GB675611A - Improvements in or relating to substituted piperazines - Google Patents

Abstract

The invention comprises 1-dialkylcarbamyl-4-substituted piperazines of the general formula <FORM:0675611/IV (b)/1> in which R and R1 are hydrogen atoms or alkyl groups of 1 to 4 carbon atoms, R11 and R111 are hydrogen atoms or aliphatic groups and X is a sulphur atom or an imino group. The invention includes also the addition salts of the above compounds and the preparation of the compounds by reacting the corresponding 1-dialkylcarbamyl piperazines or an addition salt thereof with an alkali metal thiocyanate, an aliphatic isothiocyanate, a dialkyl-thiocarbamyl halide, cyanamide, a monoalkyl-cyanamide, a dialkyl-cyanamide or an S-alkyl isothiourea. When an alkali metal thiocyanate is one of the reagents the reaction may be carried out in aqueous solution or by fusion; reactions with an aliphatic isothiocyanate or a dialkylthiocarbamyl halide may be effected in the presence of an organic solvent, and those with cyanamide or S-alkyl isothiourea in either aqueous or alcoholic solution. In examples: (1) trans - 1 - diethylcarbamyl - 2,5 - dimethyl-4-guanylpiperazine acetate is made from trans-1 - diethylcarbamyl - 2,5 - dimethylpiperazine (I) and cyanamide; (2) 1-diethylcarbamyl-4-guanylpiperazine hemisulphate is made from 1-diethylcarbamylpiperazine (II) and S-methyl isothiourea; (3) 1-diethylcarbamyl-4-thiocarbamylpiperazine is made from (II) and potassium thiocyanate; (4) 1-diethylcarbamyl-4-ethyl-thiocarbamylpiperazine is made from (II) and ethyl isothiocyanate; (5) trans-1-diethylcarbamyl - 2,5 - dimethyl - 4 - thiocarbamylpiperazine is made from (I) and potassium thiocyanate; and (6) 1-diethylcarbamyl-4-allylthiocarbamylpiperazine from (II) and allyl isothiocyanate. Specification 631,685 is referred to.