反应详情

3-Nitro-6-methylbenzoic acid (2-1) (Aldrich) was converted into methyl 3-nitro-6-methylbenzoate (2-2) using the standard procedure of MeOH and HCl gas. To a mixture of methyl 3-nitro-6-methylbenzoate (2-2) (2.0 g, 10.3 mmol) and N-bromosuccinimide (1.64 g, 9.23 mmol) in CHCl3 was added AIBN (20 mg) and this was then photolysed at reflux for 4 hours. The reaction was cooled, filtered and the filtrate evaporated to dryness. Chromatography of the residue (silica, hexane/EtOAc 92:8) afforded 2-3 as a solid (1.56 g). Rf (silica; hexane/EtOAc 10:1)=0.25. ##STR57## N-t-Butoxycarbonylglycyl-3(R)-methyl-β-alanine benzyl ester (2-4)

1. temperatureat reflux for 4 hours
2. temperatureThe reaction was cooled
3. filtrationfiltered
4. customthe filtrate evaporated to dryness