Egyt Gyogyszervegyeszeti Gyar

Egis Gyogyszergyar

Laszlo Levai

Pal Benko

Attila Mandi

Frigyes Gorgenyi

Kalman Nagy

Daniel Bozsing

Peter Tompe

Ivan Beck

Istvan Simonyi

Janos Imre

Eva Furdyga

Gyula Mikite

Eva J Tajthy Nee Juhasz

Ilona Dinnyes Nee Nagy

Erzsebet Kiss Nee Bertok

Gyorgyi Kovanyi Nee Lax

Gyorgy Mikite

Gyorgyi Zalavari Nee Dosa

Eva Poczik

Lujza E Petocz

Katalin Grasser

Attila Kis-Tamas

Gabor Fazekas

The invention relates to a process for the preparation of dimethyl-1,4-dihydro-2,6-dimethyl-4-(2'-nitro-phenyl)-pyridine-3,5-dicarbo xylate of the Formula I ##STR1## which comprises a) reacting a compound of the general Formula II ##STR2## (wherein n is 1 or 3; if n is 1, then R stands for a group of the Formula (a) ##STR3## and if n is 3, then R represents hydrogen) with methyl acetoacetate of the Formula III

1,4,Dihydro-pyridine intermediates

The invention is directed to processes for the preparation of dimethyl-1,4-dihydro-2,6-dimethyl-4-(2'-nitrophenyl)-pyridine-3,5-dicarbox ylate by reacting 1-methoxy-1-(2'-nitrophenyl)-N-(2'-nitrophenyl)methylene methanamie or 1-(2'-nitrophenyl)-N,N'-bis-(2'-nitrophenyl) methylene methanediamine with methyl acetoacetate in the presence of an amine compound or by reacting the monomeric or trimeric from of 2-nitrobenzaldimine with methyl acetoacetate.

Process for the preparation of 1,4-dihydro-pyridine derivatives

The invention relates to novel 1-phenyl-2-amino-1,3-propanediol-N-alkyl derivatives having the general formula I ##STR1## wherein R.sub.1 is hydrogen, alkyl having from 1 to 8 carbon atoms or phenoxymethyl, and

1-Phenyl-2-amino-1,3-propanediol-N-aryloxyalkyl derivatives

A plant protecting composition with pesticidal effects contains an effective amount of at least one compound of the formula ##STR1## wherein R is a C.sub.1-20 alkyl group or a phenyl or phenyl-C.sub.1-3 alkylene group having optionally one or more C.sub.1-3 alkyl or halogen substituents on the phenyl ring, and a diluent in an amount necessary to make up the final weight of the composition. To kill plant pests, the composition is applied to growing plants either prior to or after emergence.

Plant protecting agents and methods for their use

The invention relates to a novel process for producing the threo- and erythro-isomers of 1-phenyl-2-nitro-1,3-propanediol through the aldol-type alkaline condensation of benzaldehyde and nitroethanol, wherein the reaction mixture is acidified and, if desired, the isomers are separated from the obtained isomer mixture and the obtained isomers are transformed into each other through epimerization, characterized in that the condensation and, if desired, also the epimerization are carried out in the presence of catalytical amounts of an alkaline hydroxide. The process according to the invention makes it possible to produce 1-phenyl-2-nitro-1,3-propanediol, an intermediate of the antibiotic chloramphenicol, in high yields, and in an extremely advantageous way which can be carried out simply and economically even on an industrial scale.

Process for preparing the threo- and erythro-isomers of

Growing community of inventors

Budapest, Hungary

Laszlo Levai