SYNTHESIS AND PHOSPHORYLATING PROPERTIES OF IHYDRO-3-(METHYLSULFONYL)-1,3,2-BENZOXAZAPHOSPHOLE 2-OXIDE - DERIVATIVES WITH CHLORO SUBSTITUENTS ON THE BENZENE-RING

The synthesis and the use of the five-membered cyclic phosphorylating agents 1a-c are described. Their difunctional phosphorylating properti es towards alkanols and hydroxylated amino acids and the cleavage reac tion of the formed phosphoric acid triesters to diesters with oximate or platinum/hydrogen are investigated and compared to the ''parent'' c ompound ihydro-3-(methylsulfonyl)-1,3,2-benzoxazaphosphole 2-oxide([1] ). Dichlorobenzoxazaphosphole 1b is the most reactive of these reagent s with respect to phosphorylation with ring opening and oximate cleava ge of the phosphoric acid triesters, followed by o-chlorobenzoxazaphos phole 1a, the unsubstituted phosphole I, and p-chlorobenzoxazaphosphol e 1c.