References and Notes
1a
Ritter JJ.
Kalish J.
J. Am. Chem. Soc.
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4045
1b
Ritter JJ.
Kalish J.
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4048
2
Koziara A.
Osowska-Parewicka K.
Zawadzki S.
Zwierzak A.
Synthesis
1987,
487
3
Koziara A.
Zwierzak A.
Tetrahedron Lett.
1987,
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6513
4a
Davis FA.
Mancinelli PA.
J. Org. Chem.
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4b
Hirao A.
Hattori I.
Yamaguchi K.
Nakahama S.
Synthesis
1982,
461
5a
Chastrette M.
Axiotis GP.
Synthesis
1980,
889
5b
Amouroux R.
Axiotis GP.
Synthesis
1981,
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6a
Henze HR.
Allen BB.
Leslie WB.
J. Am. Chem. Soc.
1943,
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87
6b
Henze HR.
Allen BB.
J. Am. Chem. Soc.
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7
Ciganek E.
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8
Chaplinski V.
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9 Massalov, N. V.; Sokolov, V. V., unpublished results.
10
Bertus P.
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11
General Experimental Procedure for the Synthesis of Primary
tert
-Alkylamines 8-13: To a solution of the nitrile (10 mmol) in Et2O (30-50 mL) was added the respective Grignard reagent as a 1-3 M Et2O solution (3 equiv), and after stirring for 30 min Ti(Oi-Pr)4 (1 equiv) was added successively at r.t. After the mixture had been heated under reflux for 10 h, a 10% aq solution of NaOH (40 mL) was added. Stirring was continued for 15-30 min. The solution was filtered and the filtrate was extracted with Et2O (3 ¥ 30 mL). The combined Et2O layers were concentrated under reduced pressure and the residue was extracted with dilute aq 5% HCl. The combined aqueous layers were washed with Et2O (2 ¥ 30 mL), made basic by addition of aq 10% NaOH and extracted with Et2O (3 × 30 mL). A few drops of concd HCl were added to the combined Et2O phases and Et2O was evaporated to dryness to leave the respective amine hydrochloride. In some cases it was necessary to purify the amine hydrochloride by recrystallization (EtOH-Et2O).
1,1-Dibenzyl-
n
-propylamine Hydrochloride (11a): 1H NMR (250 MHz, DMSO-d
6): δ = 1.06 (t, J = 7.3 Hz, 3 H), 1.49 (q, J = 7.3 Hz, 2 H), 2.84 (d, J = 13.8 Hz, 2 H), 3.18 (d, J = 13.8 Hz, 2 H), 7.24-7.34 (m, 10 H), 8.32 (br s, 3 H). 13C NMR (250 MHz, DMSO-d
6): δ = 7.6 (CH3), 26.8 (CH2), 41.2 (CH2), 58.7 (C), 126.9 (CH), 128.4 (CH), 130.9 (CH), 134.9 (C). MS (ESI): m/z = 1067 (46) [4 ¥ M - Cl]+, 515 (18) [2 ¥ M - Cl]+, 479 (10) [2 ¥ M - HCl - Cl]+, 240 (100) [M - Cl]+. Anal. Calcd for C17H21N·HCl (275.8): C, 74.03; H, 8.04; N, 5.08. Found: C, 74.23; H, 8.14; N, 5.19.
12
Experimental Procedure for the Synthesis of 1-(2-Furyl)-1-phenyl-
n
-butylamine Hydrochloride (
17f): To the solution of furan (1.7 g, 25 mmol) in THF (10 mL) was added n-BuLi (2.9 M in hexane, 25 mmol) keeping the temperature below -10 °C, and the mixture was stirred at r.t. for 4 h to provide a solution of 2-furyllithium.
To a solution of butyronitrile (0.69 g, 10 mmol) in Et2O (30 mL) were added successively at ambient temperature PhMgBr (1.1 M in Et2O, 10 mmol) then, after stirring for 30 min, Ti(Oi-Pr)4 (2.84 g, 10 mmol) and finally the solution of 2-furyllithium. After heating under reflux for 10 h, the reaction mixture was worked up as described in the general procedure above. The product 17f was purified by column chromatography on silica gel (50 g), eluting with CHCl3-MeOH (30:1). 1H NMR (250 MHz, DMSO-d
6): δ = 0.93 (t, J = 7.2 Hz, 3 H), 1.15-1.45 (m, 2 H), 2.25-2.42 (m, 2 H), 6.46 (m, 1 H), 6.57-6.58 (m, 1 H), 7.29-7.37 (m, 5 H), 7.55 (m, 1 H), 9.47 (br s, 3 H). 13C NMR (250 MHz, DMSO-d
6): δ = 14.7 (CH3), 17.7 (CH2), 41.1 (CH2), 61.6 (C), 109.9 (CH), 111.2 (CH), 127.2 (CH), 128.6 (CH), 128.9 (CH), 130.5 (C), 143.4 (CH), 153.7 (C). MS (ESI): m/z = 970 (16) [4 ¥ M - Cl]+, 199 (100) [M - Cl - NH3]+, 157 (18). Anal. Calcd for C14H17NO·HCl (251.8): C, 66.79; H, 7.21; N, 5.56. Found: C, 66.69; H, 7.31; N, 5.26.