ISSN:
0009-2940
Keywords:
Phosphinic acid
;
Phosphaindole bromination and chlorination
;
Layer structure
;
Hydrogen bonds
;
Bromine-bromine interaction
;
Phosphorus heterocycles
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The bromination of 1-ethoxy-1-oxophosphindolin-3-one (1) with two equivalents oi bromine occurs with elimination of hydrogen bromide and ethyl bromide, providing 2,2-di- bromo-1-hydroxy-1-oxophosphindolin-3-one (4) in high yield. In the presence of triethylamine this process leads to 2,2-dibromo-1-ethoxy-1-Oxophosphindolin-3-one (3) instead. Triethylamine deprotonates 4, providing the solid triethylammonium salt 5. Silylation of 4 with chlorotrimethylsilane leads to the trimethylsilyl ester 6. Monobromination in a two-phase reaction allows the isolation of a mixture of isomers of 2-bromo-1-ethoxy-1-oxophosphindolin-3-one (2a, b). Chlorination with chlorine furnishes 2,2-dichloro-1-ethoxy-1-oxo-phosphindolin-3-one (7). The new compounds 2-7 were characterized analytically and spectroscopically (EI-MS, 1H, 13C and 31P NMR). The crystal structure of acid 4 was determined by X-ray diffraction. Solid 4 consists of aryl stacks connected by chains of P—OH…O==P hydrogen bonds and secondary Br…Br contacts.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19971301210
