145336-44-3Relevant articles and documents
Cyclic Oligophosphonic Anhydrides Stable in Aqueous Media
Alferiev, Ivan S.,Bobkov, Sergey Yu.
, p. 1213 - 1224 (2007/10/02)
Depending on reaction conditions, the phosphonylation of N-alkylacetamides with H3PO3-PCl3 in B*HCl media (B = Py, Bu3N) gives either 1-alkylaminoethylidene-1,1-bis-phosphonic acids (1a-e) or previously unknown 1-alkylaminobutane-1,1,3,3-tetrayl-tetrakisphosphonic dianhydrides (2a-e).The latter convert into monocyclic forms (3a-e) under mild acidic hydrolysis.Acyclic forms (4a-e) cannot be isolated.In the presence of higher N,N-dilakylamides the phosphonylation of acetamides affords the higher dianhydrides (2f-h).Strong acidic hydrolysis of 2 or 3 yields 3,3-diphosphonocarboxylic acids (5a-c).Reacting with H3PO3-PHal3 in B*HHal (Hal = Cl, Br), the amides R1CONHR2 (R H, Me; R2 = Alk, H)give both N-alkyl- (or N-unsubstituted) 1-aminoalkylidene-1,1-bis-phosphonic scids (6a-j) and their cyclic dimeric anhydrides (7a-g, i, j). Key words: Amides; phosphonylation; 1-aminoalkane-1,1,3,3-tetrayl-tetrakis-phosphonic anhydrides; cyclic dimeric anhydrides; 1-aminoalkylidene-1,1-bis-phosphonic acids.