Abstract: A process for production of 5-fluorouracil and its derivatives which comprises reacting a cytosine compound of the formula: ##STR1## wherein R is a hydrogen atom or a saccharide residue with fluorine or fluorine fluorosulfonate (FOSO.sub.2 F) in an aqueous medium to give the corresponding 5-fluorouracil compound of the formula: ##STR2## wherein R is as defined above.

Abstract: Process for preparing 8,2'-O-anhydropurine nucleosides having a utility as intermediates for antiviral and anticarcinogenic drugs which comprises heating 2',3'-O-sulfinyl-8-oxypurine nucleosides in an aprotic polar solvent in the presence of an alkali metal, alkaline earth metal or ammonium salt of an inorganic or organic weak acid.

Abstract: 7-Aminocephalosporanic acid derivatives represented by the general formula (III), ##STR1## wherein X is hydrogen, hydroxyl, acetate or a nucleophilic residue, which are useful as a starting material for the synthesis of cephalosporin type antibiotics low in toxicity and broad in pharmacological effect can be easily prepared by allowing to react cephalosporin C or its derivative represented by the general formula (I), ##STR2## wherein X is as defined above, or a salt thereof with an .alpha.-keto derivative represented by the general formula (II), ##STR3## wherein R.sub.1 is carboxyl, aroyl or amide when R.sub.2 is hydrogen, and is carboxyl when R.sub.2 is alkyl or aryl, or its salt. In this case, the yield of the 7-aminocephalosporanic acid derivatives can be remarkably improved by carrying out the reaction in the presence of hydrogen peroxide. The yield can be further improved by adding thiosulfuric acid or a salt thereof after the completion of the reaction to decompose the unreacted hydrogen peroxide.

Abstract: Novel cyclic adenosine monophosphate derivatives represented by the following general formula: ##STR1## wherein A stands for --S-- or --NH-- and n is an integer of from 2 to 12, ARE SUPERIOR TO KNOWN CYCLIC ADENOSIENE DERIVATIVES IN BIOLOGICAL AND PHARMACOLOGICAL ACTIVITIES, ESPECIALLY PDE-inhibiting activity and membrane permeability. Accordingly, these derivatives are very effective for remedying and controlling diseases caused by disorder of the intracellular cyclic adenosine monophosphate level, such as asthma and scabies. These derivaives can readily be synthesized by reacting an 8-halogeno cyclic adenosine monophosphate of the following general formula ##STR2## wherein X is a halogen atom such as bromine, with an alkali metal salt of a linear alkylmercaptan having 3 to 13 carbon atoms in the alkyl group or a linear alkylamine having 3 to 13 carbon atoms in the alkyl group.

Abstract: A process for preparing 2,2'-anhydrocytidine-5'-phosphate having an antitumor activity for cytidine-5'-phosphate which comprises heating a novel intermediate 2',3'-O-sulfinylcytidine-5'-phosphate in water, an aprotonic polar solvent or a cyclic tertiary amine, and a novel intermediate, 2',3'-O-sulfinyl-cytidine-5'-phosphate represented by the formula (I) ##STR1## and a process for preparing the intermediate 2',3'-O-sulfinyl-cytidine-5'-phosphate which comprises reacting cytidine-5'-phosphate with a thionyl halide in a polar organic solvent in the presence of a cyclic tertiary amine.