Title of Invention

"AN IMPROVED PROCESS FOR THE SINGLE STEP PREPARATION OF TOSYL AZIRIDINES"

Abstract

We claim : 1. A process for the preparation of copper bound bis (picolyl) amine polymer which comprises reacting macroporous bis (picolyl) amine polymers in the presence of copper salts in an aqueous medium at a pH of 2 to 6 or organic solvent such as herein described at a temperature in the range of 25 to 35°C, for a period ranging from 12 to 24 hours, removing the macroporous copper ion containing bis (picolyl) amine polymer by conventional methods, followed by washing and drying by known method to obtain copper bound bis (picolyl) amine polymer. 2. A process as claimed in claim 1, wherein the copper salt used is cupric chloride, cuprous chloride, copper nitrate, copper sulphate. 3. A process as claimed in claims 1-2 wherein the organic solvent used is dimethyl formamide, dimethyl sulfoxide, methanol, ethanol, tetrahydrafuran. 4. A process for the preparation of copper bound bis (picolyl) amine polymer substantially as herein described with reference to the examples.

Full Text

This invention relates to a process for preparation of aziridines. The invention particularly relates to a new catalytic method for the preparation of tosyl aziridines catalyzed by pyridiniumbromideperbromide (PBPB). More particularly, the invention relates to a process for the conversion of simple olefms or substituted olefins into their corresponding tosyl aziridines and selective aziridination of one of the double bond (e.g. in case of 1,3-butadiene) is achieved by using Chloramine-T and pyridinium bromide perbromide (PBPB) in organic solvents at room temperature. Aziridines and their derivatives are used in a wide variety of industrial applications.The single most important derivative is polyaziridine, which is cationic and substative to many naturally occurring anionic material such as cellulose. The use of aziridine in paper industry accounts for a major portion of its production. Polyaziridine is used to laminate plastic films. It is also used in textile industry, dying, printing, crease proofing and shrink proofing. Synthetic approaches to the aziridine ring modification of functionalized aziridine, and the reaction of aziridine have received particular attention. As a result, application of aziridine chemistry to synthesis, mechanistic studies/biological investigation has become increasingly numerous. In the prior art, synthesis of aziridine is achieved by various methods and following are representative ones. 1. The oldest approach to aziridine synthesis involves internal cyclization of amino group, a) from p-haloamine (Gabriel Synthesis) b) from sulfate ester (Wenker synthesis) c) from oxime by treating with Grignard reagent (Hoch-Campbell synthesis) (Ref: Heterocyclic compound 1964,page 535) ibid -— do 1983, part 1 vol. 42 2. Aziridines were prepared by intramolecular dehydration of alkanolamine at high temperature (above 350°) in gas phase by using catalyst like Pt, Pd, Rh, Ir. [Ref: Japan patent 89,157,952; 1989], at reduced pressure by using ALPO-11 [ Ref: Japan patent, 8996,167, 1989], by using alkali metal, alkali earth metal at 600°[ Ref: Eur patent 228,898,1987], [Ref: US. patent 134863, 1989], by using Schiff base [ Ref: Japan patent 92,217,659,1992], by using titanic silicate, alumino silicate [Ref: Stud, Surf. Sci. Catal.1993, 75, 2447], by acid base catalyst [Ref: Proc.Int.Symp.1988, 41], [Ref: Japan patent, 02,15,349,1990], by alumino phosphate, silicoaluminophosphate, monozeolite mol. sieve [Ref: PCT Int. appl. wo 8906,229. 1987] by using transition metal sulfate [Ref: Japan patent 02 75349 1990], by using Nb2O5 [Ref: US patent 4,477,591,1984], by using WO3[Ref: US patent, 4301,031. 1981], by using mixed oxide [ Ref: US patent, 4,841,061. 1989], by passing NH3 using metal complex as catalyst [Ref: US patent 4,289,656; 1980], by passing diethoxytriphenylphophorane (DTPP), [Ref: JOC, 1986, 51,95] by passing trifluoroaceticacid, methyl cyanide, Ti2CO 3 [Ref: Ger Offen. 2,429.442, 1976], . 3. Substituted epoxides were converted to aziridines by passing NH3 at high temperature by using catalyst such as La2O3, H3PO4 [Ref: Japan patent 63,303,964; 1988]. Styrene epoxides were converted to aziridines by treating with N -substituted amidophosphate in high boiling solvent. [Ref: Tet.Lett. 44,4003,1976] 4. Dichloroethane is converted to aziridine by passing NHa using sodium silicate as catalyst and HC1 as acceptor [Ref: USSR SU 914,5521. 1980], by using CaO MgO,or NaAlO2[ Ref: Khim.Prom-st 1982(4),265 Russ] 5. The aziridines were prepared from imines and methyl diazo acetate.by using Rh (III) and Mn (III) exchanged montmorillonite K-10 clays as catalyst. [Ref: Chem com 1997,1429] 6. The aziridines were prepared from alkoxy amine by using lead tetra acetate (LTA) via nitrene.[Ref:Tet Let 1973, 619; JCS.Chem Com.1969,146; JOC, 3107. 1973] 7. Aziridines were prepared from oxime by treating with LiAIKU in tetrahydrofuran [Ref: Tet let 131, 1974], also prepared by (3- iodozole using the same reagent [ Ref: JACS 1967, 91, 5046 ] ,and from azirine with the same reagent [ Ref :Tet Let 1967, 1545]. 8. Aziridines were prepared from mixture of alkoxy amine and olefin by treating with N-Chlorosuccinimide at -40°. 9. Tosyl aziridines were prepared from olefins by using Chloramine-T and bromine based catalyst phenyltrimethylammoniumtribromide (PTAB) [Ref: JACS 1998, 120, 6844], also by using Chloramine -T trihydrate and Cu (1) triflate (CuOTF) 2 [Ref: JOC, 63,1998, 9571]. Though the above mentioned processes in the prior art are to be useful for the preparation of aziridines and substituted aziridines, they suffer from the following drawbacks: 1. In the Gabriel and Wenker synthesis large amount of acid fumes are liberated during cyclization. 2. In many reactions halogenated substrate, highly alkaline condition and high temperature are used which are hazardous to the environment. 3. Most of the methods employ, catalyst such as metal complexes, methyl rhenium trioxide under homogeneous condition, however the selectivity is not satisfactory and the yields are very poor. 4. In most of the reactions highly expensive catalysts such as Pt, Pd, Rh, Ir, L^Oa, Ti, Nb, Mo, W, Zr are used. 5. In one of the methods diethoxytriphenylphosphorane (DTPP)and Grignard reagents are used which require dry solvents and it involves multisteps 6. In some of the reactions, trifluoro acetic acid, methyl cyanide, and phosphoric acid are used which are highly toxic and environmentally non-acceptable. In view of all the above disadvantages of the prior art, it is desirable to provide a process that is safe, eco friendly, inexpensive, single step and simple. The main object of the present invention is to provide a new catalytic method for preparation of tosyl aziridines. Another object of the present invention is to provide a new, direct aziridination in single step, which obviates the drawbacks as detailed above. Yet another object of the present invention is to provide a single step process for the preparation of tosyl aziridines by reacting olefins with Chloramine -T. Accordingly the Dresent invention provides an improved single step nrccess for the preparation of tosyl aziridines of formula 1 as shown in the figure below, (Formula Removed) wherein R1 = alkyl, aryl, vinyl; R2= H, CHO, COR, CH2X(X=Br,OR); R3 = H; R4 = H .which comprises of mixing a olefin, a Chloramine and a phase transfer catalyst such as herein described, in polar organic solvent and stirring the reaction mixture for 4 - 12 hours at 25° - 30°C and recovering the aziridine by conventional method as described herein to get the desired tosyl aziridine. In an embodiment of the present invention the olefin used may be simple olefin such as 1-hexne, 1-octene; substituted olefins such as styrene, trans stilbene and cyclo olefins such as cyclo hexane, cyclo octane, norbomene. In another embodiment of the present invention the recovery of aziridine may be carried out by filtering the reaction mixture through a column using adsorbent such as silica gel, neutral alumina, etc and elation of column may be carried out by organic solvent such as 10% ethyl acetate-petroleum ether, 10% chloroform -hexane, 5% acetone - pet ether and mixture thereof. In yet another embodiment of the invention the polar organic solvent used may be such as acetonitrile, methanol, toluene, dioxane etc. The phase transfer catalyst used may be such as pyridinium bromide perbromide, benzyl triethylammonium chloride, and benzyl triethylammonium bromide, (pyridinium bromide perbromide works best) In yet another embodiment of the present invention the/reagent used may be such as Chloramine - T, Chloramine - M, Chloramine - B. (Chloramine - T works best). The process for the invention is described below with references to examples, which are illustrative only and should not be construed to limit the scope of the present invention in any manner. Example-1 To a mixture of styrene (10 mmol), anhydrous Chloramine -T(TsNClNa) (11 mmol.), and acetonitrile (30ml) was added pyridinium bromide perbromide (1 mmol) . Reaction mixture was stirred vigorously for 4 hours, and then it was concentrated and filtered through a column of silica gel, eluted with 10% ethyl acetate in hexane, solvent removal afforded N- (p-Toluenesulfonyl)-2-phe'nylaziridine (75%) m.p. 94°-96°. Example-2 To a mixture of cyclohexene (10 mmol), anhydrous Chloramine -T(TsNClNa) (11 mmol.) and acetonitrile (30 ml) was added pyridinium bromide perbromide(lmmol). Reaction mixture was stirred vigorously for 12 hours, and then it was concentrated and filtered through a column of silica gel, eluted with 10% ethyl acetate in hexane, solvent removal afforded N- (p-Toluenesulfonyl)-(4.0.1)-bicycloheptaaziridine (50%). Example 3 To a mixture of 2-propene-l-ol (10 mmol), anhydrous Chloramine -T (TsNClNa) (11 mmol.), and acetonitrile (30 ml) was added pyridinium bromide perbromide (1 mmol). Reaction mixture was stirred vigorously for 8 hours,and then it was concentrated and filtered through a column of silica gel, eluted with 10% ethyl acetate in hexane, solvent removal afforded N-(p-Toluenesulfonyl)-2-hydroxymethylaziridine, (55%) m.p. 131° Example 4 To a mixture of 2-methyl-2-propene-l-ol (10 mmol), anhydrous Chloramine -T (TsNClNa) (11 mmol.), and acetonitrile (30 ml) was added pyridinium bromide perbromide (1 mmol). Reaction mixture was stirred vigorously for 16 hours, and then it was concentrated and filtered through a column of silica gel, eluted with 10% ethyl acetate in hexane, solvent removal afforded N- (p-Toluenesulfonyl)-2-methyl-2- hydroxymethylaziridine, (65%) Example 5 To a mixture of 1-hexene (10 mmol), anhydrous Chloramine -T (TsNClNa) (11 mmol.), and acetonitrile (30 ml) was added pyridinium bromide perbromide (1 mmol). Reaction mixture was stirred vigorously for 12 hours, and then it was concentrated and filtered through a column of silica gel, eluted with 10% ethyl acetate in hexane, solvent removal afforded N- (p-Toluenesulfonyl)- 2-butylaziridine (55%) Example - 6 To a mixture of butadiene (10 mmol), anhydrous Chloramine -T (TsNClNa) (11 mmol.), and acetonitrile (30 ml) was added pyridinium bromide perbromide (1 mmol). Reaction mixture was stirred vigorously for 12 hours,and then it was concentrated and filtered through a column of silica gel, eluted with 10% ethyl acetate in hexane, solvent removal afforded N-(p-Toluenesulfonyl)-2-vinylaziridine (90%) Example- 7 To a mixture of norbornene (10 mmol), anhydrous Chloramine -T (TsNClNa) (11 mmol.), and acetonitrile (30 ml) was added pyridinium bromide perbromide (1 mmol). Reaction mixture was stirred vigorously for 16 hours, and then it was concentrated and filtered through a column of silica gel, eluted with 10% ethyl acetate in hexane,solvent removal afforded N- (p-Toluenesulfonyl) -3-azatricyclo[ 3.2.1.0 2>4exo ] octane(65%) Example-8 To a mixture of mesytiloxide (10 mmol), anhydrous Chloramine -T (TsNClNa) (11 mmol.), and acetonitrile (30 ml) was added pyridinium bromide perbromide (1 mmol). Reaction mixture was stirred vigorously for 12 hours, and then it was concentrated and filtered through a column of silica gel, eluted with 10% ethyl acetate in hexane, solvent removal afforded N- (p-Toluenesulfonyl)-2-acetyl-3, 3'dimethylaziridine (45%) Example - 9 To a mixture of butadiene (10 mmol), anhydrous Chloramine -T (TsNClNa) (11 mmol.), and methanol (30 ml) was added pyridinium bromide perbromide (1 mmol). Reaction mixture was stirred vigorously for 12 hours.and then it was concentrated and filtered through a column of silica gel, eluted with 10% ethyl acetate in hexane, solvent removal afforded N- (/?-Toluenesulfonyl)-2-vinylaziridine (less than 5%) Example- 10 To a mixture of butadiene (10 mmol), anhydrous Chloramine -T (TsNClNa) (11 mmol.), and dioxane (30 ml) was added pyridinium bromide perbromide (1 mmol). Reaction mixture was stirred vigorously for 12 hours, and then it was concentrated and filtered through a column of silica gel, eluted with 10% ethyl acetate in hexane, solvent removal afforded N- (p-Toluenesulfonyl)-2-vinylaziridine (less than 5%) The advantages of the present invention are as follows: 1. The process is economically viable, environmentally safe, easy to handle and single step. 2. Chloramine -T is cheap and commercially available reagent for aziridination. 3. Selective aziridination of one of the double bond (e.g. in case of 1,3 - butadiene) is achieved in the present process. 4. No transition metals such as Rh, Pd, Cu etc. are used in the present process, so problem of disposal of such metals does not arise. We Claim: 1. An improved single step process for the preparation of tosyl aziridines of formula 1 as shown in the figure below, (Formula Removed) wherein R1 = alkyl, aryl, vinyl; R2= H, CHO, COR, CH2X(X=Br,OR); R3= H; R4 = H, which comprises of mixing a olefin, a Chloramine and a phase transfer catalyst such as herein described, in polar organic solvent and stirring the reaction mixture for 4 - 12 hours at 25° - 30° C and recovering the aziridine by conventional method as described herein to get the desired aziridine. 2. An improved process as claimed in claim 1 wherein the chloramines used is selected from Chloramine - T, Chloramine - M, Chloramines - B, preferably Chloramine - T. 3. An improved process as claimed in claims 1 and 2 wherein the phase transfer catalyst used is selected from benzyl triethylammonium chloride, benzyltriethy(ammonium bromide, NaHS04, preferably pyridinium bromide perbromide. 4. An improved process as claimed in claims 1-3 wherein the polar solvent used is selected methanol, ethanol, butanol, diethyl ether, dimethyl formamide preferably acetonitrile. 5. An improved process as claimed in claims 1 to 5 wherein the olefin used is simple olefins selected from 1 - hexane, 1 - octane; substituted olefins selected from styrene, trans stilbene and cyclo olefins such as cyclo hexane, cyclo octane, norbonene. 6. An improved process as claimed in claims 1-6 wherein the recovery of aziridine from the reaction mixture is effected by filtering it through column using adsorbent selected from silicagel, neutral alumina and solvent such as 10% ethyl acetate-petroleum ether, 10% chloroform - hexane, 5% acetone - pet ether and mixture thereof. 7. An improved single step process for the preparation of tosyl aziridines substantially as herein described with reference to example and drawing accompanying the specification.

Documents:

1596-del-1999-abstract.pdf

1596-del-1999-claims.pdf

1596-del-1999-correspondence-others.pdf

1596-del-1999-correspondence-po.pdf

1596-del-1999-description (complete).pdf

1596-del-1999-description(complete).pdf

1596-del-1999-form-1.pdf

1596-del-1999-form-19.pdf

1596-del-1999-form-2.pdf

1596-del-1999-form-3.pdf