Patent ID: 6335456
Filing Date: 2002-01-01
Classification: C07F

Abstract:
A semi-continuous process for preparing bis-silyl carboxamides of formula (I): in which R represents a linear or branched aliphatic radical containing 1-4 carbon atoms comprising reacting at least one of an amide RCONH2 (2) and the N-monotrimethylsilyl derivative thereof RCONHSi(CH3)3 (3) with a silylating agent R1Si(CH3)3 (4) according to the reactions: in which R1 is chosen from pyrazolyl, imidazolyl, 1,2,4-triazolyl, pyrrolidinyl, morpholinyl and benzotriazolyl radicals, optionally substituted with one or more linear or branched alkyl residues containing 1-4 carbon atoms characterized in that the following steps are simultaneously carried out: I. continuously and gradually introducing the amide (2) or the N-trimethylsilyl derivative thereof RCONHSi(CH3)3 (3), or alternatively the amide (2) or the N-trimethylsilyl derivative thereof and some of the silylating agent R1Si(CH3)3 (4) as a mixture or separately into a reactor containing a stirred distillation residue, comprising all or some of the silylating agent R1Si(CH3)3 (4) brought to a temperature ranging from 130Â° C. to 190Â° C., and II. gradually distilling off the resultant bis-silyl carboxamide (1) as it is formed at a pressure below atmospheric pressure.