Several known a-amino acid analogues and a new compound, N- chloroacetylphosphoramidate, a carbamyl phosphate analogue, were screened as antitumor agents. All gave 50% growth inhibition of cultures of human epidemeroid carcinoma of the nasopharynx at dosage levels of 2-8 fig/ml while showing no activity against L1210 lymphoid leukemia in vivo in BDFi mice.
![[(2-chloroacetyl)amino]-phenylmethoxy-phosphinic acid Structure](https://image.chemsrc.com/caspic/321/61727-67-1.png)