Maltol → HCID 57919191, compound

Reaction equation

Cl[C:2]1[C:3](=[O:15])[N:4](C2CCCCO2)[N:5]=[CH:6][C:7]=1Cl.[OH:16][C:17]1[C:22](=[O:23])[CH:21]=[CH:20][O:19][C:18]=1[CH3:24].C[O:26][C:27](=[O:36])[CH:28](Br)[CH2:29][CH:30]1[CH2:34][CH2:33][CH2:32][CH2:31]1>>[CH:30]1([CH2:29][CH:28]([N:4]2[C:3](=[O:15])[CH:2]=[C:7]([O:16][C:17]3[C:22](=[O:23])[CH:21]=[CH:20][O:19][C:18]=3[CH3:24])[CH:6]=[N:5]2)[C:27]([OH:26])=[O:36])[CH2:34][CH2:33][CH2:32][CH2:31]1

Participants

Reactant 3

HCID 8369Maltol

HCID 107292624,5-Dichloro-2-(tetrahydro-pyran-2-yl)-2H-pyridazin-3-one2×

HCID 57919172Methyl 2-bromo-3-cyclopentylpropanoate2×

Product 1

HCID 57919191HCID 57919191, compound

Procedure

In an analogous manner to the stepwise sequence outlined in intermediate 19, starting from 4,5-dichloro-2-(tetrahydropyran-2-yl)-2H-pyridazin-3-one (Intermediate 20) and 3-hydroxy-2-methyl-pyran-4-one and alkylating with 2-bromo-3-cyclopentyl-propionic acid methyl ester (Intermediate 10) afforded 3-cyclopentyl-2-[4-(2-methyl-4-oxo-4H-pyran-3-yloxy)-6-oxo-6H-pyridazin-1-yl]-propionic acid as a white solid (3.4 g, 30% for the final step); LC-MS: 361.1 [M+1]+ tR=3.10 min. Purity on HPLC: 97.7% (214 nm), 99.0% (254 nm), tR=5.79 min. 1H NMR (300 MHz, CDCl3): δ 7.97 (s, 1H), 7.86 (d, 1H, J=5.4 Hz), 6.59 (d, 1H, J=5.4 Hz), 6.15 (s, 1H), 5.57 (dd, 1H, J1=10.5 Hz, J2=4.5 Hz), 2.42 (s, 3H), 2.36˜2.23 (m, 1H), 2.23˜2.16 (m, 1H), 1.81˜1.57 (m, 7H), 1.32˜1.20 (m, 2H).