The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 04, 1977
Filed:
May. 27, 1975
Solomon Aronovich Giller, Riga, SU;
Karl Karlovich Venter, Riga, SU;
Margarita Aldonovna Trushule, Riga, SU;
Guntis Erikovich Berggrin, Riga, SU;
Robert Avgustovich Brinkmanis, Riga, SU;
Uldis Yanovich Mikstais, Olaine, SU;
Paul Alexandrovich Stankevich, Olaine, SU;
Other;
Abstract
A method of preparing 5-nitrofurfural diacetate which comprises nitration furfural or furfural diacetate at a temperature within the range of from -10.degree. to +10.degree. C; said nitration being effected by the gradual simultaneous addition of furfural or a furfural diacetate solution in acetic anhydride and a mixture of nitric and sulphuric acids into acetic anhydride at a temperature within the range of from -10.degree. to +10.degree. C under continuous stirring of the reaction mixture. In doing so, molar proportions of furfural or furfural diacetate and nitric acid and sulphuric acid are maintained equal to 1:1.1-2:0.036-0.041 respectively and said compounds are added into acetic anhydride at such rates as to maintain the nitration reaction temperature at a predetermined level. The reaction mixture resulting from the nitration is treated with water at a weight ratio between water and the starting acetic anhydride ranging from 1.1:1 to 1.8:1 respectively and at a temperature within the range of from 0.degree. to 15.degree. C; the reaction mixture is then neutralized with an alkali to a pH = 3.5 - 5 at a temperature within the range of from 0.degree. to 25.degree. C, maintained at a temperature of from 45.degree. to 55.degree. C, and the desired product is thereafter isolated from said reaction mixture.