CH630084A5 - Process for preparing benzimidoazo[1.2-a]quinolines - Google Patents

Description

The invention relates to a process for the preparation of benzimidazo [1,2-a] quinolines of the formula I.

(I)

in which

Ri represents a hydrogen or halogen atom or a lower alkyl or alkoxy radical, a nitro, amino, acylamino, lower mono- or dialkylamino, lower trialkylammonium, cyano, carboxyl, carboxylic acid phenyl ester or carboxylic acid alkyl ester group, where the lower carboxylic acid alkyl ester groups can be substituted by hydroxyl, lower alkoxy, lower dialkylamino or lower trialkylammonium groups, or a carboxamide or carboxylic acid hydrazide group, the nitrogen atoms of which can be substituted by a lower alkyl group, with two such lower alkyl groups together with the nitrogen atom being the pyrrolidine, Pipe

Ridin-, Hexamethylenimin-, Morpholin- or Piperazinring can form, further a sulfo-, sulfonic acid phenyl or sulfonic acid alkyl ester group, wherein the lower sulfonic acid alkyl ester group can be substituted by a hydroxy, lower alkoxy, lower dialkylamino or lower trialkylammonium group or is a sulfonic acid amide group, the nitrogen atom of which can be substituted by a lower alkyl group,

R2 is a hydrogen atom or a cyano, carboxyl, carbonio acid phenyl ester or carboxylic acid alkyl ester group, where the lower carboxylic acid alkyl ester groups can be substituted by hydroxyl, lower alkoxy, lower dialkylamino or lower trialkylammonium groups, or a carboxamide or carboxamide hydrazide Nitrogen atoms can be substituted by a lower alkyl group, where two such lower alkyl groups together with the nitrogen atom can form the pyrrolidine, piperidine, hexamethyleneimine, morpholine or piperazine ring,

20 R3 + R4 each independently represent a hydrogen atom or a lower alkyl or alkoxy group or a nitro, amino, acylamino, cyano, carboxyl, carboxylic acid phenyl ester or carboxylic acid alkyl ester group, the lower carboxylic acid alkyl ester groups being substituted by hydroxyl, lower 25 alkoxy , lower dialkylamino or lower trialkylammonium groups, or a carboxamide or carboxylic acid hydrazide group, the nitrogen atoms of which can be substituted by a lower alkyl group, two such lower alkyl groups 30 together with the nitrogen atom being pyrrolidine, piperidine, hexamethyleneimine, morpholine or can form a piperazine ring mean

R5 is a hydrogen atom or a lower alkyl, cyano, carboxyl, carboxylic acid phenyl ester or carboxylic acid alkyl ester group, where the lower carboxylic acid alkyl ester groups can be substituted by hydroxyl, lower alkoxy, lower dialkylamino * or lower trialkylammonium groups, or a carboxamide or Carboxylic acid hydrazide group, the nitrogen atoms of which can be substituted by a lower alkyl group, where two such lower alkyl groups together with the nitrogen atom can form the pyrrolidine, piperidine, hexamethyleneimine, morpholine or piperazine ring, or in each case two adjacent radicals of R2, R3 , R4 and Rs together with 45 the two nuclear carbon atoms to which they are attached can form a fused-on benzene ring,

Rö represents a hydrogen atom,

R7 represents a hydrogen atom or a cyan, sulfophenyl or acetyl group or one of the groups of the formulas

50

"C ~ -NH2,

55 in which the hydrogen atoms can be substituted by lower alkyl groups or a phenyl group,

60

or

65

-

630084

in which X represents an oxygen or sulfur atom or the group NH or N-Rn and Rs and Ri 1 are lower alkyl groups and R9 and Rio independently of one another are hydrogen or halogen atoms or lower alkyl or alkoxy groups or a phenyl or naphthyl radical , or R9 and Rio, if they are adjacent, together with the two nuclear carbon atoms to which they are bonded, can form a fused-on benzene ring, which is characterized in that aldehydes of the formula II

R

pçC

(II)

in which Y represents a hydroxyl, lower alkoxy, nitro or amino group or a chlorine or bromine atom, with compounds of the formula III

(III)

in an inert solvent at temperatures from 80 to 200 ° C. and in the presence of 0.1 to 5% by weight of a strong acid or an organic base, first to give compounds of the formula IV

(IV)

condensed and the compounds of formula IV thus obtained cyclized in an inert solvent at temperatures of 110 to 300 ° C to the compounds of formula I.

If the term “lower” or “low molecular weight” is used in the above definitions in connection with aliphatic radicals, it should denote radicals with up to 6, preferably up to 4 and in particular up to 2, carbon atoms.

The condensation of compounds II and III to IV

is expediently carried out in a solvent serving as a “water tug”, preferably an aromatic hydrocarbon, in particular benzene, toluene, xylene or in chloro- or dichlorobenzene or in mixtures of such solvents, optionally with the addition of polar solvents such as dimethylformamide or dimethyl sulfoxide as solubilizer. In general, stoichiometric amounts of the reactants are used; if necessary, an excess of aldehyde of the formula II can be used. The reaction is generally carried out at normal pressure at from 80 ° to 200 ° C., preferably from 100 ° to 150 ° C., with the addition of catalytic amounts of basic or acidic catalysts suitable for Knoe venagel condensation, such as e.g. Piperazine acetate, sulfuric acid, p-toluenesulfonic acid or boric acid. 0.1 15 to 5% by weight, preferably 0.5 to 2% by weight, based on the aldehyde of the formula II, are used.

The compounds of formula V mostly crystallize out from the solvents used and can thus be easily separated off in pure form. 20 The starting compounds of formula II are known from the literature. Those of formula III are from Chem. Rev. 74, (1974), 279 ff .; FR-PS 1580 823 and US-PS 3 105 837 known or can be easily prepared analogously to the methods specified therein.

25 The compounds IV are ring-closed to give compounds of the formula I at from 110 ° to 300 ° C., preferably from 150 ° to 250 ° C., in particular from 180 ° to 220 ° C., in one of the customary inert solvents, such as chlorobenzene, o-dichlorobenzene , Trichlorobenzene, toluene, xylene, tetralin, 30 decalin, methylnaphthalene, dimethylaniline, N-methylpyrrolidone, dimethyl sulfoxide, dimethylformamide, hexamethylphosphoric trisamide or mixtures of such solvents and, if appropriate, in the presence of basic catalysts. Preferred basic catalysts 35 are tertiary organic bases such as piperidine, pyridine, N-dimethyl-aniline, triethylamine, piperidine acetate, piperazine, but inorganic compounds such as NaOH, KOH, Na2C03, K2CO3 can also be used, these preferably in water-miscible solvents . These catalysts are used in amounts of 0.1 to 5% by weight, preferably 0.5 to 2% by weight, based on the aldehyde of the formula II. Larger amounts of catalysts are possible. The catalysts boiling in the reaction temperature range can also serve as solvents, such as dimethylaniline. Such a procedure is particularly advantageous for those starting compounds which contain an NC> 2 group for Y.

The reaction time depends on the chosen reaction temperature and the nature of the substituents Y and R7, it is generally between 15 minutes and 24 hours.

The condensation of the compounds II and III to IV and the ring closure of the compounds IV to I can, as described above, take place in two stages with isolation of the intermediate stage IV. This is particularly useful when 55 R7 = CN. However, both reactions can, in particular at temperatures above 150 ° C. or when OR in the starting compound III is a hydroxyl or alkoxy group and R7 is a phenylsulfonyl group, partially or completely parallel to one another. In this case, the end product is obtained directly by heating the starting compounds at 80 ° to 200 ° C. in an inert solvent and in the presence of 0.1 to 5% by weight of a basic catalyst, as indicated above. This is particularly the case when Y in the starting compound III represents a hydroxyl or alkoxy group or when R2, Rj, R4 and R5 together mean a fused-on benzene ring. However, the stepwise process is preferred because of the purity of the products obtained. At

5

630 084

the condensation distills off YH or - for Y = NO2 - nitrous gases.

In the benzimidazoles of the formula III, the 5- and 6-positions are equivalent. The nitrogen atoms on the imi-dazol ring are also equivalent. Condensation II + III - IV - I can result in both isomer mixtures and uniform substances. Since the position of Ri in the molecule of the formula III and I is therefore not to be determined from the outset and is also not yet known, the position of Ri was identified as above.

For the preparation of compounds of the formula I with a free amino group, one starts in a known manner either from the corresponding nitro compounds or from acetylamino compounds and reduces them - preferably with iron in an acidic medium - or saponifies after the condensation to give the desired compound of the formula I.

The compounds of the formula I obtained by the condensation can be isolated in the customary manner, in particular after the reaction mixture has cooled and crystallized out, by simply suctioning off and washing the filter material with a lower-boiling solvent, such as e.g. Methanol or acetonitrile. For cleaning, they can be recrystallized from one of the solvents mentioned above. From the compounds obtained, further compounds falling under formula I can be obtained by exchanging R7, as described in DT-AS 25 10 528.

The compounds produced according to the invention show a strong fluorescence in the solid and dissolved state, which can range from reddish blue to red depending on the substitution. The compounds are useful as optical brighteners and fluorescent dyes. They are also valuable intermediates for optical brighteners and fluorescent dyes. They are characterized by very good light fastness.

The following materials may be mentioned as substrates to be lightened or dyed: lacquers, natural and synthetic fibers, such as those made from natural or regenerated cellulose, acetyl cellulose, natural and synthetic polyamides, such as wool, polyamide 6 and 6, 6, polyesters, polyolefins, polyvinyl chloride, polystyrene or polyacrylonitrile, and also films, films, tapes or moldings made from such materials.

The water-insoluble new compounds can be used in solution in organic solvents or in aqueous dispersion, advantageously with the aid of one of the customary dispersants.

The amount of compounds to be used

Formula I, based on the material to be lightened or dyed, can vary widely depending on the area of application and the desired effect. It can easily be determined by experiment and is generally between about 0.01 and 2% by weight.

The compounds of the formula I which contain one or more nitro groups generally do not show any fluorescence per se, but can be converted into the fluorescent amino compound by reduction, for example with iron, in one step.

The following examples are intended to illustrate the invention.

example 1

157 g (1 mol) of benzimidazolyl acetonitrile and 136 g (1 mol) of 2-methoxybenzaldehyde are boiled in 1500 ml of toluene with 5 g of piperidine acetate on a water separator until the evolution of H2O has ended. It is suctioned off cold and washed with a little toluene. The backlog is under

20 addition of 2 g of piperidine in 2500 ml of 1,2,4-trichlorobenzene was stirred for 5 hours at 205-210 ° C. and the methanol formed was distilled off. After suction at room temperature and washing with methanol, 196 g (80.7% of theory) of a compound of the formula are obtained

25th

30th

35 After recrystallization from dioxane / bleaching earth, light yellow crystals of mp. 261-262 ° C. are obtained.

C16H9N3 MG 243.25 mass spectrum M + / e: 243 40 absorption maximum (in DMF): 350 nm

By implementation analogous to example (1), i.e. Using the corresponding benzaldehydes or naphthaldehydes of the formula III or of 1- (benzimidazol-2-yl) acetone as the compound of the formula IV, the compounds listed in Table I are obtained. When the catalyst piperidine acetate is replaced by equimolar amounts of dimethylformamide, dimethylaniline or pyridine, the same results are obtained.

table

Example No. Formula Mp. (° C) absorption yield max. in DMF (% of theory) (nm)

630084

6

Table (continued)

Example No. Formula

Mp (° C) absorption yield max. in DMF (% of theory) (nm)

3 H3co

255 384 75

Ha CO

196-197 382 59

295 391 59

84

HgCOCC

288-290 433 95

224-225 364 36

7

Table (continued)

630084

630084

8th

Table (continued)

Example No. Formula

Mp. (° C) absorption yield max. in DMF (% of theory) (nm)

15

II »CO

291

421

77

Example 16

9.7 g (50 mmol) of 2-nitro-4-dimethylaminobenzaldehyde and 13.6 g (50 mmol) of 2-phenyisulfonylmethylenebenzimidazole are dissolved in 120 ml of toluene and 10 ml of dimethylformamide. 0.5 g of piperidine acetate is added and the mixture is held in a water separator for 3 hours at boiling temperature. After 0.8 ml of water has formed, the toluene is distilled off with the simultaneous addition of 120 ml of dimethylaniline. The mixture is then heated to 170 ° C. for a further 5 hours with evolution of nitrous gases, cooled, the precipitated product is suctioned off and recrystallized from dimethylformamide.

13 g (63% of theory) of fluorescent yellow-green crystals of the formula which, after recrystallization from methylglycol, melt at 20 288-290 ° C.

Example 18

16.6 g (0.1 mol) of 2,4-dimethoxybenzaldehyde and 17.4 g (0.1 mol) of benzimidazolyl-2-acetone are held in 150 ml of xylene for 2 hours with 0.3 g of piperidine acetate at the boiling point on a water separator . After cooling, the product is filtered off with suction, washed with toluene and then with methanol. After drying, 24.6 g (84.7% of theory) of light yellow crystals of the formula are obtained

30th

k5c

H * C

G

r

35

H- «CO '

40

C-CK,

Mol weight: 401 (mass spectrometric)

Absorption max .: 425 nm

Example 17

9.7 g (50 mmol) of 2-nitro-4-dimethylaminobenzaldehyde and 8 g (50 mmol) of benzimidazolylacetonitrile are held in 150 ml of xylene with 0.5 g of p-toluenesulfonic acid for 3 hours at the boiling point on a water separator. After 0.9 ml of water has formed, the mixture is cooled, suction filtered and washed with xylene. The xylene-moist residue is suspended in 150 ml of dimethylaniline and stirred for 5 hours at the boiling point until the evolution of nitrous gases has ended. After cooling, the product is filtered off with suction, washed well with dimethylaniline, methanol and then with water. After drying, 9.3 g (65% of theory) of fluorescent orange crystals of the formula are obtained

which melt after recrystallization from dimethylformamide at 195-197 ° C.

45 Example 19

17.2 g (0.1 mol) of 2-oxynaphthaldehyde and 17.4 g (0.1 mol) of benzimidazolyl-2-acetone are held in 150 ml of xylene with 0.5 g of piperazine for 3 hours at the boiling point on a water separator. After 3.6 ml of water have formed, the mixture is cooled, filtered off with suction, washed with xylene and then with methanol. After drying, 29 g (91% of theory) of fluorescent yellow crystals of the formula f »: *, j

H., C

which melt after recrystallization from dimethylformamide at 244-246 ° C.

630 084

Example 20

248 g (1 mol) of di-benzimidazolyl- (2) -methane and 136 g (1 mol) of 2-methoxybenzaldehyde are boiled in 1500 ml of toluene with 5 g of piperidine acetate on a water separator until 18 ml of water are separated off. It is suctioned off cold and washed with a little toluene. The residue is stirred with the addition of 2 g of piperidine in 2500 ml of 1,2,4-trichlorobenzene for 5 hours at 205-210 ° C. and the methanol formed is distilled off.

After suction at room temperature and washing with methanol, 284 g (85.0% of theory) of a compound of the formula are obtained

After recrystallization from dimethylformamide under 20 mass spectrum M + / e: 334

Clarifying with animal charcoal gives light yellow crystals of mp. Absorption maximum (in DMF): 384 nm

269-270 ° C. By implementing analogously to Example 20, the in

C22H14N4 MG 334.4 compounds listed in the following table.

table

Example No. Formula

Mp (° C) absorption yield max. in DMF (% of theory) (nm)

21st

H8co

280-281 393

85

22

HsCO

259-260 391

69

23

H5CO

142-143 370

56

630084

10th

Table (continued)

11

630084

Table (continued)

Example No. Formula

Mp. (° C) absorption yield max. in DMF (% of theory) (nm)

28

29

30th

31

32

CONH,

284-285 76.8

269-270 55

290-293 427 80

290-291 420 85

331-333 402 81

630084

12th

Table (continued)

Example No. Formula

Mp (° C) absorption yield max. in DMF (% of theory) (nm)

2, ch3 C-K

33

34

35

285-287 384

74

251-253

80

> 335

394

65

Example 36 offset. The mixture is heated for 5 hours at the boiling point in water

10.8 g (50 mmol) of 2-oxy-3-carboxy-naphthaldehyde (1) and serum separators. After cooling, suction, washing with Ace-13.3 g (50 mmol) of benzimidazol-2-yl-benzothiazol-2-yl-methane 4s tonitrile and drying, 17.5 g (77% of theory) are orange dissolved in the heat in a mixture of 100 ml of xylene and crystals of the formula 10 ml of dimethylformamide and with 0.5 g of piperidine acetate

Example 37

8 g (0.05 mol) of dibenzimidazolyl- (2) -methane and 10 g (0.05 mol) of 4-dimethylamino-2-nitro-benzaldehyde are boiled in 250 ml of toluene with 0.5 g of piperidine acetate on a water separator until the HiO development has ended. It is suctioned off cold and washed with a little toluene. The residue is taken up in 150 ml of dimethylaniline and stirred at reflux temperature for 8 hours, the ring closure being carried out with the elimination of nitrous gases. After suction at room temperature and washing with methanol for 6 s, 9.3 g (65% of theory) of the compound from Example (26) are obtained.

B

Claims (4)

630084 1 in which Ri represents a hydrogen or halogen atom or a lower alkyl or alkoxy radical, a nitro, amino, acylamino, lower mono- or dialkylamino, lower trialkylammonium, cyano, carboxyl, carboxylic acid phenyl ester or carboxylic acid alkyl ester group, where the lower carboxylic acid alkyl ester groups can be substituted by hydroxyl, lower alkoxy, lower dialkylamino or lower trialkylammonium groups, or a carboxylic acid reamide or carboxylic acid hydrazide group, the nitrogen atoms of which can be substituted by a lower alkyl group, where two such lower alkyl groups together with the nitrogen atom can form the pyrrolidine, piperidine, hexamethyleneimine, morpholine or piperazine ring, furthermore a sulfo, sulfonic acid phenyl ester or sulfonic acid alkyl ester group, the lower sulfonic acid alkyl ester group being substituted by a hydroxyl, lower alkoxy, lower dialkylamino or lower trialkylammonium group can, or a sulfonic acid amide group, whose nitrogen atom can be substituted by a lower alkyl group means R2 represents a hydrogen atom or a cyano, carboxyl, carboxylic acid phenyl ester or carboxylic acid alkyl ester group, where the lower carboxylic acid alkyl ester groups can be substituted by hydroxyl, lower alkoxy, lower dialkylamino or lower trialkylammonium groups, or a carboxamide or carbonic acid hydrazide group Alkyl group, where two such lower alkyl groups together with the nitrogen atom can form the pyrrolidine, piperidine, hexamethyleneimine, morpholine or piperazine ring, R3 + R4 independently of one another each represent a hydrogen atom or a lower alkyl or alkoxy group or a nitro, amino, acylamino, cyano, carboxyl, carboxyl phenyl ester or carboxylic acid alkyl ester group, the lower carboxylic acid alkyl ester groups being substituted by hydroxyl, lower alkoxy, lower Dialkylamino or lower trialkylammonium groups can be substituted, or a carboxamide or carboxylic acid hydrazide group, the nitrogen atoms of which can be substituted by a lower alkyl group, two such lower alkyl groups together with the nitrogen atom forming the pyrrolidine, piperidine *, hexamethyleneimine, morpholine or piperazine ring can mean R5 is a hydrogen atom or a lower alkyl, cyano, carboxyl, carboxylic acid phenyl ester or carboxylic acid alkyl ester group, the lower carboxylic acid alkyl ester groups being substituted by hydroxyl, lower alkoxy or lower dialkyl * -NH2, in which the hydrogen atoms can be substituted by lower alkyl groups 20 or a phenyl group, in which X represents an oxygen or sulfur atom or the groups NH or N-Ri 1 and Rs and Ri 1 grapple lower alkyl and R9 and Rio independently of one another hydrogen or halogen atoms or lower alkyl or alkoxy groups or a phenyl - or naphthyl radical, or R9 and Rio, if they are adjacent, together with the two nuclear carbon atoms to which they are bound 40 can form a fused-on benzene ring, characterized in that aldehydes of the formula II CHO (II) in which Y represents a hydroxyl, lower alkoxy, nitro or amino group or a chlorine or bromine atom, with ss compounds of the formula III h2c-R7 (III) 1. Process Formula I PATENT CLAIMS for making connections of (I) amino or lower trialkylammonium groups may be substituted, or a carboxamide or carboxylic acid rehydrazide group, the nitrogen atoms of which may be substituted by a lower alkyl group, two such groups whose alkyl groups together with the nitrogen atom together with the pyrrolidine, piperidine, hexamethyleneimine, Morpholine or piperazine ring means, or two adjacent residues of R2, R3, R4 and R5 together with the two nuclear carbon atoms to which they are attached 10 can form a fused benzene ring, Rô is a hydrogen atom, R7 represents a hydrogen atom or a cyan, sulfophenyl or acetyl group or one of the groups of the formulas 15 y o 2. The method according to claim 1, characterized in that one carries out the ring closure of the compounds of formula IV in the presence of 0.1 to 5 wt .-% of an inorganic or organic base. 2nd 3. The method according to claim 1, characterized in that the compounds of formula I are prepared without isolation of the intermediate of formula IV. 3rd 630084 in an inert solvent at temperatures from 80 to 200 ° C. and in the presence of 0.1 to 5% by weight of a strong acid or an organic base, first to give compounds of the formula IV (IV) condensed and the compounds of formula IV thus obtained cyclized in an inert solvent at temperatures of 110 to 300 ° C to the compounds of formula I. 4. The method according to claim 1, characterized in that one carries out the ring closure of the compounds of formula IV in an organic base as an inert solvent.