A Potential Industrial Process for
SULFAMIDE ED. F. DEGERING AND GEORGE C. GROSS Purdue University, Lafayette, Ind.
ULFAMIDE was first prepared in impure form by Regnault (1) and subsequently by others (2-9). It is believed, however, that the present synthesis is the first in which appreciable amounts of relatively pure sulfamide have been obtained. An extensive review of the preparation and properties of sulfamide and related compounds was compiled by Audrieth and co-workers (1). Because of its similarity t o urea and the importance of the latter, sulfamide has been the subject of an appreciable amount of research. This paper reports the results obtained by the reaction of sulfuryl chloride in an inert solvent with liquid ammonia. Different variables, including temperatures ranging from -45' to 40' C., were studied. The interaction between sulfuryl chloride and such reagents as aqueous ammonia, calcium chloride octa-ammoniate, and sodium amide, and the ammonolysis of N-phthalimide sulfonyl chloride, were
also studied but with unsatisfactory results. Under proper conditions sulfuryl chloride and ammonia react principally in accordance with the equation:
S
Cl.SO2.Cl
By-products of the reaction are HZN. SO2 . NH. SOz. NHZ and H2N.SOz. (NH . SOz)6 . NH2 or the salts of these imidosulfamides. LABORATORY SYNTHESIS
Liquid ammonia (75 ml.) is placed in the reaction flask (Figure l), which is surrounded by a solid carbon dioxidechloroform-carbon tetrachloride bath. To the liquid ammonia is added slowly a solution of 20 ml. of sulfuryl chloride
The synthesis of sulfamide has been effected by condensing sulfuryl chloride with ammonia in both glass apparatus and an autoclave on a laboratory scale. Yields as high as 86 per cent have been obtained in these studies. Low temperature, vigorous agitation, and a diluent favor increased yields of the sulfamide and correspondingly decreased amounts of the imidosulfamides. Methyl acetate and acetone are satisfactory solvents for the extraction and purification of the sulfamide.
Figure 1.
+ 4NH3 +HZN.SO~.NH,+ 2NHa+C1-
Glass Apparatue 75 I
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+
July, 1943
INDUSTRIAL AND ENGINEERING CHEMISTRY
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in 210 ml. of dry petroleum ether. During the introduction of the latter, the reaction mixture is stirred vigorously (1000 r. p. m.), and the reactant is added a t such a rate that there is a slight mist in the lower part of the condenser. The addition requires front 20 to 40 minutes. The cooling bath is then removed, and the excess ammonia is allowed to distill off. The residual inert diluent is decanted. The last traces of the ammonia and of the diluent are removed from the product by warming under vacuum. The dry, white, solid residue is extracted for 2 or more hours in a Soxhlet extractor with methyl acetate. The extract is evaporated
and thermometer well. The sulfuryl chloride reservoir was connected to 6 cylinder of nitrogen. The inlet tube for the sulfuryl chloride was fitted with a nipple of I/*-inch pipe and a cap. The use of caps with different size holes determined the size of the inlet jet. The jacket was half filled with carbon tetrachloride-chloroform mixture and chilled with solid carbon dioxide. Then 400 ml. of liquid ammonia were drawn directly from the cylinder into the reaction chamber and allowed to cool. The top of the autoclave was lowered and bolted down. Eightyone ml. (1 mole) of sulfuryl chloride, dissolved in 210 ml. of petroleum ether, were then placed in the reservoir through the male end of the union. The union was connected to the r nitrogen cylinder and the pressure adjusted to 300 pounds TABLE I. CRUDEYIELDSOF SULFAMIDE OBTAINEDIN GLASS per square inch. I n runs made a t 0" C. or above, the cooling APPARATUS FROM 75 ML. OF AMMONIA AND 20 ML. OF SULFURYL was effected by ice or an ice-salt mixture. The stirrer was CHLORIDE started and the sulfuryl chloride mixture allowed to flow in Expt. No.of % a t a rate that maintained the temperature in the desired Yield No. Runs Diluente range. The cooling bath was also stirred during the entire 1 6 80 ml. p. e. (petroleum ether) 51-64 80 ml. p. e. + NazCOs (or CaCOa) added slowly 47-70 2 4 run. 3 8 80 ml. p. e. + 1-18 grams Filter-Cel in 120 ml. p. e. 38-77 4 5 200 ml. D. e. 64-81 When all of the sulfuryl chloride had been added, stirring 5 i 80-rnl.-nfheptane 66 was continued until the mixture had warmed up to 0-10" C. 6 2 80 ml. chloroform 51-55 7 2 80 ml. CClr 55-62 The bottom valve was then opened slowly to transfer the S 3 No diluent 28-38 9 5 60-20 ml e 34-60 solution to a 500-ml. flask. The solution, slightly colored 10 6 100-210 my:p: e. 52-74 by iron salts, was warmed under reduced pressure on a steam 11 3 80 ml. p. e., atirring rate, decreased to 450 r. p. m. 43-63 80 mi. p. e., stirring rate increased to as much as 1750 12 7 bath to remove the excess ammonia. The residue was ground r. p. m. 56-87 and then extracted for 2 hours in a Soxhlet extractor with Unless a All runs made a t temperature of chloroform-CClrCOz bath. methyl acetate. After removal of the solvent from the otherwise indicated, the stirring rate was 1000 r. p. m. Numerous additional preliminary runs were made, but the results are not included. extract, the residue was dissolved in 200 ml. of water, heated, filtered, acidified, and allowed to stand a week. The solution was then evaporated to dryness under vacuum on a steam cone. The dry solid was re-extracted, the solvent removed, under vacuum on a steam bath, and the residue is allowed and the residue allowed to solidify. The solid was then to crystallize. The product is ground up, dried under reground to a powder, dried in a desiccator over sulfuric acid, duced pressure, and recrystallized from water. The sulfand weighed (Table 11). amide thus obtained is a white solid which melts at 91-93' C. The yield may be increased (10to 15 per cent) by dissolving the reaction mixture in water before extraction, acidifying, TABLE11. CRUDEYIELDS OF SULFAMIDE OBTAINEDIN AN allowing the solution to stand a week at room temperature, AUTOCLAVE FROM 400 ML. OF LIQUIDAMMONIA AND 81 ML. OF evaporating to dryness on a steam bath under diminished SULFURYL CHLORIDE pressure, and extracting the residue. This increased yield Expt. No. of Jet, is a consequence of the fact that the imidosulfamides are No. Runs Inch Temp., C. % Yield hydrolyzed to give one equivalent of sulfamide and one or 1 8 0.0625 40 to 63 Oto 25 more equivalents of sulfamic acid (1, 4, 5 ) . 2 2 0.0625 -15 to -18 66 to 61 3 2 0.0625 -42 to -45 66 to 70 Acetone, ethyl acetate, ethyl methyl ketone, or methyl 4 6 0.0325 18 to 25 62 to 68 5 0.0325 -15 to 10 50 to 77 acetate may be used for the extraction. The use of methyl 6 4 0.0325 -42 to -40 78 to 86 acetate gives both a better quality product and slightly 7 4 0.0177 0 to 20 50 to 69 S 4 0.0177 -40 to -20 74 to 77 higher yields. 0 to 20 57 to 61 9 4 0.0097 10 4 0.0097 -45 to -20 70 to 75 Inert solid diluents such as Filter-Cel (Table I, experiment 3) and basic chemicals (experiment 2) tone down the violence 3 of the reaction without appreciably affecting the yield. An inert solvent likewise decreases the violence of the reNo appreciable corrosive effect of the reactants and action, but the choice of the solvent seems relatively unproducts on the reaction chamber was observed. The important (Table I). Efficient agitation prevents localized technical sulfamide thus obtained may be decolorized, when overheating. necessary, with activated carbon. Sulfamide starts to decompose at about 90' C. The use of a diluent, efficient agitation, and a low temperature all tend LITERATURE CITED to prevent localized overheating. This, in turn, prevents (1) Audrieth a n d eo-workers, Chem. Reo., 26, 76-84, 88-91 (1940). the decomposition of the sulfamide in situ and/or its con(2) Battegay a n d Denivelle, Bull. 8oc. chim., 53, 1242 (1933). densation to give imidosulfamides. (3) Battegay a n d Denivelle, Compt. rend., 194, 2216 (1932). AUTOCLAVE SYNTHESIS
I n order to operate on a larger scale, and to make a further study of the effect of the variables on the reaction, experiments were carried out in a stirred jacketed autoclave with a discharge valve a t the bottom and a reservoir a t the top to hold the sulfuryl chloride. Figure 2 is a detail drawing of the autoclave, one-sixth actual size. The autoclave was fitted with a gas release valve, safety disk, pressure gage,
(4) Ephraim a n d Gurewitsch, Ber., 43, 138 (1910). (5) Ephraim a n d Michel, Ibid., 42, 3833 (1909). (6) Mellor, "Comprehensive Treatise on Theoretical a n d Inorganic Chemistry", Vol. VIII,pp. 660-6 (1928). (7) Perrot and Perrot, Compt. rend., 199, 955 (1934). (8) T r a u b e and Reubke, Be?., 56B, 1656 (1923). (9) Wood and Battye, J . SOC.Chem. Ind., 52,346T (1933).
PRESENTED before the Division of Industrial and Engineering Chemistry a t the 104th Meeting of the AMERICAN CHEMICAL SOCIETY,Buffalo, N. Y Abstraoted from the Ph.D. thesis of G. C. Gross, Purdue University.
