Abstract: Process for preparing pure ascorbic acid from 2-keto-L-gulonic acid or its sodium salt, by carrying out the following successive steps:esterification of 2-keto-L-gulonic acid or its sodium saltlactonization to sodium ascorbateoptional separation of the sodium ascorbatedisplacement of the ascorbic acid from its saltseparation of the sodium sulphateseparation and purification of the ascorbic acid from its methanolic or aqueous-methanolic solution.

Abstract: The hydrated complex of magnesium acetylsalicylate and urea of formula ##STR1## possesses exceptional analgesic and antipyretic properties. It may be crystallized from a solution obtained by reacting acetylsalicylic acid with magnesium carbonate in the presence of urea.

Abstract: The hydrated complex of magnesium acetylsalicylate and urea of formula ##STR1## possesses exceptional analgesic and antipyretic properties. It may be crystallized from a solution obtained by reacting acetylsalicylic acid with magnesium carbonate in the presence of urea.

Abstract: The invention provides new cephalosporin derivatives of the general formula, ##STR1## which are in the form of a bicyclooct-2-ene or bicyclooct-3-ene, in which formula R.sub.1 is a radical of the general formula ##STR2## [in which R.sub.5 is hydrogen, alkyl, vinyl, cyanomethyl, protected carboxyalkyl or a protective radical and R.sub.6 is a protective radical] or an amino-protecting radical, R.sub.2 is an acid-protecting radical and R.degree. represents various organic radicals, or alternatively R.sub.1 is an amino-protecting radical or various acyl radicals, R.sub.2 is a protective radical and R.degree. represents various organic radicals, and R.sub.3 and R.sub.4 are alkyl radicals optionally substituted by alkoxy or dialkylamino, or phenyl radicals, or --NR.sub.3 R.sub.4 forms a heterocyclic ring. These products are intermediates for the synthesis of cephalosporins having antibacterial activity.

Abstract: New thiazolo[3,2-c]-1,3-benzoxazine derivatives of the general formula (I), in which X is oxygen or sulfur, R.sub.1 and R.sub.2, which are identical or different, are hydrogen or halogen atoms or alkyl, alkoxy, alkylthio or trifluoromethyl radicals, in the 7-, 8-, 9- or 10-position, and R.sub.3 is a hydrogen atom or a carboxyl radical, their salts, if appropriate, their preparation and the medicaments in which they are present.These new derivatives are particularly useful as analgesic agents.

Abstract: .alpha.-Amino(1,3-dithiin-5-yl)-acetic acid in the D-, L-, or D,L-form and in which the amino radical is free or protected by tert.-butoxycarbonyl or 2,2,2-trichloroethoxycarbonyl is a useful intermediate in the preparation of cephalosporins having valuable antibacterial activity.