Benzyl Chloride → Ethyl 2-benzyl-1,3-dithiane-2-carboxylate

HRID 847596

Reaction equation

[CH2:1]([O:3][C:4]([CH:6]1[S:11][CH2:10][CH2:9][CH2:8][S:7]1)=[O:5])[CH3:2].C([Li])CCC.[CH2:17](Cl)[C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1>O1CCCC1>[CH2:17]([C:6]1([C:4]([O:3][CH2:1][CH3:2])=[O:5])[S:7][CH2:8][CH2:9][CH2:10][S:11]1)[C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1

Participants

Conditions

Temperature: -25 °C

Procedure

A solution of 3.0 g (15.6 mmol) of 2-ethoxycarbonyl-1,3-dithiane in 40 ml of dry tetrahydrofuran was cooled under inert atmosphere to -78° C. and treated with 7.5 ml (15.6 mmol) of n-butyllithium. The resulting solution was warmed to -25° C., stirred for 20 min, recooled to -78° C., treated with 1.8 ml (15.6 mmol) of benzyl chloride, and stirred at ambient temperature for 16 h. After quenching with aqueous ammonium chloride, the mixture was extracted with ether, washed sequentially with water, aqueous sodium thiosulfate, and brine, dried over MgSO4, and concentrated in vacuo. Flash chromatography using 5% ethyl acetate in hexane gave 3.9 g (88%) of the desired compound. 1H NMR (CDCl3) δ 1.33 (t, J=7 Hz, 3H), 1.85 (qt, J=14, 3 Hz, 1H), 2.11 (dm, J=14 Hz, 1H), 2.69 (dt, J=14, 4 Hz, 2H), 3.23 (ddd, J=14, 12, 3 Hz, 2H), 3.38 (s, 2H), 4.27 (q, J=7 Hz, 2H), 7.25-7.35 (m, 5H). Mass spectrum (M+NH4)+ =300.

Workup

customrecooled to -78° C.
stirringstirred at ambient temperature for 16 h
customAfter quenching with aqueous ammonium chloride
extractionthe mixture was extracted with ether
washwashed sequentially with water, aqueous sodium thiosulfate, and brine
dry with materialdried over MgSO4
concentrationconcentrated in vacuo

Sources & evidence

ORD record: ord-66cd437431d34d62947087968164ac25
Source dataset: uspto-grants-1992_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05142056

Linked notes

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