Synthesis and reactions of 1-ethoxy-2,1-benzoxaphosphol-3-one 1-oxide, a phosphorus counterpart of phthalic anhydride

Abstract

Yields were lower when pyridine was used as catalyst. ( 14) The effectiveness of chloroacetic acid as a catalyst for this reaction was serendipitously uncovered when it was observed that crude samples of 3 reacted with aqueous lithium nitrite much more rapidly than did recrystallized samples. Investigation by TLC pointed to N-trifluoroacetylserine as a likely catalytic impurity and chloroacetic acid was selected as an acid of similar strength. Neither acetic nor hydrochloric acids were as effec-

Synthesis of novel phosphorus heterocycles: 1,3-dihydro-2,1-benzoxaphosphole 1-oxides

“…Previous work in our laboratory has centered around the syntheses of phosphorus heterocycles I-III (Chart I). 3,4 Therefore, the synthesis of the oxygen analogue (IV) of heterocycle III was desired to complete this series of phosporus heterocycles. Westheimer and others have previously reported the synthesis of the monocyclic phosphorus ester V.5 The thrust of this paper is to describe our synthetic approaches to the l,3-dihydro-2,l-benzoxaphosphole 1oxide ring system IV.…”

“…pyrrole-lcarboxylic acids (1) are antiinflammatory and analgesic agents of considerable potency,1 23 4and linear, multistep syntheses of this class of compounds have been reported. 3,4 (1) Contribution No. 577 from the Syntex Institute of Organic Chemistry.…”

Synthetic strategies for the preparation of γ-phostams: 1,2-azaphospholidine 2-oxides and 1,2-azaphospholine 2-oxides

“…They first converted 2-(diethoxyphosphoryl)benzoic acid ( 198 ) into its anhydride 1-ethoxy-3 H -benzo[ c ][1,2]oxaphosphol-3-one 1-oxide ( 199 ) by treatment with thionyl chloride under nitrogen. The mixed anhydride 199 was further treated with phosphorus pentachloride to generate ethyl (2-(chlorocarbonyl)phenyl)phosphonochloridate ( 200 ), which reacted with amine and hydrazine derivatives in the presence of triethylamine, affording the desired 1-ethoxy-2-hydrobenzo[ c ][1,2]azaphosphol-3-one 1-oxides 201 but the yields were not reported ( Scheme 31 ) [ 56 ].…”

Phosphaannulation by Palladium-Catalyzed Carbonylation of C–H Bonds of Phosphonic and Phosphinic Acids

“…Next, we envisioned that transition-metal-catalyzed carbonylation of phosphonic and phosphinic acids would be a highly desirable synthetic method to access cyclic phosphonates because carbon monoxide is regarded as an economical and atom-efficient C1 feed stock . Although a multitude of transition-metal-catalyzed chelation-assisted carbonylation of C–H bonds were demonstrated for the synthesis of acids, esters, amides, and ketones, there is no synthetic method for C–H bond carbonylation to prepare oxaphosphorinanone oxide, which can be considered as an inhibitor of β-lactamase and a bioisoster of acid anhydride. Therefore, C( sp 2 )–H bond activation of phosphonic and phosphinic acids followed by carbonylation has been an irresistible synthetic challenge.…”