Akzo Nobel N.v.

Akzo N.v.

Manfred J Bergfeld

Ludwig Eisenhuth

Ulrich Wecker

Klaus Wohlfahrt

Jurgen Seifert

Eberhard Aust

Norbert Gutlein

J Urgen Seifert

The invention pertains to a process for the preparation of glyceraldehyde, or an acetal or a hemiacetal thereof, characterized in that 3-butene-1,2-diol is dissolved in a lower alkanol and is subjected to ozonolysis to obtain a 3-hydroperoxy-3-alkoxy-propane-1,2-diol, which is subjected to a reductive treatment to obtain a hemiacetal of glyceraldehyde, which optionally may be converted into glyceraldehyde or an acetal or hemiacetal thereof, and to a process wherein the hemiacetal of glyceraldehyde is converted to a 3-aminopropane-1,2-diol derivative, by subjecting the hemiacetal of glyceraldehyde to a reductive treatment in the presence of ammonia or a primary or secondary amine. Preferably, the hemiacetal of glyceraldehyde is subjected to a reductive treatment in the presence of an amine with the formula R,R,NH, wherein R,and R,independently are hydrogen or an alkyl group with 1-18 carbon atoms, or R,and R,together with the nitrogen atom to which they are bonded form a 5- or 6-membered ring, to give a compound with the formula R,R,N&mdash;CH,&mdash;CHOH&mdash;CH,OH, wherein R,and R,have the previously given meanings.

Process for the preparation of glyceraldehyde and derivatives thereof

Process for the preparation of Gamma-Butyrolactone and the use thereof

A process for manufacturing gamma-butyrolactone by the catalytic hydrogenation of maleic anhydride, succinic anhydride or their acids in the vapor phase in the presence of catalysts based on copper oxide and aluminum oxide in reduced form is described. The process is characterized in that a catalyst is employed to conduct the reaction which is formed on the basis of 50 to 95 % by weight copper oxide, 3 to 30 % by weight aluminum oxide and 0 to 25 % by weight of a binder. Preferably the catalyst is formed on the basis of 83.5 to 85.5 % by weight copper oxide, 9 to 11 % by weight aluminum oxide, and 4.5 to 6.5 % by weight graphite. The reaction mixture obtained can be used directly without separating off the water, e.g. for manufacturing N-methylpyrrolidone.

Process for manufacturing 2-pyrrolidone or N-alkylpyrrolidones

Level-off DP cellulose, which can be disaggregated in aqueous suspension with the application of mechanical force to give microcrystalline cellulose, is prepared by an environmentally friendly partial hydrolysis of cellulose in such a manner that the cellulose is subjected to partial hydrolysis in a pressurized reactor using water under a gas pressure of 0.1 to 60 bar of oxygen and/or carbon dioxide, measured at 20.degree. C., at a temperature of 100.degree. to 200.degree. C. until the levelling-off DP has been reached. The partial hydrolysis is preferably carried out under a gas pressure of 0.5 to 30 bar, measured at 20.degree. C., and in a temperature range from 140.degree. to 180.degree. C.

Process for the preparation of level-off DP cellulose

Alkylglycosides are manufactured by continuous reaction of monosaccharides with fatty alcohols in the presence of an acid catalyst, comprising continuously adding the monosaccharides, fatty alcohols, and catalysts to a continuous stirred-tank reactor (CSTR). The reaction takes place under steady-state conditions with a conversion of 97%.+-.2.5% relative to the monosaccharide used. Water is removed continuously from the CSTR during the reaction, and the reaction mixture is removed from the CSTR in an amount which essentially corresponds to the amount of reactants and catalysts added.

Process for continuous manufacture of alkylglycosides

In a process for the preparation of 2-mercaptobenzothiazole from aniline, sulfur and carbon disulfide under pressure and for separation of the 2-mercaptobenzothiazole from the crude reaction product by cooling and recycling the desirable intermediates and by-products into the reactor together with aniline, sulfur and carbon disulfide, the reaction is carried out using a residence time in the reactor of at least one hour to a time before the 2-mercaptobenzothiazole product thus-formed begins to decompose into undesirable intermediate products. A maximum hydrogen sulfide pressure is maintained on quenching to a temperature ranging between 220 and 280.degree. C. by mixing the crude reaction product with carbon disulfide at a temperature sufficient to obtain a homogeneous quenched mixture. The hydrogen sulfide is removed completely only after crystallization of the 2-mercaptobenzothiazole.

Process for the preparation of 2-mercaptobenzothiazole

2-(aminodithio)thiazoles and 2-(aminotrithio)thiazoles are prepared by reacting a mixture of a 2-mercaptothiazole or a dithiazolyl 2,2'-disulphide with a saturated secondary heterocyclic amine and sulphur in a reaction medium containing an inert organic solvent in the presence of an oxidant. The reaction is carried out in the present of ammonia and a catalyst containing copper, a copper compound or a cerium compound, and the oxidant is molecular oxygen or a gas containing oxygen. In particular, 2-(4-morpholinodithio)benzo-thiazole, which is technically interesting as a vulcanization accelerator, can be prepared in high product yield and virtually without by-products using the oxidant which is less expensive and can be handled with greater ease.

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Erlenbach-Mechenhard, Germany

Manfred J Bergfeld