2,4-Dichloropyrimidine-d2 is the deuterium labeled 2,4-Dichloropyrimidine. 2,4-Dichloropyrimidine is a sensitizer[1].
References
[1] D W Roberts, et al. Chemistry-based risk assessment for skin sensitization: quantitative mechanistic modeling for the S(N)Ar domain. Chem Res Toxicol. 2011 Jul 18;24(7):1003-11. DOI:10.1021/tx100420w