In glacial acetic acid, N-chlorosuccinimide can be used for nuclear substitution of uracil, thymine and derivatives of 2-thiouracil, and in chloroform plus benzoyl peroxide this sam~ reagent can be used for substitution of an allylic methyl side chain. Theoretical considerations indicate that electrophilic attack should occur preponderantly at position 5 of the nucleus in 2-methylthiouracil and substances of this type. Two of the 5-chloro ...
