Reaction #1350560

Reaction equation

sodium borohydride

5-amino-2-methylphenol

2-thiophenecarboxaldehyde

sodium acetate

→

2-methyl-5-(thiophen-2-yl-methylamino)phenol

Yield 32.5%

Solvents

methanol

Conditions

Workup

1. 1
   workup.ADDITIONAfter the addition
2. 2
   workup.STIRRINGto stir for an additional 1.5 hours
3. 3
   workup.ADDITIONThe reaction mixture was poured
4. 4
   Otheronto crushed ice slurry (200 g)
5. 5
   Otherthe resulting precipitate was collected
6. 6
   Washwashed with cold water three times
7. 7
   Otherair-dried

Procedure

To a solution of 5-amino-2-methylphenol (12.30 g, 100 mmole) in methanol (100 mL) at 4° C. was added 2-thiophenecarboxaldehyde (16.82 g, 150 mmole) and sodium acetate (16.41 g, 200 mmole). The reaction mixture was stirred for 15 minutes and sodium borohydride (4.73 g, 125 mmole) was added portionwise over 1 hour at 4° C. After the addition was complete, the reaction was allowed to stir for an additional 1.5 hours. The reaction mixture was poured onto crushed ice slurry (200 g) and the resulting precipitate was collected, washed with cold water three times and air-dried to afford 2-methyl-5-(thiophen-2-yl-methylamino)phenol (7.12 g, 32% yield): mp 130.8-132.6° C.; 1HNMR (400 MHz, DMSO-d6) δ 1.94 (s, 3H), 4.34 (d, 2H, J=6.0 Hz), 5.91 (t, 1H, J=6.1 Hz), 6.00 (dd, 1H, J=2.3, 8.0 Hz), 6.11 (d, 1H, J=2.2 Hz), 6.70 (d, 1H, J=8.1 Hz), 6.95 (dd, 1H, J=3.5, 5.0 Hz), 7.00 (dd, 1H, J=0.8, 3.4 Hz), 7.34 (dd, 1H, J=1.0, 5.0 Hz), 8.79 (s, 1H); MS m/z 219 (M+).

Source