Phenanthridine derivatives and related compounds

#The invention relates to novel phenanthridine derivatives, and related compounds and to pharmaceutical compositions containing them.

#The invention provides compounds of formula I ##STR2## wherein R.sup.1 and R.sup.2 are the same or different and represent hydrogen or alkyl of 1-6 carbon atoms, R.sup.3 represents hydrogen, alkyl of 1-6 carbon atoms or phenyl, X represents Na, K, Li or CSNHR.sup.4 wherein R.sup.4 is hydrogen or alkyl of 1-6 carbon atoms and n is 3, 4 or 5 and pharmaceutically acceptable acid addition salts of compounds where X is CSNHR.sup.4. The alkyl radical R.sup.1, R.sup.2, R.sup.3 or R.sup.4 may be a straight or branched chain, having from 1 to 6 carbon atoms, e.g. methyl, ethyl, n, and iso-propyl and n-, s- and t-butyl.

#Particularly preferred compounds are those in which R.sup.1 and R.sup.2 are selected from methyl and hydrogen. Also preferred are compounds wherein n is 4. Compounds wherein R.sup.3 is hydrogen are also preferred. Preferably R.sup.4 is hydrogen.

#The invention is illustrated by the following Examples.

#7,8,9,10-Tetrahydrophenanthridine hydrochloride (29 g, 0.13 mole) was dissolved in a mixture of glacial acetic acid (200 ml.) and water (10 ml.) and hydrogenated at 50 psi of hydrogen and room temperature over platinum oxide (750 mg.) until the theoretical uptake of hydrogen (0.26 mole) was observed. The solution was filtered and the solvents removed under reduced pressure. The residue was dissolved in water (100 ml.), and pH adjusted to 9 with Na.sub.2 CO.sub.3 and the solution extracted with diethyl ether (3 .times. 100 ml.). Drying (MgSO.sub.4) and evaporation of the combined organic layers gave a colourless oil, distillation of which gave the title compound (24.5 g, 99%) Bpt 110.degree.-2.degree. C./0.05 mm

#Found: C, 82.8; H, 9.3; N, 7.1%. Calc. for C.sub.13 H.sub.17 N : C, 83.4; H, 9.2; N, 7.5.