Patent Application: US-18691402-A

Abstract:
this patent discloses the use of poly - substituted isothiouronium salts , poly - substituted guanidinium salts , or mixtures of two or more of the above compounds , as the biocidal component of microbiocidal or anti - fouling formulations .

Description:
the synthesis of the various compounds is given in the reaction schemes in terms of a general procedure . the counterion produced in the synthesis is typically iodide that is subsequently exchanged for chloride or other anions by ion exchange . procedure a can produce monosubstituted guanidinium salts or n , n - disubstituted guanidinium salts , depending on the starting amine . procedure b can produce n , n ′- disubstituted thioureas , or n , n , n ′- trisubstituted thioureas , depending on the starting amine . the first step of procedures c and d can produce n , n ′, s - trisubstituted isothiouronium salts or n , n , n ′, s - tetrasubstituted isothiouronium salts , depending on the starting thiourea . direct reaction of isothiouronium salts with ammonia ( procedure c ) gives either n , n ′- disubstituted guanidinium salts or n , n , n ′- trisubstituted guanidinium salts . alternatively , reaction of isothiouronium salts with primary or secondary amines ( procedure d ) can produce n , n ′, n ″- trisubstituted guanidinium salts , n , n , n ′, n ″- tetrasubstituted guanidinium salts , or n , n , n ′ n ′, n ″- pentasubstituted guanidinium salts , depending on the starting isothiouornium salt and starting amine . a total of nine mono -, di -, and tri - substituted guanidinium salts ( g1 ), and three tri - substituted isothiouronium salts ( t1 ) were prepared by the methods shown . all compounds shown were characterized by nmr , ms , and ir . by the methods disclosed below , the purity of the compounds was high without recourse to chromatographic separation . samples of each compound were further purified by chromatography on silica . the purified materials all showed uv cutoff values below 300 nm , and showed an ε less than one at 300 nm for all compounds . it will be obvious to someone skilled in the art that the nature of the substituent groups r 1 , r 2 , r 3 , r 4 , r 5 , r 6 in structures t1 and g1 can be varied by judicious choice of starting amines and isothiocyanates according to the reaction schemes presented . the following general procedures , given for alkyl substituents , illustrate the methods used . (!! caution !! : this procedure evolves methyl mercaptan . use a hood . avoid exposure .) an alkyl amine ( 1 eq .) and solid s - methyl isothiouronium iodide ( 2 eq .) were suspended in absolute ethanol ( 5 - 8 ml / g salt ). the mixture was stirred at reflux under a reflux condenser . the evolution of methyl mercaptan was followed using moistened lead acetate test paper . the reaction was usually complete in 6 hours , but the reflux was continued overnight . the mixture was evaporated to a solid and redissolved in water . the water was extracted on a continuous extractor overnight using chloroform , the extracts were dried over magnesium sulfate , filtered and evaporated to yield the iodide salt of the product . the iodide was converted to the chloride using amberlite ira400 resin in methanol . g1 where r 1 = c 10 h 21 , r 2 = r 3 = r 5 = r 6 = h , x − = cl − : 1 h nmr ( cdcl 3 , δ ): 0 . 95 ( br . t ., 3h ), 1 . 54 ( br . s ., 14h ), 1 . 60 ( br . m ., 2h ), 3 . 10 ( t ., 2h ), 4 . 90 ( br . s ., & gt ; sh ); 3 c nmr ( cdcl 3 , δ ): 14 . 2 , 22 . 7 , 26 . 7 , 28 . 5 , 29 . 3 ( m ), 31 . 9 , 42 . 5 , 156 . 6 ; ms (+ lsims , mnba ): 200 . 2 ( m − cl ). g1 where r 1 = c 14 h 29 , r 2 = r 3 = r 5 = r 6 = h , x − = cl − : 1 h nmr ( cdcl 3 , δ ): 0 . 95 ( br . t ., 3h ), 1 . 5 ( br . s ., 22h ), 1 . 6 ( br . m ., 2h ), 3 . 10 ( t ., 2h ), 4 . 9 ( br . s ., & gt ; 5h ); ms (+ lsims , mnba ): 256 . 2 ( m − cl ). g1 where r 1 = c 18 h 37 , r 2 = r 3 = r 5 = r 6 = h , x − = i − : 1 nmr ( dmso - d 6 , δ ): 0 . 95 ( br . t ., 3h ), 1 . 54 ( br . s ., 30h ), 1 . 60 ( br . m ., 2h ), 3 . 10 ( t ., 2h ), 4 . 90 ( br . s ., & gt ; 5h ); ms (+ lsims , mnba ): 312 . 2 ( m − i ). (!! caution !! : isothiocyanates are typically lachrymators . use a hood . avoid exposure ). an alkyl amine ( 1 eq .) and an alkyl isothiocyanate ( 1 eq .) were dissolved in toluene ( 5 ml / g amine ). the mixture was stirred at reflux for 3 - 5 hours . the product precipitated in some cases . the mixture was concentrated under reduced pressure , cooled and filtered . the precipitate was washed with pentane and air - dried . the product is sufficiently pure for the subsequent reaction . t3 where r 1 = c 10 h 21 , r 2 = h , r 3 = c 4 h 9 : 1 h nmr ( cdcl 3 , δ ): 0 . 95 ( m ., 6h ), 1 . 3 ( br . s ., 16h ), 1 . 60 ( m ., 4h ), 3 . 4 ( br . s ., 4h ), 5 . 7 ( br . s ., 2h ); 13 c nmr ( cdcl 3 , δ ): 13 . 7 , 14 . 1 , 20 . 2 , 22 . 7 , 26 . 9 , 29 . 5 ( m . ), 31 . 0 , 31 . 9 , 44 . 0 ( br . ), 139 . 5 ; ms (+ lsims , mnba ): 273 . 2 ( m + h ). t3 where r 1 = c 14 h 29 , r 2 = h , r 3 = c 4 h 9 : 1 h nmr ( cdcl 3 , δ ): 0 . 95 ( m ., 6h ), 1 . 3 ( br . s ., 24h ), 1 . 60 ( m ., 4h ), 3 . 4 ( br . s ., 4h ), 5 . 7 ( br . s ., 2h ); 13 c nmr ( cdcl 3 , δ ): 13 . 7 , 14 . 1 , 20 . 2 , 22 . 7 , 26 . 9 , 29 . 5 ( m . ), 31 . 0 , 31 . 9 , 44 . 0 ( br . ), 139 . 5 ; ms (+ lsims , mnba ): 329 . 2 ( m + h ). t3 where r 1 = c 18 h 37 , r 2 = h , r 3 = c 4 h 9 : 1 h nmr ( cdcl 3 , δ ): 0 . 95 ( m ., 6h ), 1 . 3 ( br . s ., 32h ), 1 . 60 ( m ., 4h ), 3 . 4 ( br . s ., 4h ), 5 . 7 ( br . s ., 2h ); 13 c nmr ( cdcl 3 , δ ): 13 . 7 , 14 . 1 , 20 . 2 , 22 . 7 , 26 . 9 , 29 . 5 ( m . ), 31 . 0 , 31 . 9 , 44 . 0 ( br . ), 139 . 5 ; ms (+ lsims , mnba ): 385 . 2 ( m + h ). (!! caution !! : this procedure evolves methyl mercaptan . use a hood . avoid exposure ). a substituted thiourea ( 1 eq .) was suspended in absolute ethanol ( 5 - 10 ml / g , thiourea may not dissolve ) and idomethane ( 3 eq .) was added . the mixture was sealed in a low pressure hydrogenation bottle , stirred and heated to 80 ° c . after cooling , the vessel was opened and the unreacted idomethane and solvent was removed by evaporation . the product at this stage is an isothiouronium salt of type t1 and may be worked up as indicated after the ammonia treatment below . the product was dissolved in absolute ethanol ( sml / g ) and ammonia was added via a bubbler at a rate to allow dissolution . ammonia addition was continued until a large excess was assured . the mixture was again sealed and heated at 80 ° c . for 24 hours . after cooling the vessel was opened (!! caution !! : use a fume hood ) and reheated to drive off the methyl mercaptan . the mixture was then evaporated to a thick oil . the oil was dissolved in water , extracted with methylene chloride , the extracts were dried over magnesium sulfate , filtered and evaporated to yield the iodide salt of the product . the iodide was converted to the chloride using amberlite ira400 resin in methanol . t1 where r 1 = c 10 h 21 , r 2 = h , r 3 = c 4 h 9 , r 4 = ch 3 , x − = cl − : 1 h nmr ( cdcl 3 , δ ): 0 . 9 and 0 . 95 ( 2 br . t ., 6h ), 1 . 2 ( br . s ., 16h ), 1 . 6 ( br . m ., 4h ), 2 . 8 ( br . s ., 3h ), 3 . 75 ( m ., 4h ), 7 . 8 ( br . 2h ); 13 c nmr ( cdcl 3 , δ ): 13 . 7 , 14 . 1 , 19 . 8 , 22 . 6 , 27 . 0 , 29 . 3 ( m . ), 31 . 8 , 44 . 7 , 45 . 0 , 50 . 1 , 166 . 5 ; ms (+ lsims , mnba ): 287 . 4 ( m − cl ). t1 where r 1 = c 14 h 29 , r 2 = h , r 3 = c 4 h 9 , r 4 = ch 3 , x − = i − : 1 h nmr ( cdcl 3 , δ ): 0 . 9 and 0 . 95 ( 2 br . t ., 6h ), 1 . 2 ( br . s ., 24h ), 1 . 6 ( br . m ., 4h ), 2 . 8 ( br . s ., 3h ), 3 . 75 ( m ., 4h ), 7 . 85 ( br . 1h ), 8 . 4 ( br . 1h ); 13c nmr ( cdcl 3 , δ ): 13 . 7 , 14 . 1 , 19 . 7 , 22 . 9 , 27 . 1 , 29 . 4 ( m . ), 31 . 8 , 44 . 7 , 45 . 1 , 50 . 3 , 166 . 5 ; ms (+ lsims , mnba ): 343 . 4 ( m − i ). t1 where r 1 = c 18 h 37 , r 2 = h , r 3 = c 4 h 9 , r 4 = ch 3 , x − = cl − : 1 h nmr ( cdcl 3 , δ ): 0 . 9 and 0 . 95 ( 2 br . t ., 6h ), 1 . 2 ( br . s ., 32h ), 1 . 6 ( br . m ., 4h ), 2 . 8 ( br . s ., 3h ), 3 . 75 ( m ., 4h ); 8 . 0 ( br . 2h ); 13 c nmr ( cdcl 3 , δ ): 13 . 7 , 14 . 1 , 19 . 7 , 22 . 6 , 27 . 1 , 29 . 3 ( m . ), 31 . 8 , 44 . 7 , 44 . 8 , 50 . 3 , 166 . 5 ; ms (+ lsims , mnba ): 399 . 4 ( m − cl ). g1 where r 1 = c 10 h 21 , r 3 = c 4 h 9 , r 2 = r 5 = r 6 = h , x − = cl − : 1 h nmr ( cdcl 3 , δ ): 0 . 9 and 0 . 95 ( 2 br . t ., 6h ), 1 . 2 and 1 . 4 ( br . s . + m ., 16h ), 1 . 6 ( br . m ., 4h ), 3 . 15 ( br . m ., 4h ), 6 . 4 - 7 . 0 ( br ., 4h ); 13 c nmr ( cdcl 3 , δ ): 13 . 7 , 14 . 1 , 20 . 0 , 22 . 7 , 26 . 8 , 29 . 4 ( m . ), 31 . 9 , 42 . 2 , 42 . 5 , 155 . 8 ; ms (+ lsims , mnba ): 256 . 4 ( m − cl ). g1 where r 1 = c 14 h 29 , r 3 = c 4 h 9 , r 2 = r 5 = r 6 = h , x − = cl − : 1 h nmr ( cdcl 3 , δ ): 0 . 9 and 0 . 95 ( 2 br . t ., 6h ), 1 . 2 and 1 . 4 ( br . s . + m ., 24h ), 1 . 6 ( br . m ., 4h ), 3 . 15 ( br . m ., 4h ), 6 . 4 - 7 . 0 ( br ., 4h ); 13 c nmr ( cdcl 3 , δ ): 13 . 7 , 14 . 1 , 19 . 9 , 22 . 7 , 26 . 9 , 29 . 4 ( m . ), 31 . 9 , 41 . 8 , 42 . 1 , 156 . 2 ; ms (+ lsims , mnba ): 312 . 5 ( m − cl ). g1 where r 1 = c 18 h 37 , r 3 = c 4 h 9 , r 2 = r 5 = r 6 = h , x − = cl − : 1 h nmr ( cdcl 3 , δ ): 0 . 9 and 0 . 95 ( 2 br . t ., 6h ), 1 . 2 and 1 . 4 ( br . s . + m ., 32h ), 1 . 6 ( br . m ., 4h ), 3 . 15 ( br . m ., 4h ), 6 . 4 - 7 . 0 ( br ., 4h ); ms (+ lsims , mnba ): 368 . 6 ( m − cl ). the procedure was identical to c with the exception of an alkyl amine ( 2 eq .) was used in place of ammonia . g1 where r 1 = c 10 h 21 , r 3 = r 5 = c 4 h 9 , r 2 = r 6 = h , x − = cl − : 1 h nmr ( cdcl 3 , δ ): 0 . 95 ( m ., 9h ), 1 . 2 - 1 . 4 ( m ., 18h ), 1 . 6 ( m ., 6h ), 3 . 25 ( br . m ., 6h ), 7 . 0 - 7 . 2 ( br ., 3h ); 3 c nmr ( cdcl 3 , δ ): 13 . 7 , 13 . 8 , 14 . 1 , 19 . 9 , 20 . 0 , 22 . 7 , 26 . 8 , 29 . 4 ( m . ), 31 . 8 , 31 . 9 , 42 . 3 , 42 . 6 , 155 . 4 ; ms (+ lsims , mnba ): 312 . 2 ( m − cl ). g1 where r 1 = c 14 h 29 , r 3 = r 5 = c 4 h 9 , r 2 = r 6 = h , x − = cl − : 1 h nmr ( cdcl 3 , δ ): 0 . 95 ( m ., 9h ), 1 . 2 - 1 . 4 ( m ., 26h ), 1 . 6 ( m ., 6h ), 3 . 25 ( br . m ., 6h ), 7 . 0 - 7 . 2 ( br ., 3h ); 13 c nmr ( cdcl 3 , δ ): 13 . 7 , 14 . 1 , 19 . 9 , 22 . 7 , 26 . 8 , 29 . 4 ( m . ), 31 . 8 , 31 . 9 , 42 . 5 , 42 . 8 , 155 . 7 ; ms (+ lsims , mnba ): 368 . 6 ( m − cl ). g1 where r 1 = c 18 h 37 , r 3 = r 5 = c 4 h 9 , r 2 = r 6 = h , x − = i − : 1 h nmr ( cdcl 3 , δ ): 0 . 95 ( m ., 9h ), 1 . 2 - 1 . 4 ( m ., 34h ), 1 . 6 ( m ., 6h ), 3 . 25 ( br . m ., 6h ), 7 . 0 - 7 . 2 ( br ., 3h ); 13 c nmr ( cdcl 3 , δ ): 13 . 7 , 14 . 1 , 19 . 9 , 22 . 7 , 26 . 8 , 29 . 4 ( m . ), 31 . 8 , 31 . 9 , 42 . 5 , 42 . 8 , 154 . 6 ; ms (+ lsims , mnba ): 324 . 7 ( m − i ). an experiment was designed to follow the onset and development of algal growth on painted panels held approximately 1 m below the surface in open seawater . the apparatus consisted of a moored floating superstructure with a set of test panels suspended below it . the superstructure allowed the test panels to be lifted from the water periodically to assess the extent of growth and to photograph the panels . the apparatus was designed to hold 90 test panels each 10 cm square . the experiment examined nine of the compounds prepared , at two different dose levels ( 5 and 10 wt %) in three different topside marine paints ( 9 × 2 × 3 = 54 primary samples ). none of the paints contained any commercial anti - fouling agent . a total of 12 control samples were included : 6 which were not touched , and 6 which were used for scrapes to examine the type of organisms populating the surface fouling layer . the remaining 24 test panels were assigned to randomized replicates of the primary samples , in sets of 8 for each paint type . the locations of the controls were fixed on the six arrays and the remaining 78 test panels were randomly assigned to the other locations . the lexan test panels were sandblasted to provide a surface for paint adhesion , cleaned in methanol , and then in trifluorethanol immediately prior to painting . paint samples were prepared from a weighed amount of the test compound and a known volume of paint using the measured paint density to arrive at the nominal 5 and 10 wt % dose levels . in most cases the compounds were dissolved in a few ml of methylene chloride before the paint was added . the paint samples were mixed by hand until homogeneous to the eye . a measured volume of the paint sample was spread on the cleaned test panel with a silk - screen tool using a jig designed to form a 250 μm paint layer . the painted test panels were then glued in place on the array and allowed to air dry for 72 hours . after painting , the sole identifier for the compound and formulation was from the array coordinates . given that the six arrays were virtually indistinguishable after drying , the specific location of any particular compound was essentially hidden from the subsequent observers . the experiment was initiated in the summer of 1999 . qualitatively , the panels remained clean for the first two weeks , then rapidly fouled over the next two weeks . by the end of a six - week period , the late - summer die - off of marine flora was evident from the amount of plant debris in the water column and the exposure of some previously fouled surfaces on the test panels . the main fouling observed was filamentous algae that hung from the frame of the apparatus , from the clean sections between the test panels , and from some fouled panels . the extent of fouling was assessed and scored by two independent observers . statistical controls establish excellent agreement between the observers . the observers scored the control panels as “ heavily ” fouled after a six - week exposure . at the same time , a total of 8 test panels corresponding to 6 compound - dose - paint formulations showed significantly less growth than the controls . some test panels remained completely free of algal growth after six - week exposure . formulations containing t1 ( r 1 = c 10 h 21 , r 3 = c 4 h 9 , r 2 = h , r 4 = ch 3 , x − = cl − ) showed virtually no growth over the first six weeks of the experiment in three different formulations . in two formulations , growth on panels containing g1 ( r 1 = c 14 h 29 , r 3 = c 4 h 9 , r 2 = r 5 = r 6 = h , x − = cl − ) was inhibited relative to controls during the initial growth period , but increased after five weeks to levels that were less fouled but not statistically significantly relative to controls . these data establish that these compounds inhibit initial growth on the surfaces . after a 9 - month exposure all control panels and untreated surfaces were heavily fouled with brown and green algae , and barnacles had set in many places . several other organisms inhabited regions of the dense algal mat around and on the painted panels . several test panels were significantly less fouled than control surfaces with a substantial portion of the surface (& gt ; 90 % in some cases ) free of attached algae and barnacles . all formulations containing t1 ( r 1 = c 10 h 21 , r 3 = c 4 h 9 , r 2 = h , r 4 = ch 3 , x − = cl − ) showed clear dose dependent anti - fouling activity . the majority of formulations containing g1 ( r 1 = c 18 h 37 , r 3 = c 4 h 9 , r 2 = r 5 = r 6 = h , x − = cl − ) or g1 ( r 1 = c 10 h 21 , r 3 = r 5 = c 4 h 9 , r 2 = r 6 = h , x − = cl − ) also showed dose - dependent anti - fouling activity . these data establish that these compounds inhibit marine growth on treated surfaces , both during the initial colonization phase , and over the longer term . an experiment was designed to examine the stability of the compounds in seawater over a period of time to determine the rate of microbial degradation of the compound . seawater samples ( 20 l ) were held at 1 ° c . in an east - facing window and air was bubbled for 2 hours each day to maintain saturation . compound t1 ( r 1 = c 10 h 21 , r 2 = h , r 3 = c 4 h 9 , r 4 = ch 3 , x − = cl − ) was added at an initial concentration of 100 nm . at intervals over 5 days , 100 ml samples of seawater were withdrawn and analyzed by electrospray mass spectrometry . a steady decline in the concentration of t1 ( r 1 = c 10 h 21 , r 2 = h , r 3 = c 4 h 9 , r 4 = ch 3 , x − = cl − ) was observed with an apparent half - life of 80 hours under the experimental conditions . this experiment establishes that the compound is likely to be degraded in the environment . the product of the degradation is initially the corresponding urea that is then further degraded by the microorganisms in the seawater . u . s . pat . no . 4 , 515 , 813 fancher et al application no . 426 , 366 , filed : sept . 29 , 1982 u . s . pat . no . 3 , 655 , 898 driscoll , patrick application no . 1969000083794 filed : jun . 30 , 1969 u . s . pat . no . 4 , 906 , 385 lyons et al application no . 1989000305231 filed : feb . 1 , 1989 ca patent no . 1269927 lyons et al application no . 535696 filed : apr . 27 , 1987 jp patent no . 53109903a2 nishimoto application no . jp1977000024060 filed : mar . 4 , 1977 de patent no . 2637651 young et al application no . de19762637651 filed : aug . 20 , 1976 jp patent no . 5163105a2 hamachi et al application no . jp1991000332078 filed : dec . 16 , 1991 evans , callow and wood , synergism between antifouling biocides , stud . env . sci . 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