HCID 10907345, compound → (4R)-5-(Methoxycarbonyl)-2,6-dimethyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

To 50 mg of the (4R)-1,4-dihydro-2,6-dimethyl-3-[2(2-carboxybenzoyl) aminoethyl]oxycarbonyl-4-(3-nitrophenyl)pyridine-5-carboxylic acid obtained in Example 8 was added 5 ml of sodium methoxide (28% methanol solution) and the mixture was stirred at 50° C. for 2 hours. After it was diluted with 10 ml of water, the reaction mixture was washed with 5 ml of ethyl acetate and the aqueous layer was adjusted to pH 3 before it was extracted 3 times with 10 ml each of ethyl acetate. The ethyl acetate layer was dried over anhydrous sodium sulfate and evaporated to dryness. The yellow substance thus obtained was purified on a column packed with 120 ml of Sephadex LH-20 (solvent: methanol) to obtain 22 mg of (4R)-1,4-dihydro-2,6-dimethyl-3-methyloxycarbonyl-4-(3-nitrophenyl) pyridine-5-carboxylic acid. The optical purity of this substance was analyzed by HPLC (mobile phase: hexane:ethanol:acetic acid=90:10:0.1, flow rate: 1.0 ml/minute, detection UV 254 nm) using an otical resolution column: CHIRALPAK AS (4.6 mm ×250 mm) manufactured by Daicel Chemical Industries Ltd. As a result, it revealed that the optical purity of the substance was 100% and the retention time was 12.5 minutes. 1 H-NMR(CD3OD): δ 8.09(1 H,s), 7.99(1 H,d,J=9.5 Hz), 7.65(1 H,d,J=7.7 Hz), 7.44(1 H,t,j=8.1 Hz), 5.09(1 H,s), 3.62(3 H,S), 2.34(3 H, s), 2.33(3 H,s)

Provenance & Evidence