SU1555329A1 - Method of obtaining 1,3-bis-(3,4-dihalogen-5-oxofuran-2-yl ureas - Google Patents

Abstract

This invention relates to unsaturated dihalogen-substituted lactones, in particular the preparation of 1,3-bis- (3,4-dichloro-5-oxo-furan-2-yl) urea and 1,3-bis (3,4-dibromo-5 -oxo-furan-2-yl) urea, which is used as herbicides and desiccants in agriculture. The goal is to increase the yield of target products and simplify the process. The latter is carried out by the reaction of the corresponding 2,3-dihalogen-3-formyl-acrylic (halogen-muconic) acid with urea at their molar ratio = (1.79-2.4): 1 and 110-120 ° C for 4 - 4.5 The method allows to achieve 39.0 - 64.1% yield of the target product in one stage without using a solvent. 1 tab.

Description

The invention relates to unsaturated dihalogen-substituted lactones, specifically to a method for producing 1,3-bis- (3,4-dihalo-5-oxo-furan-2-yl) ureas, which can be used as herbicides and desiccants.

The objective of the invention is to simplify the technology and increase the yield of the target product.

EXAMPLE 1 Preparation of 1,3-bis- (3,4-dichloro-5 oxo-furan-2-yl) urea. A mixture of 8.45 g (0.05 mol) of 2,3-dichloro-3-formyl acrylic acid (chloric acid) and 1.5 g (0.025 mol) of urea (molar ratio 2: 1): is heated at 120 ° С in for 4 hours. Cool, add 10 ml of hot ethanol (70-75 ° C), stir the mixture until a homogeneous mass ("5 min.") and filter. 25 ml of ethanol, 0.5 g of activated carbon are added to the precipitate, the mixture is boiled for 10 minutes, the hot solution is filtered and left at 0 ° C for 24 hours. The precipitated precipitate of the desired product is filtered and dried under vacuum at 100 ° C within 2 h. Yield 5.8 g

(64.1%). M.p. 224-226 ° C (decomp.). Lit. m.p.-224-227 ° C (decomp.). IR (9): 1772, 1686 (CO); 3363, 3297 (NH).

NMR spectrum (S, ppm, aMCO-d6): 6.60 (d, J 9 Hz, 2H,); 8.27 (d, J 9 Hz, 2H, H).

Found,%: C 29.80; H 1.28; C1 38.10; N 7.76.

C, H4Cl4Na05.

sd

SP

one

Yu

WITH

Calculated,%: C 29.86; H 1.11; C1 39.18; N 7.7.

Example 2: Preparation of 1,3-bis- (3,4-dibromo-5-oxo-furan-2-yl) urea.

A mixture of 12.9 g (0.05 mol) of 2,3-dibromo-3-formyl acrylic (bromoic) acid and 1.5 g (0.025 mol) of ureas (2: 1 molar ratio) is heated at 120 ° C for 4 h. Cool, add 15 ml of hot ethanol (70-75 ° C), mix the mixture until a homogeneous mass (5 min) and filter. 45 ml of ethanol, 0.5 g of activated carbon are added to the precipitate, the mixture is boiled for 10 minutes, the hot solution is filtered and left at 0 ° C for 24 hours. The precipitated precipitate of the desired product is filtered and dried in vacuum at 100 ° C within 2 hours. Yield 6.1 g (45.2%). M.p. 241-2 3 ° C (decomp.). Lit., so pl. 255-2 ° C (decomp.).

X O, cm-): 1771, 1690 (CO); 3405, 3296 (NH).

PMR spectrum (S, ppm,, / lMCO-dg); 6.60 (d, J 9 Hz, 2H, -CH-); 8.22 (d, J, E Hz, 2H, NH).

Found,%: C 20.24; H 0.98; Br 58.80; N 4.82.

SCHN4Vg4NgOy.

Calculated, I: C 20.02; H 0.74; Br 59.2t; N 5.19.

The synthesis and isolation of the target products was carried out in a similar way under other reaction conditions.

50

five

0

five

The results of the examples are presented in the table.

As follows from the table, compliance with the stated parameters allows to carry out the method in one stage instead of two by a known method while simultaneously increasing the yield of chlorine derivative from 32.6% to 62.1-64.1%, and the bromine derivative from 32, 2% to 39.0-45.21 (examples 1,2,3,4,7,10,11,14,16). The output over the temperature and time intervals leads to a decrease in the yield of the target products (examples 5,6,8,9, 12,13,15,17). I

Thus, the proposed method allows the reaction to be carried out in one stage without using organic solvents while simultaneously increasing the yield of the target product.

Claims (1)

Invention Formula The method of producing 1,3-bis- (3,4-dihalo-5 oxo-furan-2-yl) urea by reacting the corresponding 2,3-dihalogen-3-formyl acrylic acid with urea at 1U-120 ° C, different so that, in order to simplify the technology and increase the yield of the target product, 2,3-digalogene-3-formyl acrylic acid and urea are taken at their molar ratio of 1.79: 1-2.4: 1, and the process lead in one stage for 4-4.5 hours 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 2: 1 2: 1 2: 1 2: 1 2: 1 2: 1 2: 1 2: 1 45.2 0.05 0.06 0.05 0.05 0.05 0.05 0.05 0.05 0.05 2: 1 2; 4: 1 1.79: 1 2: 1 2: 1 2: 1 2: 1 2: 1 2: 1 Table continuation m 4,0 M 5.0 zo 4.0 3.0 4.5 4.0 56.6 64.0 64.1 15 31 4, 5 39.0 33, AND, 38.6