Sodium Hydroxide → (5-Methylthiophen-2-yl)methanamine

Participants

Reaction Steps

To a stirred solution of lithium aluminum hydride in Et2O (1M, 4.1 mL, 4.1 mmol; Aldrich) and diethyl ether (15 mL, Sure Seal, Aldrich) was added drop-wise over 10 min a solution of the 3-bromo-5-methylthiophene-2-carbaldehyde oxime (450 mg, 2.05 mmol) in Et2O (20 mL; Sure Seal, Aldrich) at room temperature and then the mixture stirred at room temperature for 4 h under a nitrogen atmosphere. To the mixture was added drop-wise and carefully with vigorous stirring water (1 mL), 15% NaOH (1 mL) and then water (3 mL). After stirring for 1 h, to this was added Na2SO4 (10 g) and stirred for another 1 h. This was filtered through Celite and washed with CH2Cl2. The filtrate and washings were combined, concentrated in vacuo to obtain 275 mg (1.33 mmol, Y. 65%) of the title compound contaminated about 30% of (5-methylthiophen-2-yl)methanamine as a brownish oil: HPLC: 1.04 min (AP 60% at 254 nm); impurity peaks at 0.55 min (AP 20% for des-Br-amine), 1.63 min (AP 11%, unknown); LC/MS m/z 189/191 (M+H—NH3); 1H NMR (500 MHz, CDCl3) δ ppm 2.43 (3H, s, CH3), 3.90 (2H, s, CH2), 6.59 (1H, s, Th—H).

Provenance & Evidence