(5-amino-2,3-dimethoxyphenyl)methanol synthesis

Yield:1111236-54-4 80%

Reaction Conditions:

Stage #1: 2,3-dimethoxy-5-nitro-benzyl alcoholwith thiophene;hydrogen;platinum on carbon in methanol;di-isopropyl ether at 20; for 20 h;
Stage #2: with hydrogenchloride in diethyl ether at 20;

Steps:

A.A29.a

Example A29; a) Preparation of intermediate 89; A mixture of 2,3-dimethoxy-5-nitro-benzenemethanol (0.0375 mol) in MeOH (150 ml) was hydrogenated at r.t. for 20 hours with Pt/C 5 % (2 g) as a catalyst in the presence of a thiophene solution (1 ml; 4 % in DIPE). After uptake of H₂ (3 eq.), the catalyst was filtered off and the filtrate was evaporated. The residue was suspended in DIPE. The precipitate was filtered off, washed with DIPE and dried (vacuo). Yield : 5.5 g of intermediate 89 (80 %).

References:

WO2009/16132,2009,A1 Location in patent:Page/Page column 82