Compounds of the formula III:

wherein R is hydrogen, alkyl of 1 to 3 carbon atoms, inclusive, or cycloalkyl of 3 to 7 carbon atoms inclusive; wherein R1 is hydrogen and alkyl defined as above; and wherein R2, R3, R4, and R5 are hydrogen, alkyl defined as above, fluorine, chlorine, bromine, nitro or alkylthio of 1 to 3 carbon atoms inclusive, are prepared by treating a compound of the formula

WHEREIN X is chlorine or bromine, and R, R2, R3, R4, and R5 are defined as above with anhydrous hydrazine or a hydrazine mineral acid salt and a base to give the compound of formula IIIA which is like III with R1 as hydrogen. Alkylation of IIIA (R1 is hydrogen) by conventional method gives the 4-N-alkylderivatives. Compounds II are produced from non-halogenated compounds I by halogenation with N-haloacid amides. The compounds of formula III (including IIIA) are sedative compounds which can be used for tranquilization of mammals.