Aminocyclohexanes—

In the multistep production of IPDI, isophorone is first converted to 3-cyano-3,5,5-trknethylcyclohexanone (231—235), then hydrogenated and ammoniated to 3-aminomethyl-3,5,5-trknethyl-l-aminocyclohexane (1) (236,237), also known as isophorone diamine (IPDA). In the final step IPDA is phosgenated to yield IPDI (2) (238). Commercial production of IPDI began in the United States in 1992 with the startup of Olin s 7000 t/yr plant at Lake Charles, Louisiana (239), and the startup of Hbls integrated isophorone derivatives plant in Theodore, Alabama (240). Hbls has a worldwide capacity for IPDA of 40,000 t/yr. 

Some workers allow the amine and carbonyl compound to stand together some time before hydrogenation (i,59), but this procedure is not always necessary nor even desirable (ii). The delay technique is illustrated by reductive alkylation of ethyl-4-aminocyclohexane carboxylate (4) with benzaldehyde to S, a route that permitted an important improvement in the production of isoquinuclidine (8) (59). 

The effect of C ,C -disubstituted amino acids (aaAAs) on peptide secondary structure has been studied in recent years.2a d While longer side-chain C ,C -di-n-alkyl amino acids promote extended peptide conformation,23 alicyclic aaAAs, in which the Ca carbon forms a cyclic bridge with itself, such a 1-aminocyclopentane-l-carboxylic acid (Ac5c) and 1-aminocyclohexane-l-carboxylic acid (Ac6c), have helix-forming characteristics similar to those of 1 -aminoisobutyric acid (Aib).2ax... 

Scheme 4.27 Frechet dendrimeric trawi-l-arenesulfonylamino-2-isoborneolsulfonyl-aminocyclohexane ligand for alkylations and arylations of ketones.

Amino-/w-cresol, a213 Aminocyclododecane, c340 Aminocyclohexane, c375 Aminodecane, d23... 

In analogy with the deamination of aminocyclohexanes,17-21 it has been found that the deamination, with nitrous acid, of 2-amino-2-deoxyaldohexoses in which the amino group has an equatorial orientation leads to 2,5-anhydrohexoses, as exemplified by the deamination of 2-amino-2-deoxy-D-glucose (10) to 2,5-anhydro-D-mannose22-25 (11). 

Larsson, O. M., Johnston, G. A. R., and Schousboe, A. (1983) Differences in uptake kinetics of cis-3-aminocyclohexane carboxylic acid into neurons and astrocytes in primary cultures. 

Aminocyclohexane carboxylic acid Model Cyclic /1-chain Amorin et al. (2003)... 

Abstract Titration of weak bases in non-aqueous solvents can provide valuable information about these weak bases. Some primary amines 1-aminobutane, 1-aminopropane, 2-aminoheptane, aminocyclohexane, 3-amino-l-phenylbutane were titrated with hydrochloric acid in toluene solvent. All the primary amines gave very well-shaped potentiometric titration curves. The same titrations were done with hydrochloric acid in methanol solvent to show the effect of amphiprotic solvent in the titrations with hydrochloric acid. 

Ferber and Bruckner reduced />-aminobenzoic acid using Adams catalyst (Pt02) at atmospheric pressure, and Schneider and Dillman reduced p-aminobenzoic acid using 10% rhodium on carbon at 140 atm. and 70°. 3-Isoquinuclidone has been prepared, by the previously mentioned investigators, by heating the dry 4-aminocyclohexane carboxylic acid at elevated temperatures. 

The described method of preparation of 3-isoquinuclidone has the following advantages The isolation of the cis form of 4-aminocyclohexane carboxylic acid is not required in order to obtain a good yield the amount of 3-isoquinuclidone that can be prepared at a time is limited only by the size of available equipment the yield is excellent and the workup is easy and straightforward. 

Synonyms Aminocyclohexane aminohexahy-drobenzene CHA hexahydroaniline hexahy-drobenzenamine... 

A-Phthaloyl-ctx-l-aminocyclohexane-4-carboxylic acid tert-butyl perester (LUGCUL) 1.459 132.0 172... 

Table 3 Isomerization of ds-4-aminocyclohexane carboxylic acid on Raney nickel catalyst (Metalyst). Effect of the amount of catalyst, temperature and H2 pressure...

In addition cts-isomer of 4-aminocyclohexane carboxylic acid isolated by fractional ciystallization from the reaction mixture obtained in the Parr reactor was also reacted over Raney nickel catalyst to prepare the desired trans-isomer with high yield. It is... 

The H-NMR spectrum of pure as-4-aminocyclohexane carboxylic acid ethyl ester is seen in Figure 1. Signals with chemical shift at 5=1.2-1.3 ppm can be assigned to the protons of the methyl group, whereas the signals of the -CH2- protons... 

Figure 1 NMR spectrum of as-4-aminocyclohexane carboxylic acid ethyl ester.

The H-NMR spectrum of lra/3s-4-aminocyclohexane carboxylic acid ethyl ester is enriched in a mixture containing ca. 10 % of the cis isomer is seen in Figure 3. The signals belonging to the protons next to the ester and amino groups in the trans isomer appeared at chemical shifts of 5=2.20 ppm and 5=2.65 ppm, respectively. The intensity of signals in the NMR spectra allows estimating the ratio of stereoisomers. 

In conclusion, 4-Amino-benzoicacid can be hydrogenated to 4-aminocyclohexane carboxylic acid on 5wt.% Ru- and Rh/A Os catalysts with 100% yield in 2 wt. % Na0H-H20 at 80-100 °C, 10 MPa H2, for 5h. However, the ratio of trans/cis stereoisomers of the product does not exceed a value of 1/1. Raw reaction mixture... 

Amino-5 -Chlorotoluene Aminocyclohexane Aminoethane 2-Aminoethanol Beta-Aminoethyl Alcohol 2-((2-Aminoethyl) Amino)Ethanol N-(2-Aminoethyl)Ethanolamine Aminoethylethanolamine Aininofonn 2-Aminoisobutane Aminomercuric Chloride Aminomethane... 

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