Methyl bromoacetate → HCID 15851016, compound

Participants

Reaction Steps

Astoundingly, as can be seen from FIG. 2, it was the use of a modification of the Heck reaction (Heck, J. Am. Chem. Soc. 90 (1968), 5518), of all possible options, which led to the desired C—C linkage. 5-Iodouracil (5) was first of all alkylated with methyl bromoacetate to give methyl 5-iodouracil-1-acetate (6). The Heck reaction of 6 with Z-protected allylamine in the presence of Pd(OAc)2 and triphenylphosphine in absolute acetonitrile was carried out with the exclusion of air and at a superelevated temperature (bath temperature of 110° C.), and yielded the compound (7) together with a small portion of the oxidized byproduct (8). The methyl ester (7) was then hydrolyzed to give the free acid (9), which was reacted with methyl 2-Boc-aminoethylglycine (10) in analogy with the method of Dueholm et al., (J. Org. Chem. 59 (1994), 5767). The desired amino-modified thymine PNA building block (11) was obtained after the ester had been subjected to alkaline hydrolysis.

Provenance & Evidence