Phase amines

Dicyclohexylarnine may be selectively generated by reductive alkylation of cyclohexylamine by cyclohexanone (15). Stated batch reaction conditions are specifically 0.05—2.0% Pd or Pt catalyst, which is reusable, pressures of 400—700 kPa (55—100 psi), and temperatures of 75—100°C to give complete reduction in 4 h. Continuous vapor-phase amination selective to dicyclohexylarnine is claimed for cyclohexanone (16) or mixed cyclohexanone plus cyclohexanol (17) feeds. Conditions are 5—15 s contact time of <1 1 ammonia ketone, - 3 1 hydrogen ketone at 260°C over nickel on kieselguhr. With mixed feed the preferred conditions over a mixed copper chromite plus nickel catalyst are 18-s contact time at 250 °C with ammonia alkyl = 0.6 1 and hydrogen alkyl = 1 1. 

Reversed phase Amines (a-Hydroxyl) aeids (a-Hydroxyl) aeids... 

A fundamental functional property of a neutralizing amine (vapor-phase amine) is its volatility. Derived from this function is relative volatility and the DR. 

All amines, except for ammonia, decompose under high temperature and pressure boiler conditions. Where hydrazine feed continues to be well in excess of scavenging needs or at pressures exceeding 800 to 850 psig (520-525 °F/271-274 °C), it begins to break down and liberate ammonia. All other functioning vapor-phase amines rapidly decompose at temperatures above 550 °F/288 °C (approximately 1,000 psig). 

The selectivity of the gas phase amination is highly dependent on the type of zeolite as shown in Figure 11 for five zeolites all containing 3 wt % of Cu. When the zeolite becomes more spacious (L, Beta) the consecutive reaction increases which is understandable. Over Cu-Y reduction predominates. 

Beyond the density changes that can be used to control method modifications in SFC, the mobile phase composition can also be adjusted. Typical LC solvents are the first choice, most likely because of their availability, but also because of their compatibility with analytical detectors. The most common mobile phase modifiers, which have been used, are methanol, acetonitrile and tetrahydrofuran (THF). Additives, defined as solutes added to the mobile phase in addition to the modifier to counteract any specific analyte-column interactions, are frequently included also to overcome the low polarity of the carbon dioxide mobile phase. Amines are among the most common additives. 

Initial D20 phase Amine salt In CDClj at equil. [G1/1H] CRF in CDCl, EDC... 

Reversed phase Amines, amides, imides, acids, profens a-Hydroxy acids, oxazolidinones, amino acids, peptides a-Hydroxy acids, acids, profens, amino acids, amino esters, hydantoins, peptides... 

Two groups [127, 128] have reported results on the solid-phase amination of aryl halides using both P(o-C6H4Me)3 and chelating ligands. It has been shown that Stille and Suzuki reactions are reliable, high-yielding processes for substrates loaded on solid supports [129]. Thus, supported aryl halides can now be used to form new C C and C-N bonds, and presumably C S, CP, and CO bonds as well. 

Table 4. Comparison of AH and Av for gas-phase amine-methanol complex formation. From D. J. Millen and G. W. Mines. J.C.S. Faraday Trans. II. 70,693 (1974). Reproduced by permission from the Chemical Society.

Acid precursor phase Amine phase Thermally regenerable capacity, 20-80 °C (meq/ ... 

In the present paper, the Pd-La/spinel catalyst for this reaction was developed. On this catalyst, the activity and selectivity were high, especially the stability was increased greatly, and it was up to 480 hours under the conditions of 220°C and LHSV=0.3h . But the high initial activity decreases along with time, which impairs the catalyst practice in industrial applications. For this reason, it is important to understand the deactivation mechanism. This work concerns an investigation into the coke formation on the Pd-La/spinel catalyst in the gas-phase amination of 2,6-DIPP. Furthermore, the correlation between coke deposition and combustion was analyzed. The results provide fundamentals not only to develop new catalysts but also to optimize the reactor operation parameters. 

Ratios of the amine/epoxy equivalents in different phases are shown in Fig. 25. Now, due to its semipermeable character, the P-phase retains the excess diamine monomer segregated at low conversions, leading to a significant departure from stoichiometry. However, the effect on the a-phase (amine defect) is not so significant because of its high volume fraction in the system. 

A specific interaction in the vapour phase between hexafluorobenzene and benzene was reported by Dantzler and Knobler. Recently, Belousova and Verkhova pointed out that interaction virial coefficients for benzene -t-n-hexane have an unusual temperature dependence and are inconsistent with Bia s for benzene with other alkanes. They suggest that this abnormal behaviour is the result of association. Vapour-phase amine complexes with methanol have been studied by i.r. spectroscopy and p, V, r-methods. Equilibrium constants were calculated from the volumetric data under the assumption that the vapours are ideal. 

Table 8.2-4 summarizes applications of amines for metal extraction. The viability of amine extraction depends directly on the identify of the anions present in the aqueous phase. Amine extraction has been discussed by Schmidt. ... 

Stage is included to control the level of iron build-up on the organic phase. Amine circuits also often require a regeneration circuit to protonate the extractant ahead of the extraction process. Other amine circuits may use a strong caustic wash to remove very strongly bound impurity species from the stripped organic phase to avoid loss of capacity on recycle of the organic to the extraction circuit. 

Actually, the liquid in the bottom of the tower always consists of two phases amine (1.0 sp gr) and hydrocarbon (0.6 sp gr). The hydrocarbon accumulates in the bottom of (he tower due to a small amount of liquid entrainment in the inlet gas. Because the hydrocarbon is lighter than the amine, it simply floats on top of the amine. 

Chiral AGP al- acid Immobilized Reverse phase Amines, (primary. 

In addition to the restrictions on amine concoitration and rich solution loading, the volumetric flow rate ratio of the continuous phase (amine) to the dispeised phase (LPG) should be m e than about 1 30 to ensure good mass transfer. Conservative design would caU for a volumetric ratio of amine to LPG of 1 15 or greats. 

In the solid phase, amine hydrohalides containing have an absorption... 

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