US 11,970,441 B2 · Method for preparing thionocarbamate and co-producing 2-mercaptoethanol or O-alkylthioethyl xanthate

Abstract

The invention belongs to the field of mineral flotation collector materials, and particularly discloses a method for preparing thionocarbamate. In the preparation process, xanthate and 2-haloethanol are esterified to obtain O-alkyl-S-hydroxyethyl xanthate, and then O-alkyl-S-hydroxyethyl xanthate and fatty amine are reacted to obtain a mixture of thionocarbamate and 2-mercaptoethanol. The mixture of thionocarbamate and 2-mercaptoethanol is washed with alkali, and the oil phase and water phase are separated. The oil phase and water phase are thionocarbamate and 2-hydroxyethylthiolate, respectively, and 2-mercaptoethanol is obtained by washing with an acid. 2-alkylthioethanol is obtained by reacting 2-hydroxyethanethiolate with alkyl halide, and then with carbon disulfide and alkali to prepare O-alkylthioethyl xanthate. Thionocarbamate, 2-mercaptoethanol and O-alkylthioethyl xanthate prepared by this method possess high yield and high purity. The process is green and environmentally friendly, and is beneficial to the industrialization of co-production.

Claims16

Dependent claims

A method for preparing a thionocarbamate, comprising the following steps:

step 1):
esterification reaction of a xanthate having a structure shown in formula I with 2-haloethanol to obtain an O-alkyl/alkylthioethyl-S-hydroxyethyl xanthate having a structure shown in formula II;
step 2):
aminolysis reaction of the O-alkyl/alkylthioethyl-S-hydroxyethyl xanthate with a fatty amine shown in formula III to obtain a reaction mixture of a thionocarbamate shown in formula IV and 2-mercaptoethanol;
step 3):
washing the reaction mixture obtained in step 2 with an alkali to convert the 2-mercaptoethanol in the reaction mixture to 2-hydroxyethyl thiolate, and separating the thionocarbamate as an oil phase from the 2-hydroxyethyl thiolate as an aqueous phase;
wherein, in formula I, M is Na+, K+ or NH4+;
in formula I, formula II and formula IV, R1 is C1 to C16 alkyl, C1 to C16 aryl, or alkylthioethyl shown in formula V;
in formula III and formula IV, R2 is C1 to C8 alkyl;
and
wherein, in formula V, R3 is C1 to C16 alkyl or aryl.

8 more elements

Dependencies are inferred from the claim text.

Method for preparing thionocarbamate and co-producing 2-mercaptoethanol or O-alkylthioethyl xanthate

Life of this patent

Method for preparing thionocarbamate and co-producing 2-mercaptoethanol or O-alkylthioethyl xanthate

Life of this patent

Abstract

Claims16