Abstract: A 6-quinazolinesulfonyl derivative of Formula (I): ##STR1## wherein R.sub.1 is a hydrogen atom or a C.sub.1-12 alkyl group:R.sub.2 is a hydrogen atom, a C.sub.1-12 alkyl group, a C.sub.4-10 cycloalkyl group, an aryl group or an aralkyl group; andR.sub.1 and R.sub.2 may be linked directly or through an oxygen atom to form a 5- to 7-membered heterocyclic ring together with the adjacent nitrogen atom; andR.sub.3 is a ##STR2## group wherein R.sub.4 is a C.sub.1-8 alkyl group; a --HN(CH.sub.2).sub.n NH.sub.2 group wherein n is an integer of 2 to 10; or a ##STR3## group; and the pharmaceutically acceptable salt thereof; and a process for the preparation thereof. The compounds of this invention have a relaxatory action for vascular smooth muscle and are useful as a vasodilator and a hypotensor.

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: 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.