Ethyl chloroformate → Ethyl 1,4-dimethoxy-3-methyl-2-naphthoate

HRID 15718

Reaction equation

C([Li])CCC.Br[C:7]1[C:16]([CH3:17])=[C:15]([O:18][CH3:19])[C:14]2[C:9](=[CH:10][CH:11]=[CH:12][CH:13]=2)[C:8]=1[O:20][CH3:21].Cl[C:23]([O:25][CH2:26][CH3:27])=[O:24]>O1CCCC1>[CH3:19][O:18][C:15]1[C:14]2[C:9](=[CH:10][CH:11]=[CH:12][CH:13]=2)[C:8]([O:20][CH3:21])=[C:7]([C:23]([O:25][CH2:26][CH3:27])=[O:24])[C:16]=1[CH3:17]

Participants

Conditions

Temperature: 0 °C

Procedure

n-Butyl lithium (1.6M in hexanes, 4.1 ml, 6.56 mmol) was added dropwise to 2-bromo-1,4-dimethoxy-3-methylnaphthalene (1.537 g, 5.47 mmol) in tetrahydrofuran (30 ml) at −50° C. The reaction was stirred for 30 min at −50° C. before dropwise addition of ethyl chloroformate (1 ml, 10.46 mmol). The reaction was allowed to warm to 0° C. over 18 h quenched by addition of hydrochloric acid (2N) and extracted with ethyl acetate. The extract was dried (Na2SO4) and the solvent evaporated under vacuum. The residue was purified by SPE (silica, 10 g) eluting with 10% ethyl acetate in cyclohexane to give ethyl 1,4-dimethoxy-2-methylnaphthalene-3-carboxylate (1.33 g, 89%).

Workup

customquenched by addition of hydrochloric acid (2N)
extractionextracted with ethyl acetate
dry with materialThe extract was dried (Na2SO4)
customthe solvent evaporated under vacuum
customThe residue was purified by SPE (silica, 10 g)
washeluting with 10% ethyl acetate in cyclohexane

Sources & evidence

ORD record: ord-68ac42a1003a457896b8b3eb493ce566
Source dataset: uspto-grants-2010_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07732622B2

Linked notes

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