Methylamines series

Let us define the respective basicity by — AG in the gas phase and — AG" in aqueous solution. For discussions concerning the relative strength in basicity of a series of methyl-amines, only the relative magnitudes of these quantities are needed. Thus the free energy changes associated with the protonation of the methylamines relative to those of ammonia are defined as... 

The Leuckart synthesis has been applied successfully in the thiophene series, iV,A -Dimethyl thenylamine and A, A -diethyl thenylamine were obtained from 2-thiophenealdehyde and the appropriate for-mamide. Seven -(2-thienyl)- -arylethylamine hydrochlorides have been prepared from the corresponding ketones in about 40-60% yields and, finally, A -methyl-1-(3-thienyl)-2-propylamine was obtained in 48% yield in the Leuckart reaction from 3-thienylace-tone, methylamine, and formic acid. ... 

Formal oxidation of pyrrolidine to the succinimide stage affords a series of compounds used as anticonvulsant agents for treatment of seizures in petit mal epilepsy. Knoevnagel condensation of benzaldehyde with ethyl cyanoacetate affords the unsaturated ester, 9. Conjugate addition of cyanide ion leads to the di-nitrile ester (10). Hydrolysis in mineral acid affords the succinic acid (11), presumably by decarboxylation of the intermediate tricarboxyllie acid. Lactamization with methylamine gives phensuximide (12). ... 

The parent drug of this series, promazine (24), was prepared originally as an antihistamine. Following the identification of the more potent chloro analog as an antipsychotic, it too came into use for that indication. The drug is prepared by straightforward alkylation of phenothiazine with w-C3-chloropropyl)di-methylamine by means of sodium hydride in xylene. ... 

Results. In the past two years we have undertaken a high pressure examination of the ion-molecule reactions occurring in a series of polar molecules—namely, methylamine, methanol, ethylamine, and ethanol (3). In all cases, the major secondary ion is the (parent +1) ion and in the first two cases, it is the only secondary ion. All hydrogenic primary ions undergo the general reaction,... 

The chemistry of most of the drugs in this family is quite simple, accounting in part for the very large number of analogues which have been made. The foundation for the chemistry in this series was laid long ago by Stolz in his classic synthesis of the ophthalmic agent adrenal one (3) in which he reacted catechol with chloroacetyl chloride and then displaced the reactive chlorine atom with methylamine to complete the synthesis. Borohydride reduction would have given epinephrine (adrenaline). 

The previous review1 has treated in detail only the following amines methylamine, dimethylamine, trimethylamine, 2-aminoethanol, ethylenediamine, nitroguanidine and similar ones. In the period of the present review, some simple molecules of interest have been treated such as the aminoethanol series, including mono-, di- and tri-substituted derivatives, as well as a number of derivatives of guanidine. These will be dealt with for purposes of internal comparison. 

When p-chlorobenzophenone dichloride reacts with methylamine there results an oil consisting of similar amounts of the syn and anti Schiff base 19. This oil, on standing at room temperature for 2 weeks, transforms to crystals of only the syn isomer. If these crystals are heated above their melting point (125°) for a few minutes, or are dissolved in cyclohexane and allowed to stand at room temperature for 2 weeks, the syn isomer reconverts to a mixture of the two isomers (61a). [This seems to be an example of the so-called second-order or crystallization-induced asymmetric transformations (61b).] A number of systems of this series were known, from previous work, to be dimorphic however, Curtin and Hausser found no case in which it was established that two crystal forms correspond to different isomers (61a). 

The simplest structures in this series are A-methyl- and A-ethylbenz-amide (4.73 and 4.74, respectively). When administered intraperitoneally in rats, these amides yielded methylamine and ethylamine, respectively, plus benzoic acid, which was detected in the urine as hippuric acid [47]. An alternative metabolic pathway is possible, involving A-dealkylation to the primary amide followed by hydrolysis its contribution, if any, must be minor, since benzamide levels in urine were negligible. 

However, the same workers performed a series of interesting voltammetric measurements [182] on dibutylmethylamine (DBMA), fluorinated dibutyl-methylamine (F-DBMA), HF-phase (protonated and unprotonated) in acetonitrile, with (Bu)4NBF4 as supporting electrolyte, both on platinum and nickel anodes. Their results are set out in the table below. 

Early publications on [VO(/3-diketonato)2] have been reviewed.355 More recently, complexes with benzoyl m-nitroacetanilide, benzoyl acetanilide545 and l,l -(l,3-phenylene)-bis(butane-1,3-dione546 have been synthesized. Other [VO(/S-dik)2] adducts have been isolated, for example [VO(acac)2] adducts with a series of pyridine N-oxides547 and several pyridine carboxamides, 48 and [VO(bzac)2] adducts with pyridine, methylamine, isoquinoline and 4-picoline.549 Equilibrium constants of 1 1 and 2 1 adducts of pyrazine with [VO(tfacac)2] have been determined (equation 38).550 In the 2 1 complex, the pyrazine bridge between two equatorial sites of adjacent vanadium atoms promotes a weak exchange interaction. The nitroxide radical 2,2,6,6-tetramethylpiperidinyl N-oxide also forms an adduct with [VO(hfacac)2] in which there is a strong interaction between the electrons on the metal and nitroxide.551... 

The possible geometrical isomers of diacidobis(diamine) complexes containing two un-symmetrical amines such as pic are shown in (109) to (113). The a series are differentiated from the / series by an approximate C2 axis, and from each other by the relative positions of the pyridine P and methylamine M nitrogen atoms. The preparative routes for cis-a and cis-fi series are outlined in Schemes 47 and 48. Although trans- [CrX2(py)a]+ salts, where X = F, Cl or Br, were used as starting materials, only cis products were produced. In many cases lithium salts LiX (X = Cl, Br or I) were added to aid crystallization. The 8 series were prepared from... 

For closely analogous representatives of sp3, sp3, and sp carbons, such as the series ethane, ethene, ethyne, or methylamine, formaldimine, hydrogen cyanide, JCH increases... 

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