T!-butylamine

It is interesting to note that the hydrolysis of certain Schiff bases in weakly acidic solutions shows a similar mechanism (22). N-protonated substituted benzylidene-t-butylamines react with hydroxide ions to amino alcohols in the rate-determining step, and at lower pH the rate is almost entirely determined by attack of water on the protonated Schiff bases as a consequence of the rapidly decreasing concentration of hydroxide ions. 

The r-butyl group is introduced as a t-butylamine and is cleaved with strong acid (70-97% yield). ... 

Various bioisosteric replacements for a phenolic hydroxyl have been explored. One such, a lactam NH, is incorporated into the design of the 3-adrenergic blocker, carteolol O)- The fundamental synthon is carbostyril derivative K This is reacted in the usual manner with epichlorohydrin to give which is in turn reacted with t-butylamine to complete the synthesis of carteolol (3 ), a drug that appears to have relatively reduced nonspecific myocardial depressant action. Carrying this de-... 

A mixture of 3 gof 8-(2-hydroxy-3-chloropropoxy)-5-methyl coumarin,4.3 g of t-butylamine and 60 ml of ethenol Is heated et 100°C in a sealed tube for 15 hours. The reaction mixture is concentrated under reduced pressure to dryness. The residue Is recrystallized from a mixture of ethanoi and ether to give 2.1 g of the desired product melting at 226° to 228 C (with decomposition). 

A mixture of 16.3 g of (2-chloro-5-methylphenyl)glycidic ether (from epichlorohydrin and 2-chloro-5-methylphenol) and 6.2 g of t-butylamine in 50 ml of ethanol is heated at reflux for 6 hours. The solvent is removed, the residue Is washed with water and then extracted with benzene. The dried extract is evaporated to give 1-t-butylamino-3-(2-chloro-5-methylphen-oxy)-2-propanol. Treatment of the free base in benzene solution with dry hydrogen chloride yields the hydrochloride salt. 

To a stirred solution of 5.7 g (0.02 m) of 4-benzyloxy-2-ureidoacetophenone in 100 ml of chloroform is added 3.2 g (0.02 m) of bromine. The mixture is stirred at room temperature for about 45 minutes and the solution is concentrated in vacuo at 25°-30°C. The amorphous residue (hydrobromide selt of 4-benzyloxy-a-bromo-3-ureidoacetophenone) is dissolved in 80 ml of acetonitrile and 98 g (0.06 m) of N-benzyl-N-t-butylamine is added. The mixture is stirred and refluxed for 1.5 hours, then it is cooled toOt in an ice bath. Crystalline N-benzyl-N-t-butylamine hydrobromide is filtered. The filtrate is acidified with ethereal hydrogen chloride. The semicrystalline product is filtered after diluting the mixture with a large excess of ether. Trituration of the product with 60 ml of cold ethanol gives 4-banzyloxy-Of-( N-benzyl-N-t-butylamino)-3-ureidoacetophenone hydrochloride, MP 200°-221°C (decomposition). 

To a solution of 32 g of benzyl-t-butylamine in 300 ml of absolute ethanol at reflux temperature was added 32 g of 3,5-dibenzyloxy-C0bromoacetophenone in 10 ml of dry benzene. The mixture was refluxed for 20 hours and then evaporated. When absolute ether was added to the residue, benzyl-t-butylamine hydrobromide was precipitated. The precipitated compound was filtered off and to the filtrate was added an excess of 2N sulfuric acid. This caused precipitation of the hydrogen sulfate of 3.5-dibenzyloxy-60-(benzyI-t-butylamino)-acetophenone which was recrystallized from acetone/ether. If the product is crystallized from different organic solvents, the melting point will vary with the type and amou nt of solvent of crystallization, but the product can be used directly for hydrogenation. 

McDowell and Stirling194 studied electronic effects upon the reactivity of aryl vinyl sulfones towards amines. Rate constants for t-butylamine addition in ethanol at 25 °C were well correlated by the Hammett equation, with p = 1.59. Comparison of this with p values for H-D exchange mentioned above191 suggested considerable carbanionic character in the transition state, perhaps in a concerted mechanism. Rates of addition of amines to alkenyl, allenyl and alkynyl p-tolyl sulfones have also been measured195. 

Oxidative carbonylation generates a number of important compounds and materials such as ureas, carbamates, 2-oxazolidinones, and aromatic polycarbonates. The [CuX(IPr)] complexes 38-X (X = Cl, Br, I) were tested as catalysts for the oxidative carbonylation of amino alcohols by Xia and co-workers [43]. Complex 38-1 is the first catalyst to selectively prepare ureas, carbamates, and 2-oxazolidinones without any additives. The important findings were the identity of the counterion and that the presence of the NHC ligand influenced the conversions. 2-Oxazohdinones were formed from primary amino alcohols in 86-96% yield. Complex 38-1 also catalysed the oxidative carbonylation of primary amines to ureas and carbamates. n-Propylamine, n-butylamine, and t-butylamine were transformed into the... 

The last reaction perhaps involves an intermediate such as 33a which expells a proton and dimethyl sulfide. Formation of the Schiff s base with t-butylamine, reduction with sodium borohydride and hydrogenolysis of the benzyl ether produces sulfonterol (28). Despite the fact that the methylene hydrogen of sulfonterol must be much less acidic than of the corresponding urea proton on carbuterol or the sulfonamide proton on soterenol, good bioactivity is retained. 

Reaction of m-chlorobenzonitrile with ethyl Grignard reagent produces ethylarylketone 191. Bromination in methylene chloride followed by displacement of the a-bromoketone moiety with t-butylamine... 

The structure of this adduct is displayed in Fig. 17 177>. As should be expected (see Chapters 3 and 4) the nitrogen atom of t-butylamine is coordinated with the tin atom at nearly right angles with respect to the four-membered ring. 

Tertiary amines have been oxidized to the corresponding nitro compounds with KMn04. For example, 2-methyl-2-nitropropane is prepared in 84% yield from t-butylamine with KMn04 (Eq. 2.55).117 In a similar fashion, 1-aminoadamantane has been oxidized to 1-nitroadamantane in 85% yield with KMn04 (see Eq. 2.63).118... 

The last few years have seen numerous applications of spin trapping to biological systems, and in these the trapping of hydroxyl radicals has assumed some importance. This work has been confined almost exclusively to nitrone scavengers 4 the fact that the hydroxyl adduct [6] of DMPO is much more persistent than that [7] of the commonly used nitrone, benzylidene-t-butylamine-N-oxide ( phenyl t-butyl nitrone ,3 or PBN) [3], may be due to a fragmentation reaction, with subsequent oxidation of the cr-hydroxybenzyl radical, as shown. 

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