Abstract: The invention relates to a filter cloth for a filter press and to a method for producing said filter cloth. The inventive filter cloth has a filtration section through which the filtrate reaches a filter element of the filter press, and an edging section which rests against the edge of the filter element. The filtration area is provided with a cloth that differs from that of the edging section. The filtration area is woven from monofil yarns while multifil yarns are woven into the edging section.

Abstract: 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 orthoforma

Abstract: Pure and extremely stable crystalline (6R)-tetrahydrofolic acids, absolutely inert even when exposed to air and elevated temperature without stabilizers being added, are prepared by a crystallization process at a pH of ≧2.

Abstract: The invention relates to a filter cloth for a filter press and to a method for producing said filter cloth. The inventive filter cloth has a filtration section through which the filtrate reaches a filter element of the filter press, and an edging section which rests against the edge of the filter element. The filtration area is provided with a cloth that differs from that of the edging section. The filtration area is woven from monofil yarns while multifil yarns are woven into the edging section.

Abstract: 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.

Abstract: Pure and extremely stable crystalline (6S)- and (6R)-tetrahydrofolic acids, absolutely inert even when exposed to air and elevated temperature without stabilizers being added, are prepared by a crystallization process at a pH of ≧3.5 for the preparation of crystalline (6S)-tetrahydrofolic acid and at a pH of ≧2 for the preparation of crystalline (6R)-tetrahydrofolic acid.

Abstract: 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.

Abstract: The invention relates to a process for preparing (6S)-folinic acid and its salts by recrystallization of alkaline-earth salts of (6R,S)-folinic acid and, where necessary, liberation of the acid from the alkaline-earth folinates and/or, where necessary, conversion into the alkali salts by at least one recrystallization in the presence of a base. The invention also relates to calcium-, magnesium-, potassium- and sodium-(6S)-folinates and to (6S)-folinic acid prepared in accordance with the invention.

Abstract: There are prepared compounds of the formulae ##STR1## where R is lower alkyl, chlorine, or bromine and n is an integer from 1 to 5. The compounds of formula (1) can be used to make erythro-9-(2-hydroxy-3-nonyl) hypoxanthine and its homologues and also to make the compounds of formulae (2) and (3). All three classes of compounds are useful as immunomodulators.

Abstract: There are prepared compounds of the formulae ##STR1## where R is lower alkyl, chlorine, or bromine and n is an integer from 1 to 5. The compounds of formula (1) can be used to make erythro-9-(2-hydroxy-3-nonyl) hypoxanthine and its homologues and also to make the compounds of formulae (2) and (3). All three classes of compounds are useful as immunomodulators.

Abstract: The yield of 4-methyl-5-hydroxymethyl-imidazole from the known reaction between formaldehyde and 4-methyl-imidazole can be increased greatly if the reaction is performed in a concentrated aqueous medium at pH 11-13.5, preferably 12-13.5, at a temperature of 20.degree.-60.degree. C., preferably 30.degree.-40.degree. C., with an amount of formaldehyde not exceeding 1.5 mole per mole of 4-methyl-imidazole.