PROCESS FOR PREPARING NEW INDOLE DERIVATIVES AND PHARMACEUTICAL COMPOSITIONS CONTAINING SUCH COMPOUNDS

Indole derivatives of Formula I (I) wherein R1 is hydrogen, alkyl of 1-6 carbon atoms, or benzyl R2 is hydrogen, alkyl of up to 4 carbon atoms, free or esterified hydroxyalkyl of up to 4 carbon atoms, or free, amidated or esterified carboxy or carboxyalkyl, R3 is hydrogen or alkyl containing 1-6 carbon atoms, R4 is hydrogen or alkyl containing 1-6 carbon atoms and R5 is hydrogen, or alkyl, alkenyl, or cycloalkyl, all of which per se contain up to 6 carbon atoms, and all of which are optionally substituted by a free or esterified carboxy group or by an optionally substituted phenyl group; or a polymethylene group of up to 8 carbon atoms linking the first indole residue to a second indole residue of Formula Ia (Ia) wherein R1, R2, R3, and R4 are as defined above, and the physiologically acceptable salts thereof with acids and, optionally, their alkali metal and alkaline earth metal salts, possess valuable pharmacological properties, such as stimulating beta -receptors and prevention of premature labor, are described.