Ryoichi Masuda

Facile synthetic methods for 3- and 5-trifluoromethyl-4-trifluoroacetyl-pyrazoles and their conversion into pyrazole-4-carboxylic acids

3- And 5-trifluoromethyl-4-trifluoroacetylpyrazoles (4 and 5) were easily synthesized in excellent yields by reaction of β,β-bis(trifluoroacetyl) vinyl ethers 1, sulfides 2, and -amines 3 with hydrazines. Hydrolysis of these compounds (4 and 5) with aqueous potassium hydroxide gave the corresponding pyrazole-4-carboxylic acids (6 and 7) in high yields

Electrophilic Chlorination by Sulfuryl Chloride in the Presence of Silica Gel

Abstract It is known that sulfuryl chloride reacts with alkyl-benzenes by a homolytic reaction mechanism and the chlorination occurs exclussively at side chains, particularly in the presence of peroxides1. Bolton reported electrophilic chlorination of alkylbenzenes by SO2-Cl2 in nitromethane as a solvent2. We now wish to communicate electrophilic chlorination of alkylbenzenes occurring by SO2-Cl2 in n-hexane or in CCl4 as solvents even in the presence of peroxides, if a small amount of silica gel is added to the reaction mixture.

A facile and convenient synthetic method for 3-trifluoroacetyl-pyrroles

3-Trifluoroacetylpyrroles are easily obtained in excellent yields by oxygen-nitrogen exchange reaction of β-trifluoroacetylvinyl ethers with 2,2-dimethoxyethylamine and subsequent cyclodehydration of the products

Synthesis and atropisomerism of meso-tetraarylporphyrins with mixed meso-aryl groups having ortho-substituents

Abstract meso-Tetraarylporphyrins having two kinds of ortho-substituted meso-aryl groups alternately at 5-, 10-, 15-, and 20-positions have been prepared by way of the modified MacDonald [2+2]-type condensation of α,α′-free aryldipyrrylmethanes with aryl aldehydes. 5,15-Di(2-acetylaminophenyl)-10,20-di-1-(2-methoxynaphthyl)porphyrin was prepared by way of two different combinations of aryldipyrryl-methanes and aryl aldehydes. The five atropisomers (αα′ββ′, αα′βα′, αβ′αβ′, αα′αβ′, αα′αα′) expected for these porphyrins were separated and characterized on the basis of the 1H NMR spectra and thermal isomerization behavior.

Silica Gel as a Catalyst for the Condensations of Aromatic Compounds with RSCl, RSCH2Cl and S2Cl2

Abstract In our recent communication1 it was reported that sulfuryl chloride reacts with alkylbenzenes to give exclussively nuclear chlorination products even in the presence of peroxides, if a little amount of silica gel is added to the reaction mixture. In this report we wish to communicate reactions of sulfenyl chlorides, chloromethyl sulfides, sulfur chloride and thionyl chloride toward aromatic compounds in the presence of silica gel.

Convenient and Selective Synthesis of 4-Trifluoromethylimidazoles

Thermally induced cyclization of 3-aryl-1,1,1- trifluoropropane-2,3-dione 2-dimethylhydrazones (5) which can be readily prepared from corresponding arenecarbaldehydes afforded selectively the title compounds (3) in high yields without formation of the regioisomers

Effect of nitrogen application at the flowering stage on the quality of soybean seeds

Abstract Application of nitrogen (N) fertilizer at the flowering stage changed the contents of storage compounds in seeds of Soybean (Glycine max L. cvs Enrei and Tamahomare). The effects of the N application on the maturation of soybean seeds were examined by comparing changes in the contents of amino acids, sugars, water, protein, and oil in seeds from N‐dressed plants (NDS) with those from undressed plants (UDS) during maturation. The application resulted in a decrease of contents of total and some amino acids (glutamine and asparagine) in developing seeds except for at the early maturation stage and in a decreased protein content of mature seeds. On the other hand, the N application led to faster accumulation of oil in developing seeds and to an increased oil content of mature seeds. Based on these results, it was concluded that the N application at the flowering stage changed the composition of solutes imported by developing seeds and resulted in variations in the contents of storage compounds. The r...

A Convenient Synthesis of 5-Trifluoromethyl-3-thiazolines and 5-Trifluoromethyl-2,3,4,5-tetrahydro-1,2,4-triazines

5-Trifluoromethyl-3-thiazolines (3) and 5-trifluoromethyl-2,3,4,5-tetra- hydro-1,2,4-triazine (5) were conveniently synthesized from 3-(N-tert- butyl-N-methylhydrazono)-1,1,1-trifluoroalkan-2-ones (1) with the use of silica gel as an effective catalyst. 5-Trifluoromethylimidazole (6) was also obtained in good yield from (1)

A facile and convenient synthesis of 5-trifluoromethyl-4-pyridazinones from aldehyde dialkylhydrazones

Abstract Several 5-trifluoromethyl-4-pyridazinones were conveniently synthesized by silica gel-mediated cyclization reaction of 1,1,1,2,2-pentafluoroalkan-3,4-dione 4-dialkylhydrazones prepared from aldehyde dialkylhydrazones and pentafluoropropionic anhydride.

Convenient synthesis of 5-trifluoromethyl-3-oxazolines and 5-trifluoromethyloxazoles

Aldehyde tert-butyl(methyl)hydrazones were acylated with trifluoroacetic anhydride to afford 3-tert-butyl(methyl)hydrazono-1,1,1-trifluoroalkan-2-ones in good yields. Several 5-hydroxy-5-trifluoromethyl-3-oxazolines were successfully synthesized by thermally induced reaction of 4 adsorbed on silica gel. Treatment of 5 with POCl 3 /pyridine and subsequent dehydrochlorination with diisopropylethylamine gave 5-trifluoromethyloxazoles in high yields