PROCESS FOR THE PRODUCTION OF FLUORINE CONTAINING N-(BETA-BROMOETHYL)AMIDE AND OF 2-(PERFLUOROALKYL)-1,3-OXAZOLINE

Abstract: A process for producing an N(β-bromoethyl)amide of a fluorine-containing carboxylic acid represented by the for­ mula: R f NHCH₂CH₂Br (II) where R₈ is a perfluoroalkyl group having from 1 to 10 carbon atoms, and/or a fluorine-containing 2-oxazoline represented by the formula: where R₈ is as defined above which comprises reacting a fluorine-containing ester represented by the formula: R₈COOR (I) where R₈ is as defined above, and R is an alkyl group having from 1 to 10 carbon atoms, with a 2-bromoethylamine hydrobromate in the presence of a base.

Description: PROCESS FOR PRODUCING 2-(PERFLUOROALKYL)-1,3-OXAZOLINE The present invention relates to a novel process for producing an N-(ss-bromoethyl)amide of a fluorine-containing carboxylic acid and/or 2-(perfluoroalkyl)-l,3oxazoline. For the production of 2-substituted-1,3-oxazoline derivatives, the following methods have been known. a) A method wherein ss-acetamido ethanol is heated to a temperature of from 260 to 280 C, or ss-bromoethylamine hydrobromate is boiled together with acetic anhydride to obtain 2-methyl-1,3-oxazoline. b) A method wherein ss-bromopropylamine hydrobromate is boiled together with acetic anhydride to obtain 2,5 dimethyl-1,3-oxazoline. c) A method wherein N-( Fbromoethyl)benzamide is treated with an alkali, or an ether solution of benzimino(B-chloroethyl)ether is evaporated over sulfuric acid desiccator, or N-benzoylethyleneimine was distilled to obtain 2-phenyl-1,3-oxazoline. d) A method wherein 2-trifluoromethyl-l,3-oxazoline is obtained from trifluoroacetonitrile and 2-chloroethyl alcohol. Among these methods for the production of 2-substituted-1,3-oxazoline derivatives, a method for obtaining 2-(perfluoroalkyl)-1,3-oxazoline is quite rare, and an effective method has not yet been found. The present inventors have conducted extensive researches to develop a process for advantageously producing a 2-(perfluoroalkyl)-l ,3-oxazoline represented by the formula EMI2.1 As a result, they have found a method for producing the compound and/or an N-(bromoethyl)amide of a fluorine-containing carboxylic acid in an extremely good yield. Namely, present invention provides a process for producing an N-(ss-bromoethyl)amide of a fluorine-containing carboxylic acid represented by the formula: EMI2.2 where Rf is a perfluoroalkyl group having from I to 20 carbon atoms, and/or a fluorine-containing 2-oxazoline represented by the formula: EMI2.3 where Rf is as defined above which comprises reacting a fluorine-containing ester represented by the formula: RfCOOR (I) where Rf is as defined above, and R is an alkyl group having from 1 to 10 carbon atoms, with a 2-bromoethylamine hydrobromate in the presence of a base. Now, the present invention will be described in detail with reference to the preferred embodiments. The reaction for the process of the present invention has been confirmed to proceed in the following two steps, e.g. by the isolation of the intermediate. RfCO2R + BrCH2CH2NH2.HBr (2-bromoethylamine hydrobromate) EMI3.1 (hereinafter referred to as an intermediate) + ROH + KBr + KHCO3 (IV) EMI3.2 KHCO3 (V) In the reaction IV of the first step, the intermediate can be obtained in better yield by firstly reacting BrCH2CH2NH2.HBr with a base, and then with R CO2R in the presence of a base. For the reactions IV and V, it is important to select the optimum combination from the various bases and various reaction solvents. For instance, in the reaciton IV, if Et2O (ethyl ether) is used as the reaction solvent, it is preferred to use K2CO3 as the base rather than KHCO3 since it is thereby possible to obtain the intermediate in better yield. Likewise, in the reaction V, if K2CO3 is used as the base, 2-(perfluoroalkyl)-l,3-oxazoline is obtainable in better yield by using EtOH (ethanol) as the reaction solvent rather than MeOH (methanol). In the present invention, as the base, there may be employed MeONa (sodium methylate), EtONa (sodium ethylate), K2CQ3, Na2CO3, Et3N (triethylamine), NaOH, t-BuOK (potassium t-butylate). On the other hand, as the reaction solvent, it is preferred to use EtOH, Et2O, THF (tetrahydrofuran) or CH3CN. The reactions IV and V are preferably conducted at a normal temperature under atmospheric pressure. The reaction can be conducted at a temperature of from about -30 to 150 0C. The reaction time varies between the reactions IV and V or depending upon the combination of the reaction solvent and the base used. However, both reactions are usually completed from a few minutes to a few hours. With respect to the amounts of the base and the reaction solvent in the reactions IV and V, the optimum amounts may be selected depending upon the types thereof or the types of the reactants. The base is used usually in an amount of from 0.3 to 10 times, preferably from 0.5 to 1.5 times by parts by weight relative to the starting material RfCO2R or the intermediate. Likewise, the reaction solvent is used usually in an amount of from 2 to 20 times, preferably from 4 to 8 times. 2-(Perfluoroalkyl)-l,3-oxazolines obtained by the process of the present invention are highly reactive compounds having a perfluoroalkyl group, and useful as a starting material for highly durable water and oil repelling agents or as a starting material for surface active agents, or as a perfluoroalkyl group introducing agent for the preparation of medical or agricultural chemicals or as an amino ethylating agent for e.g. cellulose. Now, the present invention will be described in further detail with reference to Examples. However, it should be understood that the present invention is by no means restricted by these specific Examples. EXAMPLE 1 0.01 Mol of EMI5.1 and 0.01 mol of BrCH,CH,NH,.HBr were reacted at a temperature of 20 0C in the presence of a combination of 0.01 mol of a base and.15 ml of a reaction solvent to obtain an intermediate of EMI5.2 The results are shown in Table 1. Table 1 EMI6.1 <tb> <SEP> Base <SEP> Solvent <SEP> Reaction <SEP> Reaction <SEP> Yield <tb> <SEP> time <SEP> (hr) <SEP> method <SEP> * <SEP> (%) <tb> EtONa <SEP> EtOH <SEP> 1.0 <SEP> A <SEP> 83 <tb> <SEP> " <SEP> " <SEP> 1.0 <SEP> B-10 <SEP> 93 <tb> <SEP> " <SEP> " <SEP> 3.0 <SEP> B-10 <SEP> 92 <tb> <SEP> I <SEP> " <SEP> 3.0 <SEP> B-150 <SEP> 71 <tb> K2CO3 <SEP> " <SEP> 10.0 <SEP> B-10 <SEP> 74 <tb> <SEP> " <SEP> Et2O <SEP> 10.0 <SEP> B-10 <SEP> 78 <tb> <SEP> " <SEP> THF <SEP> 10.0 <SEP> B-10 <SEP> 73 <tb> <SEP> " <SEP> CH3CN <SEP> 8.0 <SEP> B-10 <SEP> 59 <tb> Na2CO3 <SEP> Et2O <SEP> 30.0 <SEP> B-10 <SEP> 70 <tb> Et3N <SEP> " <SEP> 20.0 <SEP> B-10 <SEP> 89 <tb> NaOH <SEP> N <SEP> 35.0 <SEP> B-30 <SEP> 64 <tb> <SEP> " <SEP> EtOH <SEP> 7.0 <SEP> B-10 <SEP> 81 <tb> * Reaction method A: A base was added to a reaction solution of CF3COOEt with BrCH2CH2NH2.HBr. B-&alpha;: To the reaction solution of BrCH2CH2NH2.HBr with a base, CF3COOEt was added a minutes later. EXAMPLE 2 In 10 ml of a reaction solvent, 5 mmol of EMI7.1 prepared in Example 1 and 5.5 mmol of a base, were reacted at a temperature of 20 0C to obtain 2-(perfluoroalkyl)-1,3-oxazoline EMI7.2 The results obtained by various combinations of the bases and reaction solvents are shown in Table 2. Table 2 EMI7.3 <tb> <SEP> Reaction <SEP> Yield <tb> <SEP> Base <SEP> Solvent <SEP> <SEP> time <SEP> (hr) <SEP> (%) <SEP> <tb> K2CO3 <SEP> EtOH <SEP> 2.0 <SEP> 88 <SEP> <tb> t-BuOK <SEP> Et2O <SEP> 1.0 <SEP> 92 <tb> EtONa <SEP> EtOH <SEP> 0.25 <SEP> 65 <tb> <SEP> n <SEP> 1 <SEP> 1.5 <SEP> 53 <SEP> <tb> <SEP> 4.0 <SEP> 50 <tb> MeONa <SEP> Et2O <SEP> 0.25 <SEP> 93 <tb> <SEP> " <SEP> " <SEP> 0.5 <SEP> 84 <tb> <SEP> n <SEP> n <SEP> 1.0 <SEP> 81 <tb> <SEP> N <SEP> n <SEP> 2.0 <SEP> 80 <tb>

Claims: EXAMPLE 3 To 15 ml of EtOH, 0.01 mol of BrCH2CH2NH2.HBr and 0.021 mol of K2CO3 were added, and the mixture was stirred for 10 minutes. Then, 0.01 mol of EMI8.1 was added, and the mixture was reacted at 200C for 7 hours, whereby 2-trifluoromethyl-1,3-oxazoline was obtained in a yield of 65%. EXAMPLE 4 0.01 Mol of BrCH2CH2NH2.HBr was dissolved in 10 ml of EtOH. To this solution, a EtONa/EtOH solution prepared by dissolving 0.01 mol of sodium metal in 5 ml of EtOH, was added. Ten minutes later, 0.01 mol of EMI8.2 was added, and the mixture was stirred for 3 hours. To this solution, 0.011 mol of K2CO3 was added, and the mixture was stirred for further 22 hours, whereby 2-trifluoromethyl-1,3-oxazoline was obtained in a yield of 728. EXAMPLE 5 0.01 Mol of EMI8.3 and 0.01 mol of BrCH2CH2NH2.HBr were reacted in 15 ml of ethanol at 20 0C for 7 hours in the presence of 0.01 mol of K2C03, whereby 2-perfluoro octyl-l,3-oxazoline was obtained in a yield of 50%. CLAIMS: 1. A process for producing an N-(B-bromoethyl)amide of a fluorine-containing carboxylic acid represented by the formula: EMI9.1 where Rf is a perfluoroalkyl group having from 1 to 20 carbon atoms, and/or a fluorine-containing 2-oxazoline represented by the formula: EMI9.2 where Rf is as defined above which comprises reacting a fluorine-containing ester represented by the formula: RfCOOR (I) where Rf is as defined above, and R is an alkyl group having from 1 to 10 carbon atoms, with a 2-bromoethylamine hydrobromate in the presence of a base. 2. The process according to Claim 1, wherein the 2-bromoethylamine hydrobromate is reacted with a base and then with the compound of the formula I in the presence of a base.

Inventors: ISHIKAWA, NOBUO, SEKIYA, AKIRA
Applicants: ASAHI GLASS COMPANY LTD.
Application year: 1985
Main classification: C07C102
IPC codes: C07D263, C07C231, C07C233, C07C67