Reaction #2446089

Reaction equation

1-(cyclohexyl(methyl)amino)propan-2-yl 4-(tert-butyl)benzoate

methyl bromide

methyl bromide

→

[2-(4-tert-butyl-benzoyloxy)-propyl]-cyclohexyl-dimethyl-ammonium bromide

Solvents

DCE

Conditions

Workup

1. 1
   workup.STIRRINGstirred at rt for 8 h
2. 2
   ConcentrationThe reaction mixture was concentrated
3. 3
   Otherthe crude material was purified by chromatography on neutral alumina eluting with 2-8% methanol-DCM
4. 4
   Otherto provide an off white solid
5. 5
   OtherThe solid material was crystallized from DCM-ether

Procedure

To a stirred solution of 1-(cyclohexyl(methyl)amino)propan-2-yl 4-(tert-butyl)benzoate (22.5 g, 67.98 mmol) in DCE (150 ml) was added methyl bromide (25% solution in toluene, 103 ml, 271.90 mmol) and reaction mixture was stirred at rt for 16 h. TLC showed very small amount of unreacted starting material. Hence another 0.5 eq. of methyl bromide was added and stirred at rt for 8 h. The reaction mixture was concentrated and the crude material was purified by chromatography on neutral alumina eluting with 2-8% methanol-DCM to provide an off white solid. The solid material was crystallized from DCM-ether to provide [2-(4-tert-butyl-benzoyloxy)-propyl]-cyclohexyl-dimethyl-ammonium bromide. Yield: 15.5 g (53.5%). 1H NMR (DMSO-d6) δ 7.94 (d, J=8 Hz, 2 H), 7.57 (d, J=8 Hz, 2 H), 5.54-5.51 (m, 1 H), 3.93 (dd, J=15, 9 Hz, 1 H), 3.63 (d, J=14 Hz, 1 H), 3.42-3.36 (m, 1 H), 3.05 (s, 6 H), 2.23-2.20 (m, 1 H), 2.11-2.08 (m, 1 H), 1.87-1.83 (m, 2 H), 1.57-1.43 (m, 3 H), 1.36 (d, J=6 Hz, 3 H), 1.30 (s, 9 H), 1.23-1.08 (m, 3 H); LCMS: m/z=346.4 [M+], RT=3.00 min, (Column: Y, Program: P1). UPLC: 99.90% (200 nm), RT=4.04 min (Mobile Phase A. 0.05% TFA in water, B. Acetonitrile; Column: Zorbax® SB-C18 (4.6×50 mm) 1.8μ).

Source