Mitsui Toatsu Chemicals, Incorporated

Shinobu Aoki

Usaji Takaki

Isao Hara

Yoshihiro Yamamoto

Seiji Hasegawa

Koichi Takeuchi

Katsuharu Miyata

Yoshihisa Inoue

Toshio Matsuhisa

Isamu Sudo

Hiroharu Suzuki

An indigo compound is prepared from a corresponding indole compound which is unsubstituted at the 2- and 3- positions. The indole compound and an organic hydroperoxide are reacted in the presence of a catalyst which is a metal selected from the group consisting of the metals of Groups 4, 5 and 6 of the periodic table or a compound of the metal. The reaction is conducted while taking out water from a reaction system, said water being that introduced in the reaction system or formed during the reaction, or while controlling the amount of water, which is introduced in the reaction system, at a level not greater than 1 mole per mole of the indole compound.

Process for the preparation of indigo compounds

Disclosed herein is a process for preparing a corresponding cinnamate ester by reacting a styrene compound, carbon monoxide, an alcohol and oxygen by the use of (1) metallic palladium or a compound thereof, (2) a copper compound, (3) a compound of at least one metal selected from Groups 4A, 5A, 7A, 8A (the iron group only) and 2B in the Periodic Table and (4) a halogen compound as a catalyst which comprises treating the catalyst components recovered from the reaction liquid after completion of the reaction with an oxidizing agent in the presence of an organic acid to regenerate their catalytic activity, using the resulting catalyst components again in the reaction as a catalyst and repeating the foregoing procedure. The regenerated catalyst is recovered in catalytic activity to the extent of that of a fresh catalyst and thus gives a high reaction performance in the subsequent reaction. Thus, the catalyst containing expensive metal can be used circulatively.

Preparation process of cinnamate ester

A process for the preparation of an indigo compound which comprises reacting a corresponding indole compound having no substituent at the 2- and 3-positions with a percarboxylic acid in the presence of an alcohol solvent, or with heating over 60.degree. C. in the presence of an aprotic solvent.

An indigo compound is prepared by reacting an indole compound unsubstituted at the 2- and 3-positions with an organic hydroperoxide, preferably in the presence of a metallic compound catalyst capable of catalyzing the oxidation of the carton atom at the 3-position of the indole compound, such as a compound of a metal of group 4A, 5A or 6A of the periodic table.

Disclosed is a process for preparing an indigo compound in improved yield by reacting indole or other indole compound having no substituent at the 2- and 3-positions with an organic hydroperoxide in the presence of an additive selected from the group consisting of (1) a carboxyl compound and (2) a boric acid ester compound. The yield of the indigo compound can further be increased by using a metallic compound catalyst capable of oxidizing carbon atom at the 3-position of the indole compound, such as a compound of a metal of group 4A, 5A or 6A of the periodic table.

A process for the preparation of an indigo compound by reacting an indole compound having no substituent at the 2- and 3-positions with hydrogen peroxide in a liquid phase composed of at least two separate phases including an organic phase containing the indole compound and an aqueous phase containing hydrogen peroxide, or by reacting the indole compound with hydrogen peroxide in solution in an organic solvent.

The invention relates to a process for preparing a cinnamate ester comprising forming a reaction mixture of a styrene compound, an alcohol and a catalyst in a reactor; blowing a feed gas mixture of carbon monoxide, oxygen and an inert gas into the reaction mixture through at least one feed port; collecting a discharge gas flowing from the reactor and passing the gas through a condenser to form a condensate; recirculating the condensate into the reactor; blowing into the reaction mixture through at least one feed port other than the feed port(s) for the feed gas mixture, a gas selected from the groups consisting of the discharge gas and an inert gas; and isolating the cinnamate ester from the mixture.

It is disclosed that, in the process for producing polymethylene polyphenyl polycarbamates through the reaction of N-phenyl carbamate with formaldehyde or a formaldehyde-supplying substance in the presence of an acid catalyst, if the reaction is carried out in the concurrent presence of at least one compound or a mixture of at least two compounds selected from the group consisting of N-carboalkoxy (or cycloalkoxy)-2-oxa-4-aza-naphthalenes, bis(N-carboalkoxy(or cycloalkoxy)-anilino)-methanes and N,N'-dicarboalkoxy (or cycloalkoxy)aminobenzyl-anilines, the object product, polymethylene polyphenyl polycarbamate, can be obtained at a high yield. According to the present invention, also a more economical and easily aperable process for producing polymethylene polyphenyl polycarbamate is provided, by the recycling use of the named compound or compounds which have been concurrently present in the reaction system and after the reaction separated and recovered from the reaction product, and also by the recycling use of the aqueous acid solution which has been used as the catalyst, without the interceding removal of organic impurities formed in the reaction but simply with the adjustment of its acid concentration to the predetermined level.

Process for producing polymethylene polyphenyl polycarbamates

A process for preparing polymethylene polyphenyl polyisocyanates, in which N-phenyl carbamic acid esters are subjected to a condensation reaction with formaldehyde, and the reaction product containing polymethylene polyphenyl polycarbamic acid esters and unreacted N-phenyl carbamic acid esters is thermally decomposed to obtain polymethylene polyphenyl polyisocyanates.

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Yokohama, Japan

Shinobu Aoki