Reaction SMILES: [CH3:1][O:2][C:3]1[C:12]2[C:7](=[C:8]([O:13][CH3:14])[CH:9]=[CH:10][CH:11]=2)[N:6]=[C:5]([C:15]([N:17]2[CH2:22][CH2:21][C:20]3([CH2:31][C:30](=[O:32])[C:29]4[C:24](=[CH:25][CH:26]=[C:27]([S:33]([NH2:36])(=[O:35])=[O:34])[CH:28]=4)[O:23]3)[CH2:19][CH2:18]2)=[O:16])[CH:4]=1.CCN=C=NCCCN(C)C.[CH3:48][C:49](O)=[O:50].C(=O)([O-])O.[Na+]>C(Cl)(Cl)Cl.CN(C1C=CN=CC=1)C>[C:49]([NH:36][S:33]([C:27]1[CH:28]=[C:29]2[C:24](=[CH:25][CH:26]=1)[O:23][C:20]1([CH2:19][CH2:18][N:17]([C:15]([C:5]3[CH:4]=[C:3]([O:2][CH3:1])[C:12]4[C:7](=[C:8]([O:13][CH3:14])[CH:9]=[CH:10][CH:11]=4)[N:6]=3)=[O:16])[CH2:22][CH2:21]1)[CH2:31][C:30]2=[O:32])(=[O:34])=[O:35])(=[O:50])[CH3:48]
Reactant: COc1cc(C(=O)N2CCC3(CC2)CC(=O)c2cc(S(N)(=O)=O)ccc2O3)nc2c(OC)cccc12
Reactant: CC(=O)O
Agent: CCN=C=NCCCN(C)C
Agent: CN(C)c1ccncc1
Agent: O=C([O-])O
Solvent: ClC(Cl)Cl
Product: COc1cc(C(=O)N2CCC3(CC2)CC(=O)c2cc(S(=O)(=O)NC(C)=O)ccc2O3)nc2c(OC)cccc12
Temperature: 25 °C
Reaction time: 8 h

Procedure:
293 mg of 1′-[(4,8-Dimethoxyquinolin-2-yl)carbonyl]-4-oxospiro[chroman-2,4′-piperidine]-6-sulfonamide was dissolved in 5 mL of CHCl3, and 10.7 mg of DMAP and 120 mg of EDCI were added to it, and then 0.036 mL of AcOH was added thereto and the mixture was stirred overnight at room temperature. Aqueous saturated sodium hydrogen carbonate was added to the reaction solution, and then extracted three times with ethyl acetate, and the organic layer was washed successively with aqueous saturated sodium hydrogencarbonate solution, water and saturated brine. The aqueous layers were combined, hydrochloric acid was added to it to thereby make it have a pH of 7.5, and this was then extracted with CHCl3. The extract was dried over sodium sulfate and concentrated, and the resulting residue was purified through silica gel column chromatography (CHCl3, 4.5% MeOH/CHCl3) to obtain 317 mg of N-acetyl-1′-[(4,8-dimethoxyquinolin-2-yl)carbonyl]-4-oxospiro[chroman-2,4′-piperidine]-6-sulfonamide. 26.3 mg of the product was dissolved in 1.5 mL of THF, and 15.0 mg of PPh3, 0.011 mL of DIAD and 2.7 mL of MeOH were added to it and the mixture was stirred at room temperature for one day. The reaction solution was concentrated and purified through silica gel thin-layer chromatography (n-Hexane/EtOAc=1/5) to obtain 26.3 mg of N-acetyl-1′-[(4,8-dimethoxyquinolin-2-yl)carbonyl]-N-methyl-4-oxospiro[chroman-2,4′-piperidine]-6-sulfonamide as a colorless foam substance. This was dissolved in 0.8 mL of MeOH and 0.11 mL of water, added by 0.11 mL of saturated sodium hydrogen carbonate solution, and then stirred for 2 hours. The reaction solution was diluted with water and extracted with CHCl3. The organic layer was dried over sodium sulfate, and concentrated, and the residue was purified through silica gel thin-layer chromatography (CHCl3/MeOH=18/1) to obtain the intended compound as a colorless foam substance. 1H-NMR(300 MHz, CDCl3) δ: 8.40-8.38 (1H, m), 8.01-7.97 (1H, m), 7.80-7.74 (1H, m), 7.51-7.43 (1H, m), 7.20 (1H, s), 7.17-7.13 (1H, m), 7.11-7.06 (1H, m), 4.67-4.58 (2H, m), 4.28-4.18 (1H, m), 4.09 (3H, s), 4.03 (3H, s), 3.67-3.56 (1H, m), 3.44-3.33 (1H, m), 2.92-2.78 (2H, m), 2.68 (3H, d, J=5.4 Hz), 2.28-2.17 (1H, m), 2.13-1.88 (3H, m). MS [M+H]+=526.