SU1622368A1 - 2,7-bis-(2-aminophenyl)-2,7-dihydro-4-methylbenzo/1,2-,3,4-/bistriazol as agent for spectrometry analysis of selenium (iv) - Google Patents

Abstract

The invention relates to heterocyclic substances, in particular 2,7-bis- (2-aminophenyl) -2,7-dihydro-4-methylbenzoЈl, 2-d: 3,4-d J bistriazole. The invention relates to a new chemical compound derived from benzobistriaeol, specifically, to 2,7-bis- (2-aminophenyl) -2,7-dihydro-4-methylbenzo}, 2-d: 3,4-d J bistriazole FORMULAH HoN as a reagent for spectrographic determination of selenium (L) ( what can be used in clinical chemistry. The goal is the creation of a new bopee chgstvitelno h - rgents for a rolled up assignment, intestines are combined with about triple 2-nitroaniline with 2,4-diakgi etr., followed by ointment, and mucous: CuSO lonoty - in pigie, sic, combined with diazotny juicy J-nitroaniline, oxide: not Cuf O 1 in pyridine and reduction with iron powder in acetic acid at reflux. The yield, calculated on nitroaniline, is about 27 / o, mp 163-164, the gross reagent makes it possible to determine selenium in the presence of salts of nickel, zinc, lead with a relative error of 2-33%; Moreover, the lower limit of detection is 0.05 µg / ml versus 0.25 for 3,3-diaminobenzidine, which I interfere with salts of nickel, cobalt, titanium, molybdenum (b +), tungsten (6+) and a chromium l 3+). 3 tab. as a reagent for the spectrophotometric determination of selenium (iV), it can be suggested that it can be used in analytical chemistry, namely, in the methods of centro-photometric determination of selenium (IV), and can be used for the analysis of various samples. The nanbolre blekit by the technical / entity by the compound Jalle with J, 3 is diamigobenchidin, KOToputft is orated with selenium (IV) in acidic, neutral us. S | to: r: o: os

Description

and alkaline solutions of a strongly colored, toluene extractable compound — pyazselenable, л 20000. The determination of selenium can also be performed directly, using a photometer of the aqueous phase, 28700.

The disadvantage of this reagent in the direct spectrophotometric determination of selenium (IV) is the interfering influence of Cr (III), Ni, Co, Ti, Mo (VI W (VI). Distillation of selenium is used to separate selenium from large amounts of these elements. complicates the analysis.

The purpose of the invention is the search for new benzor derivatives, 2-d: 3,4-dJ of bistriazole, which have an increased sensitivity of the reaction with selenium (IV) and an increased selectivity of the determination of selenium (IV) in the presence of Cr, Ni, Co, Ti, MB, W and others.

Example 1, Preparation of 2,7-bis- (2-aminophenyl) -2,7-dihydro-4-methyl-benzo Li, 2-d: 3,4-d J of bistriazole.

a) 2,4-Diamino-1-methyl-5- (2-nitrophenyl) azo-benzene (I).

13.8 g (0.1 mol) of 2-nitroaniline are isolated in 70 ml of conc. HC1 and 250 g of ice at 0 - (-5) ° C, 7.6 g (0.11 mol) of sodium nitrite in 100 ml of water. The diazo-solution is added dropwise in 30-40 minutes to a solution of 12.2 g (0.1 mol) of 2,4-diaminotoluene in 50 ml of water and 10 ml of HCl at pH 4 (the desired pH is maintained by adding 30% to the reaction mass aqueous solution of sodium acetate). Stir the mixture for 1 h at room temperature, filter the precipitate filtered off, wash with n-butanol. The yield of the crystallized product is 19 g, which is 70% for 2,4-diaminopoluene. M.p. 175-7aC.

Found: C, 57.22; H, 4.82; N, 25.85.

s, 3n,

Calculated,%: C 57.55, H 4.83, N 25.81.

b) 6-Methyl-2- (2-nitrophenyl) -5- (2H) -benzotriazolamine (II).

27.1 g (0.1 mol) of compound I are acidified in a solution of pyridine-water (400: 250 ml) 100 g of copper sulphate pentahydratl (0.4 mol) by boiling with stirring for 1 h. The reaction is cooled to room temperature the mass is drunk into a mixture of ice and water, the precipitate is filtered off,

0 Q

Q

five

five

five

washed with water, air dried to constant weight, crystallized from n-butanol. The yield of the purified product is 18.8 g, which is 70% for compound I. So pl. 160-2 ° C ..

Found,%: C 57.58; H 4.15; N 25.83.

CrtHHN, Oa

Calculated,%: C 57.99, H 4.12, N 26.01.

c) 6-Methyl-2- (2-nitrophenyl) -4- (2-nitrophenyl) (2H) -beneotriazolamine (III).

The diazo solution obtained from 13.8 g of 2-nitroaniline according to method a, is added to a solution of 26.9 g (0.1 mol) of compound II in 940 ml of DMF for 40 minutes at 20 ° C and a pH of 7 (maintained during combination by adding a 30% aqueous solution of sodium acetate). The mixture is stirred for 1 h, the precipitate is filtered off, washed with water, dried, crystallized from 90% aqueous DMF. The yield of the crystallized product was 31.4 g, which is 75% per compound II. M.p. 215-7 ° C.

Found,%: C 54.36; H 3.50, N 26.86.

C "H, 4W

Calculated,%: C 54.54; H 3.37, N 26.78.

d) 2,7-Bis- (2-nitrophenyl) -2,7-dihydro-4-methylbenzo p, 2-d: 3,4-d j bistriazole (IV).

20.9 g (0.05 mol) of compound III, 52.5 g (0.21 mol) of copper sulfate pentahydrate are oxidized under the conditions described in procedure b. The yield of the product crystallized from DMF is i3.6 g, which is 65% per compound III. M.p. 230-1E

Found,%: C 54.63, H 2.90, N 27.08.

With 9NChN6 ° 4

Calculated,%: C 54.81, H 2.90 / N 26.91.

e) 2,7-Bis- (2-aminophenyl) -2,7-dihydro-4-methylbenzoЈ1,2-d: 3,4-d J - bistriazole (V).

In the solution. 20.8 g (OJ05 mol) of compound IV in 930 ml of glacial acetic acid are added at 80-90 ° C with stirring 16.8 g (0.3 mol) of iron powder. The mixture is boiled while stirring for 1 hour. The reaction mixture, cooled to l / 20 ° C, is drunk into a mixture of ice and water, the precipitate is filtered, washed with water, dried, crystalline51

from n-butanol. Analytically pure product is obtained after column chromatography on silica gel, eluent benzene. The yield of the crystallized product is 12.5 g, which is 70% per compound IV. M.p. 163-4 ° C.

Found: C, 64.42; H, 4.50; N, 31.42.

C, N (6N8

Calculated,%: C 64.03, H 4.53, N 31.44.

Table 1 shows the PMR spectra recorded in a DMSO (+100) solution or in a SDSC solution.

The IR spectra contain characteristic bands of stretching vibrations of bonds: I) Wg (10): asym 3466, N c M3367, NH2 - (8):} 3421, N02: Sim 1533,) cmr 1346; Ii) NH (10); ZS, 3460, 3356, N0,.: Asi „1547 l) forces, 1367; Iii) NH: 3336, 168 c-c1634 N-N1606; G) 2: 0LSIM 1538,} SIM1388; Iv)} r.N1613, NbOZ, N N1548, N () 2: Oanw, 1538, QCUM1372; V) LNG:} asym 3453, 3346, 1620.

The reagent 2,7-bis- (2-aminophenyl) -2,7-dihydro-4-methylbenzo Јl, 2-d: 3,4-d dbistriazole is a pale yellow powder, well soluble in DMF, pyridine, acetic acid, when heated, soluble in acetone, alcohols, chloroform dioxane, poorly soluble in benzene hydrocarbons, insoluble in water. In solid form and stable in solutions. The reagent forms a yellow compound with selenium (IV) in a wide range of acidity: 3-11 n. HC1. The maximum light absorption of the reagent is at 295 nm, and the corresponding interaction product is at 270 and 400 nm. The ratio of products of interaction is 1: 1. The optimal amount of reagent is 4-10 M, while the basic law of light absorption is observed in the range of 0.05-14 µg selenium. Color develops when heated in a boiling water bath for 30 minutes. The lower limit of detection is 0.05 µg / ml, the molar rejection ratio is 50200. The determination of selenium is not interfered with by 500-1000 times the amount of Sn (IV), Pb, Mo (VI), Ti (III), Ni, W (VI), Zn, Mn (VII), Al, Sb (III), As, 250-fold - Cd, Cr (VI), Sb (V), 50-fold - Co. He also interferes with bromide-, fluoride-.

23686

perchlorate, phosphate ions. Interfere with the definition: Te, Fe (III), V (V), Cu, Cr (III), Hg, I, NOj.

Characteristics of the compounds are presented in table 2.

Table 2 shows that the use of 2,7-bis- (2-aminophenyl) -2,7-dihydro-4-methylbenzor, 2-d: 3,4-d J of bistriazole Yu allows to increase the sensitivity and selectivity of the determination of selenium , as well as the contrast of the analytical response.

II p and m e r 2. Determination of selenium 15 in solutions containing nickel and zinc.

A weighed sample containing 0.1 g of nickel chloride or zinc chloride and 0.2 mg of selenium is dissolved in a 100 ml volumetric flask. An aliquot of the 20 part solution (1-2 ml) is placed in

ground test tubes with ground stoppers, 6.6 ml conc. IC1, 0.4 ml of 1 "M reagent solution and brought to 10 ml with water. The tubes 25 are heated in a boiling water bath for 30 minutes and then the optical density is measured at 400 nm upon cooling to room temperature. Selenium content is determined by gauge-30 perpetual schedule.

Example 3. Determination of selenium on the background of large quantities of lead.

A sample containing 0.2 g of lead acetate and 1.0 mg of selenium is grown in a 100 ml volumetric flask. An aliquot portion of the solution (1-2 ml) is placed in graduated test tubes with ground stoppers and then proceeds as in Example 2, 4Q. The results of determination of selenium (IV) are shown in Table 3.

II p and measure 4. Determination of selenium in sulfuric acid.

In graduated tubes with 45 grated stoppers with a capacity of 15-20 ml containing 2 ml of water, place 1 ml. (, 18), 6 ml conc. . HC1, 0-5 μg of selenium and 0.4 ml of a M solution of the reagent, bring the volume of water to 50 ml with up to 10 ml. Next, a determination is made as described in Example 2.

Thus, 2,7-bis- (2-aminophenyl) -2,7-dihydro-4-methylbenzo-Ј 1,2-d: 3, 4-d J bistry Aeol is 55 sensitive and selective reagent for spectrophotometric determination of selenium, which allows the determination of selenium (IV) with high sensitivity and in iris 1622368

a sufficiently large number of mixing elements, which significantly reduces the analysis time and reduces the difficulties of the process.

Claims (1)

Invention Formula 2,7-Bis- (2-aminophenyl) -2,7-dihydro-4-methylbenzo fl, 2-d: 3,4-d Dibistriazole of formula IQ as a reagent for the spectrophotometric determination of selenium (IV). Table 1 TaOLNTS