Organophosphorus compounds XVI. Synthesis of some novel 2,3-dihydro-1H-1,2-benzazaphosphole 2-oxides and -sulphides

✍ Scribed by David J. Collins; Peter F. Drygala; John M. Swan

• Book ID: 104220536
• Publisher: Elsevier Science
• Year: 1982
• Tongue: French
• Weight: 192 KB
• Volume: 23
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)87037-9

✦ Synopsis

Several derivatives of 2,3-dihydro-lH-1,2-benxaaaphosphole, a new class of benz-fused N-P heterocycle, have been synthesised by thermal and DCC-promoted N-P ring closure from xwitterionic intermediates. Previously we described' the synthesis of Z-ethoxy-l-methyl-l,Z-axaphospholidine Z-oxide in which the final ring closure to a 5-ring heterocycle involved formation of the carbon-nitrogen bond. For the related benz-annelated compounds this strategy was inappropriate, but an alternative nitrogen to phosphorus ring closure was achieved by the sequence summarised below (Scheme 1).