Hexahydroazepines

Chemical DesignationsAzacycloheptane Hexahydroazepine Homopiperidine Chemical Formula CHjCHjCHjCHjCHiCHiNH... 

Complete reduction of the azepine ring to hexahydroazepine has been effected with hydrogen and palladium,40 or platinum,135 239 catalysts. For example, ethyl 1 f/-azepine-l-carboxylate is reduced quantitatively at room temperature to ethyl hexahydroazepine-l-carboxylate (92% bp 118 —120 3C).134 136 TV-Phenyl-S/Z-azepin -amine (1), however, with platinum(IV) oxide and hydrogen in methanol yields the hexahydroazepine 2 in which the amidine unit is preserved in the final product.34 The same result is obtained using 5% palladium/barium carbonate, or 2 % palladium/Raney nickel, as catalyst. 

Under more forcing conditions (Raney nickel, MeOH, H2 pressure, 150°C, 6h). 3H-azepin-2-amine undergoes reductive deamination to hexahydroazepine (86 %).240... 

Hydrogenation of 2-butoxy-3//-azepine (3) with palladium on charcoal and hydrogen affords 2-butoxy-4,5,6,7-tetrahydro-3f/-azepine (4),79 whereas reduction of the 2-benzyloxy derivative, under the same conditions, is accompanied by debenzylation and formation of hexahydroazepin-2-one (77% mp 67-69 C).79,241... 

Whereas reduction of dimethyl 1,2,7-trimethyl-l T/-azepine-3,6-dicarboxylate (5) with platinum and hydrogen in cyclohexane yields the hexahydroazepine 6, hydrogenation in methanol solution results in loss of methylamine and formation of dimethyl 2,3-dimethylbenzene-1,4-dicar-boxylate (52% mp 66-67 C).239... 

Comparison of IP( n) values of cyclic secondary amines (Table 6) with those of the respective 1-methyl derivatives (Table 7) reveals that the effect of the additional methyl group decreases from 0.6 eV in aziridine to 0.1 eV in hexahydroazepine (hexa-methyleneimine). 

Hexachloroethane, see Carbon tetrachloride Hexahydroazepine, see Molinate Hexahydroazepine-l-carbothioate, see Molinate Hexamethyleneimine, see Molinate Hexanal, see Hexane, 1-Octene Hexane, see Benzene, Cyclohexane, 1-Octene, 3-Methylpentane... 

Hydroxy-lV-acetyl-hexahydroazepine, see Molinate Hydroxyadipic acid, see Cyclohexene Hydroxyalachlor, see Alachlor Hydroxyametryne, see Ametrvn 2-Hydroxyamino-4,6-dinitrotoluene, see 2,4,6-Trinitrotoluene... 

Soil. Hydrolyzes in soil forming ethyl mercaptan, carbon dioxide, and dialkylamine (half-life approximately 2-5 wk) (Hartley and Kidd, 1987). At recommended rates of application, the half-life of molinate in moist loam soils at 21-27 °C was approximately 3 wk (Humburg et al., 1989). Rajagopal et al. (1984) reported that under flooded conditions, molinate was hydroxylated at the 3- and 4-position with subsequent oxidation forming many compounds including molinate sulfoxide, carboxymethyl molinate, hexahydroazepine-l-carbothioate, 4-hydroxymolinate, 4-hy-droxymolinate sulfoxide, hexahydroazepine, 5-methyl hexahydroazepine-l-carbothioate, 4-keto-molinate, 4-hydroxyhexahydroazepine, 4-hydroxy-Wacetyl-hexahydroazepine, carbon dioxide, and bound residues. 

Caprolactam or (hexahydroazepin-2-one) is, without doubt, the most important azepine derivative. This seven-membered lactam is produced in vast quantities as an intermediate for the manufacture of nylon 6 (B-75MI51601, B-70MI51601). Polymerization, which is carried out at high temperatures with water as the initiator or at low temperatures with a strong base (e.g. NaH), proceeds by attack at the caprolactam carbonyl by the amino function of the open-chain monomer, e -aminohexanoic acid. 

Hydroxy-3-azabicyclo[3.2.0]heptane-l-carboxylates 1 readily underwent retro-aldolization on heating with sodium carbonate in ethanol to yield hexahydroazepine-3-carboxylate 2.71... 

In a different approach, the pyrimidine ring was formed when the l-(2-aminomethylphenyl)hexahydroazepine (663) was oxidatively cyclized with Hg(II)-EDTA to 664 (79AP838). 

A modified protocol of the Eschweiler-Clarke reaction, a reductive transamination, was also used for an efficient N-alkylation of hexahydroazepine and benzylamine in the presence of formic acid and aldehydes or ketones53. 

The byproducts of the hydrogenation of adiponitrile are small amounts of hexahydroazepine, 1,2-diaminocyclohexane and 2-(aminomethyl)cyclopentylamine, besides acyclic secondary products. In an example of a continuous process, a 1 12.5 molar ratio of adiponitrile and ammonia that was mixed with 10-fold amount of a hydrogenated reaction mixture from a prior run to give a 1 44 adiponitrile-ammonia mixture... 

The cyclisation to give the hexahydroazepine 14 was carried out at moderate dilution (0.02 M). What was the reason for this ... 

SYNS AZACYCLOHEPTANE 1-AZACY CLO-HEPTANE CYCLOHEXAMETHYLENIMINE G 0 HEXAHYDROAZEPINE HEXAMETHYLENEIMINE (DOT) HEXAMETHYLENIMINE HOMOPIPERID-INE PERHYDROAZEPINE ... 

HEXAHYDROAZEPINE see HDGOOO HEXAHYDRO-IH-AZEPINE see HDGOOO HEXAHYDRO-2-AZEPINONE see CBF700 HEXAHYDRO-2H-AZEPIN-2-ONE see CBF700 HEXAHYDRO-2H-AZEPIN-2-ONE HOMOPOLYMER see PJY500... 

The use of cyclic enamines" > " " b.436,441,443,446.447, 456.457,470-480 (-g g UQ o ) or dieneamines (e.g., 141 ) yields fused bicyclic systems, although the latter may also yield bis-thietane sulfones. Enamines derived from morpholine, piperidine, pyrrolidine, and dimethylamine are most commonly used, but derivatives of diethylamine, di- -propyl-amine, piperazine, 4-benzylpiperidine, methylpyrrolidines, hexahydroazepin, N-methylaniline, and indoline have also been treated with sulfenes to give thietane sulfones. Asymmetric induction has been observed with the optically active enamine, 142. ... 

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