Ammonia → (βR)-β-Amino-α,α-dimethylbenzeneethanol

Participants

Reaction Steps

D-Phenylglycine methyl ester hydrochloride (12) (5 g, 24.83 mmol) was added in portions, during 15 minutes, to a solution of methylmagnesium iodide [prepared from methyl iodide (9.28 ml, 148.97 mmol)] in diethyl ether (190 ml) and stirred for 3 hours. To promote hydrolysis, a saturated solution of ammonium chloride was added dropwise with vigorous stirring. The insoluble product was filtered off through celite, and the organic layer was separated and dried with sodium sulphate. Concentration in vacuo gave a colourless oil. The aqueous layer was made alkaline by addition of aqueous ammonia. The product was extracted with diethyl ether, dried with sodium sulphate and concentrated in vacuo. The oily residues were then combined and distilled to give the title compound (13) (1.66 g, 41%) as a solid which was recrystallised from 40-60 petroleum-ether; mp 49° C.; [α]D25 (c 1 in CHCl3) -23.2; (Found: C, 72.83; H, 9.05; N, 8.30. C10H15NO requires C, 72.69; H, 9.15; N, 8.48%); δH (200 MHz; CDCl3) 1.04 (3H, s, C(CH3)3), 1.21 (3H, s, C(CH3)3), 2.16 (3H, s, NH2 and OH), 3.39 (1H, s, CHPh), 7.27-7.34 (5H, m, ArCH); δC (125 MHz; CDCl3) 24.69 (CH3), 27.55 (CH3), 64.54 (CH), 72.26 (C), 127.48 (ArCH), 128.05 (ArCH), 128.23 (ArCH), 142.82 (C) ; m/z (CI+, NH3) 166 (M+ +1).

Provenance & Evidence