Facile high yielding synthesis of symmetric esters of methylenebisphosphonic acid
摘要:
The 1H-tetrazole catalyzed coupling of methylenebis(phosphonic dichloride), CH2(POCl2)(2), with primary alkyl, cyclic secondary alkyl, aromatic, and silicon- and fluorine-containing alcohols selectively affords symmetric P,P'-dialkyl partial esters as wen as homoleptic and mixed tetraesters. Two partial ester intermediates, methylenebis(2-ethylhexyl phosphonic chloride) and 2-ethylhexyl methylenebisphosphonic trichloride, were observed by H-1- and P-31 NMR spectroscopy in the esterification of CH2(POCl2)(2) with 2-ethyl-1-hexanol. (C) 2001 Elsevier Science Ltd. All rights reserved.
Facile synthesis of symmetric esters of alkylenebisphosphonic acids
申请人:——
公开号:US20030060648A1
公开(公告)日:2003-03-27
A facile synthesis of symmetric esters of C
1
-C
10
alkylenebisphopsphonic acids is disclosed in which a C
1
-C
10
alkylenebis(phosphonic dichloride) is reacted with an alcohol in the presence of a catalytic amount of 1H-tetrazole and a base in an aprotic solvent to form a first reaction mixture. The first reaction mixture is maintained for a time period sufficient to form a C
1
-C
10
alkylenebis(chloro ester phosphonate) that is reacted under basic conditions with an excess of a hydroxylated compound to form a second reaction mixture that is itself maintained for a time period sufficient to form a C
1
-C
10
alkylenebis(ester phosphonate) partial ester, homoleptic tetraester or mixed tetraester. The material so formed can be recovered or used as is.