Joint Stock Company (Jsc) “Olainfarm”

Latvian Institute of Organic Synthesis

Akciju Sabiedriba "olainfarm"

Grigory Veinberg

Ivars Kalvinsh

Aleksandrs Chernobrovijs

Maija Dambrova

Liga Zvejniece

Maksim Vorona

Ligita Karina

Ivars Kalvins

Maksims Vorona

Antons Lebedevs

Agnija Ievina

The invention relates to the R-enantiomer of N-carbamoylmethyl-4-phenyl-2-pyrrolidinone (R-Carphedon) of pharmacological value. The method of its preparation includes the N-alkylation of 4(R)-phenyl-2-pyrrolidinone with ethyl bromoacetate in the presence of a strong base and the treatment of intermediate N-ethoxycarbonylmethyl-4(R)-phenyl-2-pyrrolidinone with ammonia.

N-carbamoylmethyl-4-(R)-phenyl-2-pyrrolidinone, method of its preparation and pharmaceutical use

N-Carbamoylmethy1-4-(R)-phenyl-2-pyrrolidinone, method of its preparation and pharmaceutical use

The present invention provides a method for regeneration of chiral 2,2'-cyclopropylidene-bis(oxazolines), such as (3&R,3&#x2032;aR,8aS,8&#x2032;aS)-2,2&#x2032;-cyclopropylidenebis-[3a,8a]-dihydro-8H-indeno-[1,2-d]-oxazole and (45,4&#x2032;5,5R,5&#x2032;R)-2,2&#x2032;-cyclopropylidenebis-4,5-diphenyldihydro-4,5-oxazole, used as a part of complex catalysts for e.g. stereoselective addition reactions, from the reaction mixtures, by selective sorption of 2,2&#x2032;-cyclopropylidene-bis(oxazolines) on a sorbent, such as silica gel, isolation of the sorbent from reaction mixture, desorption of 2,2&#x2032;-cyclopropylidene-bis(oxazolines) from the sorbent with suitable organic solvent and final recovery of 2,2&#x2032;-cyclopropylidene-bis(oxazolines) from the organic solvent used for desorption process. Catalytic quality of recovered compounds does not differ from those in freshly prepared catalysts.

Regeneration of 2,2'-cyclopropylidene-bis (oxazolines)

Growing community of inventors

Riga, Latvia

Grigory Veinberg