Amines to alcohols

Fig. 1. Amine distribution general behavior. Converted alcohol to amine product as the ammonia to alcohol ratio increases.

Fig. 10.2. Reaction protocol for the transformation of alcohols to amines via mesylation and amine substitution, as shown in PGVL Flub.

Amination. Very few reactions of general scope exist for the direct conversion of alcohols to amines. Among one of the oldest is the Bucherer reaction which is used to convert naphthols (40) and phenols (41) to their amine derivative by reaction with aqueous sodium bisulphite and ammonia (Reaction XXV). 

The Ritter reaction (42,42A) is a general method for converting alcohols to amines by reaction with a nitrile and a strong acid (Reaction XXVI). In this reaction only tertiary,... 

VIII, Fe Fc O Water gds shift Dehydrogenation of cyclohcxanes Conversion of alcohols to amines... 

Numerous examples of the successful use of metal catalysts for the transformation of alcohols to amines can be found elsewhere [1,3,4,11,13-15], although most of the original information is available in the patent literature. 

Foraminate catalysts appear to have a number of desirable characteristics which make for economic and efficient operations in converting alcohols to amines. The advantages gained by using them are (1) high conversions and yields are obtainable, (2) relatively high space velocities can be employed, (3) the ratio of product amines can be varied over a wide range, and (4) the cost of the catalyst is comparatively low. 

The TOP sequence can also be carried out in the presence of a heterogeneous reductant to effect an oxidation-imination-reduc-tion process leading from activated alcohols to amines (eqs 86 and 87). Polymer-supported cyanoborohydride (PSCBH) or sodium borohydride can be used as the reductant. The use of an oxidant and reductant in the same one-pot procedure is noteworthy. 

Kearby K, Kistler S S, Swann S Jr. (1938) Aerogel catalyst conversion of alcohols to amines. Ind Eng Chem... 

In hydroxyl-containing compounds with higher acidity, a transfer of proton from alcohol to amine is possible. 

In general, Hofmann alkylations are carried out with appropriate alkyl halides or dialkyl sulfates. These reagents may have to be prepared from the related alcohols, often by rather troublesome methods. A more convenient conversion of alcohols to amines involves the alkylation of amines with toluenesulfonate esters of alcohols. These tosylates are generally prepared quite easily and may then be used as alkylating agents [1-14]. If the alcohol which is to be converted to an amine has the proper structural features, the Ritter reaction (see below) is another useful approach to the preparation of primary amines (by hydrolysis of the amide formed in the reaction) and of some secondary amines (by reduction of the amides). 

Nitriles may be reacted with certain types of alcohols or olefins in strongly acidic media to afford an alkylated amide. Since amides may be hydrolyzed to yield a free amine (as, for example, in Ferris et al. [22]), a facile method for converting olefins and alcohols to amines is... 

From what you know about wetting, contact angles, and spread monolayers, explain why a Langmuir-Blodgett layer will deposit as a F type if there are nonpolar fatty acids, yet will switch to a Z-type deposition if bipolar alcohols or amines are added (see Refs. 175, 176). What defines the critical contact angle for the deposition change ... 

Although the acetylation of alcohols and amines by acetic anhydride is almost invariably carried out under anhydrous conditions owing to the ready hydrolysis of the anhydride, it has been shown by Chattaway (1931) that phenols, when dissolved in aqueous sodium hydroxide solution and shaken with acetic anhydride, undergo rapid and almost quantitative acetylation if ice is present to keep the temperature low throughout the reaction. The success of this method is due primarily to the acidic nature of the phenols, which enables them to form soluble sodium derivatives, capable of reacting with the acetic... 

The industrial process for preparing the reagent usually permits a little hydrolysis to occur, and the product may contain a little free calcium hydroxide or basic chloride. It cannot therefore be employed for drying acids or acidic liquids. Calcium chloride combines with alcohols, phenols, amines, amino-acids, amides, ketones, and some aldehydes and esters, and thus cannot be used with these classes of compounds. 

The following are examples of the above procedure. A mixture of diethylamine and re-butyl alcohol may be separated by adding sufficient dilute sulphuric acid to neutralise the base steam distillation will remove the alcohol. The amine can be recovered by adding sodium hydroxide to the residue and repeating the distillation. A mixture of diethyl ketone and acetic acid may be treated with sufficient dilute sodium hydroxide solution to transform the acid into sodium acetate and distilling the aqueous mixture. The ketone will pass over in the steam and the non-volatile, stable salt will remain in the flask. Acidification with dilute sulphuric acid hberates acetic acid, which can be isolated by steam distillation or by extraction. 

In these cases the acyl azides formed have been used to prepare amines via Curtius rearrangement. The acyl chloride or azide intermediates can. however, also be reacted with amines or alcohols to form amides or esters. 

The rather unreactive chlorine of vinyl chloride can be displaced with nucleophiles by the catalytic action of PdCb. The conversion of vinyl chloride to vinyl acetate (797) has been studied extensively from an industrial standpoint[665 671]. DMF is a good solvent. 1,2-Diacetoxyethylene (798) is obtained from dichloroethylene[672]. The exchange reaction suffers steric hindrance. The alkenyl chloride 799 is displaced with an acetoxy group whereas 800 and 801 cannot be displaccd[673,674]. Similarly, exchange reactions of vinyl chloride with alcohols and amines have been carried out[668]. 

In addition to the preparation of l-alkenes, the hydrogenolysis of allylic compounds with formate is used for the protection and deprotection of carboxylic acids, alcohols, and amines as allyl derivatives (see Section 2.9). 

Addition of nucleophiles to both activated and unactivated alkenes is catalyzed by Pd(II). Addition of alcohols or AcOH to alkenes bearing EWGs is catalyzed by PdCl2(PhCN)2 to give the corresponding ethers and esters. The addition of an alcohol to the cyclic acetal of acrolein 82 to give the ether 83 is also possible with the same catalyst[64]. Amines add to the vinylic ether 84 to give 85, but not to simple alkenes[65]. 

A variation of the classical reductive amination procedure uses sodium cyanoboro hydride (NaBH3CN) instead of hydrogen as the reducing agent and is better suited to amine syntheses m which only a few grams of material are needed All that is required IS to add sodium cyanoborohydride to an alcohol solution of the carbonyl compound and an amine... 

At the other end of the reaction, deviations from idealized rate laws are attributed to secondary reactions such as degradations of acids, alcohols, and amines through decarboxylation, dehydration, and deamination, respectively. The step-growth polymers which have been most widely studied are simple... 

Many of these reactions are reversible, and for the stronger nucleophiles they usually proceed the fastest. Typical examples are the addition of ammonia, amines, phosphines, and bisulfite. Alkaline conditions permit the addition of mercaptans, sulfides, ketones, nitroalkanes, and alcohols to acrylamide. Good examples of alcohol reactions are those involving polymeric alcohols such as poly(vinyl alcohol), cellulose, and starch. The alkaline conditions employed with these reactions result in partial hydrolysis of the amide, yielding mixed carbamojdethyl and carboxyethyl products. 

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