Methods for the preparation of N-alkylated amines involving the use of triflate esters are known. For example, Effenberger et al, Angew. Chem., 95, 50 (1983) show the use of trifluoromethanesulfonic anhydride to esterify the hydroxyl group in certain .alpha.-hydroxycarboxylic acid esters, followed by reaction of the thus-formed triflates with mono- and disubstituted amines (alanine, phenylalanine and aspartic acid are among the specific amines mentioned) to give D- as well as L-N-substituted aminocarboxylic acid esters which, according to the authors, can be hydrolyzed in high yields without demonstrable racemization. Effenberger is also named as an inventor of European published application No. 0134392, published Mar. 20, 1985 which discloses the reaction of compounds of the general formula: ##STR9## with other compounds ##STR10## to form end products ##STR11## wherein the asterisk denotes an asymmetric carbon, x is 1 or 2, n is an integer of 1 to 6, R.sub.1 is a methyl, ethyl or benzyl residue, R.sub.2 is a straight or branched chain C.sub.1 to C.sub.8 alkyl residue which may be unsubstituted or substituted one or more times with any of fluorine, chlorine, bromine, a C.sub.1 to C.sub.8 alkoxy group, a methoxy-, ethoxy- or benzyloxy-carbonyl group or a phenyl residue that is unsubstituted or substituted with 1, 2 or 3 of the named substituents or alternatively is a phenyl residue that is unsubstituted or has 1-3 of the substituents already named; R.sub.3 is H, a straight or branched chain, unsubstituted or singly or multiply substituted C.sub.1 -C.sub.12 alkyl residue, an unsubstituted phenyl residue or one that bears 1-3 substituents or an unsubstituted naphthyl residue or one that bears 1-6 substituents, wherein the substituents are selected in each instance from F, Cl, Br, --CN, --OH, C.sub. 1 to C.sub.8 alkoxy, methoxycarbonyl, ethoxycarbonyl, benzyloxycarbonyl, di-C.sub.1 -C.sub.8 alkylamino, an unsubstituted phenyl or one that bears up to 3 substituents or an unsubstituted naphthyl or one that bears up to 6 substituents; when x is 1, R.sub.4, independently of R.sub.3, may have the same meanings as R.sub.3, except for H or may, together with R.sub.3 and a nitrogen atom, form a saturated or unsaturated ring of 4-7 atoms containing from 0 to 2 further heteroatoms selected from nitrogen, sulfur and oxyben atoms, which ring is unsubstituted or substituted with any of the substituents named for R.sub.2 and R.sub.3 ; when x is 2, R.sub.4 is a straight or branched chain 1-12 carbon alkylene residue.
A general discussion of triflates as alkylating agents, including their use in alkylating amines, is found at pages 83 and 84 of a review article entitled "Trifluoromethanesulfonic Acid and Derivatives" by Howells et al, Chem. Revs., 77, No. 1, 69-82 (1977). Hansen, J. Org. Chem., 30, 4322-4 (1965) reported that the reaction of 2,2,2-trifluoroethyl trifluoromethanesulfonate with excess diethylamine in refluxing benzene gave a good yield of the tertiary amine diethyl-2,2,2-trifluoroethylamine. Burden et al, Tetrahedron, 21, 1-4 (1965) discuss others' work demonstrating the use of triflates as N-alkylating agents, Watthey, in U.S. Pat. No. 4,410,520, discloses the use of "a lower alkanesulfonic acid, especially methanesulfonic, trifluoromethanesulfonic acid . . . " as an N-alkylating agent in the preparation of 3-amino-[1]benzazepin-2-one-1-alkanoic acids (see column 1, lines 33-46), and Kato et al, Tetrahedron Letters, No. 48, 4741-4 (1978) show the N-alkylation of puromycin aminonucleoside with L-3-phenyl-2-phthalimide-1-propanol triflate to give the corresponding N-phthaloyl derivative.
In addition, Hoechst published European patent applications Nos. 0117448, published Sept. 5, 1984 and 0126986, published Dec. 5, 1984 and the U.S. counterpart of the latter, U.S. Pat. No. 4,525,301, issued Sept. 5, 1985 on an application filed Apr. 26, 1984 describe the use of triflate intermediates in various syntheses. More particularly, European application 0117448 describes making compounds ##STR12## either by reacting ##STR13## with ##STR14## or by reacting ##STR15## with ##STR16## wherein all asterisks denote asymmetric centers and R, R.sub.1, R.sub.2, R.sub.3 and n are as defined therein. European application 0126986 and its counterpart, U.S. Pat. No. 4,525,301 teach the synthesis of compounds ##STR17## by either reacting ##STR18## with ##STR19## or else by reacting ##STR20## with ##STR21## wherein all asterisks denote asymmetric centers and R, R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are defined therein.
These Hoechst applications do not, however, disclose the preparation of compounds wherein at least one of the moieties corresponding to R(CH.sub.2).sub.n and R.sub.1 of formulae VI to XV, above, is the group ##STR22## wherein Q, P and A.sub.3 have the meanings given at pp. 2-5 hereof, supra.