Dimethyl Succinate → HCID 51031686, compound

HRID 1254160Notes

Reaction equation

HRID 1254160 reaction equation
[CH3:1][O:2][C:3]1[C:4]([CH3:14])=[C:5]([CH:9]=[CH:10][C:11]=1[O:12][CH3:13])[C:6](O)=O.O=S(Cl)Cl.[C:19]([O:27]C)(=[O:26])[CH2:20][CH2:21][C:22]([O:24][CH3:25])=O>[Pd].[O-]S([O-])(=O)=O.[Ba+2]>[CH3:25][O:24][C:22]1[C:9]2[C:5](=[C:4]([CH3:14])[C:3]([O:2][CH3:1])=[C:11]([O:12][CH3:13])[CH:10]=2)[CH:6]=[C:20]([C:19]([OH:27])=[O:26])[CH:21]=1

Participants

5

Reactant 3

HCID 7820Dimethyl SuccinateHCID 24386Thionyl ChlorideHCID 117888183,4-dimethoxy-2-methylbenzoic acid

Product 1

HCID 51031686HCID 51031686, compound

Reagents, catalysts & solvents 1

HCID 16218511Pd barium sulfateCatalyst

Procedure

4,6,7-Trimethoxy-8-methyl-2-naphthoic acid (7) is prepared in six steps according to the following reaction diagram. Reduction of 3,4-dimethoxy-2-methylbenzoic acid (1) to aldehyde (2) can be carried out by the Rosenmund reaction (SOCl2 then H2, Pd/BaSO4) (see reference 27). The aldehyde (2) is then reacted with dimethyl succinate (Stobbe reaction) (see reference 28). The coupling product (3) is not isolated but is treated directly with sodium acetate in the presence of acetic anhydride and acetic acid (AcOH/Ac2O 1:1) to give 4. After saponification, 4-hydroxy-6,7-dimethoxy-8-methyl-2-naphthoic acid (5) is obtained with a yield of 70% (3 steps). After esterification under the conditions described above (90%), compound 6 is hydrolysed to give 4,6,7-trimethoxy-8-methyl-2-naphthoic acid (7) (92%).

Workup

  1. customaccording to the following reaction diagram

Sources & evidence

ORD record
ord-9ae20df716e1407997d525ed2d83cb7b
Source dataset
uspto-grants-2013_06
Patent number
US08455540B2

Reaction notes

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