The invention pertains to the synthesis of carbamate and urea compounds. In particular the invention is directed to the synthesis of carbamate and urea compounds which may be used in the production of compounds that are used to stabilize nitrocellulose. The method of the invention comprises preparing a carbamate or urea derivative comprising reacting an amine and a carbonate or carbamate in the presence of an ionic liquid.

The invention pertains to the synthesis of carbamate and urea compounds. In particular the invention is directed to the synthesis of carbamate and urea compounds which may be used in the production of compounds that are used to stabilize nitrocellulose. The method of the invention comprises preparing a carbamate or urea derivative comprising reacting an amine and a carbonate or carbamate in the presence of an ionic liquid.

A method for producing a carbamic acid salt, including contacting a carbon dioxide-containing mixed gas having a partial pressure of carbon dioxide of 0.001 atm or more and less than 1 atm with an amino group-containing organic compound in the presence of a base in at least one organic solvent selected from the group consisting of an organic solvent having 2 or more and 8 or less carbon atoms, and a method for producing a carbamic acid ester or a urea derivative using the carbamic acid salt.

A method for producing a carbamic acid salt, including contacting a carbon dioxide-containing mixed gas having a partial pressure of carbon dioxide of 0.001 atm or more and less than 1 atm with an amino group-containing organic compound in the presence of a base in at least one organic solvent selected from the group consisting of an organic solvent having 2 or more and 8 or less carbon atoms, and a method for producing a carbamic acid ester or a urea derivative using the carbamic acid salt.

The present invention disclosed a method for preparing a thickener for tight oil and gas reservoir, which relieves damages. The technical solution includes the following steps: putting a three-flask in ice; adding perfluoroalkyl alcohol, P-toluenesulfonyl chloride and pyridine; reacting for 3 h at 0-20° C.; adding filter paper; ultrasonic dispersing for 1 h; removing the filter paper; washing the solution for 3-5 times by adding dilute hydrochloric acid to collect the intermediate product (I); adding 1,3-dihydroxy-propane-2-tert-butyl carbamate and the intermediate product (I) in another three-flask; adding potassium carbonate and N,N-dimethylformamide; reacting for 4 h at 40° C. to collect the intermediate product (II); adding trifluoroacetic acid and methylene chloride into the intermediate product (II); reacting at 45° C. for 2 h; extracting and vacuum drying; and adding 1,6-hexamethylene diisocyanate; reacting for 2 h to collect the final product (III).

The present invention disclosed a method for preparing a thickener for tight oil and gas reservoir, which relieves damages. The technical solution includes the following steps: putting a three-flask in ice; adding perfluoroalkyl alcohol, P-toluenesulfonyl chloride and pyridine; reacting for 3 h at 0-20° C.; adding filter paper; ultrasonic dispersing for 1 h; removing the filter paper; washing the solution for 3-5 times by adding dilute hydrochloric acid to collect the intermediate product (I); adding 1,3-dihydroxy-propane-2-tert-butyl carbamate and the intermediate product (I) in another three-flask; adding potassium carbonate and N,N-dimethylformamide; reacting for 4 h at 40° C. to collect the intermediate product (II); adding trifluoroacetic acid and methylene chloride into the intermediate product (II); reacting at 45° C. for 2 h; extracting and vacuum drying; and adding 1,6-hexamethylene diisocyanate; reacting for 2 h to collect the final product (III).

Carmustine may be safely and efficiently produced by reacting 2-chloroethylamine hydrochloride and 1,1′-carbonyldiimidazole to afford 1,3-bis(2-chloroethyl)-1-urea, followed by nitrosation to give the final product.

The present invention disclosed a method for prparing a thickener for tight oil and gas reservoir, which relieves damages. The technical solution includes the following steps: putting a three-flask in ice; adding perfluoroalkyl alcohol, P-toluenesulfonyl chloride and pyridine; reacting for 3 h at 0-20 C.; adding filter paper; ultrasonic dispersing for 1 h; removing the filter paper; washing the solution for 3-5 times by adding dilute hydrochloric acid to collect the intermediate product (I); adding 1,3-dihydroxy-propane-2-tert-butyl carbamate and the intermediate product (I) in another three-flask; adding potassium carbonate and N,N-dimethylformamide; reacting for 4h at 40 C. to collect the intermediate product (II); adding trifluoroacetic acid and methylene chloride into the intermediate product (II); reacting at 45 C. for 2 h; extracting and vacuum drying; and adding 1,6-hexamethylene diisocyanate; reacting for 2 h to collect the final product (III).

The present invention disclosed a method for prparing a thickener for tight oil and gas reservoir, which relieves damages. The technical solution includes the following steps: putting a three-flask in ice; adding perfluoroalkyl alcohol, P-toluenesulfonyl chloride and pyridine; reacting for 3 h at 0-20 C.; adding filter paper; ultrasonic dispersing for 1 h; removing the filter paper; washing the solution for 3-5 times by adding dilute hydrochloric acid to collect the intermediate product (I); adding 1,3-dihydroxy-propane-2-tert-butyl carbamate and the intermediate product (I) in another three-flask; adding potassium carbonate and N,N-dimethylformamide; reacting for 4h at 40 C. to collect the intermediate product (II); adding trifluoroacetic acid and methylene chloride into the intermediate product (II); reacting at 45 C. for 2 h; extracting and vacuum drying; and adding 1,6-hexamethylene diisocyanate; reacting for 2 h to collect the final product (III).

The present invention relates to a process to prepare ethylene amines of the formula NH.sub.2(C.sub.2H.sub.4NH).sub.pH wherein p is at least 3 or derivatives thereof wherein one or more units NHC.sub.2H.sub.4NH may be present as a cyclic ethylene urea unit or between two units NHC.sub.2H.sub.4NH a carbonyl moiety is present, by reacting an ethanolamine-functional compound, an amine-functional compound in the presence of a carbon oxide delivering agent, wherein the molar ratio of carbon oxide delivering agent to amine-functional compound is at least 0.6 to 1.