Phosphorus functional antimicrobial coatings for metal surfaces

Abstract

The invention relates to quaternary ammonium multi-dentate mono-, bis-, tris- and tetrakis-phosphonate compounds, processes for preparing quaternary ammonium multi-dentate mono-, bis-, tris- and tetrakis-phosphonate compounds, antimicrobial coating compositions comprising quaternary ammonium multi-dentate mono-, bis-, tris- and tetrakis-phosphonate compounds and method of treating a surface with said compositions to provide a durable, antimicrobial-treated surface.

We claim: 
     
       1. A process for preparing a quaternary ammonium mono-phosphonate acid free compound of formula (I) 
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  are independently methyl, ethyl, isopropyl or n-propyl; m is 15, 16, 17, 18 or 19; n is 0, 1, 2, 3, 4, 5 or 6; and X is chloro, bromo or iodo, comprising the steps of (a) reacting a compound of formula (II) 
       
       
         
           
           
               
               
           
         
         wherein R is independently methyl, ethyl, isopropyl, n-butyl or phenyl, with a compound of formula (III) 
       
       
         
           
           
               
               
           
         
         wherein X and n are as above and Y is a halogen selected from chloro or bromo to give a compound of formula (IV) 
       
       
         
           
           
               
               
           
         
         (b) reacting the compound of formula (IV) with a compound of formula (V) 
       
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  are independently methyl, ethyl, isopropyl or n-propyl, and m is 15, 16, 17, 18 or 19, to give a compound of formula (VI) 
       
       
         
           
           
               
               
           
         
         and (c) reacting a compound of formula (VI) with SiR 3 R 4 R 5 Z wherein R 3 , R 4  and R 5  are independently methyl or ethyl and Z is chloro, bromo, iodo or triflate in the presence of dichloromethane (DCM) between 8 to 12 hours at room temperature, or a mineral acid selected from HCl, HBr or HI to give a compound of formula (I), wherein the compound of formula (I) is isolated in pure form without chromatographic purification. 
       
     
     
       2. The process of  claim 1  wherein R 1  and R 2  are methyl. 
     
     
       3. The process of  claim 1  wherein R is ethyl. 
     
     
       4. The process of  claim 1  wherein n is 1 or 2. 
     
     
       5. The process of  claim 1  wherein m is 17. 
     
     
       6. The process of  claim 1  wherein R 3 , R 4  and R 5  are the same and methyl. 
     
     
       7. The process of  claim 1  wherein Z is chloro or triflate. 
     
     
       8. The process of  claim 1  wherein X is bromo. 
     
     
       9. A compound of formula 
       
         
           
           
               
               
           
         
       
       
        
       
     
     
       10. The process of claim 1 further wherein the compound of formula (I) is purified by recrystallization. 
     
     
       11. The process of claim 1 wherein the compound of formula (I) is N,N-dimethyl-N-(3-phosphonopropyl) octadecan-1-ammonium bromide. 
     
     
       12. The process of claim 11 wherein the compound of formula (I) has the following characterization: Mp=118-120° C.;  1 H NMR (400 MHz, MeOD, δ): 3.38-3.33 (m, 2H, H8), 3.28-3.23 (m, 2H, H7), 3.02 (s, 6H, H6), 2.02-1.90 (m, 2H, H5), 1.75-1.65 (m, 4H, H4, H3), 1.20 (brs, 30H, H3), 0.82 (t, J=6.9 Hz, 3H, H1), ppm;  13 C NMR (CDCl 3 , 100 MHz, δ): 64.26 (C7) 63.57 (C8), 49.94 (C6), 31.68 (C2 overlap), 29.41-28.86 (C2 overlap), 26.03 (C2 overlap), 22.45-22.17 (C3, C4), 16.47 (d,  1 J C-P =4.07 Hz, C5), 13.08 (C1) ppm;  31 P NMR (121.45 MHz, CDCl 3 , δ): 26.92 ppm; HRMS-DART (m/z): [M + ] +calculated for C 23 H 51 NO 3 P, 420.3601; found, 420.3608.