W-Propylamine

Methoxy,w-propylamine (MOPA, or 3-MPA), CHgCXCH NHj, MW = 89.1. Sp. gr. = 0.874. Flash point = 73 °F/22 °C. Flammable and corrosive liquid. Commonly available through chemical distributors. Good thermal stability. 

Diazirines are the cyclic isomers of the alphatic diazo compounds. Both the diaziridines and the diazirines are starting materials for the synthesis of alkyl hydrazines. 3,3-Pentamethyl-enediaziridine can be hydrolyzed quantitatively to hydrazine. Methylamine may be substituted for ammonia in the procedure resulting in l-methyl-3,3-pentamethylenediaziridine (m.p. 35-36°, yield 62% of theoretical) and then methyl hydrazine. Use of ethylenediamine leads to ethylene bis-hydrazine via a bifunctional diaziridine (m.p. 143-144°, yield 48% of theoretical). Ammonia can also be replaced by w-propylamine or cydo-hexylamine cyclohexanone by acetone. 

Toxicology. AT-nitrosodi-w-propylamine (NDPA) causes hepatic effects in animals and is a carcinogen. 

Fig. 4 HPLC-TEA chromatograms for various A-nitrosamincs (=20 ng each). (A) (1) NDPhA, (2) A-ni-trosoethylphenylamine (NEPhA), (3) A-nitrosodicyclohexylamine, (4) NMA, (5) NDBzA, (6) A-nitrosodi-w-propylamine (NDPA), (7) A-nitrosobutyl-4-hydroxybutylamine, (8) dinitrosopentamethylenetetramine, (9) NDELA. (B) A meat extract showing the presence of NDBzA and traces of A-nitrosodi-w-butylamine (NDBA) (unresolved small peak preceding that of NDBzA). Conditions Column, 250 mm X 4.1 mm (ID) packed with LiChrosorb Si 100 (5 /un) mobile phase programming, 1% acetone in w-hexane initially, then linearly programmed to 40% acetone in w-hexane in 15 min, and then held 10 min. (Reproduced with permission from Ref. 67. Copyright 1988, Institute of Food Technologists.)...

AP (protected by acetylation at N-10, (650)) was prepared in an unequivocal fashion by a different strategy starting with 2-amino-3-cyano-6-formylpyra-zine (647), which was itself prepared by two independent procedures Scheme 3.141) [261], In the first, 2-amino-3-cyano-6-chloromethylpyrazine (645) was converted to (647) via (646) by the KrOhnke procedure in excellent overall yield. In the second, the 1-oxide (644) was treated with w-propylamine,... 

PA = 226 kcal mol-1), the predominant formation (6.4 to 1) of the (/ ,.S )-di-2-hutyl ether over the (R,R)- and (S,S)-forms is attributed to a simple backside displacement in the proton-bound adduct of the starting 2-butanol enantiomer with inversion of configuration of the reaction site and loss of a molecule of water. When tri-w-propylamine is replaced by the less basic NH3 (PA = 196 kcal mol-1), fast neutralization of the proton-bound dimers of the starting 2-butanol is prevented and, therefore, they can grow, producing aggregates that resemble solution microenvironments in which S l pathways may be accessible as well. In them or in their primary substituted derivatives, consecutive nucleophilic displacements may take place. As a consequence, the stereospecificity of the process is lost and the [(/ ,5)-di-2-butyl ether]/[(/ ,/ )- and (S,S)-di-2-butyl ethers] ratio falls down to 1.2. In this case,... 

Talamoni and coworkers17 found that in methanol, allylamine has no influence on the yield of 0-Ps. Other amines, such as w-propylamine and triethylamine, increase the yield of the o-Ps. The authors ascribe this difference to the higher ionization potential of allylamine, making positive charge transfer from the solvent ions (the holes) ineffective. The ionization potential of allylamine (9.6 V) is considerably higher than that of other amines (w-propylamine 8.8 eV, triethylamine 7.8 eV, aniline 7.7 eV). They found a correlation between the ionization potentials and the enhancement factors. In water, allylamine also enhances the formation of 0-Ps, due to the much higher ionization potential of water, 12.6 eV (while the value for methanol is only 10.8 eV). 

The steric influence on the enamine-imine tautomerism has also been observed in the cyclic ketone derivatives. Cyclohexanone imines of w-propylamine, cyclohexylamine and 2-bornylamine show no signals ascribed to the enamine tautomer in their NMR spectra, but the /-butylamine38 does display signals of the enamine. In DMSO-d6 it comprises 38% of enamine 56 at equilibrium. The proportion of the 3,3,5,5-tetra-methylcyclohexanone and cyclopentanone enamines 57 and 58 is even higher, rising to 52% and 58%, respectively, in DMSO-d663. 

Unsymmetrical secondary amines are readily prepared in good yields by the catalytic reduction of Schiff bases at moderate temperatures in high-or low-pressure equipment. Many examples have been cited. The intermediate imines are prepared from primary amines and aldehydes—very seldom from ketones—and may be used without isolation (cf. method 431). For the preparation of aliphatic amines, e.g., ethyl-w-propylamine and n-butylisoamylamine, a prereduced platinum oxide catalyst is preferred with alcohol as the solvent. Schiff bases from the condensation of aromatic aldehydes with either aromatic or aliphatic amines are more readily prepared and are reduced over a nickel catalyst. In this manner, a large number of N-alkylbenzylamines having halo, hydroxyl, or methoxyl groups on the nucleus have been made. Reductions by means of sodium and alcohol and lithium aluminum hydride have also been described,... 

Fig. 16. The variation of Pmaxi the maximum rate of oxidation in torr. min of some primary and secondary aliphatic amine with temperature [114], Amine pressure 500 torr oxygen pressure 200 torr. , Methylamine , ethylamine , iso-propylamine B, dimethylamine o, w-propylamine , di-iso-propylamine a, ethylmethyl-amine , iso-butylamine , n-butylamine , diethylamine , methyl-n-propylamine di-n-propylamine , n-butylchloride.

The laboratory synthetic procedure introduced here was developed by Szostak, et al.[131] Aluminum hydroxide (Aldrich, 50-57.5% AI2O3), phosphoric acid (85% H3PO4), di-w-propylamine (DPA), hydrofluoric acid (48% HF), and deionized water were used to prepare the reaction gel with a composition of 1.0 AI2O3 1.25 P2O5 2.37 DPA 1.80 HF 156 H20. The detailed procedure for the preparation of 4 g of dry product is described below ... 

The metalloporphyrins as macrocyclic compounds have a few sites for specific and universal solvation and are able to axial coordination of some ligands. At the present time chemical modification of macrocycle is a main way of increasing of selectivity of molecular complex formation. The data obtained earlier [1,2] show that the selectivity may be increased due to specific %-% interactions of the metalloporphyrins with aromatic molecules. Aromatic molecules coplanar to the macrocycle will rise geometrical requirements to axial coordinating ligands. In particular, the results of the thermodynamic study of the axial coordination of n-propylamine by zinc(II) porphyrins in benzene have demonstrated the formation of the complexes of the metalloporphyrin containing both w-propylamine and benzene [2], The aim of this work is to study the molecular complexes of zinc (II) porphyrins prepared by slow crystallization from saturated solutions in benzene, w-propylamine and mixed solvent benzene - -propylamine. 

Figure 1. TG and DTG curres for the thermal decomposition crystallosolvaty of ZnTPhP with benzene and w-propylamine.

DIPROPYLAMINE or DI-w-PROPYLAMINE (142-84-7) Forms explosive mixture with air (flash point 63°F/17°C). May form salts with hydrochloric or other strong acids. Violent reaction with isopropyl percarbonate, nitrosyl perchlorate. Incompatible with aldehydes, nonoxidizing mineral acids, cellulose nitrate (of high surface area), cresols, isocyanates, nitrates, nitric acid, organic anhydrides, phenols, sulfuric acid. Dissolves paint and most plastics swells rubber. Attacks copper, zinc, brass, bronze, aluminum, magnesium, and their alloys. 

To a cold solution (-6°C) of 12.8 g naphthalene (0.10 mol) in 100 mL w-propylamine, 30 g ethylenediamine (0.5 mol) and 44.4 g r-butanol (0.6 mol), was added 3.5 g lithium (0.5 mol) portionwise in small pieces. The solution was warmed to 20°C and maintained by the addition of lithium. Afterl.5 h, the reaction mixture was poured over 150 g ice and 100 mL water and then extracted with ether. The ether was washed with water, brine, and evaporated under reduced pressure to give 12.2 g of a colorless solid that was triturated with methanol, filtered, and dried to give crude product. Recrystallization from 50 mL methanol gave 9.8 g 1,4,5,8-tetrahydronaphthalene, in a yield of 74%, with a purity of 93% by GLPC. 

Aminotropenium salts. w-Propylamine in acetonitrile added slowly with ice-cooling and stirring to a soln. of methoxytropylium perdilorate in abs. acetonitrile, and stirring continued 15-30 min. n-propylaminotropylium perchlorate. Y 80%. F. e., also fluoroborates, s. E. Haug and B. Fohlisdi, B. 104, 2338 (1971). 

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