The present invention, discloses optically pure compounds of l-Norepinephrine and its acid addition salts and hydrates and process for the preparation thereof. Specifically, the present invention discloses optically pure compounds of l-Norepinephrine bitartrate, its process of preparation and pharmaceutical compositions comprising the same.

A process for preparing a silver-containing catalyst for the selective oxidation of ethylene to ethylene oxide including the steps of: (a) providing a multimodal support, (b) preparing an impregnation solution comprising a silver component, (c) impregnating, at least once, the multimodal support of step (a) with the silver-containing impregnation solution of step (b) to form an impregnated support; (d) subjecting the impregnated multimodal support from step (c) to a removal means, such as a centrifuge, at least once, for a time sufficient to remove impregnated silver impregnation solution from the multimodal support and to control the amount of silver in the pores of the multimodal support by selectively removing impregnated silver impregnation solution from a set of larger pores in the multimodal support; (e) roasting, at least once, the multimodal support after the step (d); (f) optionally, repeating the impregnation step (c), (g) optionally, repeating the centrifugation step (d), and (h) optionally, repeating the calcination step (e).

A process for preparing a silver-containing catalyst for the selective oxidation of ethylene to ethylene oxide including the steps of: (a) providing a multimodal support, (b) preparing an impregnation solution comprising a silver component, (c) impregnating, at least once, the multimodal support of step (a) with the silver-containing impregnation solution of step (b) to form an impregnated support; (d) subjecting the impregnated multimodal support from step (c) to a removal means, such as a centrifuge, at least once, for a time sufficient to remove impregnated silver impregnation solution from the multimodal support and to control the amount of silver in the pores of the multimodal support by selectively removing impregnated silver impregnation solution from a set of larger pores in the multimodal support; (e) roasting, at least once, the multimodal support after the step (d); (f) optionally, repeating the impregnation step (c), (g) optionally, repeating the centrifugation step (d), and (h) optionally, repeating the calcination step (e).

A process of preparation of O-Desmethyl tramadol through potassium hydroxide mediated demethylation of Tramadol under phase transfer conditions.

A process of preparation of O-Desmethyl tramadol through potassium hydroxide mediated demethylation of Tramadol under phase transfer conditions.

The present invention provides a process for preparation of isoproterenol hydrochloride (1a) comprising catalytic hydrogenation of 3,4-dihydroxy-2-(isopropylamino)-acetophenone hydrochloride (5a) in presence of an ion exchange resin, to provide isoproterenol hydrochloride (1a).

The present invention provides a process for preparation of isoproterenol hydrochloride (1a) comprising catalytic hydrogenation of 3,4-dihydroxy-2-(isopropylamino)-acetophenone hydrochloride (5a) in presence of an ion exchange resin, to provide isoproterenol hydrochloride (1a).

There is herein provided a compound of formula (I) or a pharmaceutically acceptable salt thereof, wherein X, R.sup.1, R.sup.2, R.sup.3, R.sup.4 and n have meanings as provided in the description.

##STR00001##

There is herein provided a compound of formula (I) or a pharmaceutically acceptable salt thereof, wherein X, R.sup.1, R.sup.2, R.sup.3, R.sup.4 and n have meanings as provided in the description.

##STR00001##

The invention relates to an absorbent solution and to a method using this solution for removing acid compounds contained in a gaseous effluent, comprising water and at least one diamine with general formula (I) as follows:

##STR00001## wherein: radicals R.sub.1, R.sub.2, R.sub.3 are each selected indiscriminately among a methyl radical and a hydroxyethyl radical, and at least one radical among R.sub.1, R.sub.2, R.sub.3 is a methyl radical.