ChemInform Abstract: Chemistry of Urea Nitro Derivatives. Part 2. Synthesis of Nitramide from N,N′‐Dinitrourea. New Reactions of Nitramide.

Abstract

Convenient procedures for the preparation of nitramide from urea or urea derivatives are developed and new reactions of nitramide with formaldehyde, acetic anhydride as well as reactions where nitramide acts as nitrating agent are described. -(LOBANOVA, A. A.; IL'YASOV, S. G.; POPOV, N. I.; SATAEV, R. R.; Russ.

Preparation of 1,3‐Diazido‐2‐Nitro‐2‐Azapropane from Urea

“…We have previously reported 7, 8 the synthesis of N , N ′‐dinitrourea by nitrating urea with an anhydrous nitric‐sulfuric acid mixture (50/50) made by mixing calculated quantities of 97–98 % nitric acid and oleum (20 % SO 3 ). The monitoring of the urea nitration reaction by UV spectroscopy shows that dinitrourea is formed quantitatively.…”

“…In the first case, bis(hydroxymethyl)nitramine was derived by the technique reported in the literature 6: a reaction mixture prepared by nitration of urea 7, 8 was directly diluted with water followed by hydrolysis of N , N ′‐dinitrourea in the presence of excess formaldehyde (over 4 M ) at 0–60 °C, with the water layer being extracted with ethyl acetate. The oily product yield constituted 56–60 % calculated as 2 M 1,3‐dihydroxy‐2‐nitrazapropane from 1 M dinitrourea.…”

“…In the second case, N , N ′‐dinitrourea that was prepared by nitration of urea with a nitric‐sulfuric acid mixture 7, 8 was filtered off and dissolved in ethyl acetate, with the urea nitration product in ethyl acetate being mixed with excess formaldehyde at 0–40 °C to finally give bis(hydroxymethyl)nitramine in 60 % yield. We have improved this technique at the stage of the DNU separation: for the purpose of decreasing the viscosity of the spent mixed acid, trifluoroacetic acid was added to the reaction mixture in the ratio of 1 : 1 (mixed acid/trifluoroacetic acid); the reaction mixture was held for 15 min at −15 °C, and the precipitate was filtered off on a Schott funnel.…”

“…Urea (10 g, 0.167 M ) was added in portions upon stirring at a temperature between −5 and 0 °C to 40 mL of a mixed acid (50 wt‐% nitric acid and 50 wt‐% sulfuric acid, d =1.756 g cm −3 ) prepared from oleum (20 % SO 3 ) and 97 % nitric acid. After holding for 40 min at 0–5 °C, the reaction mixture was cooled to −5 °C 7, 8, trifluoroacetic acid (40 mL) was poured, and the mixture was cooled to −15 °C and held for 15 min. The resultant precipitate was collected on a Schott funnel, washed with trifluoroacetic acid (40 mL), and dried in vacuo for 30 min.…”

N‐Nitrourea Derivatives as Novel Potential Fungicides against Rhizoctonia solani: Synthesis, Antifungal Activities, and 3D‐QSAR

“…The synthetic route for target compounds 4–41 is outlined in Scheme 1. According to the reported procedures (26), 2,4,6‐trichloroaniline was nitrified by acetyl nitrate 1 to give the N ‐nitro‐ N ‐(2, 4, 6‐trichlorophenyl)amine 2 in yields of 75–86%. Then, at the presence of triethylamine as base (27), a subsequent reaction of BTC and intermediate 2 produced nitro (2,4,6‐trichlorophenyl) carbamic chloride 3 .…”