Preparation reaction with

Alanine, valine, and leucine, (amino-acids with alkyl substituents only) react in a manner very like that of glycine (49—53). All the reactions are rather slow and boiling solutions are normally employed in the preparative reactions. With the cis- and /raws-isomers of Pt(NHs)2Cl2 substitution of the chloride only occurs. Since the tfraws-labilising influence of the incoming groups of the amino-acids is very small, the —NH2 groups remain stable. Consequently chelated complexes are only formed by the amino-acids in the case of the cts-isomer. 

The peptide/polypeptide product is usually hydrolysed by incubation with 6 mol l-1 HC1 at elevated temperatures (110 °C), under vacuum, for extended periods (12-24 h). The constituent amino acids are separated from each other by ion-exchange chromatography and identified by comparison with standard amino acid preparations. Reaction with ninhydrin allows subsequent quantification of each amino acid present. 

Unsaturated 5(4//)-oxazolones derived from aromatic and heterocyclic aldehydes including phthalic anhydride/ antipyrine/ " chromone/ indoles/ pyridines/" ° quinolines/" diazines/" benzoxazoles/" and benzimidazoles " " have been prepared. Reaction with nitrogen nucleophiles and subsequent cycliza-tion leads to the expected 5(477)-imidazolones. 

Precursor of diazomethane, a highly toxic and unpredictably explosive gas. Possibly a carcinogen. Read details carefully before preparation. Reactions with and preparation of diazomethane should be carried out in a fume hood and behind a sturdy safety shield. Rough glass surfaces and strong sunlight are known to initiate detonation. 

The cyanoaromatic-sensitized electron-transfer photooxygenation (Foote-type) is a useful preparative reaction with a very limited class of unsaturated olefins, namely those substituted by aromatics and, at the same time, totally inert towards singlet oxygen. On the other hand, in the previous sections, it has been many times underlined that electron-transfer reactions may compete with singlet oxygen formation and, above all, that the reactions of 02 may be the only observable outcome in the presence of singlet-oxygen acceptors. 

The tetramer formed in the preparative reaction with NH4CI is also cyclic, but the ring is puckered, not planar as with the trimer (PNCl2)3. ... 

Pt2H(p-H)2(dppe)2]Bp4 preparation, reaction with styrene ... 

The complexes (PhX)Cr(CO)3 are known [15] for X=F, Cl, Br, and I, but only the fluoro and chloro examples are easily prepared. Reaction with n-BuLi might be expected to bring about halogen-Li exchange, but the halide atom (F and Cl) strongly favors ortho proton abstraction (see below) instead. In one example, (PhI)Cr(CO)3 was converted to (PhLi)Cr(CO)3 and the latter was methylated in 78% yield overall [16]. 

The preparative reaction with europium dihydride failed to produce analogous carbide hydrides. Obviously, the failure is consistent with the high stability of divalent europium. In YbCo 5H, YbCHo.s and YbOo.sCo.s, ytterbium is clearly trivalent, as shown by magnetic data (Haschke 1975), and for La and Y the hexagonal phases have also been found (Lallement and Veyssie 1968). Therefore, it can be expected that the hexagonal RCo.sH phases probably exist across the lanthanide series, which exhibit a trivalent state as their stable valence state, with the exception of europium. 

CH3 Li f-C4H9 Li f-C4H9 preparation reaction with (CH3)2Sn(CH2Br)Br [14]... 

Secondary enamines, preparation, reaction with dlke-tene, 627... 

Nacconate 100 A lachrymatory liquid b.p. 25l°C. Manufactured from phosgene and 2,4-diaminotoJuene. Used for preparing polyurethane foams and other elastomers by reaction with polyhydroxy compounds. Produces skin irritation and causes allergic eczema and bronchial asthma. 

C HgNjOjS. Colourless needles, with iH20. Prepared by reducing diazotized sulphanilic acid with an excess of sodium sulphite. It is a typical hydrazine in its reactions with ketones, and with acetoacetic ester. The latter reaction gives rise to the tartrazine dyestuffs, and is much used commercially. 

The reactions with water are summarised in Table 6.3. Since the metals are powerful reducing agents (p. 98) they cannot be prepared in aqueous solution electrolysis of the fused anhydrous halides is usually employed using a graphite anode. 

Strictly speaking the alkyl halides are esters of the halogen acids, but since they enter into many reactions (t.g., formation of Grignard reagents, reaction with potassium cyanide to yield nitriles, etc.) which cannot be brought about by the other eaters, the alkyl halides are usually distinguished from the esters of the other inorganic acids. The preparation of a number of these is described below. 

The independent preparation of potassium phthabmide (from a solution of phthalimide in absolute ethanol and potassium hydroxide in 75 per cent, ethanol) may be avoided in many cases by boiling phthalimide with the halide in the presence of anhydrous potassium carbonate. The N-substituted phthalimide (I) is frequently cleav with difficulty this is often facilitated by reaction with hydrazine hydrate to give an intermediate product, which is easily decomposed by hydrochloric acid to 3deld the insoluble hydrazide of phthaUc acid (II) and the primary amine (III) ... 

An interesting coupling reaction with the diazonium salt derived from anthranilic acid leads to an excellent method for the preparation of dlphenic acid. The reaction occurs with cuprous salts in ammoniacal solution ... 

Quinoline may be prepared by heating a mixture of aniline, anhydrous glycerol and concentrated sulphuric acid with an oxidising agent, such as nitrobenzene. The reaction with nitrobenzene alone may proceed with extreme violence, but by the addition of ferrous sulphate, which appears to function as an oxygen carrier, the reaction is extended over a longer period of time and Is under complete control. 

An ethereal solution of diazomethane free from alcohol may be prepared as follows such a solution is required, for example, in the Amdt-Eistert reaction with acid chlorides (compare Section VI,17). In a 100 ml. longnecked distilling flask provided with a dropping funnel and an efficient downward condenser, place a solution of 6 g. of potassium hydroxide in... 

The higjily water-soluble dienophiles 2.4f and2.4g have been synthesised as outlined in Scheme 2.5. Both compounds were prepared from p-(bromomethyl)benzaldehyde (2.8) which was synthesised by reducing p-(bromomethyl)benzonitrile (2.7) with diisobutyl aluminium hydride following a literature procedure2.4f was obtained in two steps by conversion of 2.8 to the corresponding sodium sulfonate (2.9), followed by an aldol reaction with 2-acetylpyridine. In the preparation of 2.4g the sequence of steps had to be reversed Here, the aldol condensation of 2.8 with 2-acetylpyridine was followed by nucleophilic substitution of the bromide of 2.10 by trimethylamine. Attempts to prepare 2.4f from 2.10 by treatment with sodium sulfite failed, due to decomposition of 2.10 under the conditions required for the substitution by sulfite anion. 

The desired pyridylamine was obtained in 69 % overall yield by monomethylation of 2-(aminomethyl)pyridine following a literature procedure (Scheme 4.14). First amine 4.48 was converted into formamide 4.49, through reaction with the in situ prepared mixed anhydride of acetic acid and formic acid. Reduction of 4.49 with borane dimethyl sulfide complex produced diamine 4.50. This compound could be used successfully in the Mannich reaction with 4.39, affording crude 4.51 in 92 % yield (Scheme 4.15). Analogous to 4.44, 4.51 also coordinates to copper(II) in water, as indicated by a shift of the UV-absorption maximum from 296 nm to 308 nm. 

Apparatus and procedure Closely similar to the preparation of tert.-Ci,H3MgCl, cyclohexyl-MgCl and cyclopentyl-MgCl (see Exp. 2). The yield (estimated from the results obtained from reactions with this reagent) is at least 90%. Here, too, it is essential to use M-butyl chloride which is free from butyl alcohol. 

Apparatus. 500-ml round-bottomed, three-necked flask with a gas inlet tube, thermometer and a gas outlet for the preparation of chlorotetrahydropyran 1-1 four--necked, round-bottomed flask with a gas inlet tube, a dropping funnel, a mechanical stirrer and a thermometer, combined with a gas outlet for the preparation of HC=CMgBr and its reaction with chlorotetrahydropyran 1-1 three-necked, round--bottomed flask with a dropping funnel, combined with a gas inlet, a mechanical Stirrer and a thermometer, combined with a gas outlet for the conversion into the allenic alcohol. 

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