Patent Publication Number: US-3879190-A

Title: Herbicidal allophanimidates

Description:
Umted States Patent 1191 1111 3,879,190  
 Fuchs 1451 Apr. 22, 1975 1 HERBlClDAL ALLOPHANlMlDATES [76] Inventor: Julius Jakob Fuchs, 1 104 Greenway 1571 ABSTRACT Rd. Wilmington. Del. 19803 Herbicidal allophanimidic acid esters of the formula:  
  7 [2-] Flled. July 3, 1972 1 1 3 5? M 21 Appl. No.: 268,768 N g -N=C-I--C-N Related U.S. Application Data 1 l [631 Continuation-impart of Ser. No. 256.254. May 24. 2 2&#39;R6 5 1972, abandoned. which is a continuation-in-part of Scr. No. 181.203. Sept. 16. 1971. abandoned. here R R R and R are selected from hydrogen and 1521 us. 01. 71/98; 71/88; 71 /94; Organic radicals least one of them 71/95; 71/99; 71 119; 71/120; 260/239 F; F an organ? 260/239 BF; 260/2471; 260/2472 A; R;, 1s se1ected from hydrogen and certam organlc 260/2472 13-. 260/2475 R; 260/243.58; Ftdlcals;  
 260093.62; 260/29363; 260/293&#39;85; R. 1s selected from certaln orgamc rad1ca1s; and  
  260/291; 260/309; 260/3268}; X,, X and X are selected from oxygen and sulfur; 2 053 3; 2 032 2 0 R; and salts of the above compounds in which R, is hy- 260/470; 260/471 R; 260/481 R; 260/482 R: dmgen- 260/455 A; 260/543 A; 260/544 C; 260/566 Preparation of the compounds by carbamoylation of D 51 1111.01 A0ln 9/12 1 5 (58] Field of Search 71/98. 99,120,119:  
 260/453 R, 552 R. 564 E 3 R X -R (56] References Cited 2 2 6 UNITED STATES PATENTS or by reaction of ammonia or an amine with 1,667,053 4/1928 Schottc 260/552 R R 2.780.535 2/1957 Snyder 71/98 1 $3 {1 3.439.018 4/1969 Brookcs ct a1 71/118 N C C N-C Y 3.488.355 1/1970 Levy 260/453 R 3,597,444 8/1971 Klayman et a1 260/3097 2 2 6 FOREIGN PATENTS OR APPLICATIONS &#34;16.958 1/1966 Japan 71/99 where Y 16470 11/1968 Japan 71/99 OTHER PUBLICATIONS Najer et a1., &#34;Action of Oxalyl Chloride on N,N- dialkylaceas. etc.&#34; (1959) CA 54 p. 9759 (1960). Sonn. Biuret and Triuret from Urea&#34; (1942) CA 37 p. 6281 (1943).  
 Primary E.\aminerG1ennon H. Hollrah An exemplary compound: methyl N-dimethylcarbamoy1-4-tert-buty1thioa11ophanimidate.  
 4 Claims, N0 Drawings HERBICIDAL ALLOPHANIMIDATES BACKGROUND OF THE INVENTION US. Pat. No. 3.530.220. issued Sept. 22. 1970. to James B. Buchanan. discloses a class of l-carbamoyl- N-(substituted carbamoyloxy)thioformimidates of the general formula where the Rs represent hydrogen or certain organic radicals and R and R&#34; represent certain organic radicals. The compounds are insecticides. acaricides. and nematocides. The patent discloses preparation of the compounds from intermediate l-carbamoyl-N- hydroxythioformimidates of the general formula R S-R&#39; The present invention resulted from efforts to discover new biologically active compounds which could be prepared from these intermediates.  
 SUMMARY OF THE INVENTION This invention is a class of novel herbicidally active compounds of the formula:  
 wherein:  
 R R R and R are each independently selected from the group consisting of hydrogen; alkyl of I through 8 carbon atoms; alkenyl of 3 through 4 carbon atoms; cycloalkyl of 3 through 8 carbon atoms; cycloalkenyl of 5 through 8 carbon atoms; cyclmtlkylalkyl of4 through 10 carbon atoms; bicycloalkyl of 7 through 10 carbon atoms; arylalkyl of 5 through 9 carbon atoms: alkynyl of 3 through 4 carbon atoms; methoxy; phenyl; the above alkyl and alkenyl groups substituted with I through 3 chlorines. bromine. iodine. I through 7 fluorines. methoxy. ethoxy. methylthio. ethylthio. cyano. methoxycarbonyl. ethoxycarlmnyl. or acetyl; the above cycloalkyl and bicycloalkyl groups substituted with I through 3 chlorines. bromine. I or 2 methyls. or alkyl of 2 through 4 carbon atoms; phenyl substituted with l or 2 chlorines. l or 2 bromines. fluorine. nitro. cyano. alkyl of I through 4 carbon atoms. methoxy. or trifluoromethyl; and the above arylalkyl groups substituted with l chlorine or I methyl;  
 R and R when taken together and R and R when taken together are. --(CH- -O(CH or --(CH:),,- where n is 2 through 6;  
 R is hydrogen; alkyl of I through 4 carbon atoms: alkynyl of 3 through 4 carbon atoms; or alkenyl of 3 through 4 carbon atoms;  
 R. is alkyl of I through 8 carbon atoms; cycloalkyl of 5 through 8 carbon atoms; alkenyl of 3 through 8 carbon atoms; phenyl; or benzyl; and  
 X X and X are each independently selected from oxygen and sulfur:  
 provided that:  
 a. at least one of R R R and R is other than hydrogen:  
 b. no more than one of R R R and R is phenyl.  
 substituted phenyl; arylalkyl or substituted arylalkyl;  
 c. the total number of carbon atoms in R and R does not exceed 10:  
 d. the total number of carbon atoms in R and R;  
 does not exceed 10;  
 e. R and R- are not both methoxy;  
 f. R. and R are not both methoxy;  
 g. when one of R,. R R and R is methoxycarbonylmethyl or ethoxycarbonylmethyl and R is hydrogen then only one of the other R R R and R can be other than hydrogen;  
 h. when R is normal alkyl of 3 through 8 carbon atoms. cycloalkyl of 6 through 8 carbon atoms and benzyl. and R is hydrogen. and one of R,. R R and R is phenyl. then only one of the other R R R and R can be other than hydrogen: and  
 i. when one of R R R and R is 2.5-dichlorophenyl and R is hydrogen. then only one of the other R,. R R and R can be other than hydrogen;  
 and salts of the above compounds in which R is hydrogen.  
  The invention also includes herbicidal compositions containing the compounds as active ingredient. methods of controlling undesired vegetation by applying the compounds. methods of preparing the compounds. and certain intermediates (Compounds of formulae II. III and V below) useful in preparing the compounds.  
 DESCRIPTION OF THE INVENTION Preferred Compounds Preferred because of higher herbicidal activity and ease of synthesis are those compounds of formula I where R, is hydrogen. alkyl of I through 6 carbon atoms. or  
 alkenyl of 3 through 4 carbon atoms:  
 R is alkyl of I through 4 carbon atoms or alkenyl of 3 through 4 carbon atoms. provided that the total number of carbon atoms in R and R does not exceed 8;  
 R is hydrogen;  
 R is alkyl of I through 6 carbon atoms; alkenyl of 3 through 4 carbon atoms or cycloalkyl of 5 through 6 carbon atoms;  
 R;, is hydrogen. alkyl of I through 6 carbon atoms. cycloalkyl of 5 through 6 carbon atoms. benzyl. or alkenyl of 3 through 4 carbon atoms:  
 R is methyl. ethyl. isopropyl or allyl;  
 X and X; are oxygen; and  
 X is oxygen or sulfur.  
  Most preferred because of their higher activity are those compounds of formula l where R, is hydrogen or methyl:  
 R is alkyl of 1 through 4 carbon atoms.  
 R; is hydrogen:  
 R is alkyl of I through 4 carbon atoms. allyl or cycloalkyl of 5 through 6 carbon atoms:  
 R,-, is hydrogen:  
 R is methyl:  
 X and X;, are oxygen: and  
 X is sulfur.  
  The compounds of formula I where R4 is phenyl or substituted phenyl are preferred for some uses as they have exhibited selective herbicidal activity in crops such as corn and cotton.  
 Preferred compounds of formula I include:  
 methyl N-n-butylcarbamyl-4n-butylthioallophanimidate Synthesis of the Final Products Compounds of formula I can be prepared by either of the following two reactions:  
 and R through R and X through X are as hereinbefore defined. except that: in the isocyanates and isothiocyanates (R NCX3). R is not methoxy: in the carbamoyl and thiocarbamoyl chlorides (R R,-,NCX -,Cl). R and R are not both H: and  
 X; in R NCX is not sulfur when X in the compound of formula II is sulfur.  
  Carbamylation reaction A is carried out in an inert organic solvent such as methylene chloride. acetone. ethyl acetate. benzene. CCI... CH Cl or petroleum ether. at a temperature in the range of about to 100C. A temperature in the range of about 0 to 100C is usually used. and a temperature in the range of about 20 to C is usually preferred. The optimum temperature in a given instance. of course. will depend upon the reactivity of the starting materials involved. When the carbamylating agent is HNCX the reaction is carried out in a nonpolar solvent. and the reactant is conveniently generated in situ by reaction of an alkali metal cyanate or thiocyanate (e.g. NaCNO or NaNCS) and an acid (e.g. HCl or CF COOH). When the carbamylating agent is R R NCX CL the reaction is carried out in a nonpolar solvent in presence of an acid acceptor such as pyridine or triethylamine.  
  Reaction B is also carried out in an inert organic solvent. such as methanol, dimethylformamide (DMF). dimethylsulfoxide (DMSO). or acetone. Temperatures in the range of about -l0 to C are suitable. A temperature in the range of about 050C is usually used. and ambient temperature is preferred.  
  Both reactions A and B can be carried out at reduced or elevated pressures. For example. pressures in the range of ().l to 3 atmospheres can be used. but atmospheric pressure is suitable in most cases. and is preferred.  
  The salts of those compounds of formula l where R is H are prepared as follows:  
 where M 1s a cation such as Li, Na&#34;. K*, Cs.  
 (Ca/2)&#34;. (Mg/2)&#34; (NH or quaternary ammonium.  
  The reaction is run in water with optional water miscible solvents.  
 R1 X RANCX N-CN=CNHR or I 5 R X2&#34;R6 RAR NCX CJ.  
 (B) R y R x l ti i n N-C-N=C-N-- R R NH I I C Y 5 R2 X2R6 III where Y is -SCH,,. Cl.  
 or JION 3 Alternatively. a salt exchange reaction can be used. as for example solution of the sodium salt in water followed by addition of a solution of calcium chloride to precipitate the less soluble calcium salt.  
 Synthesis of lntermediates Intermediates of formula ll can be prepared in various ways. as illustrated by the following processes: Process I All compounds of formula ll wherein X is oxygen can be made by the following two step process:  
 Step 1 R2. X2-R6 R2 Step 2 V l- NH R IT (X :O)  
 Step1 The Beckmann rearrangement of the formhydroxais preferred since the reaction products often crystallize out and can be isolated by filtration. or can be extracted with a water immiscible solvent. Reaction temperatures of from 0 to 40C can be employed. However. higher temperatures should be avoided since mercaptan can be split off from the starting material: thus preferred temperatures are in the range of l3()C.  
  R n S0012 N-C-N=C-Cl Process 2 The compounds of formula II wherein mates and thioformhydroxamates of formula IV to the formimidoyl and thioformimidoyl chlorides of formula X is oxygen. V can be carried out with PCl POCL, or SOCl in any X: is sulfur. inert solvent which will dissolve the reaction product. R, and R- are both other than hydrogen. and R is R. such as benzene. toluene. CCI CHCL, or CH Cl where I Methylene chloride and thionyl chloride are preferred R is methyl. ethyl. propyl. isopropyl. n-butyl. allyl,or because of gaseous reaction products being formed benzyl, from the acid chloride. and because of the high volatilcan also be made by the following two-step process:  
 Step 1 O R O S l\ n It /NCN=C:S -l- NH R NC-NH-C-NHF5 a R 2 v1 VII Step 2 VII R 1 --9 II (X =O, X =S,  
 R =R R fH, R 9H) ity of the solvent. The temperature of the reaction is p 1 not critical. Experience has shown that a reaction tem- Th6 ynthesis Of Cllrbumoyllsothlocyanates of forperature below room temperature gives increased mull VI and Comerslon 10 the Correspondmg yields of the formimidoyl chloride; thus the preferred thiobiurets f formul V&#34; c n e carried out as derange is ()-20C. The thioformhydroxamates of forscribed y P O 11nd E. e ll li m J- Orgmula lV (X S) are prepared as described in US. Pat. Chem- 2073 No. 3.560550. The formhydroxamates of formula IV p 2 (X =O) are prepared by reacting one mole of a The alkylation of thiobiurets of formula V&#34; can be l-carbamoylformhydrosamyl chloride with two equivaperformed analogous to a method given by M. R. lents of an alkoxide of the formula R ONa in an inert hflL ru S n Agr. Biol. Chem. 32, N0. 6. 71 l (1968) solvent at a temperature in the range of 7() to l()C. for alkylation of o-iodo-2-thio-3-benzylquinazolin-3.4- Step 2 (lH.3l-l)-dione to 6-iodo-2-isopropylthio-3-benzyl-4- The reaction of the formimidoyl and thioformimidoyl (3H)-quinazolone. chlorides of formula V with ammonia or amines can be M Process 3 carried out in water. lower alcohols. benzene. CH. Cl or other solvents. which do not react with ammonia or amines under the reaction conditions employed. Water Compounds of formula ll wherein X is oxygen. and R, and R are both other than hydrogen. can also be made by the following two-step process:  
  p 1 R1 c1 n vi 2Cl 9 N-C-N=C R2 Cl VIII Step 2 R X Na NH R VIII V .e II (X =0) Step I Step I is carried out in water or an inert organic sol- The chlorinated of isothiocyanates to imidoyldichlorides of formula VIII is known in the art and can be performed analogous to a method given by E. Kuehle et al.. Angew. Chem. 79. 663 (1967). who teaches converting dichloroacetylisothiocyanate with chlorine to dichloroacetylcarbonimidoyl dichloride.  
 Step 2 The stepwise replacement of the two chlorine atoms is best accomplished in alcohols as solvents. in which all reactants are soluble. The reaction temperature must be low in the first step. since imidoyldichlorides react above room temperature with alcohols to carbamates. Preferred temperatures in the first step are 20 to +l()C. Since the second Cl-atom is less reactive than the first. slightly higher reaction temperatures are possible with a preferred range of -l0 to 30C. Process 4 All compounds of formula ll wherein R- is H. except those wherein R is methoxy. can be made as follows:  
  This reaction can be conducted as described in German Patent No. 1.962.797.  
 Process 5 The compounds of formula ll wherein R and R are H. X is oxygen. X is sulfur. R is hydrogen. and R is R where R; is as defined above. can be made as follows:  
  vent in presence of a base such as sodium hydroxide or l5 tricthylamine. Temperatures in the range of ()50C and atmospheric pressure are satisfactory.  
  Step 2 is carried out in an inert organic solvent such as methanol. DMF. DMSO. or acetone at a temperature in the range of about l() to 100C; ambient temperature is preferred.  
  intermediates of formula lll can be prepared by the following processes Process 7 All compounds of formula III wherein R and R are H and Y is SCH or Cl can be prepared as follows:  
  Step l is the same as step I of Process 6 and is carried out under the same conditions.  
  Step 2 is carried out in an inert non-polar solvent such as acetonitrile or methylene chloride. A reaction temperature in the range of about ()100C and atmo- This reaction is performed analogous to step 2 of Process 2. The starting material (X) can be prepared according to US. Pat. No. 2.37l.l l3 Process 6 spheric pressure are satisfactory. If desired a catalyst such as triethylamine or dibutyltin dilaurate can be used. When R is H. the reactant (HNCX,) is conveniently generated in situ by reaction of an alkali metal V All compounds of formula ll can be made as follows: isocyanate or thiocyanate and an acid. Step 1 X1 X X 126 u u I IX ClCSQH CH3SC-N=C-NHR Step 2 1 XI -1m II Process 8 pound (B) covers a longer chain. all intermediates ex All compounds of formula III can be prepared as folisting in either form (A) or (B) are hereafter called allows: lophanimidates.  
  for example: X3 5 CH 0 S-CH -CH=CH II III n i 2 2 N- C-N=C-NHCH is taucomeri c with where Z is imidazolyl when Y is imidazolyl and Z is Cl CH when Y is SCH or C]. W 3 CH o When Y is SCH;, or Cl this reaction is carried out 1 2 under the conditions given for Process 6. step 1. Exam- N-C-NH-C=N-CH ple 7 below gives the conditions when Z and Y are both imidazolyl. 3  
 Nomenclature of the final products R 0 O H H-N=C-N-C-N allophanimidic acid R2 H H Positions:  
 I N l 2 3 it N 1 2 3 l CH O S O C u I ll IH3 for example: N-C-N=C-N-C--NH-C-CH Y i 3 CH -CH CH CH Name: cyclohexyl N-methyl-N-ethylcarbamoyl-2- methyl-4-tert-butylthioallophanimidate Name: allyl N-methyl-4.4-dimethylthioallophanimidate lt should be kept in mind that. where R H. tauto- 40 The compounds of this invention can also exist in meric forms of the molecule are possible and do exist: geometrically isomeric fmms (Ci-5 and trims and 3 5 R x X X R R X x R ti I n l n I 5 4 N-C- N=C-N-C-N N-C-N-C=N-f-C-N /i 2 H 5 2 H 5 F0... (A) Form lfR H. all compounds of this class will still be named until 115 o n in structures C and D. as outlined above.  
  X X R X X 1 1 ,2 l I 1 2 N-C- N=C-NH--R is tautomeric with N-C-NH-C=N--R Positions: I I l 3 2 1 N Compound (A) is a pseudourea derivative; Compound Compound C and D have different physical properties (B) is an allophanimidate. Since the name of Comsuch as infrared spectra.  
 lORMULA&#39;l&#39;lON ANI) USl-I ()l&#39; llll-i COMPOUNDS &#39;lhe compounds of formula I are useful as hcrhicides. &#39;l&#39;hey may he used at rates of 2.5 to 40 kilogram/hcu tare to control all vegetation in industrial sites. along rights-of way. pipelines. tank farms. and the like. At rates of (H25 to h kilogram/hectare certain of these compounds can he used for selective weed control in many crops including asparagus. soybeans. stone fruits. pineapple. sugarcane. sisal. alfalfa. and corn. The precise rate of material to use in any situation will depend upon the weeds to he controlled. climatic and edaphic conditions and whether selective weed control is desired.  
  The compounds of this invention may be combined with all other herbicides and are particularly useful in comhination with hromacil t3-sechutyl-5-hromo-omethy luracil diuron (3-/3.4-dichlorophenyl/- l l dimethyl-urea paraquat l.l &#39;-dimethyl--l.-l&#39;- hipyridinium ion). 1.] -dimeth vl-3.3-(N-tert-hutylcarhaunt\yloxyphcnyl )urea. 4-amino-(\-tert hutyl-3- lnethyl-thio-as-triazin-5t4H) one. and the S-tria/ines such as 2-ehloro--l ethylamino-o-isopropylamiuo-S- tria/ine. for controlling a broad spectrum of weeds.  
  The compounds of formula I can he formulated for herbicidal use in the various ways which are conventional for herbicides ofsimilar physical properties. Useful formulations include wettahle powders. oil suspensions and solutions. aqueous dispersions. dusts. granules. pellets. and high strength compositions. Broadly speaking. these formulations consist essentially of about I to 90% by weight of herhicidally active material (including at least one compound of formula I in a herhicidally effective amount) and at least one of a) ahout (H to 20% by weight of surface active agent and h) about 5 to M i by weight of essentially biologically inert solid or liquid diluent. More specifically, the various types of formulations will generally contain these ingredients in the following approximate proportions.  
  &#39;l&#39;he actual percentages that can he realized with a U particular compound of formula I will depend upon its physical properties.  
  The manner of making and using such herbicidal formulations is described in numerous patents. See. for example. l.uckenhaugh US. Pat. No. 3.309.192. Loux US. Pat. No. 3.235.357. &#39;l&#39;odd U.S. Pat. No. 2.655.445. Hamm et al. US. Pat. No. 2.8o3.752. Scherer et al. US. Pat. No. 3.079.244. (iysin et al. U.S. Pat. No. 2.891.855. and Barrons US. Pat. No. 2.642.354.  
  While conventional application of sprayahle formulations have usually heen made in a dilute form (for example at a rate of about 200 liters per hectare or more). the compounds of formula I can also he applied at higher concentrations in the typical ultra-lowvolume&#34; (Ul.\-&#39;) or low volume applications from aircraft or ground sprayers. For this purpose \vettahle powders can he dispersed in small amounts of aqueous or nonaqueous carrier. The emulsiliahle concentrate suspensions can he used directly or with minor dilution. Special compositions. particularly suitable for Ul.\&#39; applications are solutions or finely divided suspensions in one or more carrier such as petroleum oils. dialkylformamides. N-alkylpyrrolidones. and dimethylsulfoxide.  
  Herhicidal activity of the compounds of this invention was discovered in a greenhouse test. Seeds ofcrabgrass (Digiluriu spp. harnyardgrass (lz&#39;chinmhlou cruxgulli). wild oats (.-lveml /i1!uu). (uxxiu luru. morningglory (lpomeu spp. mustard (Brusxieu spp. marigold (&#39;I&#39;ugeles spp.). dock (Rmma crixpux). and nutsedge ((yperux rommlus) tubers were planted in sand or soil and treated preemergence with the chemicals dissolved in a solvent. At the same time johnsongrass (.S&#39;m&#39;glnun lmlepense) having four leaves. crahgrass and barnyardgrass with three leaves and nutsedge from tuhers with two leaves were treated postemergence. Treatment rates are indicated in the following &#39;lahle. &#39;lreated plants and controls were maintained in a greenhous for lo days. then all species were compared to controls and lercent By vvt-i m 55 visually rated for responses to treatment. A qualitative rating (type of injury) was made; the letter was used weuahlt- Ponders 25 no a 7;) l to to indicate chlorosis. and the letter (i to indicate ()ll Suspensions oi t. Sulutlons i B 55 u l growth retardation. A quantltatn e ratmg as also Aqueous [)ispelslulls to so .u) so v m made on a scale of (l to It); a rating ol 0 means no ettect l i Q W and a rating of It) means maximum effect. e.g. com- (uanulesaud l&#39;ellets l ls (n m t) 15 I1 k. R l t. h. hl V I r Sump&#34;, p c c l .llll1! .\..lll tns test or some lg y .tctlu walons no m u in o 1 compounds of this invention lollow:  
 &#39;lahle lostelma&#39;gcnulreemergence l.h. .Iohnllarnllarn- Mornper Nuts son- (rah yard (rah yard Wild Nutsing Mus- Mari- 15 By using the appropriate reactants. the following illustrative compounds of formulae 1. II and V can be prepared similarly:  
 Compounds of Formula V N-methylethylcarhamoyll -methylthioformimidoyl chloride N-methylhutylcarhamoyll -methylthioformimidoyl chloride Ndiethylcarhamoyl l -methylthioformimidoyl chloride N-dihutylcarhamoyll -methylthioformimidoyl chloride N-diallylcarhamoyll -methylthioformimidoyl chloride N-pentamethylenecarhamoyll -methylthioformimidoyl chloride N-diethylenoxycarhamoyll-methylthioformimidoyl chloride N-methylethylcarhamoyl-l-ethylthioformimidoyl chloride N-methylbutylcarbamoyll -isopropylthioformimidoyl chloride N-diethylcarbamoyll -butylthioformimidioyl chloride N-dihutylcarhamoyll -cyclohexylthioformimidoyl chloride N-diallylcarbamoyll -ethylthioformimidoyl chloride N-pentamethylenecarhamoyll-ethylthioformimidoyl chloride N-diethylenoxycarbamoyll -propylthioformimidoyl chloride Compounds of Formula II methyl N-methyl-4 4-diethylenoxythioallophanimidate ethyl 4-methyl-4-ethylthioallophanimidate isopropyl 4-methyl-4-butylthioallophanimidate butyl 44-diethylthioallophanimidate benzyl 4.4-dibutylthioallophamimidate sec-butyl 4.4-diallylthioallophanimidate ethyl 4.4-tetramethylenethioallophanimidate ethyl N-octyl-4 4-dimethylthioallophanimidate hutyl N-sec-hutyl-4-methyl-4-ethylthioallophanimidate ethyl N.4-dibutyl-4-methylthioallophanimidate cyclohexyl N-isopropyll4.4-diethylthioallophanimi date isopropyl N-propyl-4.4-dibutylthioallophanimidate Compounds of Formula 1 methyl phanimidate m.p l l2-l 13C methyl N-dimethylcarbamoyl-4-ethylthioallophamimidate. m.p. 95-97C N-dimethylcarbamoyl-4-methylthioallo- 6 16 methyl N-dimethylcarbamoyl-4-propylthioallophanimidate. m.p. 6674C methyl N-dimethylcarhamoyl-4-isopropylthioallophanimidate m.p. 86-89C methyl N-dimethylcarbamoyl-4-butylthioallophanimidate &#39;n,,&#39;-&#34; 1.5530 methyl N-dimethylcarbamoyl-4-octylthioallophanimidate. [1 L531! methyl N-dimethylcarhamoyl-4-allylthioallophanimidate. m.p. 5558C methyl N-dimethylcarbamoyl-4-pr0pynylthioallophanimidate methyl N-dimethylcarbamoyl-4-cyclohexylthioallophanimidate. m.p. 889lC methyl N-dimethylcarbamoyl-4-cyclohexylmethyltliioallophanimidate methyl N-dimethylcarbamoyl-4-norbornylthioallophanimidate methyl N-dimethylcarbamoyl-4-phenylthioallophanimidate. m.p. l22-l23C methyl N-dimethylcarbamoyl-4-( o-fluo rophenyl )thioallophanimidate. m.p l25l27C methyl N-dimethylcarbamoyl-4-( 3 .4-  
 dichlorophenyl)thioallophanimidate. m.p. l54l55C methyl N-dimethylcarbamoyl-4-( p-methoxyphenyl )thioallophanimidate m.p. l26l27C methyl N-methylethylcarbamoyl&#39;4-tert-butylthioallophanimidate methyl N-methylbutylcarbamoyl-4-allylthioallophanimidate methyl N-diallylcarbamoyl-4-methylthioallophanimidate methyl N-dibutylcarbamoyl-4-methylthioallophanimidate methyl N-dibutylcarbamoyl-4-phenylthioallophanimidate methyl N-dibutylcarbamoyl-4-(3 4-dichlorophenyl)thioallophanimidate methyl N-pentamethylenecarbamoyl-4-tert-butylthioallophanimidate ethyl N-dimethylcarbamoyl-4 methylthioallophanimidate. m.p. l()9l l 1C ethyl N-dimethylcarbamoyl-4-ethylthioallophanimidate isopropyl phanimidate cyclohexyl N-dimethylcarbamoyl-4-isopropylthioallophanimidate isopropyl phanimidate allyl N-dimethylcarbamoyl-4-allylthioallophanimidate cyclopentyl N-dimethylcarbamoyl-4-propynylthioallophanimidate isopropyl N-dimethylcarbamoyl-4-cyclohexylthioallophanimidate hexyl N-dimethylcarbamoyl-4-cyclohexylmethylthioallophenimidate ethyl N-dimethylcarbamoyl-4-phenylthioallophanimidate methyl N-dimethylcarbamoyl-4-tert-butyll .3-dithioallophanimidate N-dimethylcarbamoyl-4-propylthioallo- N-dimethylcarbamoyl-4-butylthioallomethyl N-dihutylcarbamoyl-4-methyl-1.3-dithioallophanimidate methyl N-dimethylcarbamoyl-4-cyclohexyl-l.3-dithioallophanimidate methyl N-diallylcarbamoyl-4-phenyll 3-dithioallophanimidate methyl N-dimethylcarbamoyl-4-( 3 4-dichlorophenyl l,3-dithioallophanimidate methyl N-dimethylcarbamoyl-2-methyl-4-( 3.4-  
 dichlorophenyl)-thioallophanimidate. m.p. 87-89C.  
 methyl N-dimethylcarbamoyl-2methyl-4-phenylthioallophanimidate hyl N-dimethylcarbamoyl-2-methyl-4- fluorophenyl)thioallophanimidate m.p. 74-77C methyl N-dimethylcarhamoyl-2-methyl--l-( pmethoxyphenyl)thioallophanimidate methyl N-dimethylcarhamoyl-lmethyl-4( pbromophenyl)thioallophanimidate. m.pi 9899C.  
 methyl N-dimethylcarbamoyl-2-ethyl-4-(pcyanophenyl )thioallophanimidate methyl N-dimethylcarbamoyl-2-ethyl4-(pcumenyl)thioallophanimidate methyl N-dimethylcarbamoyl-2-propyl-44pnitrophenyl )thioallophanimidate methyl N-dimethylcarbamoyl-Z-isopropyl-4-(mchlorophenyl )thimtllophanimidate methyl N-dimethylcarbamoyl-2-sec-butyl-4-( 3 .5-  
 dichlorophenyl) thioallophanimidate methyl N-dimethylcarban1oyl-2-butyl-4-(ptrifluoromethylphenyl )-thioallophanimidate methyl N-methylethylcarbamoyl-2-methyl-4-phenylthioallophanimidate methyl N-methylbutylcarbamoyl-2-hutyl-4-(ofluorophenyl)thioallophanimidate methyl cyanophenyl )thioallophanimidate methyl N-dibutylcarbamoyl-Z-propyl-4-(p bromophenyl)thioallophanimidate methyl N-dibutylcarbamoyl-2-ethyl-4-( mchlorophenyl)thioallophanimidate methyl N.N-pentamethyleneearbamoyl-2-methyl-4- phenylthioallophanimidate methyl N.N-diethylenoxycarbamoyl-2-methyl-4- phenylthioallophanimidate ethyl N-dimethylcarbamoyl-Z-methyl-4phenylthioallophanimidate isopropyl N-dimethylcarbamoyl-Z-methyl-44ofluorophenyl)thioallophanimidute cyclohexyl N-dimethylcarbamoyl-2-methyl4-(pmethoxyphenyl) thioallophanimidate ethyl N-dimethylcarhamoyl-Z-methyl-4-(pbromophenyl)thioallophanimidate propyl N-dimethylcarbamoyl-2-ethyl-4-(pcyanophenyl)thioallophanimidate ethyl N-dimethylcarbamoyl-2-ethyl-4-(p-cumenylnhioallophenimidate hexyl N-dimethylcarbamoyl-2-propyl-4-(pnitrophenyl)thioallophanimidate propyl N-dimethylcarbamoyl-Z-isopropyl-4-( mchlorophenyl)thioallophanimidate ethyl N-dimethylcarbamoyl-2-sec-butyl-4-( 3.5-  
 dichlorophenyl )-thioallophanimidate EXAMPLE 2 To a solution of 65 parts of dimethylcarbamoylisothiocyanate (a compound of formula VI) in 350 parts methylene chloride are added within minutes at 0C. parts of cone. aqueous ammonia with good agitation. The resulting slurry of crystals is stirred for an additional I5 minutes at 0C and then filtered to give 70 parts of l l-dimethyl-4-thiobiuret (a compound of formula Vll). m.p. l84-l85C.  
  To a solution of 58.5 parts of l.l-dimethyl-4- thiobiuret in 200 parts of water. 200 parts of methanol N-diethylcarbamoyl-Z-isopropyl-4-(p and 32 parts of 50% aqueous sodium hydroxide are added at 25C. within l0 minutes 62.5 parts of iodoethanev The reaction mass is then stirred at 25C. for 2 hours. Evaporation of the methanol and part of the water under vacuum gives 64 parts of crude ethyl 4.4- dimethylthioallophanimidate (a compound of formula ll). which is recrystallized from water-methanol (50:50) and shows a melting point of 9()-93C.  
  A solution of 5 parts of ethyl 4.4-dimethylthioallophanimidate and L8 parts of methylisocyanate in parts of methylene chloride was refluxed for 2 hours. After evaporation of the solvent. the residue was recrystallized from ethylacetate to give ethyl N- dimethylcarbamoyl-4-methylthioallophanimidate (a compound of formula I). m.pi l09l l l.5C.  
  By using the appropriate reactants. the following illustrative compounds of formulae I and ll can be prepared similarly:  
 Compounds of Formula II propyl 4.4-dimethylthioallophanimidate benzyl 4.4-dimethylthioallophanimidate ethyl NA,4-trimethylthioallophanimidate butyl Nethyl-4A-dimethylthioallophanimidate propyl N-propyl-4 4dimethylthioallophanimidate ethyl N-isopropyl-4.4-dimethylthioallophanimidate isopropyl N-butyl-4 4-dimethylthioallophanimidate propyl 4,4-diethylthioallophanimidate isopropyl 4 4-dipropylthioallophanimidate butyl 4.4-dibutylthioallophanimidate benzyl 4-ethyl-4methylthioallophanimidate butyl N-ethyl-4-isopropyl-4-methylthioallophanimidate propyl N-propyl-4 4-diisopropylthioallophanimidate ethyl N-isopropyl-4.4-diethylthioallophanimidate isopropyl N-butyl-4.4-dibutylthioallophanimidate ethyl 4.4-dimethylthioallophanimidate isopropyl 4 4-dimethylthioallophanimidate allyl 4.4-dimethylthioallophanimidate dimethylthioallophanimidate henzyl 4,4-dimethylthioallophanimidate methyl N-allyl-44-dimethylthioallophanimidate methyl N-propargyl-4 4-dimethylthioallophanimidate butyl 4.4-  
 Compounds of Formula 1 N-diethylcarbamoyl-4-tert-butylthioallopropyl Ndimethylcarbamoyl-4-tert-butylthioallophanimidate. m.p. l02-l0-1C isopropyl N-dimethylcarbamoyl-4-tert-butylthioallophanimidate. wax  
 methyl N-dimethylcarbamoyl-Z-allyl-4-(phenyl)thioallophanimidate.  
 methyl N-dimethylcarbamoyl-2-propynyl-4- (phenyl)thioallophanimidate allyl N-dimethylcarbamoyl-4-tert-butylthioallophanimidate. m.p. 9o--98C butyl N-dimethylcarbamoyl-4-tert-hutylthioallophanimidate. m.p. 6466C benzyl N-dimethylcarbamoyl-4-tert-butylthioallophanimidate. m.p. l24l26C EXAMPLE 3 To a solution of 130 parts of dimethylcarbamoylisethiocyanate (a compound of formula Vl). in 700 parts of methylene chloride at C are added within 1 hour I42 parts of chlorine gas. The resulting red solution is then evaporated under vacuum to crude dimethylcarbamoylformimidoyl dichloride (a compound of formula Vlll) as residue. which is then puritied by distillation. b.p. 52C/0.4 mm.  
  A sodium cyclohexylmercaptide solution. prepared from 5.4 parts of sodium methylate and l 1.6 parts of cyclohexylmercaptan in 100 ml. methanol by refluxing for 10 minutes. is added at l0C. to a solution of 16.9 parts of dimethylcarbamoylformimidoyl dichloride in 50 ml methanol. prepared at -l0C. After stirring the reaction mixture for 10 minutes at -l0C. (NaCl pres em). 5 parts of gaseous ammonia are sparged into the mixture at l0C. and then the temperature allowed to rise to 30C. When the temperature has fallen back to 25C.. the NaCl is filtered and the filtrate evaporated. For purification. the product is then dissolved in methylene chloride and repeatedly extracted with dilute aqueous hydrochloric acid. The HCl-extracts are combined. and after filtration through Celite. the pH is adjusted to 7 by the addition of sodium hydroxide. After cooling to 0C.. the precipitated solids are isolated by filtration and are purified by recrystallization from petroleumether to give pure cyclohexyl 4.4-dimethylthioallophanimidate (a compound of formula ll). m.p. 84.586C.  
  A mixture of 5 parts of cyclohexyl 4.4-dimethylthioallophanimidate and 4 parts t-butylisocyanate in 70 parts of methylene chloride is refluxed for 2 hours. 5  
 After evaporation of the solvent. the oily residue is triturated with petroleumether to give solids. which are recrystallized from cyclohexane to give pure cyclohexyl N-dimethylcarbamoyl-4-t-butylthioallophanimidate (a compound of formula I).  
  By using the appropriate reactants. the following illustrative compounds of formulae l and ll can be prepared similarly:  
 COMPOUNDS OF FORMULA lll allyl N-butyl-4.4-dibutylthioallophanimidate sec-butyl N-isopropyl-4.4-diisopropylthioallophariimidate allyl N-( Z-butynyl)-4.4-dimethylthioallophanimidate cyclooctyl-4.4-dimethylthioallophanimidate 2-octenyl-4.4-dimethylthioallophanimidate Compounds of Formula l allyl N-dimethylcarbamoyl-4-tert-butylthioallophanimidate allyl N-dimethylcarbamoyl-4-methylthioallophanimidate sec-butyl N-dimethylcarbamoyl-4-tert-butylthioallophanimidate cyclohexyl N-dimethylcarbamoyl-4-tert-butylthioallophanimidate phenyl-N-dimethylcarbamoyl-4-tert-butylthioallophanimidate cyclohexyl N-dimethylcarbamoyl-4-allylthioallophanimidate allyl N-dimethylcarbamoyl-4-allylthimillophanimidate sec-butyl-N-dimethylcarbamoylA-allylthioallophanimidate allyl N-dimethylcarbamoyl-4-cyclohexylthioallophanimidate sec-butyl N-dimethylcarbamoyl-4-cyclohexylthioallophanimidate cyclohexyl N-dimethylcarbamoyl-4-cyclohexylthioallophanimidate allyl N-dimethylcarbamoyl-2-(Z-butynyl)-4-phenylthioallophanimidate sec-butyl N-dimethylcarbamoyl-2-isopropyl-4-( 3,4-  
 dichlorophenyl )-thioallophanimidate cyclohexyl N-dimethylcarbamoyl-2-methyl-4-(mchlorophenyl)thioallophanimidate cyclohexyl N-diethylcarbamoyl-4-tert-butylthioallophanimidate phenyl N-diethylcarbamoyl-4-tert-butylthioallophanimidate cyclohexyl N-dipropylcarbamoyl-4-allylthioallophanimidate allyl N-isopropyl-N-methylcarbamoyl-4-allylthioallophanimidate sec-butyl N-diethylcarbamoyl-4-allylthioallophanimidate allyl N-diethylcarbamoyl-4-cyclohexylthioallophanimidate allyl N-diethylcarbamoyl-2-butyl-4-phenylthioallophanimidate sec-butyl N-diethylcarbamoyl-2-isopropyl-4-( 3.4-  
 dichlorophenyl)-thioallophanimidate methyl N-dimethylcarbamoyl-4-benzylthioallophanimidate cyclooctyl N-dimethy]carbamoyl-4-isopropylthioallophanimidate Z-octenyl N-dimethylcarbamoyl-4-isopropylthioallophanimidate EXAMPLE 4 To a solution of l6.9 parts of dimethylcarbamoylformimidoyl dichloride (a compound of formula Vlll) in 25 ml methanol. prepared at -l0C. is added within 10 minutes at l0C. a solution of 5.4 parts sodium methylate in ml methanol. Sodium chloride precipitates. The reaction mixture is stirred for l0 minutes at l0C and then 5 parts of gaseous ammonia are sparged into the mixture at l 0C. The temperature is then allowed to rise to 25C. the methanol evaporated under vacuum. and the residue triturated with methylene chloride. After filtration of the inorganic salts. the methylene chloride filtrate is evaporated and the residue recrystallized from a little water to give pure methyl 4.4-dimethylallophanimidate (a compound of formula ll). m.p. 80-82.5C.  
  Parts of methyl 4.4-dimethylallophanimidate and 20 ml of t-hutylisocyanate are refluxed overnight. The next day the solution is evaporated to give an oil. which crystallizes when triturated with petroleum-ether under cooling. In order to remove some unreacted starting material and by-products. the solids are first triturated with water and filtered. After drying the solids are then triturated with carbon tetrachloride and impurities removed by filtration. The carbon tetrachloride filtrate is then evaporated and the residue recrystallized from petroleum-ether to give pure methyl N- dimethylcarhamoyl-4-t-butylallophanimidate (a compound of Formula 1) mp. 96-98C.  
  By using the appropriate reactants. the following illustrative compounds of formulae l and I] can be prepared similarly:  
 Compounds of Formula ll ethyl 4.4-dimethylallophanimidate isopropyl 4.4-dimethylallophanimidate propyl 4.4-dimethylallophanimidate allyl 4,4-dimethylallophanimidate butyl 4.4-dimethylallophanimidate cyclohexyl 4,4-dimethylallophanimidate methyl N.4,4-trimethylallophanimidate propyl N.4.4-trimethylallophanimidate methyl N-butyl-4.4-dimethylallophanimidate ethyl 4.4 diethylallophanimidate isopropyl 4.4-diethylallophanimidate propyl 4.4-dibutylallophanimidate allyl 4.4-diisopropylallophanimidate butyl 4.4-diethylallophanimidate cyclohexyl 4.4-dihutylallophanimidate Compounds of Formula I EXAMPLE 5 2 Parts of methyl 4-isopropylallophanimidate (a compound of formula ll) and 5 parts of isopropyl isocyanate are stirred overnight at room temperature in 5 parts methylene chloride with a catalytic amount of dibutyltin dilaurate. The solvent is removed under reduced pressure to give a solid residue which is recrystallized from hexane: chlorobutane (1:1). Parts of pure methyl N-isopropylcarbamoyl-4-isopropylallophanimidate (a compound of formula I). m.p. 8689C. is collected.  
  Using an appropriate compound of formula ll from the list below and an appropriate isocyanate. each com- N-dimethylcarbamoyl-4-isopropylallophanim i- N-dimethylcarbamoyl-4-tertpound of formula I listed below can be prepared similarlv:  
 Compounds of Formula ll methyl 4-tert-butylallophanimidate methyl 4-cyclohexylallophanimidate methyl 4-cyclooctylallophanimidate methyl ,4-octylallophanimidate methyl 4-allylallophanimidate methyl 4-eyclopentylallophanimidate methyl 4-cyclopropylallophanimidate methyl 4-0yelopropylmethylallophanimidate methyl 4-cyclohexylmethylallophanimidate methyl 4-( 2-cyclooetylethyl )allophanimidate methyl 4-( norborn-Z-yl )allophanimidate methyl 4-propargylallophanimidate methyl 4-( hut-Z-ynyl )allophanimidate methyl 4-methoxyallophanimidate methyl 4-(Z-chloroethyl)allophanimidate methyl 4-( l.ll-trichloroethyl)allophanimidate methyl 4-( Z-bromoethyl )allophanimidate methyl 4-(Z-iodoethyl)allophanimidate methyl 4-trifluoromethylallophanimidate methyl 4-fluoromethylallophanimidate methyl 4-( Z-methoxyethyl )allophanimidate methyl 4-ethoxymethylallophanimidate methyl 4-methylallophanimidate methyl 4-ethylallophanimidate ethyl 4-butylallophanimidate methyl 4-benzylallophanimidate methyl 4-( I-ethylthioethyl)allophanimidate methyl 4-( Z-cyanoethyl )allophanimidate methyl 4-methoxycarhonylmethylallophanimidate methyl 4-acetonylallophanimidate methyl 4-(Z-chlorocyclohexyl)allophanimidate methyl 4-( 3hromocyclohexyl )allophanimidate methyl 4-( Z-methylcyclohexyl )allophanimidate methyl 4-( 3.4-dimethylcyclopentyl )allophanimidate methyl 4-(4-hutylcyclohexyl)allophanimidate methyl 4-( Z-ethylcyclopropyl )allophanimidate methyl 4-sec-butylallophanimidate methyl 4-phenylallophanimidate Compounds of Formula 1 methyl N-tert-hutylcarhamoyl-4-terthutylallophanimidate m.p. l2()l22C methyl N-cyclohexylcarhamoyl-4-cyclohexylallophanimidate methyl N-methylcarbamoyl-4-cyclooctylallophanimidate methyl N&#39;octylcarbamoyl-4-ethylallophanimidate methyl N-allylcarhamoyl-4-allylallophanimidate. m.p.  
 methyl N cyclopentylcarbamoyl-4-cyelopentylallophanimidate methyl N-cyclopropylcarbamoyl-4-cyclopropylallophanimidate methyl N-cyclopropylmethylcarbamoyl-4- cyclopropylmethylallophanimidate methyl N&#39;cyclohexylmethylcarhamoyL-icyclohexylmethylallophanimidate methyl N-methylcarbamoyl-4-( Z-cyclooetylethyl )allophanimidate methyl N-( norhorn-Z&#39;yl )carhamoyl-4- methylallophanimidate methyl N-propargylcarhamoyl-4-propargylallophanimidate methyl N-isopropylcarhamoyl-4-( but-Z-ynyl )allophanimidate 23 methyl N-isopropylcarbamoyl-4methoxyallophanimidate methyl N-( Z-chloroethyl )carhamoyl-4-( Z-chloroethyl- )allophanimidate methyl N-isopropylcarbamoyl-4-( l.2.2-trichloroeth \&#39;l- )allophanimidate methyl N-methylcarlmmoyl-4-( Z-bromoethyl )allophanimidate methyl N-tert-butylcarhamoyl-4-t 2iodoethyl )allo phanimidate methyl N-methylcarbamoyl-4-perfluoropropylallophanimidate methyl N-isopropylearbamoyll-trifluoromethylallophanimidate methyl N-tert-butylcarhamoyll-fluoromethylallophanimidate methyl N-methylcarbamoyl-4-(2-methoxyethyl)allophanimidate methyl N-tert-butylcarbamoyl-4-ethoxymethylallophanimidate methyl N-cyclohexy|carbamoyl-4-(Z-methylthioethyl- )allophanimidate methyl N-ethylcarbamoyl-4-( Z-ethylthioethyl )allophanimidate methyl N-(Z-eyanoethyl)carbamoyl-4-(Z-cyanoethyl- )allophanimidate methyl N-benzylcarbamoyl-Lisopropylthioallophanimidate methyl N-(p-methylbenzylcarbamoyl)-4-methylthioallophanimidate methyl N-( p-chlorobenzylcarbamoyl )-4-tert-hutylthioallophanimidate methyl N-tert-butylcarbamoyl-4-methoxycarbonylmethylallophanimidate methyl N-methylcarbamoyl-4-acetonylallophanimidate methyl N-isopropylcarbamoyl-4-(Z-chlorocyclohexyl- )allophanimidate methyl N-propylearbamoyl-4-(3-bromocyclohexyl)allophanimidate methyl N-isopropylearbamoyl-4-(Z-methylcyelohexyl- )allophanimidate methyl N-tert-butylcarbamoyl-4-( 3 .4-  
 dimethylcyclopentyl)-allophanimidate methyl N-methylcarbamoyl-4-(4-butylcyclohexyl)allomethyl N-methylcarbamoyl-4-phenylallophanimidate methyl N-tert-butylcarbamoyl-4-secbutylallophanimidate methyl N-sec-butylcarbamoyl-4-isopropylallophanimidate. m.p. 6670C methyl butylallophanimidate methyl N-methylcarbamoyl-4-allylallophanimidate methyl N-allylcarbamoyl-4-tert-butylallophanimidate N-methylcarbamoyl4-tertethyl N-butylcarbamoyl-4-allylallophanimidate ethyl N-butylcarbamoyl-4-tert-butylallophanimidate ethyl N-butylcarbamoyl-4-cyclohexylallophanimidate ethyl N-butylcarbamoyl-4-( p-bromophenyl )allophanimidate methyl N-ethylthiocarbamoyl-4-tert butylallophanimidate methyl phenylallophanimidate N-ethylthiocarbamoyl-4- EXAMPLE 6 methyl 4-methylthioallophanimidate methyl 4-tert-butylthioallophanimidate methyl 4-ethylthioallophanimidate methyl 4-octylthioallophanimidate methyl 4-isopropylthioallophanimidate methyl 4-allylthioallophanimidate methyl 4-butylthioallophanimidate methyl 4( l-cyclooctylethyl)thioallophanimidate methyl 4-( norborn-Z-yl )thioallophanimidate methyl 4-propargylthioallophanimidate methyl 4-(hex-3-ynyl)thioallophanimidate methyl 4-propylthioallophanimidate methyl 4-methoxythioallophanimidate methyl 4( Z-chloroethyl )thioallophanimidate methyl 4-( l.2.2-trichloroethyl)thioallophanimidate methyl 4-( Z-bromoethyl )thioallophanimidate methyl 4-(2-iodoethyl)thioallophanimidate methyl 4-perfluoropropylthioallophanimidate methyl 4-trifluoromethylthioallophanimidate methyl 4-fluoromethylthioallophanimidate methyl 4-(Z-methoxyethyl)thioallophanimidate methyl 4-(ethoxymethylthioallophanimidate methyl 4-( 2-methylthi0ethyl)thioallophanimidate methyl 4-( Z-ethylthioethyl )thioallophanimidate methyl 4-( Z-cyanoethyl)thioallophanimidate methyl 4-methoxycarbonylmethylthioallophanimidate methyl 4-acetylthioallophanimidate methyl 4-(Z-chlorocyclohexyl)thioallophanimidate methyl 4-( 3-bromocyclohexyl )thioallophanimidate methyl 4-( Z-methylcyclohexyl)thioallophanimidate methyl 4-( 3.4-dimethylcyclopentyl )thioallophanimidate methyl 4-(4-butylcyclohexyl)thioallophanimidate methyl 4-( Z-ethylcyclopropyl )thioallophanimidate methyl 4-sec-butylthioallophanimidate methyl 4-cyclohexylthioallophanimidate methyl 4-phenylthioallophanimidate butyl 4-methylthioallophanimidate butyl 4-allylthioallophanimidate octyl 4-butylthioallophanimidate ethyl 4-tert-butyll .3-dithioallophanimidate methyl 4-allyl-l .3-dithioallophanimidate methyl 4-isopropyll .3-dithioallophanimidate methyl 4-tert-hutyll .3-dithioallophanimidate methyl 4-see-butyl-l.B-dithioallophanimidate Compounds of Formula I methyl N-methylcarhamoyl-4-tert-hutylthioallophanimidate. m.p. l32l33C methyl N-tert-hutylcarbamoyl-4-cyclohexylthioallophanimidate map. l37-l 44C methyl Nethylearbamoyl-4-allylthioallophanimidate methyl N-oetylcarhamoyl-4-methylthioallophanimidate methyl N-oetylearbamoyl--l-propynylthioallophanimidate methyl N-isopropylearhamoyl-4-cyelohexylmethylthioallophanimidate. mp. l23l 25C methyl N-allylearhamoyl-4-phenylthioallophanimidate methyl N-ethylearhamoyl-4-( 3,4-dichlorophenyl )thioallophanimidate methyl N-butylcarbamoyl-4-(peyanophenyl)thioallophanimidate methyl N-see-butylearbamoyll-isopropylthimtllophanimidate. mp. l()4l l 1C methyl N-methylearhamoyl--l-( Z-eyclooetylethyl )thioallophanimidate methyl NmethylcarhamoyL-l-( norhorn-Z-yl )thioallophanimidate methyl N-propargylcarbamoyI-4-propargylthioallophanimitlate methyl N isopropylearbamoyl-4-(4- ethyleyelohexyl )thioallophanimidate methyl N-isopropylearhamoyl-4-methoxythioallophanimidate methyl N-( Z-chloroethyl )carbamoyl-4-( 2- ehloroethyl )thioallophanimidate methyl N-isopropylearbamoyl-4-( l .11.]-  
 triehloroethyl )thioallophanimidate methyl N methylcarbamoyl-4-(Z-bromoethyl)thioallophanimidate methyl N-tert-butylcarbamoyl-4-( Z-iodoethyl)thioallophanimidate methyl N-methylcarbamoyl-4-perfluoropropylthioallophanimidate methyl N-isopropylcarbamoyl-4-trifluoromethylthioallophanimidate methyl N-tert-hutylcarhamoyl-4-fluoromethylthioall0- phanimidate 5 methyl N&#39;methylearbamoyl-4-(Z-methoxyethyl)thloallophanimidate methyl N-tert-butylcarhamoyl-4-ethoxymethylthioallophanimidate methyl N-cyclohexylcarbamoyl-4-( Z-methylthioethyl thioallophanimidate methyl N-ethylcarbamoyl-4-(Z-ethylthioethyl)thioallophanimidate methyl N-( Z-eyanoethyl )Carhamoyl-4-l 2- cyanoethyl )thioallophanimidate methyl N-tert-butylcarhamoyl-4- methoxyearbonylmethylthioallophanimidate methyl N-methylcarbamoyl--l(eyelooet-Z-enyl)thioallophanimidate methyl N-isopropylcarbamoyl-4-l 2- chlorocyclohexyl )thioallophanimidate methyl N-propylcarhamoyl-4-t 3.4.4-  
 trichlorocyclohexyl)thioallophanimidate butyl N-methylearbamoyl-4-methylthioallophanimidate butyl N-allylearbamoyl-4-tert-butylthioallophanimidate hutyl N-methylearbamoyl-4-(m-ehlorophenyl)thioallophanimidate octyl N-butylcarhamoyl-4-allylthioallophanimidate octyl Nbutylcarbamoyl-4-tert-hutylthioallophanimidate octyl N-butylcarhamoyl-4-p-nitrophenyl )thioallophanimidate ethyl N-tert-hutylthioearbamoyl-4-isopropylthioallophanimidate methyl N-allylthiocarhamoyl 4-tert-butylthioallophanimidate methyl N-isopropylthioearhamoyl-4-methylthioallophanimidate methyl N isopropylthiocarbam0yl-4-isopropylthioallophanimidate methyl N-tert-hutylthiocarbamoyl-4-tert-butylthioallophanimidate methyl N-sec-butylthiocarbamoyl-4-sec-butylthioallophanimidate methyl N-methylearbam0yl-4-(cyclopent-Z-enyl)thioallophanimidate EXAMPLE 7 methyl N-methylcarbamoyl 4-(hexahydro- 4.7methanoindenyl)thioallophanimidate methyl N-methylcarbamoyl-4-( 3,4-dibromophenyl )thioallophanimidate methyl N-methylcarbamoyl-4-( p-tolyl )thioallophanimidate methyl N-ethylcarhamoyl-4-(a.a-dimethylhenzyl)thioallophanimidate methyl N-methylearhamoyl-4-furfurylthioallophanimidate methyl N-isopropylcarhamoyl-4-(hut-Z-enyl)thioallo&#39; phanimidate 17.5 Parts methyl 4-isopropylthioallophanimidate (a compound offormula II) is dissolved in 150 parts methylenechloride. This solution is added dropwise to a stirred solution of l7.8 g N.N&#39;-thiocarbonyldiimidazole in I50 parts methylene chloride. The temperature is maintained at during the addition and for 18 hours thereafter. Still maintaining 0. 9.3 parts aniline is added. After this addition the mixture is allowed to warm to room temperature for 2 hours. The reaction mixture is then washed with several portions of water. to remove the imidazole formed. dried with magnesium sulfate. and the solvent evaporated at room temperature under reduced pressure. The residue is a good grade ofcrude methyl N-isopropylcarbamoyl-4-phenyll.3-dithioallophanimidate (a compound of formula I).  
  By substituting the appropriate methyl 4-substituted thioallophanimidates for the methyl 4-isopropylthioallophanimidate and/or appropriate amine for the aniline. the following allophanimidates can be prepared similarly:  
 methyl N-tetramethylenecarbamoyl-4-phenyll .3-  
 dithioallophanimidate methyl N-tert-butylcarbamoyl-4-phenyll .3-dithioallophanimidate methyl N-sec-butylcarbamoyl-4-phenyl-l .3-dithioallophanimidate methyl N-diisopropylcarbamoyl-4-phenyl-1.3-dithioallophanimida&#39;te methyl N-isopropylcarbamoyl-4-cyclohexyl-1.3-dithioallophanimidate methyl N-ethylthiocarbamoyl-4-tert-butyll .3-dithioallophanimidate methyl N-tert-butylthiocarbamoyl-4-phenyl-l.3-dithioallophanimidate methyl N-cyclopropylcarbamoyl-4-phenyl l .3-dithioallophanimidate methyl N-isopropylthiocarbamoyl4-isopropyl-l .3-  
 dithioallophanimidate methyl N-tert-butylthiocarbamoyl-4-tert-butyll .3-  
 dithioallophanimidate methyl N-tert-butylthiocarbamoyl-4-isopropyll .3-  
 dithioallophanimidate EXAMPLE 8 319 Parts of 2-methyl-Z-thiopseudourea sulfate (salt of a compound of formula lX). 2300 parts of acetonitrile and 400 parts triethylamine are combined. 400 Parts isopropylisocyanate are added rapidly and the temperature comes to 35C. The solvent is removed under reduced pressure 2 days later and the oil is dissolved in dichloromethane and washed with water. The organic layer is dried and evaporated to give a tan solid. The solid is recrystallized from dichloromethanezhexane to give 813 parts methyl N-isopropylcarbamoyl-4- isopropylthioallophanimidate (a compound of formula I). (m.p. l25-l27C).  
  The corresponding isomer can be formed as follows: 25 Parts of the geometrical isomer of methyl N-isopropylcarbamoyl-4-isopropylthioallophanimidate is dissolved in 25 parts dimethylformamide and heated to 40C. After l hour. 12 parts of water is added to give 21 parts white solid after drying (m.p. l25-l27C.). The infrared spectrum is different from starting material.  
  By substituting different isocyanates for the isopropyl isocyanate in the above example. the following compounds of formula I are prepared: methyl N-tert-butylcarbamoyl-4-tert-butylthioallophanimidate. mp. ll53C methyl N-cyclohexylcarbamoyl-4-cyclohexylthioallophanimidate. m.p. l38-l40C methyl N-allylcarbamoyl-4-allylthioallophanimidate methyl N-cyclopentylcarbamoyl-4-cyclopentylthioallophanimidate methyl N-cyclopropylcarbamoyl-4-cyclopropylthioallophanimidate methyl N-cyclopropylmethylcarbamoyl-4- cyelopropylmethylthioallophanimidate methyl N-eyclohexylmethylcarbamoyl-4- cyclohexylmethylthioallophanimidate methyl N-sec-butylcarbamoyl-4-sec-butylthioallophanimidate. m.p. 105 l 08C EXAMPLE 9 To a solution of I19 parts of 4-thiobiuret (a compound of formula X) in 400 parts of water. 400 parts of methanol and 80 parts of 50% aqueous sodium hydroxide are added within it) minutes at C. I42 parts 15 of iodomethane. The reaction mass is then stirred at 25C for 2 hours. Evaporation of the methanol and part of the water under vacuum gives crude methyl thioallophanimidate (a compound of formula ll). which can be used without further purification for subsequent reactions.  
  A mixture of 13 parts of methyl thioallophanimidate 74 parts of methylene chloride and 6 parts of methylisocyanate is refluxed for 2 hours. After standing overnight at room temperature. the solution is evaporated under vacuum to give crude methyl N- carbamoyl-4-methylthioallophanimidate (a compound of formula I).  
  By using the appropriate reactants. the following additional illustrative compounds of formula I and ll can be prepared similarly:  
 Compounds of Formula ll ethyl thioallophanimidate isopropyl thioallophanimidate propyl thioallophanimidate butyl thioallophanimidate octyl thioallophanimidate Compounds of Formula I methyl N-carbamoyl-4-ethylthioallophanimidate methyl N-carbamoyl-4-isopropylthioallophanimidate methyl N-carbamoyl-4-tert-butylthioallophanimidate ethyl N-carbamoyl-4-cyclohexylthioallophanimidate isopropyl N-carbamoyl-4-allylthioallophanimidate propyl N-carbamoyl-4-allylthioallophanimidate butyl N-carbamoyl-4-tert-butylthioallophanimidate octyl N-carbamoyl-4-methylthioallophanimidate octyl N-carbamoyl-4-phenylthioallophanimidate octyl N-carbamoyl-4-( 3 .4-dichlorophenyl )thioallophanimidate EXAMPLE l0 5.4 Parts of dimethylcarbamoyl chloride is combined with I0 parts pyridine and stirred until the temperature returns to 25C. 8.0 Parts methyl 4.4-dimethylthioallophanimidate (a compound of formula ll). in parts methylene chloride is added in one portion. The mixture is refluxed overnight. then cooled to give a white solid. The solid is removed and the organic layer is extracted with 200 parts water at pH 3. dried and evaporated to give 5 parts methyl N-dimethylcarbamoyl-4.4- dimethylthioallophanimidate (a compound of formula I). m.p. ll5.5-l l7.5C.  
  By substituting dimethylthiocarbamoyl chloride for the dimethylcarbamoyl chloride and methyl 4.4- dimethyl-l .3-dithioallophanimidate for the methyl 4.4- dimethylthioallophanimidate. there can be obtained methyl N-dimethylthiocarbamoyl-4.4-dimethyll .3-dithioallophanimidate.  
  By using the appropriate compound of formula [I from the list below. the compounds of formula I in the list below can be prepared similarly:  
 Compounds of Formula ll methyl 4.4diethylthioallophanimidate methyl 4.4-tetramethylenethioallophanimidate methyl 4.4-hexamethylenethioallophanimidate methyl 4.4-ethylenethioallophanimidate methyl 4.4-ethyleneoxyethylenethioallophanimidate methyl 4-isopropylA-methylthioallophanimidate methyl 4-butyl-4-methylthioallophanimidate methyl 4-cthyl-4-methylthioallophanimidate methyl 4-tertbutyl-4-methylthioallophanimidate methyl 4.4-dimethylallophanimidate methyl 4.4-diethylallophanimidate methyl 4-isopropyl-4-methylallophanimidate methyl 4-tert-butyl-4-methylallophanimidate methyl 4.4-tetramethyleneallophanimidate ethyl 4.4-dimethylthioallophanimidate isopropyl 44-dimethylthioallophanimidate tert-butyl 4.4-dimethylthioallophanimidate benzyl 4.4-dimethylthioallophanimidate methyl 4.4-dimethyl l .3-dithioallophanimidate methyl 4-phenyl4-methyll .3-dithioallophanimidate methyl 4.4-pentamethylene-l3-dithioallophanimidate Compounds of Formula I methyl N-dimethylcarbamoyl-4.4-diethylthioallophanimidate methyl N-dimethylcarbamoyl--l.4-tetramethylenethioallophanimidate methyl N-dimethylcarbamoyl-4.4-hexamethylenethioallophanimidate methyl N-dimethylcarbamoyl-4.-l-ethylenethioallophanimidate methyl N-dimethylcarbamoyl-4.4-  
 ethyleneoxyethylenethioallophanimidate methyl N-dimethylcarbamoyl-4-isopropyl4-methylthioallophanimidate methyl N-dimethylcarbamoyl-4-butyl-4-methylthioallophanimidate methyl N-dimethylcarbamoyl--l-ethyl-4-methylthioallophanimidate methyl N-dimethylcarbamoyl-4-tert-butyl-4-methylthioallophanimidate methyl N-dimethylcarbamoyl-4 4-dimethylallophanimidate methyl N-dimethylcarbamoyl-4.4-diethylallophanimidate methyl N-dimethylcarbamoyl-4-isopropyl-4- methylallophanimidate methyl N-dimethylcarbamoyl-4-tert-butyl-4- methylallophanimidate methyl N-dimethylcarbamoyl-4.4-tetramethyleneallophanimidate ethyl N-dimethylcarbamoyl-4.4-dimethylthioallophanimidate isopropyl N-dimethylcarbamoyl-4.4-dimethylthioallophanimidate tert-butyl N-dimethylcarbamoyl-4.4dimethylthioallophanimidate benzyl N-dimethylcarbamoyl-4.4-dimethylthioallophanimidate methyl N-dimethylcarbamoyl-4.4-dimethyl l .3-dithioallophanimidate methyl N-dimethylthiocarbamoyl-4.-l-dimethylthioallophanimidate methyl N-dimethylthiocarbamoyl-4.4-  
 pentamethylenedithimillophanimidate EXAMPLE I l 5.6 Parts of Z-methyl-2-thiopsuedourea sulfate (salt of a compound of formula IX). is placed in 50 parts water and cooled to 5C. 4.5 Parts of methyl chlorothioformate is added in one portion followed by 4.8 parts of 50% sodium hydroxide added dropwise. A solid forms and is collected after 30 minutes. The N-( lamino- 1 -methylthiomethylene )thiolmethylcarbamate (a compound of formula Xll). m.pv -65C. is dissolved in 40 parts of methylene chloride with 4.2 parts of tert-butylisocyanate and stirred overnight. The solvent is removed under reduced pressure to give a solid. This solid is recrystallized from chlorobutanezhexane lzl to give 6.2 parts of methyl 4-tert-butyl-N- methylthiolcarbonyl-l-thioallophanimidate (a compound of formula III) m.p. lO5-l06C.  
  7.9 Parts of methyl 4-tert-butyl-Nmethylthi0lcarbonyl-l-thioallophanimidate and 2.9 parts of morpholine are combined in 50 ml of methanol and stirred overnight. The solution is poured into 50 parts water and the resulting solid is collected. The solid is recrystallized from acetonitrile to give 2.4 parts of methyl N- tert-butylcarbamoyl-44-ethyleneoxyethylenethioallophanimidate (a compound of formula I). m.p. l43-l44C.  
  By using the appropriate reactants. the following illustrative compounds of formulae l and Ill can be prepared sililarly:  
 Compounds of Formula II] methyl 4-isopropyl-N-methylthiolcarbonyl-l-thioallophanimidate methyl 4-methyl-N-methylthiolcarbonyl-l-thioallophanimidate methyl 4-sec-butyl-N-methylthiolcarbonyl-l-thioallophanimidate methyl 4-phenyl-N-methylthiolcarbonyll thioallophanimidate methyl 4-benzyl-N-methylthiolcarbonyll -thioallophanimidate methyl 4-ethyl-N-methylthiolcarbonyll -thioallophanimidate methyl 4isopropyl-N-methylthiolcarbonyll .3-dithioallophanimidate methyl 4-methyl-N-methylthiolcarbonyll .3-dithioallophanimidate methyl 4-phenyl-N-methylthiolcarbonyl-1.3-dithioallophanimidate methyl 4-tert-butyl-N-methylthiolcarbonyl-l.3-dithioallophanimidate Compounds of Formula I methyl N-isopropylcarbamoyl-4.4-dimethylthioallophanimidate methyl N-ethylcarbamoyl-4,4-tetramethylenethioallophanimidate. m.p. l0ll05C methyl N-methylcarbamoyl-4.4-pentamethylenethioallophanimidate methyl N-phenylcarbamoyl-4,4-bis( 2-chloroethyl )thioallophanimidate 31 methyl N-benzylcarbamoyl-4.4-dipropylthioallophanimidate methyl Ntert-butylcarbamoyl-4.4-tetramethylenethioallophanimidate. m.p. l48-l5()C methyl N-isopropylcarbamoyl-4.4-diethylthioallophanimidate. m.p. 67-68C methyl N-isopropylthiocarbamoyl-4.4-dimethylthioal lophanimidate methyl N-isopropylthiocarbamoyl-4.4-  
 tetramethylenethioallophanimidate methyl N-phenylthiocarbamoyl-4.4-dipropylthioallophanimidate methyl N-tert-butylthiocarbamoyl-4.4-  
 tetramethylenethimillophanimidate EXAMPLE 12 18.8 Parts of methyl 4-butyl-4-methylthioallophanimidate (a compound of formula ll) is dissolved in 200 parts methylene chloride with parts triethylamine. l 1 Parts methyl chlorothioformate is added slowly dropwise and a solid forms. After 2 hours the solid is collected and the filtrate is evaporated to give methyl 4-butyl-4-methyl-N- methylthiolcarbonyl-l-thioallophanimidate (a compound of formula III). This product is dissolved in 50 parts methanol and 10.] parts diisopropylamine is added in one portion. The mixture is stirred overnight. then poured into 50 parts water to give a solid. The solid is collected and recrystallized from acetonitrile to give a good yield of methyl N-butyl-N- methylcarbamoyl-4.4-diisopropylthioallophanimidate (a compound of formula I).  
  By using the appropriate compound of formula ll and the appropriate amine. the following compounds of formula I can be prepared similarly: methyl N-tetramethylenecarbamoyl-4.4-dimethylthioallophanimidate methyl N-tetramethylenecarbamoyl-4.4-dibutylthioallophanimidate methyl N-tetramethylenecarbamoyl-4-isopropyl-4- methylthioallophanimidate methyl N-tetramethylenecarbamoyl-4.4-pentamethyleneallophanimidate methyl N-tetramethylenecarbamoyl-4.4-bis( 2- chloroethyl )-thioallophanimidate methyl N-tetramethyleneearbamoyl-4.4-diisopropylthioallophanimidate methyl N-tetramethylenecarbamoyl-4.4-diethylthioallophanimidate EXAMPLE 13 5.0 Parts of methyl N-tert-butylcarbamoyl-4.4- dimethylthioallophanimidate (a compound of formula I) is suspended in water and 1.5 parts 50% sodium hydroxide is added with stirring. After solution is obtained. the water is removed under reduced pressure to give methyl N-tert-butylcarbamoyl-4.4-dimethylthioallophanimidate. sodium salt.  
  By substituting the appropriate compounds of formula l and bases. the following salts can be prepared in similar manner: methyl N-isopropylcarbamoyl-4-isopropylthioallophanimidate. potassium salt methyl N-tert-butylcarbamoyl-4-isopropylthioallophanimidate. calcium salt methyl N-methylcarbamoyl-4-isopropylthioallophamimidate. magnesium salt methyl N-tert-butylcarbamoyl-4-tert-butylthioallophanimidate. thioallophanimidate. lithium salt methyl N-tert-butylcarbamoyl-4-tert-butylthioallophanimidate. ammonium salt 7 methyl N-tert-butylcarbamoyl-4-tert-butylthioallophanimidate. cesium salt EXAMPLE I4 A solution of 12.5 parts thiophosgene in 150 parts methylene chloride is prepared. This is cooled to. and maintained at. -l()C while a mixture of methyl 4.4- diethylthioallophanimidate (a compound of formula II) 18.9 parts. triethylamine 10 parts. and methylene chloride 150 parts. is added over a hour period. After the addition is complete the mixture is stirred at l()C for an additional hour. lsopropylamine. 12 parts. is added and the mixture is allowed to warm to room temperature and stirred 1 hour. The reaction mixture is then washed with an equal volume of ice water and the methylene chloride layer collected. dried with magnesium sulfate. and the solvent evaporated at room temperature under vacuum. The residue is a good grade of crude methyl N.N-diethylcarbamoyl-4-isopropyl-l.3- dithioallophanimidate.  
 I claim:  
  1. A method for the control of undesired vegetation comprising applying to the locus of such undesired vegetation a herbicidally effective amount of a compound of the formula:  
 wherein:  
 R,. R R and R are each independently selected from the group consisting of hydrogen; alkyl of 1 through 8 carbon atoms: alkenyl of 3 through 4 carbon atoms; cycloalkyl of 3 through 8 carbon atoms; cycloalkenyl of 5 through 8 carbon atoms: cycloalkylalkyl of4 through 10 carbon atoms; bicycloalkyl of7 through 10 carbon atoms; hydrocarbyl arylalkyl of 5 through 9 carbon atoms; alkynyl of 3 through 4 carbon atoms; and phenyl:  
 R is hydrogen: alkyl of I through 4 carbon atoms; alkynyl of 3 through 4 carbon atoms: or alkenyl of 3 through 4 carbon atoms;  
 R is alkyl of 1 through 8 carbon atoms; cycloalkyl of 5 through 8 carbon atoms: alkenyl of 3 through 8 carbon atoms: phenyl; or benzyl: and  
 X,. X and X are each independently selected from oxygen and sulfur;  
 provided that:  
 a. at least one of R,. R R and R,-, is other than hydrogen:  
 b. no more than one of R,. R R and R is phenyl or arylalkyl;  
 c. the total number of carbon atoms in R, and R does not exceed 10:  
 d. the total number of carbon atoms in R and R does not exceed 10; and  
 e. when R is normal alkyl of 3 through 8 carbon atoms. cycloalkyl of 6 through 8 carbon atoms and benzyl. and R is hydrogen. and one of R,. R R  
  1 x R x3 Rs II II N-C-N=CN-C-N l .32 Xz-Il6 4 wherein:  
 R R R and R are each independently selected from the group consisting of hydrogen: alkyl of 1 through 8 carbon atoms; alkenyl of 3 through 4 carbon atoms; cycloalkyl of 3 through 8 carbon atoms; cycloalkenyl of 5 through 8 carbon atoms: cycloalkylalkyl of4 through carbon atoms; bicycloalkyl of 7 through 10 carbon atoms: hydrocarbyl arylalkyl of 5 through 9 carbon atoms: alkynyl of 10 provided that:  
 3 through 4 carbon atoms; and phenyl:  
 R is hydrogen; alkyl of I through 4 carbon atoms; alkynyl of 3 through 4 carbon atoms: or alkenyl of 3 through 4 carbon atoms:  
 R is alkyl of I through 8 carbon atoms; cycloalkyl of 5 through 8 carbon atoms: alkenyl of 3 through 8 carbon atoms; phenyl; or benzyl; and  
 X.. X,. and X,, are each independently selected from oxygen and sulfur;  
 a. at least one of R,. R R and R is other than hydrogen:  
 b. no more than one of R,. R R and R is phenyl or arylalkyl:  
 c. the total number of carbon atoms in R and R does not exceed l0;  
 d. the total number of carbon atoms in R.. and R does not exceed 10: and  
 e. when R. is normal alkyl of 3 through 8 carbon atoms. cycloalkyl of 6 through 8 carbon atoms and benzyl. and R is hydrogen. and one of R R R and R,-, is phenyl. then only one of the other R,. R R and R,-, can be other than hydrogen: and the alkali metal. alkaline earth and ammonium salts of the above compounds in which R is hydrogen.  
  4. Composition as defined in claim 3 wherein the compound is methyl N-isopr0pylcarbamoyl-4- isopropylthioallophanimidate.