Prepn. of new phosphorylated N-tri:organo:silyl-amide in high yield - from corresp. unsubstituted amide and hexa:organo-di:silazane used as pesticide intermediate
Prepn. of new phosphorylated N-(triorganosilyl)- amides of formula (R1O)(R2Y)P(X)-NH-SiR3R4R5 (I) comprises reacting phosphoric acid diester amides (or mono- or di-thio analogues) of formula (R1O)(R2Y)P(X)NH2 (II) with hexa-organo-disilazones of formula NH(SiR3R4R5)2 (III) in inert solvents. In the formulae X,Y is O or S; R1, R2 are each 1-6C alkyl, substd. alkyl, 2-methoxyethyl (when X=O) or opt. substd. phenyl; and R3-R5 are each 1-6C alkyl or aryl. . Pref. (II) is reacted with an equimolar amt. of (III), opt. in presence of an ammonium or phosphonium salt, at below 110 deg. C while passing a slow stream of Ar through the soln.. Prod. is worked up under mild conditions. Esp (i) if X=Y=O; (II) is treated with (III) and heated to 80 deg. C over 1 hrs., the mixt. is stirred for 6 hrs., solvent and excess (III) are removed, volatiles are removed at 0.1Torr and the residue is purified by distn.; (ii) if X=S and Y=O; (II) is treated with (III) at low temp., the temp. is increased to 60-90 deg. C and after complete conversion the mixt. is worked up as in (i); (iii) if X=O and Y=S; (II) and (III) are completely reacted at 80-110 deg. C, solvents are removed, the residue is suction-filtered through a sinter tube, volatiles are removed at 0.1Torr and the residue is purified by distn.; (iv) if X=Y-S; a mixt. of (II) and (III) is completely reacted at 60-90 deg. C then worked up as in (iii). USE/ADVANTAGE - (I) are starting materials for N-phosphorylated open chain amides or heterocycles potentially useful as pesticides, e.g. insecticides, nematocides and fungicides. (I) are obtd. from inexpensive starting materials in high yield (up to 99.4% in examples), simply.
