GB481735A - Manufacture of nitrosamines - Google Patents

Abstract

Nitrosamines are manufactured by the action of caustic alkali on diazonium compounds of 1-amino-4-nitrilobenzenes of the general formula <FORM:0481735/IV/1> where X and Y are substituents other than hydroxyl or solubilizing groups, or on the corresponding alkali syn-diazotates, if necessary at a raised temperature. The products are intermediates for the manufacture of dyestuffs. In examples: (1) 1-amino-5-methyl-2-chloro-4-nitrilobenzene is diazotized, the diazo solution is introduced into a cold potassium hydroxide solution, and the resulting syn-diazo compound is heated with a further addition of potassium hydroxide; (2) 1-amino-2 : 5-dimethoxy-4-nitrilobenzene is similarly treated, except that caustic soda is employed; (3) 1-amino-2-methoxy-5-chloro-4-nitrilobenzene is treated as in (1); (4) a diazo solution from 1-amino-2-methoxy-5-chloro-4-nitrilobenzene is introduced into a caustic potash solution at 50-60 DEG C.; (5) 1 - amino - 5 - methoxy - 2 - diethylaminosulphonyl-4-nitrilobenzene is diazotized and the diazo solution is introduced into a cold caustic potash solution. Other starting materials specified are the 2-methyl-5-chloro-, 5-methyl-2-bromo-, 5 - ethyl - 2 - chloro-, 5 - methoxy- or 5 - ethoxy - 2 - chloro-, 2 - phenoxy - 5 - chloro-, 5 - methoxy - 2 - trifluoromethyl-, 5 - methyl-2-diethylaminosulphonyl-, 5 - methyl - 2 - methyl-sulphonyl-, 5 - methyl - 2 - butylsulphonyl-, 2 : 5-diethoxy-, 2 : 5-dimethyl-, 2 : 5-dichloro-and 2-methyl-5-methoxy-derivatives of 1-amino-4-nitrilobenzene. 1 - Amino - 4 - nitrilobenzenes of the general formula given above, and in particular the starting materials of the foregoing examples, are obtainable by diazotizing the corresponding 1-nitro-4-aminobenzenes, introducing a nitrilo-group by the Sandmeyer reaction, and reducing the nitro-group.