Abstract: A process for the preparation of a compound of formula (I): ##STR1## in which X and Y are identical and represent halogen, or X is halogen and Y is hydrogen, which comprises halogenating 2-methyl-6-methoxynaphthalene, of formula (II): ##STR2## in the presence of a free radical initiator.

Abstract: A process for the preparation of a compound of formula (I): ##STR1## in which X and Y are identical and represent halogen, or X is halogen and Y is hydrogen, which comprises halogenating 2-methyl-6-methoxynaphthalene, of formula (II): ##STR2## in the presence of a free radical initiator.

Abstract: A process for the preparation of a penam derivative of formula (I): ##STR1## wherein R.sup.A is hydrogen or a group of formula (Ia): ##STR2## wherein X is --CO.sub.2 R.sup.1, or SO.sub.3 R.sup.1 ; R is C.sub.1-6 alkyl, aryl, or heterocyclyl; R.sup.1 is hydrogen, or a pharmaceutically acceptable salt-forming ion or ester-forming radical, and R.sup.2 represents hydrogen or a pharmaceutically acceptable salt-forming ion or in vivo hydrolyzable ester-forming radical; which process comprises reacting a compound of formula (II): ##STR3## wherein R.sup.B is hydrogen, a removable amino blocking group, or a group of formula (IIa): ##STR4## wherein Y is --CO.sub.2 R.sup.x or --SO.sub.3 R.sup.x ; R is as defined with respect to formula (I) above; R.sup.x represents an ester-forming radical, R.sup.Y represents hydrogen, a salt-forming radical or a carboxyl-blocking group, and R.sup.

Abstract: A process for the isolation of a solid salt of p-hydroxymandelic acid, which process comprises reacting phenol with glyoxylic acid in the presence of sodium or potassium hydroxide, acidifying to a pH less than 3, extracting the resulting solution with a water-immiscible solvent to provide a solution of p-hydroxymandelic acid and precipitating the salt therefrom.