JPS6038372A - Manufacture of sulfonylurea - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for converting a sulfonamide represented by the following formula (1): T-5Q, -NH2 (wherein T represents the meaning defined in formula I below) into diphenyl carbonate in the presence of a base. to form a salt of lerphenyl carbamate represented by the following formula m: (wherein T represents the meaning defined in the formula ① below, and Me represents a cation of sodium or potassium or a tertiary amine). , this salt is converted into a free phenyl carbamate represented by the following formula ■a: [wherein T represents the meaning defined in formula I below], and this is further converted to the free phenyl carbamate represented by the following formula ■: [wherein R1 and R2 is the formula 1 below
The sulfonamide of formula (2) is reacted with diphenyl carbonate in a neutral solvent at 60°C with exclusion of moisture, and then the intermediate is reacted with an amine represented by The phenyl carbamate of formula 111a is liberated from the salt of the formed phenyl carbamate by subsequent addition of anhydrous acid without isolating the phenyl carbamate of formula 111a, and finally it is reacted with an amine of formula 1 at 20 to 150°C. 9 T-5ow-NH-CO-N-R+ (412 [wherein, R1 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms] , R represents a group represented by the following formula, E represents =N- or -CH-, R3 is an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or・Represents a rogene atom, and R4 is an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, or a carbon atom? 1 to 4
an alkoxy group, an alkyl group having 1 to 4 carbon atoms, a C 1 to 40 alkoxy group,
represents a haloalkyl group having 1 to 4 carbon atoms or a haloalkoxy group having 1 to 4 carbon atoms, R5 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and T is a substituent represented by the following formula: Y represents a hydrogen atom or a halogen atom, X represents a hydrogen atom, a halogen atom, a nitro group, an alkyl group having 1 to 4 carbon atoms, a haloalkyl group having 1 to 4 carbon atoms, a carbon atom Alkenyl group having 2 to 4 carbon atoms, 2 to 4 carbon atoms
a haloalkenyl group having 20,000 to 4 carbon atoms, an alkynyl group having 20,000 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a haloalkoxy group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms; Alkoxy group having 1 to 4 carbon atoms, alkylthio group having 1 to 4 carbon atoms, alkylsulfinyl group having 1 to 4 carbon atoms, alkylsulfonyl group having 1 to 4 carbon atoms, haloalkylthio having 1 to 4 carbon atoms group, an alkylsulfonyloxy group having 1 to 4 carbon atoms, a phenyl group, an unsubstituted phenylsulfonyloxy group or a phenylsulfonyloxy group mono- or polysubstituted with an alkyl group having 1 to 4 carbon atoms, or a phenylsulfonyloxy group having 1 to 4 carbon atoms; represents 1 to 4 dialkylsulfamoyl groups, and A is a member of an unsubstituted or substituted bridge consisting of 3 or 4 atoms and containing 1 to 2 heteroatoms, which is bonded to Together with the carbon atoms that are 5
The two oxygen atoms are separated by at least one carbon atom, and the oxygen and sulfur atoms are present as a 18O- or -5O2- group. Combine with each other only if. ] The present invention relates to a method for producing a sulfonylurea represented by the following.

The sulfonylurea of formula (2) exhibits excellent herbicidal activity and can therefore be advantageously used as a herbicidal composition.

Sulfonylureas of formula I and methods of making and using them are described, for example, in U.S. Pat. No. 4,124,405, 4.16.
9.719 and 4.25B, 621, European Patent Application No. 83810005.5 and South African Patent No. 4874/81.

It is known that p-)toluenesulfonylphthylurea can be prepared from p-toluenesulfonylphenyl carbamate and butylamine. [Japanese Patent Application No. 33
-154B4, C,A.

1962/I 7218g) From the sodium salt of p-) toluenesulfonamide and diphenyl carbonate, 1) to form the sodium salt of -1'-ruenesulfonyl phenyl rubamate, from which N-p-) toluenesulfonyl It is also known to isolate phenyl rubamate in its free form by adding acid. [
Japanese Patent Application No. 33-13483, C, A, 19
62/l7218f) In the process described, the hydrolyzable sulfonylphenyl carbamate is isolated as an intermediate in the presence of water in a cumbersome process (ether extraction). The yield of phenyl-p-)luenesulfonyl carbamate is only 50% of the theoretical value.
It is Chi.

The final product 1-(p-toluenesulfur 1-
The yield of 3-butyl urea is 47 times the theoretical value based on the p-toluenesulfonamide used. The method for producing the sulfonylurea of formula (1) using this method is not commercially advantageous due to the above-mentioned drawbacks.

According to the method of the invention, preferably the following formula 11a: [wherein X represents the meaning defined above]. ] is used.

Sulfonamides of formula (1) as starting materials suitable for carrying out the production process of the present invention are shown below.

2-fluorobenzenesulfonamide, 2-chlorobenzenesulfonamide, 2-nitrobenzenesulfonamide, 2-) tilbenzenesulfonamide, 2
-Trifluoromethylbenzenesulfonamide, 2-methoxybenzenesulfonamide, 2-difluoromethoxybenzenesulfonamide, 2- (2'-chloroethoxy)-benzenesulfonamide, 2- (2'-methoxyethoxy)- Benzene sulfonamide, 2-n-7” lovirthiobenzene sulfonamide
, 2-methylsulfonylbenzenesulfonamide, 2-n-furobylsulfonylbenzenesulfonamide, 2-methylsulfonyloxypendylsulfonamide, 2-n-propylsulfonyloxybenzenesulfonamide, 2-dimethylsulfonamide Famoylbenzenesulfonamide and 2,5-dihydrobenzofurano-7-ylsulfonamide When Y represents a hydrogen atom in the arylsulfonamide of formula (1) used, the amine of formula (1) preferred by the method of the present invention are shown below: 2-amino-4-methyl-6-medoxy S-triazine, 2-amino-4-methyl-6-medoxypyrimidine, 2-amino-4-methyl-6-difno-olomethoxypyrimidine, 2-amino-4,6-simethoxypyrimidine, 2-amino-4,6-simethoxy-S-doriazine, 2-amino-4,6-simethylpyrimidine, 2-amino-4-methoxy-6-ethoxy s-) riazine, 2-amino-4-dimethylamino-6-medoxy s-
) riazi/, 2-amino-4-cyclopropyl-6-methoxy-5-
) riazine, 2-amino-4-methoxy-6-medoxymethylpyrimidine, 2-amino-4-methoxy-6-chloropyrimidine, 2-amino-4-methoxy-6-chloroamethylpyrimidine, 5-amino -1,5-dimethyl-1,2,4-triazole, and 3-amino-5-methoxy-1-methyl-1°2.4-
Triazole.

Several variants are possible in carrying out the method according to the invention. According to a first variant, the sulfonamide of formula (1) is first reacted with an equal amount of base and converted into an alkali metal salt, such as a sodium or potassium salt, or a salt of a suitable tertiary amine. In the second step of the synthesis reaction,
The resulting salt is finally formed into a solution or suspension in a neutral solvent with exclusion of moisture.

The subsequent reactions according to the process of the invention are carried out in a neutral solvent in the absence of water.

Suitable neutral solvents are, for example, acetonitrile, tetrahydrofuran, dioxane, 1,2-dimethoxyethane, dimethylformamide, N,N-2 methylacetamide or N-methylpyrrolidone or mixtures of these solvents.

Particularly suitable as solvent is acetonitrile.

There are several methods possible for converting the sulfonamide of formula H into its salt.

To prepare an alkali metal salt, first the sulfonamide of formula (2) is reacted with an alkali metal hydroxide in a solvent (eg alcohol). A second solvent, for example toluene, can be added to this and, after distilling off the solvent, the alkali metal salt can be obtained in the form of a dry residue. If desired, this may then be dried in vacuo.

Suitable alkali metal hydroxides are II hydroxide and potassium hydroxide. Potassium hydroxide is preferred as the alkali metal hydroxide.

The sodium or potassium salts of sulfonamides of formula (1) can be obtained in a similar manner by reacting free sulfonamides of formula (1) with sodium or potassium alcoholades in alcoholic solution. The obtained alkali metal salt of sulfonamide No.2 is dried if desired, and then suspended in a neutral solvent.

The tertiary ammonium salt of the sulfonamide of formula (1) is prepared as an anhydrous solution by mixing equivalent amounts of the sulfonamide and the appropriate tertiary amine in a neutral solvent, and can be used as such.

The tertiary amine must also have sufficient basicity in order to form a salt with the sulfonamide. Tertiary amines suitable for salt formation are, for example, 1,8-diazabicyclo(
5,4,0)-undec-7-ene or 1,5-diazabicyclo(4,5,O)raney-5-ene. These salt-forming tertiary amines are commercially available and can be recovered after the reaction.

The suspensions or solutions of alkali metal or tertiary ammonium salts of sulfonamides obtained in this way can be converted into the corresponding sulfonylureas in various ways according to the process of the invention. According to a preferred method, which can be carried out in one reaction vessel, the salt suspended or dissolved in a neutral solvent is mixed with an equivalent amount of diphenyl carbonate and the mixture is subjected to the desired reaction to form the sulfocarbamate salt. 1 to 12 hours, 3 to 3 hours
Stir at 0°C. The total amount of sulfocarbamate is liberated from the sulfocarbamate salt by adding a suitable equivalent of an anhydrous acid such as methanesulfonic acid or hydrogen chloride and dissolving, if desired, at 30°C. Methanesulfonic acid is preferred as the acid anhydride. Preference is likewise given to using hydrogen chloride dissolved in acetonitrile. The resulting sulfocarbamate solution is reacted with an equivalent amount of a heterocyclic amine, raising the temperature of the reaction mixture initially from 20° C. to the boiling temperature of the solvent (but up to 150° C.) to yield the sulfonylurea. The acid and heterocyclic amine can also be added at the same time.

In another method, the heterocyclic amine is converted to the corresponding salt by addition of acid in a separate vessel in a neutral solvent and used as such.

The suspended or dissolved sulfocarbamate salt is then added to the suspended or dissolved amine salt at a temperature between room temperature and the boiling point of the solvent. After the addition of the nulfolbamate, the reaction mixture is heated as described above until the reaction is complete.

According to yet another particularly preferred variant of carrying out the process of the invention, the tertiary amine used to form the salt with the sulfonamide is removed from the sulfonamide, diphenyl carbonate and the intermediate salt. into the phenyl carbamate salt form by dropping it into a pre-formulated mixture of aqueous solvents. Further processing of this intermediate is carried out by one of the methods already described.

The simplest way to treat the reaction mixture is to cool it to 20 DEG C. to crystallize the sulfonylurea formed in pure form. The reaction product is obtained in pure form after filtration, subsequent washing and drying. After further treatment of the mother liquor, the solvent, the phenol formed as a by-product and, if desired, the salt-forming amine used can be separated off in pure form. If sufficient or no crystals of sulfonylurea are formed, the solvent is first distilled off, optionally the by-product phenol is distilled off under reduced pressure, and the distillation residue is distilled into water and a water-immiscible solvent. , for example in toluene or cyclohexanone in a warm state, and then the sulfonylurea is crystallized from the organic layer separated at elevated temperature by cooling.

The product is weighed and subsequently washed and dried. Furthermore, by distilling and working up the mother liquor and the separated aqueous layer, the solvent, ie the phenol produced as a by-product, and the optionally used salt-forming amine can be isolated in pure form. The yield is 2 based on the amount of sulfonamide used.
50 to 80% throughout the stages.

Compared to the prior art processes, the process according to the invention allows the production of hydrolyzable sulfonylphenyl carbamates in high yields with the exclusion of moisture, and in addition, all reaction steps are carried out in one reaction vessel. It is advantageous in that it makes it possible to

A particularly preferred variant of the invention, which consists in introducing a tertiary amine into a mixture of sulfonamide, diphenyl carbonate and solvent, allows substitution of unstable groups with which the desired products cannot be obtained with other variants. A sulfonamide of formula H can be converted to the corresponding sulfonylurea. Examples of such sulfonamides include 2-
Alkylsulfonyloxybenzenesulfonamides having 1 to 4 carbon atoms, unsubstituted phenylsulfonyloxybenzenesulfonamides, phenylsulfonyloxybenzenesulfonamides mono- or polysubstituted with alkyl groups having 1 to 4 carbon atoms; 2-
(2-haloC1-C4alkoxy)-benzenesulfonamide.

By applying this particularly advantageous process variant it is generally possible to obtain higher yields of sulfonylureas than with other process variants.

2-IN,N-dimethylsulfamoyl)-benzenesulfonamide 26.41 (0.1 mol) is added to 1001 ml of setonitrile. 1,8-diazabicyclo(5,4,Ol undec-7-ene (DBU l
15.7F (a 1 7k) emka L, sono i
The mixture is stirred at room temperature for 1 hour. diphenyl carbonate 21.4
1 (0.1 mol) and continued stirring for 1 hour.

After standing for 15 hours, methanesulfonic acid 97y (0,1
mol) is added dropwise as it cools. later 2-amino-4-
Chloromethyl-6-medoxypyrimidine 17.3y (0
, 1 mol) and the suspension is heated to reflux for 1 hour. During this time, a solution first forms and the product soon precipitates as crystals. The reaction mixture is cooled and the product filtered off with suction to give slightly yellow product 32F. Melting point: 214 to 2
16°C (decomposition). Yield: 70% of theory 0-urea 2-trifluoromethylbenzenesulfonamide 11
．． jy (0.05 mol), 30 ji of methanol and 5.8 y (0.05 mol) of potassium tert-butyrad are mixed in a flask with a stirrer and the solvent mixture is distilled off under reduced pressure. Potassium salt of residual sulfonamide 1xo
Suspended in yk dioxane 20F, diphenyl carbonate IQ,
Add 8p (0.05 mol) and continue stirring at room temperature for 12 hours. During this time a suspension of the potassium salt of the phenyl carbamate is formed. Next, 1.8y (105 mol) of hydrogen chloride gas and all 2-amino-4-methoxy-6-medoxymethylpyrimidine a5p (0.05 mol) were added to 25yt7C of dioxane.
The dissolved and cooled solution is introduced with stirring, so that the hydrochloride salt of the amine forms as a suspension. Next, the suspension of the phenyl carbamate salt is added to this suspension for 30 minutes at the same temperature. The reaction mixture is kept at reflux temperature for a further 30 minutes, after which the dioxane is distilled off at normal pressure and the phenol is distilled off under reduced pressure. The residue consisting of solid KC1 and oily organic part was dissolved in toluene 2 at 60°.
Dilute with 5f. Dissolve KCl in 20 parts of water and separate the two layers by 6 parts.
Separate at 0°C. The toluene layer is cooled and the recrystallized product is washed and dried. Yield: i 5y (
71% of theory) Preparation of urea 2-Methylsulfonyloxy-benzenesulfonamide 25.1. F (α1 mol), diphenyl carbonate 2t4
y (1 mole of El) and acetonitrile 501 are stirred together. The mixture produced in this way has 0 hiko and 5
1,8-diazabicyclo(
5,4,0)-undec-7-ene (DBU) 15.
7jll T O, 1 mol) is added dropwise and the resulting solution is left to stand at room temperature for 15 hours. Methanesulfonic acid 9.7F ([11 mol)] is added dropwise to the cooled solution at 0 to 5° C. with stirring for 10 minutes. Next, 17 Jp (11 mol) of 2-amino-4-chloromethyl-6-methoxypyrimidine
is added and the resulting suspension is heated to reflux for 1 hour. During this time a clear solution forms. This is cooled and the precipitated product is allowed to pass by suction. Product yield is 295y. Melting point: 177-179°C, yield: 65% of theory.

Claims (1)

[Claims] (T-5Q, -N for 11th order equation) (■). A sulfonamide represented by the following formula m (wherein T represents the meaning defined in the following formula !) is reacted with diphenyl carbonate in the presence of a base. Express the meaning, Me
represents a cation of sodium or potassium or a tertiary amine), and this salt is formed by the following formula Ia: [wherein T represents the meaning defined in the following formula (■)] The free phenyl carbamate represented by the formula
The reaction between the sulfonamide of formula (1) and diphenyl carbonate is carried out in a neutral solvent at 30° C. with the exclusion of moisture, Without subsequent isolation of the intermediate,
The phenyl carbamate of formula 111a is liberated from the formed phenyl carbamate salt by subsequent addition of anhydrous acid, and finally it is combined with the amine of formula
The following formula 1: % formula % (wherein R1 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R3 represents a group represented by the following formula: E represents =N- or =CH-, Rs represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a halogen atom , R4 is an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, or a cycloalkyl group having 1 to 4 carbon atoms.
an alkoxy group, a C1-C4 alkoxy group, a C1-C4 alkyl group,
R represents a no-roalkyl group having 1 to 4 carbon atoms or a no-roalkoxy group having 1 to 4 carbon atoms; R5 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; : Represents a substituted phenyl group represented by, Y represents a hydrogen atom or a halogen atom, and X represents a hydrogen atom, a halogen atom, a nitro group, and a carbon atom number of 1
alkyl group having 1 to 4 carbon atoms, haloalkyl group having 1 to 4 carbon atoms, alkenyl group having 2 to 4 carbon atoms, haloalkenyl group having 2 to 4 carbon atoms, alkynyl group having 2 to 4 carbon atoms, having 2 to 4 carbon atoms; alkoxy group having 1 to 4 carbon atoms, haloalkoxy group having 1 to 4 carbon atoms, alkoxy group having 1 to 4 carbon atoms-alkoxy group having 1 to 4 carbon atoms, alkylthio group having 1 to 4 carbon atoms, alkylthio group having 1 to 4 carbon atoms, an alkylsulfinyl group having 1 to 4 carbon atoms, an alkylsulfonyl group having 1 to 4 carbon atoms, a haloalkylthio group having 1 to 4 carbon atoms, a yl group having 1 to 4 carbon atoms; 4 alkylsulfonyloxy group, phenyl group, unsubstituted phenylsulfonyloxy group or phenylsulfonyloxy group mono- or polysubstituted with an alkyl group having 1 to 4 carbon atoms, or dialkylsulfur group having 1 to 4 carbon atoms represents a moyl group, and A is a member of an unsubstituted or substituted bridge containing 3 or 4 atoms, 1 or 2 heteroatoms, which is connected to the carbon atom to which it is attached. together 5
It forms a negative or 6-membered non-aromatic heterocycle, in which the two oxygen atoms are separated by at least one carbon atom, and the oxygen and sulfur atoms are separated by -SO- or -SO, - bond to each other only when present as groups. ) A method for producing a sulfonylurea represented by (2) In the above formula (■), R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R represents a group represented by the following formula: E represents =N- or =CH- , R3 represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a halogen atom, and R4 is an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms. , 1 to 4 carbon atoms
alkoxy group, halogen atom, carbon number 1 to 4
alkoxy - represents an alkyl group having 1 to 4 carbon atoms, a haloalkyl group having 1 to 4 carbon atoms or a haloalkoxy group having 1 to 4 carbon atoms, and R5 is a hydrogen atom or a C 1 to 4 alkyl group; represents an alkyl group, T represents a substituted phenyl group represented by the following formula: Y represents a hydrogen atom or a halogen atom, X represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms, a carbon haloalkyl group having 1 to 4 atoms,
C2-C4 alkenyl group, C2-C4 haloalkenyl group, C2-C4 alkynyl group, C1-C4 alkoxy group, C1-C4 hydrogen group alkoxy'M-1 C1 -C4 alkylthio, C1 -C4
represents an alkylsulfinyl group having 1 to 4 carbon atoms, an alkylsulfonyl group having 1 to 4 carbon atoms, a haloalkylthio group having 1 to 4 carbon atoms, or a dialkylsulfamoyl group having 1 to 4 carbon atoms, and A is 6 atoms or 4 A member of an unsubstituted or substituted bridge consisting of atoms and containing one or two heteroatoms, which, together with the carbon atoms to which it is attached, has 5
It forms a negative or 6-membered non-aromatic heterocycle, in which the two oxygen atoms are separated by at least one carbon atom, and the oxygen and sulfur atoms are separated by -SO- or -SO ! 2. A process according to claim 1 for producing sulfonylureas which bond to each other only when present as - groups. (3) The following sulfonamides of formula ■: 2-fluorobenzenesulfonamide, 2-chlorobenzenesulfonamide, 2-nitrobenzenesulfonamide,
2-methylbenzenesulfonamide, 2-trifluoromethylbenzenesulfonamide, 2-methoxybenzenesulfonamide, 2-difluoromethoxybenzenesulfonamide, 2-(2'-chloronidoxin-benzenesulfonamide, 2-(2 '-MeI-xyethoxy)-benzenesulfonamide, 2-n-7'ropylthiobenzenesulfonamide, 2-methylsulfonylbenzenesulfonamide, 2-n-propylsulfonylbenzenesulfonamide, 2-methylsulfonyloxybenzyl any one of the sulfonamides of sulfonamide, 2-n-butylsulfonyloxybenzenesulfonamide, 2-dimethylsulfamoylbenzenesulfonamide, and 2.3-9 hydrohenzofurano-7-ylsulfonamide; (4) The method according to claim 1, in which a sulfonamide represented by the following formula (a): λ [wherein X represents the meaning defined above] is used. The method described. (5) In the above formula (1), R1 represents a hydrogen atom, and R1 is 4
-Methyl-6-medoxyS-) riazin-2-yl group, 4-methyl-6-medoxypyrimidin-2-yl group,
4-Methyl-6-difluoromethoxypyrimidine-2-
yl group, 4-methoxy-6-chloromethylpyrimidine-
2-yl group, 4,6-simethoxy8-triazine-2
-yl group, 4,6-cymethoxypyrimidin-2-yl group, 4,6-dimethylpyrimidin-2-yl group, 4-methoxy-6-ethoxytriazin-2-yl group, 4-dimethylamino -6-MedoxyS-) riazin-2-yl group, 4-cyclopropyl-6-methoxy-8-triazin-2-yl group, 4-methoxy-6-medoxymethylpyrimidin-2-yl group, 4 -methoxy-6-chloropyrimidin-2-yl group, 1,5-dimethyl-1,2,4-
triazol-3-yl group or 5-methoxy-1-
2. A process as claimed in claim 1, in which an amine representing the methyl-1,2,4-)lyazol-3-yl group is used. (6) The solvent used in the reaction is acetonide 1-nor, tetrahydrofuran, dioxane, 1,2-dimethoxyethane, dimethylformamide, N. 2. The method according to claim 1, wherein the compound is selected from the group consisting of N-dimethylacetolimide or N-methylpyrrolidone. (7) The method according to claim 6, wherein the reaction is carried out in acetonitrile. (81) The process according to claim 1, which comprises first liberating the total amount of phenyl carbamate from the phenyl carbamate salt by adding an acid, followed by adding an amine. (9) As required depending on the purpose. A method according to claim 1, in which phenyl carbamate is liberated from a phenyl carbamate salt by K by simultaneously adding an acid and an amine. The method according to claim 1, in which methanesulfonic acid or hydrogen chloride is used to liberate αB sulfonylphenyl carpamate or to form a salt with the amine. (+21 Patent where the acid used is methanesulfonic acid The method according to claim 11. 0 The method according to claim 11, wherein the acid used is hydrogen chloride dissolved in acetonitrile. Q4) The base used is hydroxide) IJium, potassium hydroxide , sodium alcoholade, potassium alcoholade or tertiary amine. a9 The method according to claim 14, wherein the base used is potassium hydroxide. aQ The base used is 1,8-diazobicyclo (5゜4
．． 0) undecyl-ene or 1.5-diazabicyclo+ 4.3. 15. The method of claim 14, wherein O) tan-5-ene. aη A phenyl carbamate salt is formed by dropping the tertiary amine used to form the salt with the sulfonamide into a mixture of the sulfonamide, diphenyl carbonate, and a neutral solvent with the exclusion of moisture.
The method described in section. 17. The method according to claim 16, wherein after the reaction, the base used is regenerated and recycled. α1 Claim 1 in which the reaction is carried out in one reaction vessel
The method described in Section 8.