Formyl hydrazine

Triazole has been prepared by the oxidation of substituted 1,2,4-triazoles, by the treatment of urazole with phosphorus pentasulfide, by heating equimolar quantities of formyl-hydrazine and formamide, by removal of the amino function of 4-amino-l,2,4-triazole, by oxidation of l,2,4-triazole-3(5)-thiol with hydrogen peroxide, by decarboxylation of 1,2,4-triazole-3(5)-carboxylic acid, by heating hydrazine salts with form-amide,by rapidly distilling hydrazine hydrate mixed with two molar equivalents of formamide, i by heating N,N -diformyl-hydrazine with excess ammonia in an autoclave at 200° for 24 hours, and by the reaction of 1,3,5-triazine and hydrazine monohydrochloride. ... 

Analog erhalt man aus Trimethyl-formyl-hydrazin Tetramethyl-hydrazin (55% d.Th. Kp 71-72°). Die Reduktion von l,2-Dimethyl-l,2-diformyl-hydrazin ergibt nur 15% d.Th. Tetramethyl-hydrazin5 (zur Arbeitsvorschrift s. ds. Handb., Bd. X/2, S. 50). 

Functional biaryl derivatives are important industrial chemicals. They are used as monomers for the production of high performance and other polymers, as well as dyes, pharmaceuticals and agrochemical intermediates. We have developed an improved method for the dehalogeno-dimerization of aryl bromides to yield biaryl derivatives under mild conditions (temperature < 100°C, atmospheric pressure) using a common base, a 5 % Pd/C catalyst (0.1 - 10 % w/w, based on the starting material) in an aqueous medium and formyl hydrazine as the reducing agent. Several examples of biaryl derivatives are discussed. 

Table 2. The scope of formyl hydrazine promoted bromoaryl dimerization... 

The development of an advantageous large scale synthesis of 2 starting from 4-bromophtalic acid 5 was based on the formyl hydrazine method (Eqn. 8). In the course of this work we made some interesting observations on the conditions under which 4 operates. 

The reaction of A-alkyl-A -formyl hydrazines with imidoyl chlorides gives 3,4-substituted 1-alkyl-4//-1,2,4-triazolium salts in a one-pot reaction. ... 

Fusion of a 1,2,4-triazole ring to pyrrolo-benzodiazepine (1992JHC1005) and pyrrolo-benzothiadiazepine (1992SC1433) rings has been reported starting from 0X0 203 and included formation of the phosphonic imidate with formyl hydrazine (Scheme 42, Section 3.1.1.2). 

Oxadiazol 10 g (8,62 mmol) l-(Ethoxy-methylcn)-2-formyl-hydrazin werden unter Normaldruck erhitzt, wobei nach einem Ethanol-Vorlauf das 1,3,4-Oxadiazol iiberdestilliert. Dieses wird durch nochmaligc Destination iiber eine Vigreux-Kolonne gereinigt Ausbeute 3,0 g (50%) Sdp. 150° n 1,4300. 

A detailed description of the prepn of 4 amino-y-sym-triazole by heating formylhydra-zine at 150—200° is given in Ref 3 Formyl-hydrazine was obtained by heating a mixt of ethylformate and hydrazine hydrate in ale fat 18 hours. In Refs 4 5 is described a method of prepn of this a min otri azole starting with the treatment of hydrazine hydrate and carbon monoxide at high pressure and elevated temps... 

Benzo-1,2,4-triazin kann durch intramolekulare Cyclisierung von 2-(2-Nitro-phenyl)-1-formyl-hydrazin mit Natriumsulfid erhalten werden (s.ds. Handb. Bd. X/2, S. 304). 

Gyromitrin is a volatile derivative of hydrazine (see Figure 4) with the chemical formula of acetaldehyde methyl formylhydrazone and is readily converted to N-methyl-N-formyl hydrazine and N-methylhydrazine. It is primarily a liver toxin although the red blood cells and central nervous system are also involved. The... 

Formyl hydrazine (formic acid hydrazide) [624-84-0] M 60.1, m 54 , 54-57 , pKest 2.5. RecrystalUse it from EtOH and dry it in vacuo. Store below 10 it may disproportionate on storage to 1,2-drforrrtyl hydrazine and hydrazine. It forms a blue [Cu(CH4N20)]S04 salt with CUSO4. Beilstein 2 H 93,2 HI 127,2IV 85.]... 

Silylation of Formyl Hydrazone. Addition of the ethyl Grignard reagent to formyl hydrazone 46 via in situ silylation using BSA provided the corresponding formyl hydrazine with excellent diastereoselectivity in favor of the desired 5, 5 -diastereoisomer 47 (eq 44). ... 

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