Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C231/00—Preparation of carboxylic acid amides
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C231/00—Preparation of carboxylic acid amides
  • C07C231/10—Preparation of carboxylic acid amides from compounds not provided for in groups C07C231/02 - C07C231/08

Definitions

• the invention relates to a process for the preparation of N-alkyl-substituted carboxamides.
• the process according to the invention is carried out in the presence of acids which are inert under the distillation conditions.
• Acids which can be used for the process according to the invention should form carbonium ions with components which form carbonium ions and should not lead to decomposition of the reaction mixture or of the reaction product under the distillation conditions.
• acyl residues (Y) of an acid from the range of phosphoric acids with oxidation state 5 are the acyl residues of orthophosphoric acid and polyphosphoric acid.
• phosphoric acid and sulfuric acid esters may be mentioned: dimethyl phosphate, diethyl phosphorate, monobutyl phosphate, di-2-ethylhexyl phosphate, mono-n-butyl phosphate, mono-n-butyl sulfurate, mono-2-sulfuric acid -hexyl) ester, sulfuric acid mono- (2-hydroxyethyl) ester, phosphoric acid mono- (2-hydroxyethyl) ester.
• acyl residues of phosphoric monoesters or diesters and sulfuric acid monoesters are to be mentioned as acyl residues of phosphoric monoesters or diesters and sulfuric acid monoesters.
• Examples include the following aliphatic or aromatic phosphonic acids: methanephosphonic acid, ethanephosphonic acid, methanephosphonic acid monomethyl ester, vinylphosphonic acid, ethane diphosphonic acid 1,2, phenylphosphonic acid, benzylphosphonic acid, benzylphosphonic acid mono-methyl ester.
• Examples include the following sulfonic acids: methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, butanesulfonic acid, trifluoromethanesulfonic acid, perfluorobutanesulfonic acid, benzenesulfonic acid, benzene-1,3-disulfonic acid, toluenesulfonic acid, ethane-disulfonic acid 1,2, butane disulfonic acid 1,4 , Benzyl sulfonic acid, 4- (2-dodecyl) phenyl sulfonic acid, hexadecyl and octadecyl sulfonic acid.
• sulfonic acids methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, butanesulfonic acid, trifluoromethanesulfonic acid, perfluorobutanesulfonic acid,
• carboxylic acids are: dichloroacetic acid, trichloroacetic acid, perchloropropionic acid, trifluoroacetic acid.
• Examples include the following acids which are particularly preferred for the process according to the invention: trichloroacid and trifluoroacetic acid.
• Components that are known to be activated after the Ritter reaction with acids to form a carbonium ion may be mentioned as a component that forms carbonium ions for the process according to the invention.
• these are secondary or tertiary aliphatic alcohols, esters and olefins.
• radicals R 12 to R 15 may be linked to form cycloaliphatic or aromatic, carbocyclic rings.
• Alkyl radicals (R g to R 10 , R 12 to R 16 ) can be, for example, straight-chain or branched hydrocarbon radicals having 1 to 12 carbon atoms. The following may preferably be mentioned: methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, isopentyl, hexyl and isohexyl.
• Aralkyl radicals (R B to R 10 , R 12 to R ' 6 ) can be a straight-chain or branched hydrocarbon radical with up to 6, preferably with up to 3 carbon atoms in the aliphatic part, and a radical from the benzene series, preferably phenyl and naphthyl, in the aromatic part , to have. Examples include: benzyl, phenethyl, benzhydryl and phenyldimethylmethyl.
• Aryl radicals (R 1 and R 12 to R 16 ) can be aromatic carbocyclic radicals having 5 to 8 carbon atoms, such as phenyl, naphthyl and diphenyl, preferably phenyl.
• Alkenyl residues (R'6) can be vinyl, propenyl and cyclopropenyl.
• Examples of acid residues (R ") are the sulfate, phosphate, acetate, trichloroacetate and trifluoroacetate residue.
• the process according to the invention is generally carried out in the temperature range from about 0 ° C. to about 120 ° C., preferably from 10 ° C. to 100 ° C., particularly preferably from 25 ° to 90 ° C. At temperatures above 60 ° C, it may be advantageous to carry out the reaction under pressure in order to react with unreacted or excess, low-boiling reaction components, e.g. Hydrocyanic acid to keep in the liquid reaction phase.
• low-boiling reaction components e.g. Hydrocyanic acid
• nitrile at least stoichiometrically based on the carbonium-ion-forming component; an excess of nitrile compared to carbonium-ion-forming components up to 10: 1 can advantageously be used, in general it is recommended to use the nitrile in a molar ratio of 1 to 3 compared to the components forming carbonium ions.
• Favorable space-time yields are also obtained if the molar amount of the acid reaches at least the value of the sum of the molar amounts of carboxamide already present in the reaction medium and the component which forms carbonium ions. An excess of the acid above this value increases the reaction rate; In general, it is advisable to use the acid in a ratio of 1 to 3 compared to the sum of the carbonium ion-forming component and the carboxamide.
• catalytic amounts of perfluoroalkanesulfonic acids such as perfluorobutane- or perfluorooctanesulfonic acid or perfluoroalkane carboxylic acids, such as trifluoroacetic acid, are added to the reaction to increase the reaction rate.
• perfluoroalkanesulfonic acids such as perfluorobutane- or perfluorooctanesulfonic acid or perfluoroalkane carboxylic acids, such as trifluoroacetic acid.
• the additions are between 1 and 10 mol% of the total amount of acid.
• the distillation according to the process of the invention can be carried out in a conventional manner.
• it can be carried out in the following distillation apparatus: thin-film evaporators, falling film evaporators and coiled tube evaporators.
• the distillation according to the process of the invention can generally at distillation bottom temperatures of 90 ° to 180 ° C, preferably from 100 ° to 150 ° C, and at a pressure of 0.1 mbar to 1 bar, preferably from 0.1 mbar to 100 mbar , be performed.
• the N-alkyl-substituted carboxamide and the acid are obtained after distillation.
• An optionally obtained mixture of carboxamide and acid can optionally be partially recycled back into the reaction.
• the process according to the invention can be carried out batchwise or continuously.
• the reaction mixture is fed to a conveniently continuously operating distillation apparatus, preferably a thin-film evaporator, a falling-film evaporator or a snake tube evaporator, and separated depending on the reaction conditions (eg temperature, pressure, evaporator area and residence time) completely or partially the carboxamide.
• the distillation bottoms which in addition to the acid used according to the invention also contains residual carboxamide, can of course be completely separated by further distillation. However, it is also possible, particularly in the case of continuous operation, to return all or part of the distillation bottoms to the reaction. Around To keep the proportion of by-products low, 0.1 to 5% of the distillation bottoms are advantageously separated off and this part is optionally subjected to a separate workup, for example residue combustion.
• the boiling point of the acid is lower than that of the carboxylic acid amide, it may be expedient to separate the acid from the remaining carboxylic acid amide by carrier gas or vapor vapor distillation.
• Inert gases such as helium, argon and nitrogen, for example, are suitable as carrier gases, and the nitriles used, such as hydrocyanic acid, acetonitrile and acrylonitrile, are suitable as carrier vapor.
• Chlorine hydrocarbons, such as chlorobenzene and dichlorobenzene can also be used for a carrier steam distillation, for example.
• the method according to the invention advantageously also saves an extraction step, without which processing by distillation is not possible according to DT-AS 2 144 230.
• the process according to the invention has the advantage that no waste acids or waste salts are obtained in the isolation of the reaction product; it can therefore be carried out advantageously and without polluting the environment.
• N-substituted carboxamides which can be prepared by the process according to the invention can be used as printing aids or in the production of textile auxiliaries or can be converted to amines.
• Example 1 The bottom product obtained in each case as in Example 1 (36% tert-butylformamide, 64% methanesulfonic acid) is reacted and worked up in accordance with Example 1 with hydrocyanic acid and tert-butanol.
• the table shows the products used and received:
• tripropen 126 g of tripropen are added dropwise to a solution of 18 g of water in 170 g of trifluoroacetic acid at room temperature, the stirred mixture is heated to 65 ° C. and 40 g of hydrocyanic acid are metered in over the course of 45 minutes.
• the reaction mixture is kept at 60 to 65 ° C for one hour and then worked up by distillation at a pressure of 12 to 15 Torr, the bottom temperature of the distillation being raised from room temperature to 149 ° C.
• the trifluoroacetic acid used and the excess hydrocyanic acid and small amounts of Ni-nonyl-formamide are obtained as distillate from the boiling range ⁇ 30 ° C.-139 ° C./15 torr, which can be used again for the reaction, and then 146 g of pure one Ni-nonyl-formamide with a boiling range of 142 to 146 ° C / 13 Torr.
• a stirred mixture of 880 g of a C 12 alkylbenzenesulfonic acid and 130 ml of hydrocyanic acid is heated to 50 ° C. under reflux. For this, 181 g are tert. Butanol and 70 ml of hydrocyanic acid were added dropwise. After 1.5 hours, the excess hydrocyanic acid is distilled off in vacuo. At an evaporator temperature of 135 ° C and a pressure of 0.5 torr, the reaction mixture is subjected to thin-film distillation. 101 g of tert are obtained. Butylformamide and 950 g of distillation bottoms, which is used again for the reaction. Under the reaction conditions given above, 80 ml of hydrocyanic acid with 75 g of tert are used in this bottom product. Butanol implemented. The subsequent thin film distillation gives 110 g of tert. Butylformamide.
• the distillation bottoms contain 35% tert. Butylformamide. Under the specified conditions, it is again tert with 75 g. Butanol and 80 ml HCN implemented. The subsequent thin-layer distillation (as stated above) gives 64 g (94% strength) of tert. Butylformamide and 555 distillation bottoms, which was used in the reaction with the same result.
• 660 g of p-dodecylbenzenesulfonic acid are placed in a stirred vessel equipped with a thermometer, dropping funnel, reflux condenser and drying tube. At 20 - 25 ° C, 160 ml of hydrocyanic acid are added. As soon as the hydrocyanic acid has been stirred in well, the mixture is heated to 30 ° to 35 ° C. and dripped within 30 minutes. 148 g tert. Butanol too. The temperature is kept at 40 - 42 ° C by gentle cooling. The mixture is then stirred for 3 h at this temperature, then the unreacted hydrocyanic acid is distilled off in vacuo. 75-80 ml of hydrocyanic acid are obtained.
• the bottom product can be used again with the same result.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)

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• 1977
  • 1977-06-08 DE DE2725889A patent/DE2725889C3/de not_active Expired
• 1978
  • 1978-05-19 IN IN382/DEL/78A patent/IN148189B/en unknown
  • 1978-05-30 US US05/911,009 patent/US4246199A/en not_active Expired - Lifetime
  • 1978-06-06 IT IT49725/78A patent/IT1104726B/it active
  • 1978-06-06 JP JP6734878A patent/JPS5416401A/ja active Pending
  • 1978-06-06 EP EP78100102A patent/EP0000059B1/de not_active Expired
  • 1978-06-06 DE DE7878100102T patent/DE2860163D1/de not_active Expired
  • 1978-06-07 BR BR787803654A patent/BR7803654A/pt unknown
  • 1978-06-07 ZA ZA00783259A patent/ZA783259B/xx unknown
  • 1978-06-07 ES ES470565A patent/ES470565A1/es not_active Expired

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