Abstract:
PROBLEM TO BE SOLVED: To provide a new process for the continuous preparation of a 5- alkoxy-substituted oxazole in high yield and high space-time yield. SOLUTION: The process for the continuous preparation of a 5-alkoxy- substituted oxazole of formula I (R 1 is a substituted or unsubstituted 1-6C alkyl; and R 2 is H or a substituted or unsubstituted 1-6C alkyl) comprises the conversion of a continuously charged α-isocyanoalkanoic acid ester of formula II to the 5-alkoxy-substituted oxazole of formula I in a reactor at ≥80°C in the presence of an assistant selected from continuously charged alcohols and esters and the continuous discharge of the reaction product from the reactor. COPYRIGHT: (C)2003,JPO
Abstract:
PROBLEM TO BE SOLVED: To provide a method for producing a 5-alkoxy-substituted oxazole, especially a 4-methyl-5-alkoxy-substituted oxazole and further a method for producing a pyridoxine derivative. SOLUTION: The method for producing the substituted oxazole is carried out as follows. An α-isocyanoalkanoic acid ester is converted into the 5-alkoxy- substituted oxazole in the presence of an assistant composed of an alcohol or an ester at >80°C. The resultant 5-alkoxy-substituted oxazole is taken out of the reactional mixture simultaneously with the conversion. COPYRIGHT: (C)2003,JPO
Abstract:
PROBLEM TO BE SOLVED: To provide a method for continuously producing a 5-alkoxy-substituted oxazole and a method for producing a pyridoxine derivative by using the same. SOLUTION: This method for obtaining a pyridoxine derivative is provided by converting an α-isocyanoalkanoic acid ester expressed by the formula II in the presence of continuously supplied base at ≥80°C temperature to a 5- alkoxy-substituted oxazole I, taking it out from a reactor at the same time with the reaction, performing a reaction of the compound I with a compound VI to make a compound VII, and acid-treating it to obtain a pyridoxine derivative IX (in formulae, R 1 is an alkyl, R 2 is H or an alkyl, R 3 , R 4 are each independently a protection group of hydroxy group). COPYRIGHT: (C)2003,JPO
Abstract:
PROBLEM TO BE SOLVED: To provide a method for producing a 5-alkoxy-substituted oxazole and a method for producing a pyridoxine derivative. SOLUTION: The 5-alkoxy-substituted oxazole is obtained by converting an α-isocyano alkylic acid ester in the presence of a base at >80°C and separating the 5-alkoxy-substituted oxazole from the reaction mixture simultaneously with the converting reaction, and the pyridoxine derivative is obtained by converting an amino acid into an amino acid ester, converting the obtained into a formamido acid ester, converting the obtained into an α-isocyanoalkyl acid ester, converting the obtained into a 5-alkoxy-substituted oxazole in the presence of a base at >80°C and separating the 5-alkoxy-substituted oxazole from the reaction mixture simultaneously with the converting reaction, reacting the obtained 5-alkoxy-substituted oxazole with a protective diol to obtain an Diels-Alder adduct and treating the obtained with an acid and removing the protective group to convert into the pyridoxine derivative. COPYRIGHT: (C)2003,JPO
Abstract:
PROBLEM TO BE SOLVED: To develop a method for producing a ketone on a large industrial scale in high selectivity without using extremely high temperature while dispensing with expensive post-treatment. SOLUTION: The cross-aldol condensation of an aldehyde and a ketone is carried out in high yield and extremely high selectivity in the case of performing the reaction in the presence of a catalyst system composed of a specific secondary amine and a >=2C carboxylic acid even in the case of a ketone and an aldehyde enabling the condensation in itself under aldol condensation condition and capable of forming an enamine.
Abstract:
The invention relates to novel comb polymers supporting, on a carbon backbone, poly-C 2 -C 4 -alkylene ether side chains A and functional groups B, which exist in the form of anionic groups at a pH > 12, and to the salts of comb polymers of this type. The invention also relates to the use of these comb polymers as additives in preparations containing a mineral binder. The polyalkylene ether side chains A have the following formula *-U-(C(O)) k -X-(Alk-O) n -Y-Z A, wherein: * represents the binding site to the carbon backbone of the comb polymer; U represents a chemical bond or an alkylene group with 1 to 8 C atoms; X represents oxygen or a group NR; k represents 0 or 1; n represents an integer whose mean value, with regard to the comb polymer, ranges from 5 to 300; Alk represents C 2 -C 4 alkylene, Alk being able to be the same or different within the group (Alk-O) n ; Y represents a linear or branched alkylene group with 2 to 8 C atoms, which can support a phenyl ring; Z represents a 5- to 10-membered nitrogen heterocyclic compound that, as ring members, can comprises, in addition to the nitrogen atom and the carbon atoms, 1, 2 or 3 additional heteroatoms selected among oxygen, nitrogen and sulfur, the nitrogen ring members being able to contain a group R', and 1 or 2 carbon ring members can exist in the form of a carbonyl group; R represents hydrogen, C 1 -C 4 alkyl or Benzyl, and; R' represents hydrogen, C 1 -C 4 alkyl or Benzyl.
Abstract:
The present invention relates to novel comb polymers which bear poly-C2-C4-alkylene ether side chains A and functional groups B which at a pH of >12 are present in the form of anionic groups on a carbon backbone and also the salts of such comb polymers. The invention also relates to the use of these comb polymers as additives in preparations comprising a mineral binder. The polyalkylene ether side chains A have the following formula: *—U—(C(O))k—X-(Alk-O)n—Y—Z A.