Reaction #42208

Reaction equation

Intermediate 7

methyl 4-methylbenzenesulfonate

(±)-1-(2,3-dihydronaphtho[1,2-b]furan-2-yl)methanamine

diisopropylethylamine

benzyl chloroformate

→

(±)-benzyl 2,3-dihydronaphtho[1,2-b]furan-2-ylmethylcarbamate

Yield 90.4%

Conditions

Procedure

Treatment of (±)-1-(2,3-dihydronaphtho[1,2-b]furan-2-yl)methanamine (1.19 g, 5.97 mmol) with diisopropylethylamine (0.849 g, 6.57 mmol) followed by benzyl chloroformate (1.07 g, 6.27 mmol) generally according to the procedure described for Intermediate 7 afforded 1.80 g (90%) of (±)-benzyl 2,3-dihydronaphtho[1,2-b]furan-2-ylmethylcarbamate as a white solid. Rf=0.47 (silica, ethyl acetate:hexanes 1:4); mp 110-112° C.; Anal. calcd. for C21H19NO3: C, 75.66; H, 5.74; N, 4.2. Found: C, 75.4; H, 5.57; N, 4.12. Chiral HPLC separation of (±)-benzyl 2,3-dihydronaphtho[1,2-b]furan-2-ylmethylcarbamate (Chiralcel OJ, ethanol) provided two fractions. Fraction 1 (Rt=19.572 min, Chiralcel OJ, ethanol); Fraction 2 (Rt=30.782 min, Chiralcel OJ, ethanol).

Source