Eprova Ag

Merck Patent Gesellschaft MIT

Neotherapeutics, Inc.

Merck Eprova Ag

Eprova Ag Forschungsinstitut

Heinrich Bollinger

Alvin Jerald Glasky

Hans Rudolf M&uuml;ller

Hans-Rudolf Muller

Ulrich Heywang

Martin Kurz

Sergio Bianchi

Hans Rudolf Müller

Ernst Felder

Peter Schwaninger

An improved method of synthesis of a 9-substituted hypoxanthine derivative comprises the steps of: (1) reacting aminocyanacetamide with triethyl orthoformate to form an imidoester derivative of aminocyanacetamide; (2) forming a compound having a reactive amino group on a hydrocarbyl moiety, the hydrocarbyl moiety being linked through an amide group to a physiologically active moiety or an esterified derivative of a physiologically active moiety including therein an esterified benzoyl group; (3) reacting the imidoester with the compound having the reactive amino group on the hydrocarbyl moiety to form a derivative of aminoimidazole-4-carboxamide substituted at the 1-position with a hydrocarbyl moiety linked through an amide group to a physiologically active moiety including therein an optionally esterified benzoyl group; (4) forming the six-membered heterocyclic ring of the purine moiety of the hypoxanthine by reacting the derivative of 5-aminoimidazole-4-carboxamide formed in step (3) with triethyl orthoformate to form a 9-substituted hypoxanthine compound substituted at the 9-position with a hydrocarbyl moiety linked through an amide group to a physiologically active moiety including therein an optionally esterified benzoyl group; and (5) hydrolyzing the ester of the optionally esterified benzoyl group if present.

Methods of synthesis for 9-substituted hypoxanthine derivatives

The bifunctional compound N-4-carboxyphenyl-3-(6-oxohydropurin-9-yl) propanamide monopotassium salt occurs in a number of crystal forms which differ in their stability. Of these forms, the most stable is designated Type I, which is a monopotassium salt monohydrate in which the water is held as water of crystallization. Other crystalline forms, designated Type II and Type III, convert to Type I. Methods are disclosed for the synthesis of Type I and for the conversion of Type II or Type III to Type I.

Crystal forms of 9-substituted hypoxanthine derivatives

With the present method, a process which can be employed industrially can be used for the first time for the direct production of aminocyanoacetamide. The method is based on the reaction of cyanoacetamide with nitrites to form nitrosocyanoacetamide at a pH of around 2 and on the subsequent catalytic hydrogenation of nitrosocyanoacetamide to form aminocyanoacetamide.

Method of producing aminocyanoacetamide

Method for debenzylation of dibenzylbiotin

The invention relates to a selective process for the preparation of N-L-.alpha.-aspartyl-L-phenylalanine-1-lower alkyl ester which comprises:

Process for the preparation of lower alkyl esters of

A method for the synthesis of serinol and serinol derivatives substituted at the nitrogen atoms by reacting a lower 1,3-dialkoxy-isopropyl halide with ammonia or an amine to form a 1,3-dialkoxy-isopropylamine and then removing the ether groups by heating with a hydrogen halide acid. The method allows the production of serinol and serinol derivatives using inexpensive starting materials in a simple manner and obtaining a high purity product which is free of interfering isomers. Novel compounds obtained by the method which are useful as pharmaceutical intermediates, X-ray contrasting agents and cytostatic or psychopharmacological drugs are also disclosed.

Process for the preparation of serinol and of serinol derivatives, and

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Beringen, Switzerland

Heinrich Bollinger