ALKYL HYDANTOINS

摘要

PROBLEM TO BE SOLVED: To obtain the subject new compound useful as an intermediate for effectively producing (L)-Boc-N-methyl-leucine and analogous compounds thereof and useful as a producing material for medical and agrochemical compounds. SOLUTION: This compound is represented by the formula (R1 is a 1-6C alkyl; R2 and R3 are each H or a 1-6C alkyl) e.g. 5-alkylidene-1-alkylhydantoin. The compound is obtained e.g. by reacting 1-substituted hydantoin with 0.8-1.5 molar times compound containing bromine (e.g. bromine or N- bromosuccinimide) in the presence of a solvent such as acetic acid at 70-120 deg.C to brominate 5-position of the hydantoin, then reacting the brominated product with 1-2 molar times phosphite based on the applied 1-substituted hydantoin and then reacting the resultant product with 1-5 molar times compound containing a carbonyl group (e.g. isobutly aldehyde) in a solvent e.g. ethanol in the presence of a base (e.g. triethylamine) at room temperature.