Improvements in or relating to the manufacture of heterocyclic compounds

Benziminazole glycosides of the formula where R and R1 are hydrogen, methyl or ethyl and R2 is a residue of the formula n being 2 and R3 being -CH2OR4 or -CHOR4 -CH2OR4 or else n being 3 and R3 being -H or -CH2OR4 (R4=acyl), are prepared by reacting the silver derivative of the benziminazole with the halogen derivative of the appropriate acylated sugar; the product may, if desired, be deacylated. The reaction is carried in a dry inert solvent, e.g. benzene, toluene or xylene dried over sodium. The materials are heated to 150 DEG C. or reflux temperature for 1/2 -5 hours. The product may have the a - or b -configuration or may be a mixture of both isomers. It is preferably isolated as the picrate. In the examples silver 5 : 6-dimethylbenziminazole is reacted with acetobromo-L-arabinose, acetobromoglucose, acetobromoribose and bromo-tribenzoyl-D-ribose, silver benzininazole with acetobromoribose and acetobromo-D-xylose, silver 5-methylbenziminazole with acetobromarabinose and silver 4 : 5-dimethylbenziminazole with acetobromoglucose. According to the Provisional Specification R2 is a residue of the formula -CHOH(CHOH)n CH2OH or the corresponding furano, pyrano or open-chain sugar residues, n being not greater than 4. Such residue is preferably acetylated during the reaction. The sugar may be a hexose pentose or methylpentose. Reference has been directed by the Comptroller to Specification 682,960.