7-(trifluoromethoxy)-3,4-dihydroisoquinolin-1(2H)-one synthesis

Yield:1340134-64-6 4.1%

Reaction Conditions:

with phosphorus pentoxide;trichlorophosphate at 110; for 1 h;

Steps:

51 Preparation of Intermediate 7-(Trifluoromethoxy)-3,4-dihydroisoquinolin-1(2H)-one (I-51d)

Preparation of Intermediate 7-(Trifluoromethoxy)-3,4-dihydroisoquinolin-1(2H)-one (I-51d)
Using an analogous procedure and workup as described for the preparation of intermediate I-1d above, ethyl 4-(trifluoromethoxy)phenethylcarbamate (I-51c: 3.2 g, 11.5523 mmol) in POCl₃ (32 mL) was reacted with P₂O₅ (3.27 g, 23.104 mmol).
The resulting mixture was stirred at 110° C. for 1 hour to afford the crude product.
Purification by column chromatography on silica gel (1.5% methanol in DCM) afforded 110 mg of the product (4.1% yield).
¹H NMR (300 MHz, CDCl₃): δ 7.30-7.10 (m, 3H), 4.22 (t, 1H), 3.42 (q, 2H), 2.8 (t, 2H)

References:

US2014/45872,2014,A1 Location in patent:Paragraph 0855