Abstract: Disclosed herein is a process for preparing a compound of structure (I): ##STR1## which comprises cyclization of a compound of structure (II) ##STR2##

Abstract: This invention comprises a process for preparing benzopyran derivatives represented by formula (I) ##STR1## in which, R.sup.1 is C.sub.1-20 alkyl, C.sub.2-20 alkenyl, C.sub.2-20 alkynyl, or a group of structure (i), (ii) or (iii).

Abstract: A process for preparing substituted benzopyran derivatives which comprises a final step cyclisation of the corresponding open-chain intermediates.

Abstract: A process for the preparation of a compound of formula (A): ##STR1## wherein X is hydrogen, hydroxy, chloro, C.sub.1-6 alkoxy or phenyl C.sub.1-6 alkoxy and R.sub.a and R.sub.b are hydrogen, including acyl and phosphate derivatives thereof; which process comprises:i) the preparation of a compound of formula (I): ##STR2## wherein R.sub.1 is C.sub.1-6 alkyl, or phenyl C.sub.1-6 alkyl in which the phenyl group is optionally substituted; R.sub.2 is hydrogen, hydroxy, chlorine, C.sub.1-6 alkoxy, phenyl C.sub.1-6 alkoxy or amino; and R.sub.3 is halogen, C.sub.1-6 alkylthio, C.sub.1-6 alkylsulphonyl, azido, an amino group or a protected amino group, which process comprises the reaction of a compound of formula (II): ##STR3## with a compound of formula (VII): ##STR4## wherein Q is a leaving group, J is hydrogen or halo and R.sub.

Abstract: A process for preparing pharmaceutically active compounds of formula (A): ##STR1## wherein X is hydrogen, hydroxy, chloro, C.sub.1-6 alkoxy or phenyl C.sub.1-6 alkoxy; and R.sub.a and R.sub.b are hydrogen, or acyl or phosphate derivatives thereof, which process comprises the preparation of an intermediate of formula (I): ##STR2## wherein R.sub.1 is C.sub.1-6 alkyl, or phenyl C.sub.1-6 alkyl in which the phenyl group is optionally substituted; R.sub.2 is hydrogen, hydroxy, chlorine, C.sub.1-6 alkoxy, phenyl C.sub.1-6 alkoxy or amino; and R.sub.3 is halogen, C.sub.1-6 alkylthio, C.sub.1-6 alkylsulphonyl, azido, an amino group or a protected amino group, via the reaction of a compound of formula (II): ##STR3## wherein R.sub.2 and R.sub.3 are as defined for formula (I) with: (a) a compound of formula (III): ##STR4## wherein R.sub.4 and R.sub.5 are independently hydrogen, C.sub.1-6 alkyl, or phenyl, or R.sub.4 and R.sub.5 together are C.sub.

Abstract: A process for the preparation of a compound of formula (I) ##STR1## which process comprises reacting a compound of formula (II): ##STR2## wherein the amino group is optionally protected, with a side chain intermediate of formula (III): ##STR3## wherein Q is a leaving group, R.sub.x and R.sub.y are protected hydroxymethyl or acyloxymethyl, or group(s) convertible to hydroxymethyl or acyloxymethyl; and R.sub.z is hydrogen or a group convertible thereto; and thereafter converting the 6- and 8- chloro substituents to hydrogen by means of reduction; converting R.sub.x and R.sub.y when other than hydroxymethyl or acyloxymethyl, to hydroxymethyl or acyloxymethyl, optionally converting R.sub.x /R.sub.y hydroxymethyl to acyloxymethyl or vice versa, deprotecting the 2-amino group where necessary and converting R.sub.z, (when other than hydrogen) to hydrogen; and optionally forming a pharmaceutically acceptable salt thereof.

Abstract: A crystalline monohydrate of the compound of formula (A) or a crystalline sodium salt monohydrate of the compound of formula (A): ##STR1## having antiviral activity, processes for their preparation and their use as pharmaceuticals.