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A neutral α-glucosidase (EC 3.2.1.20) activity was shown to be associated with granules which are sedimentable at 10 000 g after differential centrifugation of mouse peritoneal macrophage homogenates. When the post-nuclear supernatant was centrifuged in a sucrose density gradient, high activities for neutral α-glucosidase and β-glucuronidase (EC 3.2.1.31) were detected in the bottom fractions because of aggregation of the granules. Neutral α-glucosidase-containing granules were completely disaggregated by the addition of 20 units/ml of heparin and 10 mM Tris-HCl (pH 7.2), which caused only a partial disaggregation of β-glucuronidase-containing granules. The addition of a high concentration of heparin, Tris buffer, or KCl to the gradient gave the same patterns of disaggregation of the granules. Under the condition in which about 50% of the total β-glucuronidase activity was released into the medium, depending on phagocytosis, very little α-glucosidase was released. These observations suggested that neutral α-glucosidase may localize in non-lysosomal granules.

Treatment of 4,4′-dihaloazoxybenzenes with sulfuric acid afforded 4,4′-dihaloazobenzenes (6) as the major product and 5-halo-2-(p-halophenylazo)phenols, the Wallach rearrangement products as minor products, besides 2-halo-5-(p-halophenylazo)phenols, 2-halo-4-(p-halophenylazo)phenols, and 4-(p-halophenylazo)phenols as abnormal rearrangement products. The reaction of fluoro compound gave the azophenols (3a or 5a) in the best yields. However, the ratio of 3a to 5a was found to vary with the concentration of sulfuric acid. Treatment of 4-haloazoxybenzenes with sulfuric acid gave 4-(p-halophenylazo)phenols and 4-haloazobenzenes (13) as major products together with 2-(p-halophenylazo)phenols and 5-halo-2-(phenylazo)phenols as minor products. Yields of reduction products 6 and 13 increased as the halosubstituent became heavier in the following sequence: F→Cl→Br→I.

Mechanisms of the carboxy-inversion process in the thermal decomposition of benzoyl cyclohexanecarbonyl peroxide and related diacyl peroxides have been investigated in detail by elabolate 18O-tracer experiments which involve measurements of 18O-scrambling of benzoyl cyclohexyl carbonate resulting from the initial carboxy-inversion process under the reaction conditions. A detailed analysis of the 18O-tracer experimental results reveals that the carboxy-inversion process of Case I and II peroxides involves three kinds of ion pairs. The extents of the contribution of these ion pairs in the carboxy-inversion process of benzoyl cyclohexanecarbonyl, peroxide and m-chlorobenzoyl cyclohexanecarbonyl peroxide have been determined. Details of the mechanisms of the thermal decomposition of diacyl peroxides have been discussed based on the 18O-tracer, kinetic, product-distribution and CIDNP experimental results and solvent effects on the decomposition.

Treatment of azoxybenzene with p-toluenesulfonic acid in acetic anhydride gave tosylates of 4- and 2-(phenylazo)phenols, and the corresponding acetates as by-product, besides azobenzene. However, a similar reaction of 4,4′-difluoroazoxybenzene gave 2-tosyloxy-4,4′-difluoroazobenzene as rearrangement product, besides 4-fluorophenyl tosylate and 4-fluorophenyl acetate. Meanwhile, the reaction of 4,4′-diacetoxyazoxybenzene afforded 4-acetoxyphenyl tosylate and hydroquinone diacetate in high yields. These unique reactions involve C–N bond cleavage, and may proceed through a pathway involving formation of benzenediazonium ion as the key intermediate.

Specifically 18O-labeled p-substituted benzoyl cyclohexyl carbonates (1) were prepared and heated at 45, 70 and 75°C, and novel stepwise oxygen scrambling was found to take place in 1. On being heated at 45°C, the carbonic carbonyl oxygen atom and the oxygen atom sandwiched between the two carbonyl carbon atoms of 1 were found to scramble. The 18O-scrambling among the above two and carboxylic carbonyl oxygen atoms of 1 was found to take place at 70 or 75°C. A good first order kinetic dependence was observed for the first step of the scrambling at 45°C but no substituent effect. An intramolecular mechanism involving two steps of equilibration is proposed.

Relative reactivities of aromatic nitro, nitroso, hydroxylamino, azoxy, azo and hydrazo compounds in the reduction with RSe − were found to fall in the following order

Glow discharge electrolysis of CD3CO2H in 0.006 M NaCl solution and also in carbonate-free distilled water simultaneously gives rise to both HOCD2CD2H and CD2HCO2H, indicating the coupling of OH and H radicals with the CD2CO2H radical intermediate.

Diaryl disulfides were found to be reduced smoothly to the arenethiols by BNAH in the presence of a catalytic amount of 3-methyllumiflavin under mild conditions.

Alkaline hydrolysis of alkyl nitrites and related carboxylic esters was investigated. Marked differences between alkyl nitrites and the corresponding esters in hydrolysis are as follows. (1) Alkaline hydrolysis of alkyl nitrite is much slower than that of the corresponding ester. (2) However, acid hydrolysis of alkyl nitrite is markedly faster than that of the corresponding ester. (3) There is no concurrent oxygen exchange between the nitroso-oxygen of n-hexyl nitrite and hydroxide in alkaline hydrolysis at 45.0 and 55.1°C. (4) The polar effect of substituents on the leaving alkoxide group in alkaline hydrolysis of alkyl nitrites is roughly two-fold larger than that for the esters, i.e.ρ° 1.46 for substituted benzyl nitrites, 0.994 for substituted benzyl benzoates, 0.764 for substituted benzyl acetates ρ* 2.54 for alkyl nitrites, 1.26 for alkyl benzoates, 1.28 for alkyl acetates. (5) The steric requirements for alkaline hydrolysis of alkyl nitrites are less than those for the esters, i.e. Taft δ-values 1.03 for alkyl nitrites, 1.52 for alkyl benzoates, 1.50 for alkyl acetates. These differences are rationalized in terms of the two main differences of the electrophilic centres, (1) the greater electronegativity of nitrogen than of carbon, and (2) the presence of a lone pair on nitrogen but not on carbon.

Mechanisms of the carboxy-inversion process in the thermal decomposition of benzoyl cyclohexanecarbonyl peroxide and related diacyl peroxides have been investigated in detail by elabolate 18O-tracer experiments which involve measurements of 18O-scrambling of benzoyl cyclohexyl carbonate resulting from the initial carboxy-inversion process under the reaction conditions. A detailed analysis of the 18O-tracer experimental results reveals that the carboxy-inversion process of Case I and II peroxides involves three kinds of ion pairs. The extents of the contribution of these ion pairs in the carboxy-inversion process of benzoyl cyclohexanecarbonyl, peroxide and m-chlorobenzoyl cyclohexanecarbonyl peroxide have been determined. Details of the mechanisms of the thermal decomposition of diacyl peroxides have been discussed based on the 18O-tracer, kinetic, product-distribution and CIDNP experimental results and solvent effects on the decomposition.

Kinetic studies on the ammonolysis and aminolysis of phenethyl nitrite were carried out in 61% dioxan–water. Good second-order rate constants were obtained for the reactions except that with trimethylamine which is autocatalysed by the trimethylammonium ion formed. The rate of the trimethylammonium ion catalysed reaction was obtained from the slope of the plots of apparent second-order rate constants against concentration of trimethylammonium ion. There was no general base catalysis in any of the reactions. Solvent kinetic deuterium isotope effects were found to be 1.96 and 2.21 for the reactions with methylamine and morpholine, respectively, and 2.44 for the trimethylammonium ion catalysed reaction with trimethylamine. Bronsted plots are scattered, since substitution of hydrogen by a methyl group on NH3 markedly increases the nucleophilicity, e.g. the relative rates NH3 : MeNH2 : Me2NH : Me3N were 1 : 5.5 × 102 : 5.1 × 105 : 5.3 × 106. However, logarithms of the rate constants are correlated linearly with the vertical ionization potentials of these amines. All these results suggest that the reaction is ‘orbital controlled’ and proceeds via concerted displacement of alkoxide by amine rather than addition–elimination. The results are rationalized in terms of the high electronegativity of nitrogen and the presence of a lone pair of electrons on nitrogen.