Acetic Acid → Benzo[b]thiophene-2,5-dicarboxylic acid 2-tert-butyl ester 5-methyl ester

HRID 545472Notes

Reaction equation

[S-2:1].[Na+].[Na+].C(O)(=O)C.[C:8]([O:12][C:13](=[O:16])[CH2:14]Cl)([CH3:11])([CH3:10])[CH3:9].C([O-])([O-])=O.[K+].[K+].[CH3:23][O:24][C:25](=[O:37])[C:26]1[CH:31]=[CH:30][C:29]([N+]([O-])=O)=[C:28]([CH:35]=O)[CH:27]=1>CN(C=O)C.O>[CH3:23][O:24][C:25]([C:26]1[CH:31]=[CH:30][C:29]2[S:1][C:14]([C:13]([O:12][C:8]([CH3:11])([CH3:10])[CH3:9])=[O:16])=[CH:35][C:28]=2[CH:27]=1)=[O:37]

Participants

Conditions

Temperature: 0 °C

Procedure

To a suspension of sodium sulfide (7.95 g, 102 mmol) in anhydrous DMF (200 mL) at 0° C. were added acetic acid (5.80 mL, 102 mmol) and additional DMF (100 mL). The mixture was allowed to stir at 0° C. for 30 min and chloro-acetic acid tert-butyl ester (14.6 mL, 102 mmol) was added followed by additional DMF (50 mL). The resulting mixture was allowed to stir at 0° C. for 30 min and at rt for 30 min. To this mixture were added K2CO3 (16.4 g, 119 mmol) and 3-formyl-4-nitro-benzoic acid methyl ester (17.68 g, 84.55 mmol) in DMF (30 mL). The resulting mixture was heated at 55° C. for 22 h, cooled to rt and poured into water (1.2 L). The solid formed was filtered, washed with water (300 mL) and crystallized from MeOH to give benzo[b]thiophene-2,5-dicarboxylic acid 2-tert-butyl ester 5-methyl ester as a pale solid. MS (EI): cal'd 237.0 (M-tbutyl+H+) exp 237.1 (M-tbutyl+H+).

Workup

stirringto stir at 0° C. for 30 min and at rt for 30 min
temperatureThe resulting mixture was heated at 55° C. for 22 h
temperaturecooled to rt
customThe solid formed
filtrationwas filtered
washwashed with water (300 mL)
customcrystallized from MeOH

Sources & evidence

ORD record: ord-fc977b313a834612b9976ab993c1a22e
Source dataset: uspto-grants-2011_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07935724B2

Reaction notes

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