Ammonium formate, hydrolysis

The optically active 1,4-cyclohexenediol monoacetate 525, prepared by hydrolysis of the me.so-diacetate with lipase, was converted into the optically pure cyclohexenone 526 by an elimination reaction in the presence of ammonium formate. Optically active carvone (527) was prepared from 526[343],... 

The Leuckart-Wallach reaction is the oldest method of reductive amination of carbonyl compounds. It makes use of formamide, formic acid or ammonium formate at high temperature. The final product is a formamide derivative, which can be converted to an amine by reduction or hydrolysis. The method has been applied to the preparation of 1,2-diamines with a norbornane framework, which are interesting rigid analogues of 1,2-diaminocyclohexanes. As a matter of fact, starting from N-acetyl-2-oxo-l-norbornylamine 222, the diamide 223 was obtained with excellent diastereoselectivity and then converted to the M-methyl-N -ethyl derivative 224 by reduction with borane [ 104] (Scheme 34). On the other hand, when the reac-... 

Many water-insoluble ketones, aliphatic, aryl aliphatic, and heterocyclic, respond favorably to treatment with ammonium formate or formamide to form with subsequent hydrolysis the primary amines. A typical procedure for the synthesis of a-phenylethylamine (66%) from acetophenone and ammonium formate has been applied to many other ketones (65-84%). Nuclear alkoxyl, halo, and nitro groups are not disturbed. The reaction with formamide as the reducing agent is catalyzed by ammonium formate, ammonium sulfate, or magnesium chloride. ... 

The hydrolysis of ammonium formate will be considered next. A solution of this salt will have an acid reaction since formic acid is a stronger acid than ammonia is a base. The dissociation constants are ... 

Petrini and co-workers used the bis(methoxymethyl)-protected nitrone 150, also derived frern L-tartrate, as an electrophile rather tfaiui as a 1,3-dipole (Scheme 21, top line) (89). In their key step, reaction with 4-ben loxybutylmagnesium bromide gave the cyclic hydroxylamine 151 in 82% yield (de 90%). Transfer hydrogenation with ammonium formate and a palladium catalyst cleaved both the hydroxylamine and the benzyl ether, affording the aminoalcohol 152. Cyclization via the corresponding primary chloride created the protected indolizidine 153, acidic hydrolysis of t ch completed this short synthesis of ( + )-132 in 16%... 

The parent 1,3,5-triazine is easily hydrolyzed in aqueous media. Thus, when 1,3,5-triazine is dissolved in cold water, pure ammonium formate is obtained in 94% yield 1 hydrolysis with cold aqueous alkali results in formation of formimidamide.2... 

The separation of sugar nucleotides from such extracts is by no means easy, especially since it has to be as rapid as possible in order to minimise hydrolysis losses. Adsorption onto a basic ion-exchange resin is commonly used as a first step. It can be performed as a column method, as a batch extraction or, on a micro-scale, on sheets of ion-exchange materials. Considerable losses may occur on the resin. Elution can be by one of several different procedures, of which washing with ammonium chloride is one of the more useful (Recondo, Dankert and Passeron, 1965), since the salt is somewhat volatile. Other systems used include displacement by the chlorides of calcium, sodium or lithium, or by ammonium formate buffer. Hydrolysis losses are particularly likely with the last. 

Optically active amines can also be generated directly from ketones with ammonium formate in a catalytic version of the Leuckart-Wallach reaction (Equation 15.89). The imine is derived from the ammonia generated from the ammonium formate, and the reducing equivalent is derived from the formate. In the presence of the [Ru(BINAP)Cl2]2 catalyst, the amine and formamide were formed as the major products. After hydrolysis of the formamide, the amine was isolated in high yield and ee. 

Similar to methanamide, ammonium formate decomposition proceeded in a wide temperature window. As ammonium formate does in fact not need to be hydrolyzed, formic acid decomposition is the limiting reaction for the quantitative conversion of the precursor solution to NH3 and CO2. However, if mixtures with urea, such as Denoxium are being used, the temperature needs to be sufficient to enable urea hydrolysis. Therefore, an in-pipe or side stream system equipped with an Au/Ti02 hydrolysis catalyst could in fact be used to provide NH3 from either AdBlue , Denoxium or Admide(R). This would enable the flexibility to ensure efficient NH3 production, and, consequently, NO reduction, even in cold climates or during long refill intervals. Guanidinium formate solution would also be an optional NH3 precursor solution for a side stream reactor if the reactor could be electrically heated at temperatures below 250 °C, but would not qualify for direct injection into the main exhaust pipe. 

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