1,188,610. Mono- and dis-azo dyestuffs. J. R. GEIGY A.G. 26 April, 1968 [28 April, 1967], No. 19864/68. Addition to 1,109,628. Heading C4P. The invention comprises dyestuffs containing no ionic groups forming salts in water and having the general formula wherein A is a carbocyclic or heterocyclic aromatic radical which may contain an arylazo group, one of X 1 , X 1 and X 3 is -O-, -S- or -NH- and each other X is -NH-, at least one of R 1 , R 2 and R 3 is a radical -alk -O-Z wherein alk is an optionally substituted alkylene radical and Z is H, an acyl radical or an optionally substituted hydrocarbon radical and the other R's each represent an optionally substituted alkyl, cycloalkyl, or aralkyl group or a phenyl radical bound by -O- or -S- to the pyrimidine nucleus. Preferably A is a phenyl radical having a nitro group in the o- and/or pposition to the azo link which may be further substituted or a benzthiazolyl-(2)- radical optionally substituted by chlorine, bromine, nitro, cyano, thiocyano, alkyl, alkoxy or alkylsulphonyl. Other values of A specified include naphthalene, pyrazole, thiazole, oxadiazole, thiodiazole, triazole, pyridine, benzothiazole, indazole or quinoline. They are prepared by diazotization and coupling or by acylation of the corresponding compound where at least one R 1 , R 2 and R 3 is -alk-OH. Coupling may take place in presence of methanol, D.M.F., ethylene glycol monoethylether or cetyl or oleyl polyglycol ethers. The dyestuffs give yellow, orange, red and brown shades on hydrophobic organic textile fibres e.g. polyesters, cellulose 2¢ and triacetates.