Phosphorylation of polyesterpolyoles Boltorn-H20 and -H40 with pyrocatechol chlorophosphite

Abstract

Hyperbranched aliphatic polyester of the grade Boltorn-H20 were obtained by polycondensation of 2,2bis(hydroxymethyl)propionic acid with polyhydric alcohols [1, 2]. They were phosphorylated with 2,4-bis(3,5-di-tert-butyl-4-hydroxyphenyl)-1,3,2,4-dithiadiphosphethane 2,4-disulfide [3] and 2-(N,N-diethylamido)1,3,2-dioxaphosphorinane [4]. In these reactions insertion products formed of a monomer fragment ArPS2 from 1,3,2,4dithiadiphosphethane-2,4-disulfide into the O–H bonds and substitution products arising from the cleavage of P–Cl bond resulting in the formation of fragments C– O–P(III). The organic compounds with a tricoordinate phosphorus atom are commonly synthesized by reacting hydroxy compounds with acid chlorides of the trivalent phosphorus acids or with chlorophosphines [5]. In extension of the synthetic potential of the modification with phosphorus of hyperbranched polymers we report here on the results of the investigation of the reactions between the polyesterpolyols of the brands Boltorn-H20 (Ia) and -H40 (Ib) with pyrocatechol chlorophosphite (II). In the presence of triethylamine in the medium of chloroform–benzene, 1:1, the reactions proceed under mild conditions at all hydroxy groups affording 2-(O-1,3,2dioxapyrocatecholphosphorinano)polyesters Boltorn-H20 (IIIa) and -H40 (IIIb) whose 31P NMR spectra contain singlet signals in the region characteristic of phosphites [6], at δ 128.4 and 128.1 ppm respectively, unlike the signal of initial chlorophosphite II at δ 173.2 ppm [6]. 2-(O-1,3,2-Dioxapyrocatecholphosphorinano)polyester Boltorn-H20 (IIIa). To a solution of 6.0 g (2.9 mmol) polyesterpolyol Ia and 4.6 g (45.5 mmol) of triethylamine in the mixture of 15 ml of anhydrous benzene and 15 ml of chloroform at 20°C in a flow of dry argon under stirring was added dropwise 8.0 g (45.5 mmol) of chlorophosphite II. The mixture was stirred for 2 h at 20°C and kept for 12 h at 20°C. The precipitate was filtered off and washed with anhydrous benzene. The solvent was evaporated from the filtrate at a reduced pressure (0.5 ppm) for 1 h at 40°C and in a vacuum (0.02 ppm) for 1 h at 40°C. We obtained as a residue 4.1