Sodium ethoxide → 4-Chloro-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylic acid ethyl ester
Reaction equation
[CH2:1]([O:3][C:4]([C:6]1[C:11](=[O:12])[NH:10][C:9]2[S:13][CH:14]=[CH:15][C:8]=2[C:7]=1O)=[O:5])[CH3:2].[O-]CC.[Na+].C(OC(C1C(Cl)=C2C=CSC2=NC=1[Cl:32])=O)C>>[CH2:1]([O:3][C:4]([C:6]1[C:11](=[O:12])[NH:10][C:9]2[S:13][CH:14]=[CH:15][C:8]=2[C:7]=1[Cl:32])=[O:5])[CH3:2]Participants
Procedure
A preferred intermediate in the preparation of compounds of structure (III) is 4-chloro-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylic acid ethyl ester, depicted by formula (42) below. To prepare this intermediate, methyl-2-amino-thiophene-3-carboxylate was reacted with ethylmalonyl chloride to yield intermediate 2-(2-ethoxycarbonyl-acetylamino)-thiophene-3-carboxylic acid methyl ester, depicted by formula (39). This intermediate was converted to 4-hydroxy-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylic acid ethyl ester, depicted by formula (40), by reacting it with sodium ethoxide, and then converting it into 4,6-dichloro-thieno[2,3-b]pyrdine-5-carboxylic acid ethyl ester, depicted by formula (41). Hydrolysis of 4,6-dichloro-thieno[2,3-b]pyrdine-5-carboxylic acid ethyl ester, depicted by formula (41), yielded 4-chloro-6-oxo-6,7-dihydro-thieno[2,3-b]pyridine-5-carboxylic acid ethyl ester, depicted by formula (42), as shown in Scheme 20.
Sources & evidence
- ORD record
- ord-51743c374d2c4ba6983ad687e74b564b
- Source dataset
- uspto-grants-2008_04
- Patent number
- US07365200B2
Reaction notes
Loading…