Process for the preparation of oxazaphosphorine-2-amines

A process for the preparation of oxazaphosphorine-2-amines of formula 1:

• in which
• R1 is H, 2-bromoethyl, 2-chloroethyl, or 2-mesyloxyethyl;
• R2 is H or 2-chloroethyl;
• and
• R3 is H, 2-bromoethyl, 2-chloroethyl or 1-phenylethyl;
• or
• R1 and R2, together with the linked N atom, form an aziridine ring;
• said process comprising reacting a phosphoryl halide of formula 2, an amine of formula 3, and an amine of formula 4:
• in which R1, R2 and R3 have the same meanings as formula 1, R4 is H, or R3 and R4, together with the linked N atom, form an aziridine ring, X is chlorine or bromine, X only being bromine if R1 or R3 is 2-bromoethyl, and Y, which is optionally present, is hydrogen chloride or hydrogen bromide;
• with an auxiliary base as an acid binding agent in the presence of inert solvents without isolation of an intermediate compound;
• whereby, in a first step, one compound each of the formulae 2 and 3 are reacted and, in a second step, a compound of the formula 4 is reacted;
• or whereby, in a first step, one compound each of the formulae 2 and 4 are reacted and, in a second step, a compound of the formula 3 is reacted.