Patent GB-594218-A (GB)
Title: New monoazo dyestuffs
IPC: C09B29/08
Filed: 1945-06-29
Abstract: Monoazo dyestuffs are manufactured by coupling a diazotized 4 - nitroaniline of the general formula <FORM:0594218/IV/1> wherein X represents halogen, nitro or cyano and Y hydrogen or halogen, with the sulphuric ester, or a salt thereof, of an amine capable of coupling in the p-position to the amino group and of the general formula <FORM:0594218/IV/2> wherein R represents an alkyl radical of 5 to 8 carbon atoms and R1 a straight chain alkylene radical of 2 to 5 carbon atoms attached to N by its terminal carbon atom, and wherein R and R1 together contain not more than 10 carbon atoms, which amine may carry in the m-position to the amino group a halogen atom, a methyl group or an alkoxy group of 1 to 4 carbon atoms. Alternatively, the free hydroxyalkylamine of the general formula above is employed as coupling component, and the product is converted into its sulphuric ester by means of a known agent for this purpose, e.g. sulphuric or chlorosulphonic acid.  The products, in the form of their alkali metal or ammonium salts, dye cellulose acetate artificial silk in dischargeable red, bordeaux, violet or brown shades from a neutral, slightly acid or slightly alkaline bath, e.g. from a neutral bath containing Glauber's salt or sodium chloride, and are suitable for application from dilute or "long" liquors such as are employed in dyeing with the winch.  They may also be employed for printing cellulose acetate artificial silk and for dyeing wool, natural silk, tin-weighted silk, leather and nylon fibres or fabrics. Examples describe the production of the following dyestuffs: 2 - chloro - 4 - nitroaniline, 2 : 4 - dinitroaniline, 6 - chloro - 2 : 4 - dinitroaniline, 2 : 6 - dichloro-4-nitroaniline, 4-nitro-2-cyanoaniline or 2 - chloro - 4 - nitro - 6 - cyanoaniline --> the sodium salt of the sulphuric ester of N-n-hexyl-N - b  - hydroxyethylaniline; 2 : 6 - dichloro - 4 - nitroaniline --> the sodium salt of the sulphuric ester of N - n - hexyl - N - b  - hydroxyethyl - m - chloraniline; 4 - nitro - 2 - cyanoaniline --> the sodium salt of the sulphuric ester of N-n-hexyl-N-g -hydroxy-n-propylaniline; 2 : 4 - dinitroaniline --> the sodium salt of the sulphuric ester of N-n-octyl-N-b -hydroxyethylaniline or N - n - hexyl - N - b  - hydroxyethyl - m - toluidine; 6 - chloro - 2 : 4 - dinitroaniline --> the sodium salt of the sulphuric ester of N-n-hexyl-N-b -hydroxyethyl - m - toluidine; and 2 - chloro - 4 - nitroaniline --> the sodium salt of the sulphuric ester of N-n-amyl-N-b -hydroxyethylaniline.  In a further example, 2-chloro-4-nitroaniline is diazotized and coupled with N-n-hexyl-N-b -hydroxyethylaniline and the product is treated with sulphuric acid. Additional components specified are: diazo components: 2-bromo-4-nitroaniline, 2 : 6-dibromo-4-nitroaniline, 2 - chloro - 6 - bromo - 4 - nitroaniline and 6 - bromo - 2 : 4 - dinitroaniline; coupling components: N - n - heptyl- and N - isoamyl - N - b -hydroxyethylaniline, N-n-hexyl-N-b -hydroxy-n-propylaniline and N-n-hexyl-N-b -hydroxyethyl - m - anisidine.  Specifications 181,750, 237,739, [both in Class 2 (iii)], 429,936, 431,564, 447,561, 513,419 and 575,342 are referred to.