The invention discloses a preparation method for an agent capable of promoting growth
gene expression of pigs. The invention relates to synthesis of
amino acid derivatives, specifically to a preparation method for a growth-
gene-expression promoting agent N-methyl-D-
aspartic acid, i.e., a derivative of D-
aspartic acid. The preparation method comprises the following steps: with D-
aspartic acid as a
raw material, reacting D-aspartic acid with
methanol and
thionyl chloride so as to produce dimethyl-D-aspartate
hydrochloride; then subjecting dimethyl-D-aspartate
hydrochloride and 40%
formaldehyde to hydroxymethylation under an alkaline condition so as to produce N-
hydroxymethyl-D-aspartic acid; and then carrying out hydrogenation at normal temperature and normal pressure under the action of a Pd / C catalyst so as to obtain N-methyl-D-aspartic acid. The preparation method is simple; the prepared N-methyl-D-aspartic acid is stable in quality; no environmental
pollution is produced during preparation; and the prepared N-methyl-D-aspartic acid can promote the growth of
livestock and poultry, improves the
utilization rate of feeds, the carcass quality of pigs and the rate of
lean meat, and is convenient for promotion and application.