Hydrolysis general procedures

In agreement with the results of Cattelain, further methylation of the 3-methylmercapto derivative (96) results practically exclusively in 2-methyl-3-methylmercapto-5-oxo-2,5-dihydro-l,2,4-triazine (97). Further methylation of 5-methylmercapto derivative (90) yields 2-methyl-5-methylmercapto-3-oxo-2,3-dihydro-l,2,4-triazine (100). Their structure was confirmed by acid hydrolysis leading to 2-methyl-3,5-dioxo derivatives (62), As was already mentioned, this reaction is a suitable general procedure for preparing the 1-alkyl derivatives of 6-azauracil. ... 

The procedure described is a modification of the general procedure of Angyal2 for the preparation of aldehydes from benzylamines by the Sommelet reaction. Isophthalaldehyde has been prepared from w-xylene by preparation of the tetrachloro derivative and hydrolysis,3 from isophthaloyl chloride by the Rosenmund reaction,4 from a,a -dibromo-m-xylene by the Sommelet reaction,5 and from isophthaloyl chloride by reduction with lithium tri-Cbutoxyaluminumhydride.6... 

General Procedure for the Formation of Benzene Derivatives (see Eq. 2.48) At 0°C, dimethyl acetylenedicarboxylate (284 mg, 2 mmol) and CuCl (198 mg, 2 mmol) were added to a solution of zirconacyclopentadiene (1 mmol) in THF, prepared in situ according to the known procedure [12]. The reaction mixture was then allowed to warm to room temperature and was stirred for 1 h. After hydrolysis with 3 n HC1, the mixture was extracted with diethyl ether. The combined extracts were washed sequentially with water, aq. NaHC03 solution, brine, and water, and then dried over MgS04. Concentration in vacuo followed by flash-chromatography eluting with a mixture of hexane and diethyl ether (10 %) afforded benzene derivatives. 

The preparation of protected derivatives of D-allo- and L-fl//o-threonine by enzymatic hydrolysis of 5(47/)-oxazolones using hog kidney acylase has also been described. This methodology has been extended to a wide variety of amino acids and, at present, constitutes a general procedure to prepare non-quaternary... 

Table 1 General Procedures for Acid Hydrolysis of Peptides and Proteins1 -71...

AIkylalkanoic Acids 4 General Procedure for the Hydrolysis of l-(2-Alkyl-l-oxoalkyl)-z,a-diincthyl-2-pyrrolidinemethanols 21 ... 

Alkylated Carbonyl Compounds by Cleavage of Alkylated SAMP/RAMP-Hydrazoncs General Procedure for Acidic Hydrolysis of Methoiodides ( Salt Method )3 ... 

Alkylglycine Methyl Esters 2 General Procedure for the Hydrolysis of rra/is-2,5-Disubstituted 3,6-Dialkoxy-2,5-dihydropyrazines l7,8 ... 

This is a general method of preparing enamines from a secondary aliphatic amine and cyclohexanone or cyclopentanone. Acylation of such enamines is the first step in a general procedure for increasing the chain length of a carboxylic acid by 5 or 6 carbon atoms and of a dicarboxylic acid by 10 or 12 carbon atoms.6 Alkylation of enamines of cyclohexanones by alkyl halides 7 or electrophilic olefins,8 followed by hydrolysis, is a good route to a-monoalkyl cyclohexanones. 

The hydrolysis of a hindered amide can often be difficult. V. Bavetsias of the Cancer Research UK Laboratory in Surrey reports (Tetrahedron Lett. 2004, 45, 5643) that mcthanolic Fe(NO,),9H,0 will smoothly hydrolyze pivalamides such as 1 at room temperature. If this proves to be a general procedure for hindered amides, it will be a welcome addition to the armamentarium of organic synthesis. 

I-Aininoalkylphosphinic Adds 33 from Hydrolysis of 39 General Procedure 61 ... 

Hydrolysis of Benzylideneamines 15 to a-(PerflUoroalkyl)amine Hydrochlorides 16 General Procedure 14... 

The most convenient procedure for deprotection of these esters is aqueous alkaline hydrolysis a general procedure for this operation, including possible variations in technique which might be required in certain instances, is discussed in Section 9.6.17, p. 1266. 

Substituted aromatic carboxylic acid amides of the type ArCONHR and Ar-CONR2 are only slowly attacked by aqueous alkali and are characterised by hydrolysis under acidic conditions 70 per cent sulphuric acid (prepared by carefully adding 4 parts of acid to 3 parts of water) is the preferred reagent. Use the general procedure which has been outlined on p. 1229 characterise the acidic and basic components. 

Although the acetoacetic ester synthesis and the malonic ester synthesis are used to prepare ketones and carboxylic acids, the same alkylation, without the hydrolysis and decarboxylation steps, can be employed to prepare substituted /3-ketoesters and /3-diesters. In fact, any compound with two anion stabilizing groups on the same carbon can be deprotonated and then alkylated by the same general procedure. Several examples are shown in the following equations. The first example shows the alkylation of a /3-ketoester. Close examination shows the similarity of the starting material to ethyl acetoacetate. Although sodium hydride is used as a base in this example, sodium ethoxide could also be employed. 

PcrfIuoroHlkyl)ethanols Hydrolysis of Iodides General Procedure ... 

General procedure for the Suzuki reaction using triflates [121] The following procedure employs K2CO3, which may cause hydrolysis of labile esters within the coupling components. 

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