1.2.3- Triazole amination

Amide 202 is a key intermediate for the synthesis of various antifungal compounds (TAK-456 and TAK-457). Amide 202 is prepared via the coupling reaction of substituted triazole amine 200 and glycine derivative of tetrazole 201 using DEPC.76... 

Ethyl diethoxyphosphinylpropynoate (122) can act as a good dienophile it also reacts with azides to form C-phosphorylated-l,2,4-triazoles. Amines add to l,2-bis(dialkoxyphosphinyl)acetylene to give the enamines (123) when the latter are derived from primary amines, they can be C-alkylated via their lithio derivative. ... 

Investigation of five-membered ring analogs of the pyrimidine and tiiazine sulfonylureas 1 to useful structure activity correlations as well as some hi y active herbicides. Substituted triazole amines afforded some of the more interesting sulfonylureas of this class. 

Condensation of cyanoimidate 16 with substituted hydrazines was known (6) to give a mixture of isomeric triazole amines 17 and 18. We found that sulfonylureas derived from 18 exhibited significant herbicidal activity while those derived from 17 were inactive at comparable application rates. The disadvantage with this method of preparing dialkyltriazole sulfonylureas was that the desired aminotriazole intermediate 18 was Ae minor regioisomer formed in the condensation of 16 with alkylhydrazines. 

Fig. 1. HeterocycHc amines usedia azo dyes, (a) 2-Amino-6-nitrohenzothiazo1e [6285-57-0], (b) 3-amiao-5-nitro-2,l-benzisothiazole [14346-19-1], (c) 3-amiQo-4JT-l,2,4-triazole [65312-61 -0], (d) 5-amiQo-l,2,4-thiadiazole [7552-07-0, (e) 4,4 -diamiQo-2,2 -biphenylsulfone [6259-19-4], (f)...

Amination at an azole ring nitrogen is known for Af-unsubstituted azoles. Thus 4,5-diphenyl-1,2,3-triazole with hydroxylamine-O-sulfonic acid gives approximately equal amounts of the 1- (104) and 2-amino derivatives (105) (74AHC(16)33). Pyrazole affords (106) and indazole gives comparable amounts of the 1- and 2-amino derivatives. 

Halogeno-l-methyl-l,2,3-triazoles undergo substitution reactions with amines, but the 4-halogeno analogs do not. 5-Chloro-l,4-diphenyl-l,2,3-triazole with sodium cyanide in DMSO gives the cyano derivative (63JCS2032). 1-Substituted 3-chloro- and 5-chloro-l,2,4-triazoles both react with amines. 

Diacylhydrazines (32) on heating with a primary amine undergo cyclization to the 1,2,4-triazole derivative (38). It is assumed that the amidrazone (37) is an intermediate in the reaction. Most practical syntheses of 1,2,4-triazoles now utilize an amidrazone or a derivative of this alicyclic intermediate containing three nitrogen atoms, and these variations are discussed in Chapter 4.12. 

That aminals and enamines are in equilibrium under certain conditions has been demonstrated (38). l,l-Di(N-morpholino)ethane 18, when heated with excess diethylamine for 24 hr at 60 and then treated with 4-nitro-phenylazide, gave the triazole (19) in 80% yield. The authors contend that... 

An indole protected by a Mannich reaction with formaldehyde and dimethyl-amine is stable to lithiation. The protective group is removed with NaBH4 (EtOH, THE, reflux). The related piperidine analogue has been used similarly for the protection of a triazole. ... 

The diazotization of heteroaromatic amines is basically analogous to that of aromatic amines. Among the five-membered systems the amino-azoles (pyrroles, diazoles, triazoles, tetrazoles, oxazoles, isooxazoles, thia-, selena-, and dithiazoles) have all been diazotized. In general, diazotization in dilute mineral acid is possible, but diazotization in concentrated sulfuric acid (nitrosylsulfuric acid, see Sec. 2.2) or in organic solvents using an ester of nitrous acid (ethyl or isopentyl nitrite) is often preferable. Amino derivatives of aromatic heterocycles without ring nitrogen (furan and thiophene) can also be diazotized. 

Hydroxyenones have also been used in catalytic amide formation, although 1,2,4-triazole is required as a co-catalyst. Assumed protonation of the Breslow intermediate and tautomerisation generates an acylazolium intermediate, which is trapped by triazole, releasing the NHC and generating the acyltriazole 60 that is the active acylating agent for the amine (Scheme 12.11) [16]. 

The most common corrosion inhibitors, which may form protective films on the metal surfaces, are borates, molybdates, nitrates, nitrites, phosphates, silicates, amines, triazoles, and thiazioles (e.g., monoethanolamine, urotropin, thiodiglycol, and mercaptobenzothiazole). The addition of such inhibitors does not effectively protect against corrosion [137]. Some corrosion inhibitors are shown in Figure 14-3. 

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