Nitration of acenaphthene (AcN) with either nitric acid or metallic nitrates in acetic anhydride has been studied by means of the differential thermal analysis (DTA) technique. A thermistor bead, on which a small amount of AcN was pasted, was inserted in a reaction vessel being kept at 20°C, and the temperature change due to the reaction was recorded. It was found that the thermal variation at the earlier stages of reaction is correlated with the reactivity of the nitrating agents used. The order of the reactivity of nitrating agents was determined from the heights of DTA curves.
The authors have examined the effects of metal components of the catalysts on activity in the liquid phase oxidation of acrolein (Acr.). An oxidation reaction was carried out by flowing oxygen at the atmospheric pressure and a temperature of 2045°C. The V2O5 catalyst gave the most desirable results with respect to the selective oxidation. With 10-2 mol/l of V2O5, the conversion of acrolein and the selectivity of acrylic acid (Acr. A.) were 3O40% and about 60%, respectively. The following empirical rate equations were obtained. -d [Acr.] / dt =k1 [Acr.] 1.0 [V2O5] 0.10 d [Acr.A.] / dt =k2 [Acr.] 1.8[V2O5] 0.17 Values of apparent activation energy for acrolein consumption and acrylic acid formation were 6.8 and 6.5 kcal/mol, respectively. From these equations, the selectivity of acrylic acid could be calculated as follows : SAcr.A. =0.154 exp (340/RT) [Acr.] 0.8[V2O5] 0.07 Thus, the concentration of acrolein appears to have more effect on the selectivity than V2O5 concentration and reaction temperature. According to a comparison of various solvents, benzene is considered to give the most desirable activity to the V2O5 catalyst for synthesizing acrylic acid.
The orientation in the azo-coupling reaction of 1-phenanthrol (1) and 4-phenanthrol (8) was determined and compared with that of α-naphthol. In an alkaline aq. ethanolic solution, (1) was coupled with 0.2 moles of benzenediazonium chloride to yield 4-azo (2) (91.8 mol%), 2-azo (3) (7.5 mol%), and 2, 4-disazo (4) (0.5 mol%) compounds. Similarly, (8) gave 1-azo (9) (89.2 mol%), 3-azo (10) (8.0 mol%), and 1, 3-disazo (11) (2.8 mol%) compounds, and α-naphthol gave 4-azo (94.1 mol%) and 2-azo (5.9 mol%) compounds. Thus these two phenanthrols behave quite similarly to each other and also to α-naphthol. The structures of the products were determined by the following transformations : (3) and (10) were derived from 1, 2-and 3, 4-phenanthrenequinone by the condensation with phenylhydrazine, respectively ; (4), formed from (2) and (3) by the further coupling ; (11), similarly formed from (9) and (10); (2) was converted via 4-amino-1-phenanthrol to its triacetyl derivative by the reduction and successive acetylation ; (9), converted via 1-amino-4-phenatnhrol (characterized as the triacetyl derivative) to 1, 4-phenanthrenequinone by the reduction and successive oxidation.
An industrial method for the synthesis of peptides using a trityl group as the protecting group has been investigated. The derivatives of the amino acids, containing a liophilic group in their side chain, such as γ-methyl, ethyl and benzyl glutamate, β-methyl, ethyl and benzyl aspartate and S-trityl cystein, were N-tritylated directly in good yields with 2-equiv. of trityl chloride in aprotic solvents in the presence of triethyl amine. In these reactions, it was found that the α-carboxyl group of amino acids derivatives was simultaneously tritylated during the N-tritylating process. Using these trityl derivatives, glutathione (GSH), α-aminobenzyl penicilline (ABP) and aspartyl phenylalanine methyl ester (APAM) were prepared in good yields.
10-Chlorobenzanthrone (6) was synthesized from chlorobenzene by a 5-stage reaction. In the last stage, p-chlorophenyl-α-naphthylketone had been reported to give (6) only in 5% yield, but it was found that the addition of sodium chloride in the reaction medium increased the yield to 25%. (6) was treated with manganese dioxide in the mixture of polyphosphoric acid and conc. sulfuric acid to give 10, 10′-dichloro-3, 3′-dibenzanthronyl in 29% yield. By the Ullmann coupling reaction of (6), the expected 10, 10′-dibenzanthronyl could not be prepared, but dichlorodibenzanthronyl was obtained.