Iodide hydrolysis

Yet a further increase in potency is observed when the para-isobutyl group is replaced by a benzene ring. One published synthesis for that compound is quite analogous to the malonate route to the parent drug. The acetyl biphenyl (50-1) is thus converted to the corresponding arylacetic acid by reaction with sulfur and morpholine, followed by hydrolysis of the first-obtained thiomorpholide. This is then esterified and converted to malonate anion (50-2) with sodium ethoxide and ethyl formate. The anion is quenched with methyl iodide hydrolysis of the esters followed by decarboxylation yields the NSAID flubiprofen (50-3) [51]. 

Several types of copper-loaded polymer have been prepared. Hydrocarbon spacers were introduced between polystyrene and copper (23). Six synthetically useful copper-promoted reactions including a Diels-Alder reaction, an epoxide ring-opening, and an aryl iodide hydrolysis were examined by using the polymeric catalyst [34]. Use of the copper-loaded polymers often either improved the yield or reduced the reaction time compared with those for conventional copper salts. 

Examples of the reaction of carbon disulfide with lithium dimethylhydrazone anions derived from ketones were reported by Oliva and Delgado. In these reactions, the initial lithium dimethylhydrazono-alkanedithioate (56) was not isolated but was instead alkylated to yield an alkyl dithiolate (57 equation 26). High yields of products were obtained using various alkyl iodides. Hydrolysis of the product hydra-zone was not described. 

ANSWER (b) Ethyl 3-oxopentanoate can be alkylated twice, first Avith methyl iodide and then Avith ethyl iodide. Hydrolysis and decarboxylation give the desired product. 

The hydrolysis of phosphorus tribromide or triiodide is used in the preparation of hydrogen bromide and hydrogen iodide respectively ... 

In view of the high cost of methyl iodide in the above preparation of anisole, and the fact that, unless absolute methanol is used, the ready hydrolysis of the methyl iodide may cause a low yield of the ether, the preparation of anisole may be ad antageously replaced by that of phenetole. I he reaction is not of course a methylation, but is nevertheless of the same type as that used in the preparation of anisole. 

Lithium l,3-dithian-2-ides (p. 6, 8) may be alkylated with alkyl bromides or iodides. Steric hindrance is usually of little importance and the resulting ketone can be easily liberated by hydrolysis (D. Seebach, 1969). 

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). 

The structure of compound A was established in part by converting it to known compounds Treat ment of A with excess methyl iodide in the presence of silver oxide followed by hydrolysis with dilute hydrochlonc acid gave a tnmethyl ether of D galactose Companng this trimethyl ether with known trimethyl ethers of D galactose allowed the structure of compound A to be deduced... 

Phlonzm is obtained from the root bark of apple pear cherry and plum trees It has the molecular formula C21H24O10 and yields a compound A and D glucose on hydrolysis in the pres ence of emulsin When phlorizin is treated with excess methyl iodide in the presence of potassium carbonate and then subjected to acid catalyzed hydrolysis a compound B is obtained Deduce the structure of phlorizin from this information... 

Barbier reported (1) in 1899 that a mixture of methyl iodide, a methyl ketone, and magnesium metal in diethyl ether produced a tertiary alcohol. Detailed studies by his student Victor Grignard are documented in his now classical doctoral thesis, presented in 1901. Grignard estabUshed (2) that the reaction observed by Barbier could be separated into three distinct steps Grignard reagent formation, Grignard reaction, and hydrolysis. 

The equihbrium constant of this reaction is 5.4 x 10 at 25°C, ie, iodine hydrolyzes to a much smaller extent than do the other halogens (49). The species concentrations are highly pH dependent at pH = 5, about 99% is present as elemental at pH = 7, the and HIO species are present in almost equal concentrations and at pH = 8, only 12% is present as and 88% as HIO. The dissociation constant for HIO is ca 2.3 x 10 and the pH has tittle effect on the lO ion formation. At higher pH values, the HIO converts to iodate ion. This latter species has been shown to possess no disinfection activity. An aqueous solution containing iodate, iodide, and a free iodine or triodide ion has a pH of about 7. A thorough discussion of the kinetics of iodine hydrolysis is available (49). 

Phosphine generated by the above procedures is usually contaminated to varying degrees with diphosphine, which renders it spontaneously flammable. Pure phosphine can be produced by hydrolysis of phosphonium iodide [12125-09-6] PH I, which can be made by the action of water on a mixture of phosphoms and diphosphoms tetraiodide [13455-00-0] (71). 

Only the small amounts of T and T that are free in the circulation can be metabolized. The main route is deiodination of T to T and i-T, and from these to other inactive thyronines (21). Most of the Hberated iodide is reabsorbed in the kidney. Another route is the formation of glucuronide and sulfate conjugates at the 4 -OH in the Hver. These are then secreted in the bile and excreted in the feces as free phenols after hydrolysis in the lower gut. 

Living VE polymerization is usually terminated by addition of alcohols, phenols, amines, etc, that can replace iodide. Without some base present to neutralize generated HI, an aldehyde end group forms if moisture is present because of acid-catalyzed hydrolysis (41). 

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