Pyridine-3-sulfonamide

A mixture of THF and DMPU has been used as a solvent for Sml2 in various reactions such as cyclization of alkynyl halides [90,91], tandem iodo-enone cy-clization/samarium enolate aldol reaction [92], coupling of (3-silylacrylic esters [93], deprotection of arenesulfonamides [94] and pyridine-2-sulfonamides [95], radical ring-opening reactions of cyclopropyl ketones and the trapping of the resulting samarium(III) enolates by a variety of electrophiles [96] (Scheme 41). 

Pyridine-2-sulfonamides are cleaved by Smlj to furnish amines. Therefore, such amine derivatives are synthetically useful. 

The formation of nicotinic acid derivatives by base-mediated nitrogen to carbon rearrangement of -substituted pyridine 2-sulfonamides (Scheme 189) has been reported. ... 

Since the antibiotin factor does not inhibit those bacteria which synthesize biotin, the antibiotin factor appears to combine only with the externally supplied biotin and cannot penetrate effectively to the sites of biotin synthesis and utilization. This is analogous to the findings with the synthetic inhibitory growth factor analogs (e.g., pyrithiamin and thiamin, pantoyl taurine and pantothenic acid, pyridine-2-sulfonamide and nicotinamide) where the inhibitory action is largely confined to those otgan-isms which do not synthesize the growth factor. 

Plants. Degraded rapidly. DT50 1.5-4.5 days main metabolic pathways were hydrolysis of the sulfonyl urea bridge to form the pyridine sulfonamide and pyrimidine amine, and hydroxylation on the pyrimidine ring... 

A Step 3 derivative of the current invention, 5-isopropyl-N-[6-(4-hydroxy-2-butynyloxy)-5-(o-methoxyphenoxy)-2-(4-pyridyl)-4-pyrimidinyl]-2-pyridine sulfonamide, was converted into the butyl carbamate derivative, (I), by reacting with butyl isocyanate as illustrated in Eq. 3 and described by the author. 

The N-triazolo[l,5-a]pyridine sulfonamides (37) are prepared by the general methods outlined in Scheme 2.4.7 [32, 36]. A substituted 2-aminopyridine (38) is reacted with ethoxycarbonylisothiocyanate to give the thiourea (39). Reaction of 39 with hydroxylamine in the presence of a base yields the 2-aminotriazolo[l,5-a]-pyridines (40). Compound 40 is then reacted with substituted sulfonyl chloride in the presence of a catalytic amount of dimethyl sulfoxide and pyridine to give 37. 

The structure-activity relationships for substitutions on the phenyl ring of the triazolo[ 1,5-a]pyridine sulfonamides (37) are similar to 13. Disubstitutions are... 

Coupling Processes. Figure 7 shows several methods for forming a sulfonylurea bridge between the pyridine sulfonamide and the pyrimidine amine. 

Much of the development of the chemistry of sulfanilamidoselenazole derivatives is a result of the important role played by sulfonamides in chemotherapy and more particularly the good activity of sulfathiazoie against bacterial infections. Backer and De Jonge (441 prepared these derivatives by reaction of 2-amino-4-methyl- and 2-aminO-4-phenyl-selenazoles with A -acetylsulfanilic acid chloride in pyridine.. Alkaline... 

Phenols. Phenols are unreactive toward chloroformates at room temperature and at elevated temperatures the yields of carbonates are relatively poor (< 10%) in the absence of catalysis. Many catalysts have been claimed in the patent Hterature that lead to high yields of carbonates from phenol and chloroformates. The use of catalyst is even more essential in the reaction of phenols and aryl chloroformates. Among the catalysts claimed are amphoteric metals or thek haUdes (16), magnesium haUdes (17), magnesium or manganese (18), secondary or tertiary amines such as imidazole (19), pyridine, quinoline, picoline (20—22), heterocycHc basic compounds (23) and carbonamides, thiocarbonamides, phosphoroamides, and sulfonamides (24). 

Sulfonamides (R2NSO2R ) are prepared from an amine and sulfonyl chloride in the presence of pyridine or aqueous base. The sulfonamide is one of the most stable nitrogen protective groups. Arylsulfonamides are stable to alkaline hydrolysis, and to catalytic reduction they are cleaved by Na/NH3, Na/butanol, sodium naphthalenide, or sodium anthracenide, and by refluxing in acid (48% HBr/cat. phenol). Sulfonamides of less basic amines such as pyrroles and indoles are much easier to cleave than are those of the more basic alkyl amines. In fact, sulfonamides of the less basic amines (pyrroles, indoles, and imidazoles) can be cleaved by basic hydrolysis, which is almost impossible for the alkyl amines. Because of the inherent differences between the aromatic — NH group and simple aliphatic amines, the protection of these compounds (pyrroles, indoles, and imidazoles) will be described in a separate section. One appealing proj>erty of sulfonamides is that the derivatives are more crystalline than amides or carbamates. 

The fluoraza reagents consist of two types of compounds one in which a fluorine atom is bound to the nitrogen atom of an amide or, more often, a sulfonamide and one in which a fluorine atom is bound to the nitrogen atom of a tertiary amine such as pyridine, quinuclidine, or triethylenediamine 1,4-diaza-bicyclo[2 2.2]octane. The positive charge on the nitrogen is counterbalanced by a non-nucleophilic anion such as triflate or tetrafluoroborate. 

Methyl pyrazine-2-carboxylic acid is refluxed with thionyl chloride in anhydrous benzene for approximately 12 hours. Benzene and thionyl chloride excess is removed by distillation. Then some anhydrous dioxane is added and this acid chloride solution is allowed to drop into p-(/3-aminoethyl)-benzenesulfonamide suspension in dioxane and anhydrous pyridine. The resulting mixture is then refluxed for 3 hours. Dioxane is removed by distillation and then the residue is washed with water and acetic acid. The raw acylated sulfonamide is then filtered and crystallized from 95% ethanol, thus obtaining a product of MP 200 to 203 C. 

There is obtained from 4-[)3-[5-methyl-isoxazolyl-(3)-carboxamido]-ethyl]-benzene-sulfonamide (prepared from 5-methyl-isoxazole-(3)-carboxylic acid chloride and 4-()3-aminoethyl)-benzene-sulfonamide hydrochloride, MP 213° to 214°C in pyridine) and chloroformic acid methyl ester, in a yield of 69%, the compound N-[ [-4-[)3-[5-methyl-isoxazolyl-(3)-carbox-amido] -ethyl] ] -benzene-sulfonyl] ] -methyl-urethane in the form of colorless crystals of MP 173°C. 

Besides sulfonamides, chiral sulfoximines have also been used in C - N bond formation under microwave irradiation [103]. The only heteroaryl chloride used in the study—namely, 2-chloropyridine—gave the desired M-(pyridin-2-yl)sulfoximine at a yield of 43% (Scheme 101). Interestingly,... 

Sulfonic esters are most frequently prepared by treatment of the corresponding halides with alcohols in the presence of a base. The method is much used for the conversion of alcohols to tosylates, brosylates, and similar sulfonic esters. Both R and R may be alkyl or aryl. The base is often pyridine, which functions as a nucleophilic catalyst, as in the similar alcoholysis of carboxylic acyl halides (10-21). Primary alcohols react the most rapidly, and it is often possible to sulfonate selectively a primary OH group in a molecule that also contains secondary or tertiary OH groups. The reaction with sulfonamides has been much less frequently used and is limited to N,N-disubstituted sulfonamides that is, R" may not be hydrogen. However, within these limits it is a useful reaction. The nucleophile in this case is actually R 0 . However, R" may be hydrogen (as well as alkyl) if the nucleophile is a phenol, so that the product is RS020Ar. Acidic catalysts are used in this case. Sulfonic acids have been converted directly to sulfonates by treatment with triethyl or trimethyl orthoformate HC(OR)3, without catalyst or solvent and with a trialkyl phosphite P(OR)3. ... 

The ZwKKER reaction involving Co salts is frequently used for the detection of barbituric acid derivatives [31-35], but some purine, pyridine and piperidine derivatives and heterocyclic sulfonamides also yield colored derivatives. The Zwkker reaction is particularly sensitive when it is possible to form a tetrahedral complex [Co(Barb)2 Xj] (X = donor ligand, e.g. amine) [4]. 

Succinic acid, see 2-Chlorophenol. Cyclopentene, Maleic hvdrazide. 4-Nitrophenol, Phenol, 2,4.5-T Succinic semialdehyde, see Pyridine Succinyl-CoA, see Cyclohexane Sulfanilamide, see Asulam Sulfanilic acid, see Asulam Sulfonamide, see Prosulfuron Sulfonic acid, see Prosulfuron Sulfur, see Aldicarb. Benzene, Captan. Ferbam. 

---