Reaction #66906

ord-a90466c8353941d38fddfb07bee5af59

Reaction equation

Oc1ccccc1O
catechol
CC(=O)O
acetic acid
FB(F)F
BF3
CC(=O)c1cccc(O)c1O
2,3-dihydroxyacetophenone

Solvents

Conditions

Detailed conditions
See reaction.notes.procedure_details.

Procedure

6-Amino-2,3-dimethoxyacetophenone (2) was also prepared according to published methods. The starting catechol (28) was acetylated, in microwave oven set at 300 Watt power, by reacting with mixture of acetic acid (29) and BF3. Et2O to yield 2,3-dihydroxyacetophenone (30) which was further reacted with diiodomethane in DMF, in the presence of K2CO3, to afford 2,3-methylenedioxyacetophenone (31). Subsequent nitration of compound 31 with 70% HNO3 afforded 2,3-methylenedioxy-6-nitroacetophenone (32). Without purification, compounds 32 was hydrogenated, and purified with column chromatography to provide 6-amino-2,3-methylenedioxyacetophenone (2).10 Another published method was followed in preparation of 6-amino-3-methoxy-4-benzyloxyacetophenone (3). First, the benzylation of the starting acetovanillone (33) with benzylbromide (34) gave 4-benzyloxy-3-methoxyacetophenone (35) which was nitrated to yield 4-benzyloxy-3-methoxy-6-nitroacetophenone (36).11 The so-obtained compound 36 was reduced with SnCl2 to afford compound 3.

Source

DOI: 10.6084/m9.figshare.5104873.v1Patent: US08524740B2uspto-grants-2013_09