Abstract: A magnetic tape cassette comprises a compact reel lock mechanism which includes a pair of reel lock arms engaging with outer peripheries of a pair of tape reels, a sliding member serving as a cover for a single opening through which an end of an optical tape end detecting element is inserted into the cassette casing, a cam member which provided on the sliding member for rotating the pair of reel lock arms, and a guide member guiding said sliding member. When the tape cassette is out of a recording and/or reproducing apparatus, the single opening is closed by the sliding member and the reel lock arms restrict rotation of reels. Conversely, when the tape cassette is inserted into the recording and/or reproducing apparatus, the sliding member is pushed up by the end of the optical detecting element and as a result the cam member moves upward along with said sliding member.

Abstract: 5-fluoro-2'-deoxyuridine derivatives expressed by general formula (1) and their pharmacologically permissible salts ##STR1## wherein A indicates a saturated or unsaturated divalent aliphatic hydrocarbon group having 1 to 30 carbon atoms; the letter n indicates 0 or 1, and when n is 0, it indicates that Y is directly bound to an oxygen atom; Y represents a hydrogen atom, phenyl group, or substituted phenyl group; however, when Y is a hydrogen atom, n is 1; R indicates a hydrogen atom or alcohol-protecting group.These compounds have a very strong antitumor activity.

Abstract: Novel 5- or 7-monohalogenated or 5,7-dihalogenated .sup.6 -PGI.sub.1 and 5- or 7-monohalogenated or dihalogenated PGI.sub.2 (except 5-monofluorinated PGI.sub.2). The novel halogenated prostacyclins are useful for controlling vascular actions and also in organ transplantation, extra-corporeal circulation and the like. The present invention also provides processes for preparing the novel halogenated prostacyclins.

Abstract: A novel compound selected from the group consisting of 7-(or 6- or 4-)thiaprostaglandin E.sub.1 derivatives of the formula (I). ##STR1## wherein A represents --CH.sub.2 -- or ##STR2## in which n is 0, 1 or 2, provided that only one A cut of three is ##STR3## R.sup.1 -R.sup.7 and G are as defined in the specification, the 15-epimers of said thiaprostaglandin E.sub.1 derivatives, the enatiomers of said thiaprostaglandin E.sub.1 derivatives or their 15-epimers, and mixtures of these compounds.A 7-thiaprostaglandin E.sub.1 derivative and/or its optical isomer may be prepared by reacting a 2-organo-2-cyclopentenone (II) with an organic copper-lithium compound (III) to effect conjugation reaction. A 6-thiaprostaglandin E.sub.1 derivative and/or its optical isomer may be prepared by subjecting an .alpha.,.beta.-unsaturated ketone (IV) and a thiol (V) to the Michael addition reaction.

Abstract: A compound selected from thiazolo[3,2-a]pyrimidines or their enolate derivatives represented by the following general formula ##STR1## wherein R.sup.1 and R.sup.2 are identical or different, and each represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 3 to 10 carbon atoms, a substituted or unsubstituted phenyl group, a substituted or unsubstituted cycloaliphatic group having 3 to 8 carbon atoms, a substituted or unsubstituted phenylalkyl group or a substituted or unsubstituted acyl group having 2 to 7 carbon atoms, provided that R.sup.1 and R.sup.2 are not simultaneously hydrogen atoms or substituted or unsubstituted acyl groups having 2 to 7 carbon atoms; and R.sup.1 and R.sup.2, when taken together, may form, with the nitrogen atom to which they are bonded, a 5- or 6-membered ring which may further contain one or more hetero atoms;and acid addition salts of these compounds.

Abstract: A derivative of thiazolo [3,2-a] pyrimidine expressed by formula (I) ##STR1## (where R indicates a phenyl group or a benzyl group which has a halogen atom, a lower alkyl or lower alkyloxy group as a substituent group, an alicyclic group or an arylethyl group), and a process for the preparation of a compound of formula (I) comprising cyclizing a compound expressed by formula (II) by application of heat ##STR2## (where a definition of R is as same as that given in case of formula (I) and R' indicates a halogen atom or lower alkyloxy group). A drug which contains this compound as active ingredient is useful for curing autoimmune diseases such as rheumatoid arthritis, nephritis, etc.

Abstract: Novel substituted hydrazide derivatives of 7-(substituted)amino-3-methylene-cepham-4-carboxylic acids expressed by the formula ##STR1## wherein R.sub.1 represents alkyl containing at least 3 carbon atoms, cycloalkyl, or optionally substituted aryl, and one of R.sub.2 and R.sub.3 represents hydrogen with the other being hydrogen or the same as R.sub.1 ; or R.sub.1 and R.sub.2 form a heterocyclic ring optionally through a hetero atom together with the attached nitrogen and R.sub.3 represents hydrogen atom; and Z.sub.1 represents amino or protected amino; and acid addition salts thereof, which are useful as intermediates for synthesizing cephalosporin antibiotics.