O-TOLUIDINE HYDROCHLORIDE synthesis

Yield:636-21-5 545 mg

Reaction Conditions:

Stage #1:1-methyl-2-nitrobenzene with phosgene;sodium tetrahydroborate;copper(II) sulfate in methanol at 20;
Stage #2: with hydrogenchloride in methanol;diethyl ether

Steps:

General Procedure for the Reduction of Aromatic Nitro Compounds
General procedure: The catalyst precursor in form of a 0.04 M CuSO4 and 0.004 M CoCl2 solution (3.0 ml,3.0 mol% CuSO4, 0.3 mol% CoCl2) was added to a magnetically stirred solution ofthe nitro compound (4 mmol) in 25 ml methanol. The reaction was initiated by addingan initial portion of 210 mg (5.6 mmol) NaBH4, resulting in a color change to black(catalyst generated in situ) and vigorous gas evolution. Additional portions of NaBH4(7 × 35 mg, 7 × 0.9 mmol) NaBH4 were added in intervals of 3 min. Although thereaction was carried out at room temperature and under normal atmosphere, the generation of heat due to the exothermic character of the reaction usually heated the reaction mixture to 30-40C and cooling is generally not necessary on a small scale. However,for large scale reactions (10 mmol), a reflux condenser was attached. After 25 min,the reaction mixture was quenched by adding 30 ml of water and extracted with 3 ×40 ml of CH2Cl2. The combined organic layers were dried over MgSO4. After removal of the drying agent, 6 M HCl in ether (10 ml) was added to produce the more stable hydrochloride, which was freed from excess HCl, CH2Cl2 and Et2O under reduced pressure(10 mmHg). An aliquot of the amine was analyzed using GC-MS, 1H-NMR and 13C-NMR. The NMR data for the compounds are shown in Table 2.

References:

Ficker, Mario;Petersen, Johannes F.;Hansen, Jon S.;Christensen, Jorn B. [Organic Preparations and Procedures International,2014,vol. 46,# 2,p. 176 - 182]

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