Chinoin Gyogyszer Es Vegyeszeti Termekek Gyara Rt.

Sandor Szoke

Gyorgy Lugosi

Maria Bakonyi

Gyorgy Csermely

Jeno Ghyczy

Tibor Zsolnai

Istvan Szepessy

Maria Hima Nee Toth

The invention relates to a new and improved process for the preparation of 6-demethyl-6-deoxy-6-methylene-5-oxytetracycline and the 11a-chloro derivative thereof by dehydrating 11a-chloro-5-oxytetracycline-6,12-hemiketal, which comprises treating 11a-chloro-5-oxytetracycline-6,12-hemiketal or an acid salt thereof with a dehydrating mixture formed by the reaction of chloro sulfonic acid and formic acid and isolating the 11a-chloro-6-demethyl-6-deoxy-6-methylene-5-oxytetracycline and salt thus obtained and optionally dehalogenating the same by reaction with a reducing agent. The advantage of the process of the present invention is that it is simple, economical and suitable for industrial scale manufacture and provides a pure product of high quality by excellent yields.

Process for the preparation of

The invention concerns a new process for the preparation of biologically active 2-[(alkoxycarbonyl)amino]-5-(alkylthio)-1H-benzimidazoles of the general formula (V) ##STR1## wherein R and R.sup.1 independently stand for alkyl having 1 to 3 carbon atoms.

Process for preparing alkylthiobenzimidazoles

This invention relates to a process for the preparation of aluminum alloys having a high reducing capacity for use in reductions in organic chemistry. According to this method a discontinuous heterodisperse superficial alloy is formed by subjecting an aluminum alloy prepared by a metallurgical process to superficial activation and/or treating aluminum with a salt of a metal having a greater normal electrode potential than that of aluminum; whereby the solution of said metal in a protic solvent is reacted with granular aluminum and/or an aluminum alloy. The catalyst prepared according to the invention is especially suitable for the reduction of a nitro or nitroso group into an amino group. The aluminum alloys having a high reducing capacity are also within the scope of the invention.

Aluminum alloys having a high reducing capacity and preparation thereof

Compounds of the formula, ##SPC1## Wherein R.sup.1 and R.sup.2 each stand for hydrogen or a group of the general

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Budapest, Hungary

Sandor Szoke