反应详情

(R)-N-Isobutylserine methyl ester HCl salt (Method B3a; 2.28 g, 10.8 mmol) was treated with SOCl2 followed by 2-methyl-4-nitrophenyl isothiocyanate in a manner analogous to Method C2a. The resulting material was purified by column chromatography (SiO2, gradient from hexane to 10% EtOAc/hex) to give 3-isobutyl-4-methylene-2-(2-methyl-4-nitrophenylimino)-1,3-thiazolidin-5-one (0.028 g, 10%) followed by (S)-3-isobutyl-4-carbomethoxy-2-(2-methyl-4-nitrophenylimino)-1,3-thiazolidine HCl salt (0.192 g, 56%). 3-Isobutyl-4-methylene-2-(2-methyl-4-nitrophenylimino)-1,3-thiazolidin-5-one: TLC (25% EtOAc/hex) Rf 0.40. (S)-3-isobutyl-4-carbomethoxy-2-(2-methyl-4-nitrophenylimino)-1,3-thiazolidine HCl salt: TLC (free base, 25% EtOAc/hex) Rf0.50.

1. customThe resulting material was purified by column chromatography (SiO2, gradient from hexane to 10% EtOAc/hex)