Merck + Co., Inc.

Joseph S Amato

Leonard M Weinstock

Sandor Karady

Raymond Cvetovich

Paul J Reider

Ichiro Shinkai

John M Williams

Edward J Grabowski

Ulf H Dolling

Thomas M Liu

James A McCauley

David L Hughes

James M McNamara

Robert A Reamer

Frederick W Hartner

Zhen Li

Apurba Bhattacharya

Robert S Hoerrner

Johnnie L Leazer, Jr

James J Bergan

Joel J Friedman

A crystalline pharmaceutically acceptable benzenesulfonate salt of Compound A of formula:

Crystalline pharmaceutically acceptable salts of an oxazolidinone derivative

The present invention relates to the process for the preparation of the substituted azetidinone having the formula: ##STR1## comprising a convergent synthesis wherein the azetidinone portion of the molecule is coupled to the lower benzodioxole portion via a base catalyzed addition to an isocyanate.

Process for preparing substituted azetidinones

An improved process for formation of a 5-oxime on avermectin derivatives comprises the treatment of the oxo-compound with hydroxylamine in aqueous isopropanol at pH 1.8-2.1.

Process for 4'-epi-acetylamino-4'-deoxy-5-oximinoavermectin B.sub.1

Anti-ulcer agents having a methylsulfinyl bridge between a substituted pyridine moiety and a substituted benzimidazole moiety are prepared by oxidizing the corresponding compounds, having a methylthio bridge, with magnesium monoperoxyphthalate in a suitable solvent. The reaction may be run in an aromatic hydrocarbon solvent, wherein the product may crystallize out of the reaction solution and may be directly isolated by filtration.

Process for the preparation of antiulcer agents

There is disclosed a novel form of avermectin compounds wherein the avermectin compounds are crystallized as alcohol solvates to greatly enhance stability of the avermectin drug during long-term storage. The avermectin compounds have utility as highly potent antiparasitic, insecticidal, and anthelmintic agents and compositions for that use are also disclosed.

Stable solvates of avermectin compounds

An improved process for formation of a 5-oxime on avermectin derivatives comprises the treatment of the oxo compound with O-(trimethylsilyl)hydroxylamine in the presence of a Lewis acid.

Process for 4'-EPI-acetylamino-4'-deoxy-5-oximinoavermectin-B.sub.1

A process for preparing compounds of the formula ##STR1## which comprises reacting an imidazolide of the formula ##STR2## with an amine of the formula NHR.sub.4 R.sub.5 in the presence of a Grignard reagent to form a compound of formula I or reacting an imidazolide of formula II with a compound of the formula R.sub.6 Mgx to form a compound of formula I.

Methods of synthesizing benign prostatic hypertropic agents and their

Disclosed is a process for preparing the R and S enantiomers of a compound of the formula; ##STR1## which comprises; (1) reacting an enzyme with a prochiral diester of the formula ##STR2## where M.sup.1 and M.sup.2 are the same, to produce a chiral monoester of the compound of formula II;

Enzymic process for preparing leukotriene antagonists

This invention relates to a novel process for preparing unsymmetrical dithioacetals and dithioketals from aryl aldehydes and ketones.

Process for unsymmetrical dithioacetals and dithioketals

A novel synthon useful in the conversion of penicillin is a compound of the formula ##STR1## wherein R.sub.3 is a number of the group consisting of trimethyl-silyl, t-butyl dimethyl silyl, trimethyl silyl, methyl, benzyl or nitrobenzyl, and R.sub.5 is the same or different member of the group R.sub.3 is prepared by the naphthalene sulfonyl azide exchange reaction with benzyl acetoacetate, p-nitrobenzylacetoacetate, or methylacetoacetate to obtain the corresponding 2-diazo compound which is then silylated in hexamethyl-disalazine.

Silyl, benzyl, p-nitrobenyl, or methyl esters of diazoacetate, a synthon

A process for preparing .alpha.-alkyl amino acids by enantioretentive .alpha.-alkylation of .alpha.-amino acids is described. The products are bioactive compounds including some useful as therapeutic agents.

Process for preparation of alpha-alkyl amino acids

A stereospecific conversion of penicillin to thienamycin, using diisopropylamine borane and magnesium trifluoroacetate to prepare the hydroxyethyl side chain and acetoacetate dianion equivalent disilylethyl to prepare the .beta.-ketoester side chain.

Stereospecific synthesis of thienamycin from penicillin

Substituted-1,2,5-thiadiazole-1-oxides, their preparation and pharmaceutical use as elastase inhibitors are disclosed.

Substituted-1,2,5-thiadiazole-1-oxide compounds, compositions and use

An improved process for the preparation of thiazoles is disclosed. The process utilizes a substituted imine and sulfur dioxide heated in the presence of a catalyst. The thiazoles are known important chemical intermediates.

Process for the preparation of thiazoles

A process is provided for preparing an ester of 7-amino-7-methoxy-3-acetoxymethyl or methyl-2- or 3-cephem-4-carboxylic acid by reaction of an imino halide ##STR1## wherein R' is a carboxyl blocking group, and R.sup.3 is an amino protecting group, X is halo, preferably bromo or chloro, and A is hydrogen or acetoxy with the following cuprous methyl complex:

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Brooklyn, NY, United States of America

Joseph S Amato