Oxalyl chloride → HCID 15565856, compound
Reaction equation
[CH2:1]([O:3][C:4]([C:6]1[C:11](=[O:12])[N:10](CC2C=CC(OC)=CC=2)[C:9]2[CH:22]=[CH:23][S:24][C:8]=2[C:7]=1O)=[O:5])[CH3:2].C(Cl)(=O)C([Cl:29])=O>>[CH2:1]([O:3][C:4]([C:6]1[C:11](=[O:12])[NH:10][C:9]2[CH:22]=[CH:23][S:24][C:8]=2[C:7]=1[Cl:29])=[O:5])[CH3:2]Participants
3
Procedure
The preferred intermediate in the preparation of compounds of structure (I), 7-chloro-5-oxo-4,5-dihydro-thieno[3,2-b]pyridine-6-carboxylic acid ethyl ester depicted by formula (4) below, was also prepared by an alternative route as shown in Scheme 34. In this method, methyl-3-amino-thiophene-2-carboxylate was reacted with 4-methoxy benzylchloride to yield methyl 3-(4-methoxybenzylamino)thiophene-2-carboxylate, depicted by formula (65). This intermediate was reacted with ethylmalonyl chloride followed by a cyclization reaction to yield 7-hydroxy-4-(4-methoxybenzyl)-5-oxo-4,5-dihydro-thieno[3,2-b]pyridine-6-carboxylic acid ethyl ester, depicted by formula (67). Chlorination of 7-hydroxy-4-(4-methoxybenzyl)-5-oxo-4,5-dihydro-thieno[3,2-b]pyridine-6-carboxylic acid ethyl ester, depicted by formula (67) by reacting with oxalyl chloride followed by deprotection yielded the intermediate 7-chloro-5-oxo-4,5-dihydro-thieno[3,2-b]pyridine-6-carboxylic acid ethyl ester, depicted by formula (4), as shown in Scheme 34.