[CH3:1][O:2][C:3](=[O:14])[C:4]1[CH:9]=[C:8]([N+:10]([O-:12])=[O:11])[CH:7]=[C:6]([NH2:13])[CH:5]=1.CCN(CC)CC.[Cl:22][CH2:23][CH2:24][CH2:25][C:26](Cl)=[O:27]>C(Cl)Cl>[CH3:1][O:2][C:3](=[O:14])[C:4]1[CH:9]=[C:8]([N+:10]([O-:12])=[O:11])[CH:7]=[C:6]([NH:13][C:26](=[O:27])[CH2:25][CH2:24][CH2:23][Cl:22])[CH:5]=1To a solution of 3-amino-5-nitro-benzoic acid methyl ester (D1) (38 g, 194 mmol, 1 equiv) in CH2Cl2 (350 ml) was added NEt3 (32 ml, 230 mmol, 1.2 equiv) followed by 4-chlorobutyryl chloride (24.7 ml, 220 mmol, 1.13 equiv) dropwise over 20 nm. The resulting mixture was allowed to warm to room temperature and stirred for 30 min. The organic phase was then washed with 2N aqueous HCl solution, dried over MgSO4 and concentrated in vacuo. The residue was triturated with iso-hexane and Et2O to give 3-(4-chloro-butanoylamino)-5-nitro-benzoic acid methyl ester D2 (56 g, 96%) as a brown solid.
Wird geladen…
