O-4-Methyluridine, O-2-methyluridine and (4H)uridine phosphoramidites were prepared with 2'-O-silyl protection, The methyl modified pyrimidines were synthesised from uridine via the triazolide (O-4-methyl) or 2,5'-cyclo derivative (O-2-methyl). An improved synthesis of protected 4-thiouridine was also performed.