 (C-2, 6), and 125.65 (C-3, 5). Formal potential. Polarography was used to determine the formal potential of the reagent in deaerated solutions. Measurements were made with an EG & G Princeton Applied Research (PAR) Model 174A polarographic system and a dropping mercury electrode (DME), a platinum wire counter electrode and saturated calomel reference electrode (SCE). All potentials are reported vs. the SCE and have a maximum associated uncertainty of ?O.OOl V; voltages were checked with other equipment. Reagents. A 5 mM solution of bromamine-N was prepared by dissolving 1.65 g of the solid in 1 1 of deionized water; the solution was stable for one month when stored in an amber-colored bottle. This solution was standardized by the iodimetric method of Bishop and Jennings [4] . Solutions (about 4 mg ml-‘) of reduced glutathione (>98.0%, Aldrich Chemical), isoascorbic acid (D-araboascorbic acid;>98.0%; Eastman Kodak), and DL-methionine (Pfaltz and Bauer) were prepared in deionized water; similar concentrations of sodium sulfite (lOO.O%, Baker Chemical), and sodium arsenite (99.9%, Fisher Scientific) were prepared in deaerated, deionized water. These solutions were standardized titrimetrically [ 1, 23 . Thioglycolic acid (>95.0%; Eastman Kodak) concentration (4 mg ml-‘) was
431
checked as described earlier [ 51. Aqueous solution of other compounds were prepared from reagents of acceptable grades of purity. Titration conditions. Known volumes (l-25 ml) of ascorbic acid or glutathione solutions were mixed in lOO-ml Erlenmeyer flasks with 5-10 ml of 1 M sulfuric acid, 0.1 ml of 1% potassium iodide solution, and 1 ml of 1% starch solution. After dilution to 50 ml with deionized water, the solution was titrated with 5 mM bromamine-N to the appearance of a stable blue. Similar procedures were used for other species except that sulfite was titrated under an atmosphere of nitrogen, arsenite was titrated after addition of 50 ml of 1 M NaHC03 solution instead of sulfuric acid, and thioglycolic acid was titrated after addition of 0.6-1.00 g of potassium iodide but no sulfuric acid. For methionine, the starch method failed but indigo carmine was found to be a suitable indicator. To an aliquot (l-25 ml) of methionine solution, 5-10 ml of 1 M sulfuric acid or 5 ml of anhydrous acetic acid, and O.l0.2 ml of 0.05% (w/v) indigo carmine indicator were added and the solution was diluted with distilled water to 50 ml. The resultant blue solution was titrated carefully with 5 mM bromamine-N solution to the pale yellow endpoint. The indicator correction was determined by a blank titration. The reaction products of the bromamine-N titration of ascorbic acid were identified by thin-layer chromatography to be p-nitrobenzenesulfonamide and dehydroascorbic acid. Oxidized glutathione and methionine sulfoxide were identified by paper chromatography in the relevant titrated solutions. Sulfate and arsenate were detected with spot tests [6]. Results and discussion
The structure of bromamine-iV is considered, from the characterization study, to be -
0I.
.Br
It was concluded from titrations of thiosulfate that the reduction halfreactions of bromamine-l\r in acidic and alkaline media can be represented as follows RNBr- + 2H’ + 2e- + RNH, + Br-
(acidic medium)
(1)
RNBf + 2Hz0 + 2e- + RNHz + Br- + 2 OH-
(alkaline medium)
(2)
where R = p-02NC6H4S02- and RNHz is p-nitrobenzenesulfonamide. Under polarographic conditions in 0.3 M KzS04, bromamine-N exhibits a single, well defined, cathodic wave. The slope, E,,, - E,,4 = 40 mV, of this wave indicates a quasi-reversible two-electron transfer. Coulometric measurements confirmed a value of n = 1.99 * 0.02. Similar results were obtained for
432 TABLE 1 Performance data for titration of some compounds with bromamine-N Compound
Amount taken (mmol)
Titration consumeda (mmol)
Amount founda (mmol)
Standard deviationa (pmol)
Glutathione Thioglycolic acid Methionine Ascorbic acid Sodium sulfite Sodium arsenite
0.1334 0.2177 0.1414 0.1144 0.1588 0.1540
0.0670 0.1093 0.1415 0.1147 0.1588 0.1542
0.1340 0.2187 0.1415 0.1147 0.1589 0.1543
0.46 0.38 0.28 0.35 0.45 0.25
aAverage of five determinations.
chloramine-T. The formal potentials of bromamine-N and chloramine-T were calculated using procedures described for quasi-reversible polarographic waves [7, 81. The values found were 0.012 + 0.005 and 0.000 + 0.005 V for bromamine-N and chloramine-T, respectively. The formal potential for chloramine-T is similar to that reported previously (-0.09 V in 0.5 M K,SO,) [9]. The values of the formal potential indicate that the oxidizing strengths of bromamine-N and chloramine-T differ only slightly. Some typical titration data are presented in Table 1. The observed stoichiometries of oxidation of all species are in agreement with those obtained in titrations with other oxidizing titrants. For methionine, the direct titrations with chlorine derivatives such as chloramine-T are, only successful in the presence of bromide [ 1, 21 whereas those with bromamine-N do not require bromide. Errors for titrations of 4 to 100 mg of all species were between 0 and 0.54%, with an average value of 0.33 f 0.11% for 48 titrations. As part of another program of investigating possible alternatives to chlorine as disinfectants in drinking water and wastewater treatment, the viricidal efficacy of bromamine-N was compared with that of chlorine, chloramine-T [lo], or chloramine-N. These studies suggested that bromamine-N should be considered as a possible alternative to chlorine in drinking and wastewater disinfection. We gratefully acknowledge support by the James W. McLaughlin Fellowship Fund (to N.M.M.G. and N.M.T.), the University of Texas Medical Branch, Galveston, and the Robert A. Welch Foundation (Grant No. H-416 to N.M.T.). We also thank Dr. D. J. Leggett, Department of Chemistry, University of Houston, for the n.m.r. spectra. One of us (N.M.M.G.) thanks the University of Mysore, India for leave of absence. REFERENCES 1 N. M. Made Gowda, N. M. Trieff, D. S Mahadevappa, V. M. S. Ramanujam and R. S Trieff, Microchem. J., 27 (1982) 87. 2 N. M. Made Gowda, V. M. S. Ramanujam, N. M. Trieff, G. J. Stanton and D. S. Mahadevappa, Microchem. J., 26 (1981) 95.
433 3 C. G. R. Nair, R. Lalitha Kumari and P. I. Senan, Talanta, 25 (1978) 525. 4 E. Bishop and V. J. Jennings, Talanta, 8 (1961) 697. 5 D. S. Mahadevappa, Cm-r. Sci., 34 (1965) 530. 6 F. Feigl, Spot Tests m Inorganic Analysis, Elsevier, Amsterdam, 1958. 7 J. Koryta, Electrochim. Acta., 6 (1962) 67. 8 J. M. Hale and R. Parsons, Collect. Czech. Chem. Commun., 27 (1962) 2474. 9 J. Heyrovsky and J. Kuta, Principles of Polarography, Academic Press, New York, 1966, p. 555. .O N. M. Made Gowda, N. M. Trieff and G. J. Stanton, Appl. Environ. Microbial., 42 (1981) 469.