Hydrolysis scheme

Methylamino)-4-methylselenazole was obtained by methylation of the potassium salt of 2-acetamido-4-methylselenazole with methyl iodide, followed by hydrolysis (Scheme 13) (26). 

Active Raney nickel induces desulfurization of many sulfur-containing heterocycles thiazoles are fairly labile toward this ring cleavage agent. The reaction occurs apparently by two competing mechanisms (481) in the first, favored by alkaline conditions, ring fission occurs before desul-, furization, whereas in the second, favored by the use of neutral catalyst, the initial desulfurization is followed by fission of a C-N bond and formation of carbonyl derivatives by hydrolysis (Scheme 95). 

By condensing a-haloketones with diacetylaminothioacetamide (13), Pyl et al. (533) obtained the corresponding 2-aminomethylthiazoles (15) after hydrolysis (Scheme 8). 

Hydroxyhexahydropyridazine was freed from the polymer (168) by hydrolysis (Scheme 91) (79TL1333). Cyclic azo compounds may also be employed for example with 1,2,4-triazole-3,5-dione, adducts (169,170) are formed first and these are subsequently transfor-... 

The y-nitrogen atom of a sulfonic acid azide is electrophilic and reacts in an electrophilic aromatic substitution with an activated benzene or naphthalene derivative, e.g., a phenoxide ion, forming a l-tosyl-3-aryltriazene (2.47). The 1,4-quinone diazide is obtained by hydrolysis (Scheme 2-30, Tedder and Webster, 1960). The general applicability of this reaction seems to be doubtful. With 1-naphthol the 1,2-naphthoquinone diazide was obtained, not the 1,4-isomer. 

The insertion of alkynes into a chromium-carbon double bond is not restricted to Fischer alkenylcarbene complexes. Numerous transformations of this kind have been performed with simple alkylcarbene complexes, from which unstable a,/J-unsaturated carbene complexes were formed in situ, and in turn underwent further reactions in several different ways. For example, reaction of the 1-me-thoxyethylidene complex 6a with the conjugated enyne-ketimines and -ketones 131 afforded pyrrole [92] and furan 134 derivatives [93], respectively. The alkyne-inserted intermediate 132 apparently undergoes 671-electrocyclization and reductive elimination to afford enol ether 133, which yields the cycloaddition product 134 via a subsequent hydrolysis (Scheme 28). This transformation also demonstrates that Fischer carbene complexes are highly selective in their reactivity toward alkynes in the presence of other multiple bonds (Table 6). 

Each enantiomer of 67 was earlier obtained by an a-chymotrypsin-catalysed resolution of its diethyl ester 68 or its cyclic analogue 69, followed by chemical hydrolysis (Scheme 6)7°... 

Acid-catalyzed hydrolysis of the latter followed by Jones oxidation furnished racemic peshawarine (43) (Scheme 12). Simanek et al. (59) transformed the same amino acetal 47, obtained in optically active form from the Emde degradation of rhoeadine methiodide (48), to ( )-43, also by hydrolysis and oxidation. However, the optical activity was lost during hydrolysis (Scheme 12). 

Recent kinetic studies on thiophosphoric aryl ester dianilides suggest analogous decomposition. The rate law observed is in agreement with a hydrolysis scheme in which both the monoanion and the dianion decompose to metaphosphorothioimi-date and its anion, respectively, which then react fast with water133). 

As mentioned earlier, the McDonald group was able to extend their epoxide-domino-cyclization strategy to 1,5,9-triepoxides [10]. Indeed, they were successful in converting precursor 1-143 into the tricyclic product 1-146 in 52 % yield after hydrolysis (Scheme 1.36) [41]. As a possible mechanism of this polyoxacyclization it can be assumed that, after activation of the terminal epoxide by BF3, a sequence of intramolecular nucleophilic substitutions by the other epoxide oxygens takes place, which is induced by a nucleophilic attack of the carbonate oxygen, as indicated in 1-144 to give 1-145. 

The 1,4-addition of RMgX or RLi to nitroalkenes produces nitronate intermediates, which are converted into nitroalkanes, nitrile oxides (oxime chlorides), or carboxylic acids, depending on the conditions of hydrolysis (Scheme 4.14).94... 

Other macrocyclic ligands 218 with a single pendant arm have been prepared from l,4,7-triazacyclio[5.2.1.04 10]-decane 40 <1996ICA(246)343> by reacting with appropriate alkyl bromide/alkenyl bromide followed by base hydrolysis (Scheme 34). 

Figure 4 Hydrolysis scheme for cisplatin-based anticancer agents. Where L = U = NH3 cisplatin is indicated. When L = NH3 and V = 2-picoline or cha the rates of aquation of the trans-chloride ligands are different.

In order to establish the bridgehead carbon configuration with certainty and to demonstrate the usefulness of the method, desilylation and deprotection of 438b in acidic conditions have been performed. Since they are accompanied by double bond migration and loss of chirality, a dimethylcuprate alkylation has been carried out before acid hydrolysis (Scheme 59) [112]. 

On the other hand, an electronically stabilized heavy ketone by the coordination of the nitrogen atom shows extremely low reactivity. It does not react with phosphanes, phosphates, ketones, epoxides, Mel, HC1, etc., although it undergoes methanolysis and hydrolysis (Scheme 21).168... 

The reaction of CO2 with 1,3-butadienes in the presence of Ni catalysts usually gave an isomeric mixture of carboxylic acids 89 and 90 after hydrolysis (Scheme 32).47,48 The oxa-7r-allylnickel complexes 87 and 88 might be the reaction intermediates, which could be formed through oxidative cyclization of Ni(0) with C02 and the dienes. When Me2Zn was used as a transmetallation agent to react with the oxa-7r-allylnickel intermediates under a C02 atmosphere, further carboxylation took place at the 7r-allylnickel unit. Thus, the 1,4-diesters 95 were obtained after acidic hydrolysis and treatment with diazomethane as shown in Scheme 32.47... 

Many alkyl carbenoids insert into saturated and unsaturated zirconacycles to afford zirco-nacydohexanes and -hexenes 126, which give the expected products 127 upon hydrolysis (Scheme 3.30) [48,50,68], There should be comparable scope for further elaboration of the six-membered zirconacycles, as has already been established for the five-membered analogues. Yields are generally high, one exception being the insertion of lithiated chloroace-tonitrile into saturated zirconacycles, where double insertion predominates [50],... 

The reaction of 6-methyl-3-phenyl-(l//)pyrazolo[5,l-c][l,2,4]triazole 56 with phenyldiazonium chloride affords 177-6-methyl-3-phenyl-7-phenylazo-pyrazolo[3,2-f][l,2,4]triazole 183 the structure of this compound was unequivocally assigned when compared with an identical product prepared in the reaction of compound 56 with acetic anhydride followed by azo coupling and basic hydrolysis (Scheme 5) <2003RRC533>. 

In spite of the anomalous ring-opening decomposition of nicotinotriazine compounds under conditions of alkaline hydrolysis (Scheme 7.34), the product of reaction of a bis(aminonicotinotriazine) dye with cellulose is the same as that from the analogous bis(aminochlorotriazine) dye in terms of hue, colour fastness and stability of the dye-fibre bond. If desired, these bis(aminonicotinotriazine) dyes can be applied satisfactorily at 80 °C and pH 11, as was evident for Cl Reactive Blue 187. They have slightly higher reactivity... 

In further work on nylon [145], this trifunctional reactant was applied simultaneously with various nucleophilic dyes of the aminoalkyl type (Scheme 7.71). As in the case of the Basazol system on cellulose (Scheme 7.60), the intended formation of covalent dye-fibre linkages has to compete with side reactions, such as partial hydrolysis (Scheme 7.70), di- or trimerisation that may lead to less than optimum fastness, or substrate crosslinking that may adversely influence desirable fibre characteristics. 

Acceptor-substituted allenes can be prepared from the corresponding propargyl precursors by prototropic isomerization (see Section 7.2.2). Conversely, such allenes can also be used to synthesize propargyl compounds. For example, treatment of the sulfoxides 417 with 1 equivalent of a lithiation reagent leads to the intermediates 418, which furnish propargyl sulfoxides 419 by hydrolysis (Scheme 7.55) [101]. If the electrophiles used are not protons but primary alkyl halides or carbonyl compounds, the products 420 or 421, respectively, are formed by C,C linkage. 

Friesen et al. reported that 2,3-allenols 340 can be converted to the corresponding carbamate derivatives 343, in which the terminal C=C bond of the allene moiety can be iodinated to afford diiodides 344. Under the catalysis by an Ag+ salt, compounds 344 react to give iminocarbonates 345 and oxazolindinones 346, leading to diols 347 and amino alcohols 348, respectively, after hydrolysis (Scheme 10.138) [160-162], A similar reaction was observed with trichloroacetimidates 350 [163],... 

The reaction is believed to begin with the metalation of the substrate via aromatic electrophilic substitution (SEAr) followed by CO insertion and nucleophilic displacement by water or another protic nucleophile such as tri-fluoroacetic acid (TFFA) to give, respectively, the aromatic carboxylic acid or its mixed anhydride derivative, from which the acid is freed by hydrolysis (Scheme 24). 

Among the electrophilic reaction parmers of the enamine nucleophiles, aldehydes and ketones are arguably the most important class. The addidon of an enamine to a carbonyl compound affords aldol products after hydrolysis (Scheme 13). In this process, one or two new stereogenic centers and one carbon-carbon bond are formed. 

The application of the naphthalene-catalyzed (10%) lithiation to benzylic ureas 69 under Barbier-type conditions in THF at —78 or — 30°C led to the formation of the expected products 35, after hydrolysis (Scheme 28) °. 

The naphthalene-catalyzed (3%) lithiation of carbamoyl or thiocarbamoyl chlorides 91 in the presence of carbonyl componnds or imines as electrophiles in THF at temperatnres ranging between —78 to 20 °C led to the expected fnnctionalized amides or thioamides 92 after hydrolysis (Scheme 39) . ... 

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