SU786266A1 - Process for producing 2-benzimidazolylarylketones - Google Patents

Description

one

This invention relates to an improved process for the preparation of 2-benzimide-. azo-slate ketones that can be used in the synthesis of new pesticides.

A known method for producing 2-benzoyl-1-methylbenzimidazole, which consists in the fact that 1-methyl-2- (a-oxybenzyl) -benzimidazop is oxidized with chromic acid anhydride Cl.

The disadvantage of this method is the low yield of the product — about 40%, calculated on the starting O-phenylenediamine, from which 1-methyl-2- (oC-hydroxybenzyl) -benzimidazole is obtained.

There is also known a method for preparing 2-benzoyl-1-methylbe 13 1 -midazole, which consists in that 2-benzoylbenzimidazole is subjected to alkylation with dimethyl sulfate in dry acetone in the presence of carbonate 2 ..

The disadvantage of this method is the inaccessibility of the starting 2-benzoylbenzimidazole, obtained by oxidation

2-benzylbenzimidazole in foot acetic acid, the use of poisonous dimethyl sulfate, the complexity of the process,

In addition, a method for preparing 2-acylimidazoles of formula t is known.

X.n o

Tf

 N

k

where P is a quaternary alkyp, substituted alkyl, aryl, mixed aryan, phenyl, biphenyl, naphthyl, pyridyl, pyrazolyl, furyl, thienyl, or a radical of the formula

: g /.

to

 ff

where A is a direct connection; -C-, -C-CHj, D

or, 1i 1

R is alkyl, ari or aralkyl. X and Y. are each independently a hydrogen atom, a halogen atom, phenyl or halondphenyl, or X and Y together with -CH "CH" supplement the benzene ring, which consists in that the imidazole of the formula XJ, l I to where R, X and Y have the above values, are reacted with a compound of the formula RC02 where B is a halogen atom, a halocarbonip, a halocarbonylmethotype or a halocarbonylphenyl or RR, and 2. is a halogen atom, in the presence of a strong polar organic solvent and a strong base at a temperature of 0-5 { , 3}. However, in this method with a good yield. In the interaction of the corresponding imidazole and acid halide kis. lots received only imidazole derivatives. From the 2-benzimidazolylaryl ketones shown, only compounds of the formula -K. And II; -c-Ar, where AV- is furi.n or 1-methylbenzimdzado and the product yield is low l / 8%, moreover, the compound of formula (k), where A | - 1-methylbenzimidazolyl, obtained by the interaction of 1-methylbenzimidazl (1 mol) and phosgene (0.5 mol). The disadvantage of this method is the duration of the process (h) and the fact that it is not possible to obtain in a high yield derivatives of 2-benzimidazolipari ketones by this method. The closest in technical and achievable effect to the proposed method is to obtain 2-benzoyl-1-methylbenzimidazole, which consists in that 1-methylbenzimidazole is reacted with AND-butyllithium in anhydrous ether at -7 ° C for 2 h, followed by treating the resulting compound with trimethiphlorosilane at -7СРС, stirring the resulting reaction mixture for 4 h at room temperature, and isolated b with a yield of 79% 2-trimethylsilyl-1-methylbenzimidazole isolated and subjected to condensation with benzoyl chloride under heating up for 4 hours 3- J. desired product yield based on 1-methylbenzimidazole was 6 5%. The disadvantage of this method is the length and complexity of the process, the use of organometallic compounds and low (-70 ° C) temperatures, and the yield of the desired product is not high enough. The aim of the invention is to simplify the process technology, increase the yield, as well as expand the range of target products. This goal is achieved by the proposed method for the preparation of 2-benzimidazole-aryl ketones of the general formula - C-Ar Ri where R is a hydrogen atom, methyl, R / 2. is a hydrogen atom, a nitro group or a methoxy group, Ar is a phenyl monosubstituted by a phenyl halide atom, mono- or disubstituted lower the alkoxy group of phenyl, which consists in the fact that the benzimidazole derivative of the formula where R and R- have the above values, is reacted with aromatic acid hporanhydride of the formula where AU has the above values, in the presence of a tertiary amine at 120-21 0 0 for 0.5–2 h. The process can be conducted without a solvent or in an absolute aprotic polar solution. Triethylamine, acetonitrile, dimethylformamide is introduced into the reaction after thoroughly drying it. Hapogenic anhydrides are preliminarily chased. Example 1. 1-Metip-2-benzoylbeneimidazop (la). To a solution of 1.85 g {0.014 mol) 1-methyl-benzimidazop in 5 mp of dimethipformamide at Buprop-3 MP (2.1 g, 0.021 mol) of triethipamine, 2.41 mp (2, & 4g, O, 021 ppm of baseoylporide and heated in Vacuum at ISO-ISS C for 1 hour with periudical agitation. After opening the ampute, the triethipamine hydrochloride is precipitated, washed with 2 MP of dimethylformamide and mediated by stirring, the solution is drunk at 150 MP with 57% inert cream. with mechanical stirring for 30 minutes, then filtered and alkalinized with 20% sodium hydroxide solution. The fallen sediment crystallizes from aqueous alcohol. The yield is 2.5 g (77%). According to the melting point (71 ° C) and IR spectrum, the substance is identical to the sample obtained in 1J. Example 2, 1-Metip-2-benzoylbenzimidazole (1a) Acylation in acetonitrile. To a solution of 1.77 g (O, O13 mop) of 1methylbenzimidazole in 7 ml of absolute acetonitrile were added 2.65 ml (1.9 g of 0.019 mg) of triethylamine, 2 mp (2.46 g, 0.019 mol) of benzoyl hydrochloride and heated in a vial of 140 ° C for 1 h, then transferred to 150 ml of dilute hydrochloric acid, and then as in Example 1. Yield 2.65 g (83%), m.p. 71 C (of CPF). Example 3. 1-Metip-2-benzoipbenzimidazole. Solventless acylation. To 1.68 g (0.0127 mol) of 1-methylbenzimidazole, 2.51 mp (1.81 g, 0, O18 mol) of triethypamine, 2.07 ml (2.52 g, 0.018 mol) of benzoyl chloride were added and heated to test tube with a stirrer, protecting the reaction mixture from the moisture of air at 14 ° C for 1 h with occasional stirring. The mixture, cooled to 50-6 ° C, is dissolved in 25 ml of acetone and poured into 150 mp of dilute hydrochloric acid. Further, as in example 1. Yield 2.5 g (83%). M.p. 71-72 0 (from alcohol). The IR spectra of all three samples are identical. Example 4. 1-Methyl-2- (O-bromo benzoyl) benzimidazole (16). To a solution of 1.15 g. (0.0087 mol) of 1-etipbenzimidazop in 4 ml of dimethylformamide add 1.40 mp (1.01 g, 0.01 mp) of triethipamine, 1.62 mp 2.21 g, 0.012 mp a) p-bromobenzoylphosphate, read and heated in an ampoupe at 120 ° C IB for 1.5 hours. The precipitate of triethylamine hydrochloride is washed, washed with 1.5 MP dimethyl formathlide, the latter is connected to the mother liquor and drank 150 MP with dilute syrup Kispoty. Then - as in example 1. Output 2.64 g (94%), so pl. 133С (from alcohol). Example 5. 1-Metip-2-P-bromobenzoip) benzimidazop. Atsipirovaniya without solvent. To 1.63 g (0.012 mp) of 1-methylbenzimidazop, add 2.5 ml (1.8 g, 0.018 mp) of triethylamine, 2.3 mp (3.97 g, 0.018 mol) of O-bromobenzoyl chloride and heat in an apparatus with After refluxing the benzimidazop, the mixture is stirred, the temperature is raised to 140 ° C and maintained for 1 hour, periodically stirring a mass of mass. Cooled to 50-6СРС, the reaction mixture is treated as in Example 3. A colorless crystalline substance is obtained with a mp. 133 ° C (from alcohol), yield 2.94 g (75%). The IR spectrum of the substance is identical to the product in Example 4. IR spectrum (SNA): 1660 (CO) cm. PMR spectrum (,,): сG4.1 ( s, ZN), 7.4 (m, 6H), 7.6 (m, 2H). Found,%: 8.8 Ss i-f Calculated,%: N8.9. Example 6. 1-Methyl-2- (and chlorobenzoyl) benzimidazole (1c). To a solution of 1.40 g (0.011 mol) of 1-methylbenzimidazole in 6 ml of dimethylformamide was added 2.2 mp (1.6 g, 0.016 mol) of triethylamine, 2 ml (2.77 g, 0.016 mol) of up-hporbenzoyl chloride and the mixture is heated in an ampoupe at 12CP C for 1.5 h. Then, as in Example 1. Yield 2.14 g (75%). A colorless cristoplic substance is obtained with m. . 129 C (from alcohol). IR spectrum (SNCO: 1660 cm (CO). PMR spectrum (CU-,): cf4, l. (s, 3N), 7.3. (m, 5H), 7.8 (m, 1H), 8.2 (m, 2H). Found,%: N 10.5. WITH ,. . Calculated,%: N 10.3. Example 7. 1-Methyl-2- (p-methoxybenzoyl) benzimidazole (1 g). Observe the sequence, 1.85 g (O, O14 mol) of 1-methylbenzimidazole, 3 mp (2.1 g, 0, O21 mol of triethylamine, 3.57 g (O, 021 mp)) are introduced into a flask with a mixer and a tight shutter. methoxychloride and heated to 8 ° -85 ° C. The semi-molten lumpy mass is stirred, the temperature is raised to 18 ° C and maintained for 1 hour. The reaction mixture, which is set to 50-60 ° C, is dissolved in 35 ml of acetone and drank in 15O ml of diluted (57 %) hydrochloric acid. Further - as in measure 1. Yield 3.21 g (86%). A colorless substance is obtained with a melting point of 92 ° C (from alcohol). IR spectrum (SCHEZ): 1650 cm ( SO) PMR-s ectr (CDCEy) sG 3.8 (s, ZN), 4.1 (s, ZN), 6.9 (d. 2H), 7.2 (m, ZN), 7.8 (m. 1H), 8.3 (m, 2H). Found: N10.5; CB -14 Calculated,%: N10.5. Example 8. 1-Methyl-2- (3,4-dimethoxybenzoyl) -benzimidazole (1d). lithium-free solubilization 1.52 g (0.012 mp) of 1-methylbenzimidazole, 2.5 ml (1.8 g, 0.018 mol) of triethylamine and 3.2 g (0.016 mol) of 3,4-dimethoxybenzoyl chloride are reacted and isolated product, as in measure 7. The yield is 2.8 g (78%). Colorless crystals with m. Pl. 130 131 C (from alcohol). IR spectrum (SNSE): 164 O cm (CO PMR spectrum (CDce): sGs, 9 (s, 6H), 4.0 (s, EH), 6.8 (d, 1P), 7.3 (m , ZN), 7.8 (m, 2H), 8D (d, 1H). Found,%: VJ 9.6 C N.b b Calculated,%: N 9.4. Example 9. 1-Methyl-2-benzoyl -5-nitrobenzimidazole. 0.9 g (0.0051 mol) 1 methyl-5-nit robenzimidazole is mixed with 1 ml (1.22 g, 0.001 mol) benzoyl chloride, 1.5 ml (1.08 g, O, O1 mole) of triethylamine and 1 ml of acetoxytrile. The mixture is heated to 195-21 ° C and stirred for 2.5 hours. After cooling, the mixture is transferred to a flask with 20 ml of acetone and 60 ml of hydrochloric acid (1: 3), boiled within 1 h, decolorize with activated charcoal and filter. The mixture is cooled to pH 9, boiled until the smell of triethylamine is cooled, and the precipitate is filtered off. The yield is 1.1 g (70%). t.nh. 191-193 C. Found,%: W 14.18. ,, 0 Calculated, %: W14.54. Example 10. 1-Methyl-2-benzoic forehead nzimi d azo L. A mixture of 5.04 g (0, O38 mol) of 1-methylbenzimidazole, 5.3 ml is heated in a three-necked flask with reflux condenser. 3.8 g, 0.038 mol) of triethylamine, 15 ml of aietonitrile, 4 ml (4.9 g, 0.038 mol) of benzoyl chloride at 170 C (thermometer in a bath) for 0.5 h. Then it is cooled to 40-6 O С and transfer t in 450 ml of 5% hydrochloric acid. Next, process as in example 1. Output 7 g (77%). T. pl. 71 ° C (from alcohol). Examples of syntheses performed in different modes (in temperature and in time) than indicated above. Example 11. l-Metip-2-benzoylbenzimidazole (1a). The test was carried out as in Example 1, but with EO-Eb C. The outputs (1a) do not exceed 0.3 g, i.e. eight%. Example 12. 1-Methyl-2-benzoylbenzimidazole (1a). The experiment was carried out as in Example 1, but the boepe is long and at. When heated for 2 hours, the yield drops to 66% (2.1 g). Five-hour heating at this temperature further lowers the yield (1.5 g, 30% ZO) and leads to the appearance of an unidentified side substance. Example 13.2-Benzoipbenzimidazole. Solventless acylation. In the reaction flask, observing the sequence and stirring, prepare a mixture of 1.06 g (0.09 mol) of benzimidazole unsubstituted for K | H group, 3.6 m (2.6 g, O, O26 mol) of triethylamine, 3 ml (3.66 g, 0, O26 mol) benzoyl chloride. Then the temperature is raised to 90 ° C and the stirring is continued for .15–20 min, after which it is brought to il40 ° C and maintained for 1–1.2 h with occasional stirring of the semi-molten reaction mass. Further, as in Example 8, with the difference that the target product is isolated with concentrated aqueous ammonia solution. Yield 1.5 g (51%) of T. pl. (from alcohol). P. p and m er 14. 1-Met1 l-5-methoxy-2-benzoylbenzimidazole. To 0.9 g (0.0056 mol) of 1-metip-5-methoxybenzimidazole, 1 ml (0.78 g) of acetonitrile, 1.5 mp (1.08 g) of triethylamine and 1 Ml (O, 08m,

Claims (2)

Claim Ag is phenyl monosubstituted with a phenyl halogen atom mono- or disubstituted with a lower apoxy group phenyl using a benzimidazole derivative and aromatic acid chloride, characterized in that, with a chain of simplifying the process technology, increasing the yield and expanding the range of target products, a benzimidazole derivative of the formula where 4 > and 1? 2. have the above meanings, are reacted with an aromatic acid chloride of the formula Ar — O where Ar has the above meanings, in the presence of a tertiary amine at 120-210 ° C for 0.5-2 hours 2. The method according to π. 1, due to the fact that the process is conducted in an absolute aprotic polar solvent.