Abstract: The process of reducing 2,4-dinitrophenol to 2-amino-4-nitrophenol by reduction with a hydrosulfide in aqueous alkaline solution at temperatures from 20.degree.-100.degree. C. is improved by maintaining the pH at 7 to 9.5 during the reduction.
Abstract: Hydrogenation of mononitroaromatic compounds, particularly nitrobenzene, nitrotoluene and their monochloro and monohydroxy ring substitution products, using hydrogen sulfide as reducing agent and a titanium dioxide catalyst at 200.degree.-400.degree. C. and atmospheric pressure.
Type:
Grant
Filed:
February 23, 1981
Date of Patent:
April 20, 1982
Assignee:
Allied Corporation
Inventors:
Charles T. Ratcliffe, Stuart L. Soled, Anthony J. Signorelli, Irving L. Mador
Abstract: A process for the preparation of 2-mercaptobenzothiazole is disclosed. The process comprises heating a reaction mixture comprising nitrosobenzene, hydrogen sulfide and carbon disulfide in a molar ratio of about 1:1.5 to 4:1 to 3, respectively, to a temperature from about 200 to about 300.degree. C., for a time sufficient to convert at least a portion of the reactants into 2-mercaptobenzothiazole. In an alternative process, there is first reacted nitrosobenzene with hydrogen sulfide in a molar ratio of about 1:1.5 to 4, at a temperature from about 20 to about 100.degree. C. for a period of time sufficient to substantially reduce the nitrosobenzene, and subsequently reacting the resulting product mixture with from about 1 to about 3 mole equivalents of carbon disulfide per mole of originally charged nitrosobenzene, at a temperature from about 200.degree. C. to about 300.degree. C.
Abstract: A process for producing p-hydroxybenzaldehyde through p-aminobenzaldehyde from p-nitrotoluene, comprising reacting p-nitrotoluene with sodium polysulphide in an alcohol-alkali aqueous solution mixed solvent in the presence or absence of an aprotic polar compound to produce p-aminobenzaldehyde, diazotizing the p-aminobenzaldehyde and then hydrolyzing the diazotized p-aminobenzaldehyde to produce p-hydroxybenzaldehyde.
Abstract: Amino substituted aromatic compounds may be prepared by treating the corresponding nitro substituted aromatic compound at an elevated temperature and pressure in the presence of a catalytic composition of matter comprising metal catalyst complexes selected from the group consisting of metal phthalocyanines and metal carbonyls in which the metal portion of the compound is a Group VIII metal. Reaction conditions which may be employed will include temperatures ranging from about 90.degree. to about 300.degree. C. and pressures ranging from about 5 to about 5000 atmospheres.