Toluene → Benzene, 1,1'-(1,2-ethynediyl)bis[2-methoxy-

HRID 879943Notes

Reaction equation

HRID 879943 reaction equation
[CH3:1][O:2][C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][C:4]=1[CH2:9][CH2:10][CH3:11].C[CH2:13][O:14][CH2:15][CH3:16].[C:17]1(C)[CH:22]=CC=C[CH:18]=1>>[CH3:1][O:2][C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][C:4]=1[C:9]#[C:10][C:11]1[CH:22]=[CH:17][CH:18]=[CH:16][C:15]=1[O:14][CH3:13]

Participants

4

Reactant 3

HCID 1140TolueneHCID 3283Diethyl EtherHCID 125237921-Methoxy-2-propylbenzene

Product 1

HCID 11064451Benzene, 1,1'-(1,2-ethynediyl)bis[2-methoxy-Yield 97%

Procedure

In a dry 25 mL Schlenk-tube, which has been flooded with argon, 1-methoxy-2-(prop-1-yl)benzene (146 mg, 1 mmol), complex 23a.(Et2O) (22 mg, 0.02 mmol, 2 mol %) and molecular sieve (1 g, 5 Å, powder) were suspended in 5 mL of toluene. The reaction mixture was stirred for 2 h at room temperature, was filtered over a short silica gel column (2 cm), the filtrate was concentrated and the residue was purified by column chromatography (SiO2, hexane/EtOAc, 20:1). 1,2-bis(2-methoxyphenyl)ethine (115 mg, 0.48 mmol, 97%) was obtained as colorless solid. M.p.=126-127° C.; 1HNMR (400 MHz, CD2Cl2): δ=7.49 (ddd, J=7.3, 1.6, 0.5 Hz, 2H), 7.33 (ddd, J=7.9, 7.7, 1.9 Hz, 2H), 6.95 (td, J=7.9, 1.0 Hz, 4H), 3.92 (s, 6H); 13C NMR (100 MHz, CD2Cl2): δ=160.3 (2×C), 133.7 (2×CH), 130.1 (2×CH), 120.8 (2×CH), 113.0 (2×C), 111.3 (2×CH), 90.1 (2×C), 56.2 (2×CH3); IR (film): v=3105, 3033, 2998, 2963, 2937, 2833, 1945, 1903, 1863, 1598, 1574, 1498, 1464, 1456, 1432, 1274, 1241, 1184, 1162, 1115, 1047, 1020, 937, 750 cm−1; MS (EI) m/z (%): 238 [M+] (100), 237 (32), 223 (23), 221 (15), 207 (10), 195 (5), 178 (8), 165 (14), 152 (9), 131 (19), 111 (6), 97 (3), 89 (3); HRMS (ESI): m/z: calculated for O16H14O2+Na: 261.0886; found: 261.0884.

Workup

  1. filtrationwas filtered over a short silica gel column (2 cm)
  2. concentrationthe filtrate was concentrated
  3. customthe residue was purified by column chromatography (SiO2, hexane/EtOAc, 20:1)

Sources & evidence

ORD record
ord-3e861d4c3c3a487d94450a6cefc7ef23
Source dataset
uspto-grants-2015_03
Patent number
US08993470B2

Reaction notes

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