1-Chloronaphthalene → Naphthalene

HRID 1953366Notes

Reaction equation

[Mg+2].[Cl-].[Cl-].Cl[C:5]1[C:14]2[C:9](=[CH:10][CH:11]=[CH:12][CH:13]=2)[CH:8]=[CH:7][CH:6]=1.C1(C2C3C(=CC=CC=3)C=CC=2)C2C(=CC=CC=2)C=CC=1>C1COCC1>[CH:13]1[C:14]2[C:9](=[CH:8][CH:7]=[CH:6][CH:5]=2)[CH:10]=[CH:11][CH:12]=1

Participants

Conditions

Temperature: 55 °C

Procedure

Under vacuum (0.1 mbar), 3.70 g (150 mmol) of Mg powder was baked out (100-150° C.) and, after cooling, 0.66 g (2 mmol) of 9,10-diphenylanthracene (DA, Aldrich), 50 ml of THF and 2 to 3 drops of ethyl bromide was added. After stirring the mixture for 1 h, a deep-blue solution had formed (formation of the Mg-DA radical anion, see description). To this solution, 0.26 g (2 mmol) of anhydrous FeCl2, 20 ml of THF and 10.2 ml of an 0.49 M solution of MgCl2 in THF (5 mmol) was added, followed by stirring for another 30 min. Thereupon, 13.6 ml (100 mmol) of 1-chloronaphthalene was added dropwise within 30 min, the color of the solution turning from deep-blue to brown, and the solution warming up to 55° C. After 2 h of stirring, the yield of the Grignard compound of 1-chloronaphthalene was 63%, and after 5 h, it was 67% (as determined by acidimetric titration). The protolysis of a 10 ml sample of the solution (total volume 95 ml; cf. Example 1) yielded 0.92 g of naphthalene (corresponding to a yield of 1-C1OH7MgCl of 68%), binaphthyl and no other products (GC analysis).

Workup

stirringAfter 2 h of stirring
waitafter 5 h

Sources & evidence

ORD record: ord-2fb871d7861d40788e99e5bdb93fb2e2
Source dataset: uspto-grants-2000_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06117372

Reaction notes

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