Dale D. Dixon

Synthesis of N-tert.-butyl aromatic amines via heterogeneous acid catalysis

Abstract Heterogeneous acid catalysts have been employed in the synthesis of N -tert.-butyl aromatic amines from isobutene and arylamines. This technique provides a highly selective route to N -tert.-butylanilines, compounds not readily available by conventional alkylating methods. The selectivity of N -alkylation is highest when heterogeneous acid catalysts of moderate Bronsted acidity are used at temperatures of 100–180°C. The selectivity between N and ring alkylation is also highly dependent upon the type and location of substituents on the aromatic ring.

ortho-selective Alkene alkylation of Arylamines via acid catalysis

Abstract Acid catalysis provides a general synthesis methodology for introducing alkene alkylating agents selectively to the ortho positions of arylamines. In contrast to aluminum alkyl catalyzed olefin ortho-alkylation of arylamines, this reaction proceeds through a positively charged intermediate and is especially useful for placing branched alkyl groups ortho to amino functionality. Lewis and Bronsted acids both provide high ortho-selectivity with solid acids providing the highest selectivity and ease of use. Reaction rates increase with increasing acid strength. The ortho-selectivity of this technique is enhanced by operating at temperatures and residence times which minimize Nalkylates and para-alkylates. Reaction selectivity is also influenced by substituents on the arylamine and alkene reactants.

Synthesis of ortho-alkyl arylamines from N-alkyl arylamines via acid catalysis

Abstract N -isopropylaniline is converted to ortho -isopropylaniline in high selectivity by passing the N -alkylate over a heterogeneous acid catalyst under a positive pressure of propylene. Useful solid catalysts include H-Y zeolite, silica/aluminas and γ-alumina. The selectivity of this procedure contrasts with the para -selectivity of the classical Hofmann-Martius reaction.

Allylamines from allyl alcohol

A process for preparing allylic amines which comprises contacting an allylic alcohol with ammonia or a primary or secondary amine in the presence of an effective amount of a phosphorus containing substance at a temperature sufficient to effect a reaction between the allylic alcohol and the ammonia or organic amine to produce an allylic amine.

Selective catalytic syntheses of mixed alkyl amines

Abstract Selective synthesis of mixed alkyl amines was achieved by amine-alcohol condensation over strontium hydrogen phospate (SrHPO4). Condensation occurred without product equilibration over the catalyst, and consequently amine products could be prepared selectively by appropriate control of the reaction conditions. New synthetic routes to several poly-functional mixed amines were developed from readily available starting materials. Tertiary methylamines reacted with alcohols when a cyclic product could be formed. Initial results favor a mechanism in which a phosphate ester is formed on the catalyst surface and then undergoes a nucleophilic displacement reaction with the reactant amine.

Adhesion of fluorinated polyester cord to rubber

Abstract Surface fluorination of polyester cord increases adhesion of the cord to rubber fivefold. Fluorinated polyester fabric retains the high tensile strength necessary for efficient reinforcement of rubber tires.

Nitriles from olefins and ammonia via one-carbon homologation

Abstract The reaction of simple olefins and ammonia was studied over various heterogeneous transition metal catalysts. Group eight transition metals of Fe, Co and Ni provide nitriles one carbon extended from the starting olefins. The reaction of ethylene/ammonia and propylene/ammonia over a nickel catalyst was studied to develop an understanding of mechanism and of synthetic utility. Experimental data provides evidence for a nitrile-forming reaction mechanism involving an apparent one-carbon homologation via formation of a cyanide synthon. Accompanying this reaction is the reduction of olefin by generated hydrogen. Experimental evidence indicates that the nitrile-forming process does not require the simultaneous reduction of olefin.