Hydrazines 5-mercapto

Alkylthio, arylthio, and thioxo. The thioxo group in pyrimidine-2,4-dithione can be displaced by amines, ammonia, and amine acetates, and this amination is specific for the 4-position in pyrimidines and quinazolines. 2-Substitution fails even when a 5-substituent (cf. 134) sterically prevents reaction of a secondary amine at the 4-position. Acid hydrolysis of pyrimidine-2,4-dithione is selective at the 4-position. 2-Amination of 2-thiobarbituric acid and its /S-methyl derivative has been reported. Under more basic conditions, anionization of thioxo compounds decreases the reactivity 2-thiouracil is less reactive toward hot alkali than is the iS-methyl analog. Hydrazine has been reported to replace (95°, 6 hr, 65% 3deld) the 2-thioxo group in 5-hexyl-6-methyl-2-thiouracil. Ortho and para mercapto- or thio- azines are actually in the thione form. ... 

Substituents in the 6-position (cf. 267) show appreciable reactivity. 6-Bromo-as-triazine-3,5(2j, 4j )-dione (316) undergoes 6-substitution with secondary amines or hydrazine, with mercaptide anions or thiourea (78°, 16 hr), with molten ammonium acetate (170°, 24 hr, 53% yield), and with chloride ion during phosphorous oxychloride treatment to form 3,5,6-trichloro-as-triazine. The latter was characterized as the chloro analog of 316 by treatment with methanol (20°, heat evolution) and hydrolysis (neutral or acid) to the dioxo compound. The mercapto substituent in 6-mercapto-as-triazine-3,5(2iI,4if)-dione is displaced by secondary... 

According to REM, hydrazine hydrate Is reacted with 2 mols of ammonium thiocyanate to produce 1,2-bislthlocarbamoyl) hydrazine which by loss of ammonia and rearrangement produces 5-amino-2-mercapto-1,3,4-thiadiazole. That compound is acetyied with acetic anhydride. 

Similarly, condensation of 206 with carbon disulfide under basic conditions gives rise to the mercapto-substituted tricyclic system 207 in good yield (Equation 55) <2000AF904>. This approach has also been used for related systems of substituted pyrimidines <1999JHC1119, 2000PS( 163) 1 >. Hydrazine-substituted pyrimidines have also been reacted in an analogous manner <1998JRM1248>. 

The reaction of 2-mercapto-4-(2, 4 -dichlorophenyl)-5-cyanopyrimidin-6(l//)one 421 (obtained by stirring ethyl cyanoacetate and thiourea with 2,4-dichlorobenzaldehyde in sodium ethylate at room temperature, in 70% yield), with a solution of monochloroacetic acid and />-cholorobenzaldehyde in glacial acetic acid, in the presence of sodium acetate, affords 2-[(/>-chlorophenyl)methylene]-6-cyano-7-(2, 4 -dichlorophenyl)thiazolo[3,2-tf]pyrimidin-3,5-dione 422. Finally, the reaction of compound 422 with hydrazine hydrate converts it into product 423 (Scheme 49) < 1996PS( 116)39>. 

Types of compounds are arranged according to the following system hydrocarbons and basic heterocycles hydroxy compounds and their ethers mercapto compounds, sulfides, disulfides, sulfoxides and sulfones, sulfenic, sulfinic and sulfonic acids and their derivatives amines, hydroxylamines, hydrazines, hydrazo and azo compounds carbonyl compounds and their functional derivatives carboxylic acids and their functional derivatives and organometallics. In each chapter, halogen, nitroso, nitro, diazo and azido compounds follow the parent compounds as their substitution derivatives. More detail is indicated in the table of contents. In polyfunctional derivatives reduction of a particular function is mentioned in the place of the highest functionality. Reduction of acrylic acid, for example, is described in the chapter on acids rather than functionalized ethylene, and reduction of ethyl acetoacetate is discussed in the chapter on esters rather than in the chapter on ketones. 

Acetazolamide Acetazolamide is 5-acetamido-l,3,4-thiadiazole-2-sulfonamide (9.7.5). The synthesis of acetazolamide is based on the production of 2-amino-5-mercapto-l,3, 4-thiadiazole (9.7.2), which is synthesized by the reaction of ammonium thiocyanate and hydrazine, forming hydrazino-N,N -( ji-(thiourea) (9.7.1), which cycles into thiazole (9.7.2) upon reaction with phosgene. Acylation of (9.7.2) with acetic anhydride gives 2-acetylamino-5-mercapto-l,3,4-thiadiazol (9.7.3). The obtained product is chlorinated to give 2-acetylamino-5-mercapto-l,3,4-thiadiazol-5-sulfonylchloride (9.7.4), which is transformed into acetazolamide upon reaction with ammonia (9.7.5) [24,25]. 

So erhiilt man aus 2-Mercapto-5-(4-pyridyl)-l,3,4-oxadiazolen mit Hydrazin 3-Amino-2-mer-capto-5-(4-pyridylJ-i,2,4-lriazol [55% Schmp. 240° (Zers.)]714 ... 

Die aus primaren Alkanthiolen sowie aus 2-Mercapto-propan und N-Chlor-succinimid erhaltlichen2 N-Alkylthio-phthalimide reagieren mit Tris-[dimethylamino]-phosphan in Benzol exotherm zu N-Alkyl-phthalimiden, die in ublicher Weise mittels Hydrazin zu den Alkylaminen gespalten werden konnen3. Die Gesamtreaktion stellt also eine Variante der Gabriel-Synthcse dar ... 

Hydrazin (2-Mercapto-l-methyl-ethyl)- E16a, 458 (Aziridin + H2S)... 

Hydrazin l-[2-(2-Mercapto-propylthio)-propyl]-l-methyl-E16a. 476 (N-Alkyl.)... 

Pyrazolidin 1,2-Bis-[2-methyl-propyl]-4-mercapto- El 6a, 555 (Hydrazin-1,2-Cycloalkyl.)... 

Dicyanopyrazine with sodium methoxide in methanol with ammonia at reflux gave 5,7-diimino-6//-pyrrolo[3,4-i)]pyrazine (65) (1442) and 2,3-dicyano-5,6-dimethyl(and 5,6-diphenyl)pyrazine with hydrazine by the procedure of Patel and Castle (1339) gave 2,3-dimethyl(and 2,3-diphenyl)-5,8-diaminopyrazino[2,3-rfJ-pyridazine(s) (66) (1435). Fusion of 2-chloro-3-cyano-5,6-diphenylpyrazine with urea and thiourea was reported to give 4-amino-2-hydroxy(and mercapto)-6,7-diphenylpteridine (848). 

On heating 4-chloro-, 4-mercapto-, or 4-hydrazinoquinazolines with hydrazine hydrate in a sealed ampoule, the 3-(2-aminophenyl) derivatives of 4-aminotriazole and triazole are formed in yields of and 22%, respectively [Eq. (45)] [72JCS(P1)1842]. 

A hypothetical intermediate 2-hydrazinoquinazolone that without doubt forms from 2-mercapto compound 76 and hydrazine consequently cyclizes to give amine 77 (03JHC973). 

Anstelle von Carbonsaure-nitrilen soil auch die Umsetzung von Aldehyden und Hydrazin mit a-Mercapto-ketonen 1,3-Thiazole liefern89. 

Die freien 5-Amino-4-mercapto-l, 3-thiazole lassen sich gewinnen, wenn nachtraglich zur Reaktionsmischung Hydrazin zugeben wird721- 722 ... 

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