Acetic Acid → HCID 57750059, compound

A solution of 2-tert-butyl 8-methyl 3,4-dihydro-1H-pyrido[4,3-b]indole-2,8(5H)-dicarboxylate (0.5 g, 1.5 mmol) in dichloromethane/trifluoroacetic acid (1:1, 10 mL) was stirred at room temperature for 1 h. The reaction mixture was then concentrated, diluted with acetic acid (5 mL) and concentrated again to give an oily residue. The residue was dissolved in THF/MeOH (4:1, 10 mL) followed by the addition of benzaldehyde (170 μL, 180 mg, 1.7 mmol), sodium triacetoxyborohydride (485 mg, 2.3 mmol) and acetic acid (175 μL, 185 mg, 3.1 mmol). Additional amounts of benzaldehyde (4×170 μL) and sodium triacetoxyborohydride (4×485 mg) were added over the course of the ensuing 8 h. The resulting reaction mixture was stirred at room temperature overnight then poured over saturated sodium bicarbonate solution (30 mL). The aqueous layer was then extracted with dichloromethane (3×30 mL) and the combined organic layer was washed with water (2×30 mL), dried over MgSO4, filtered and concentrated. Column chromatography (neat dichloromethane→3% MeOH/CH2Cl2) provided methyl 2-benzyl-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole-8-carboxylate as a white crystalline solid (320 mg, 66%). 1H NMR (CD3OD): δ 8.17 (1H, d, J=1.1 Hz); 7.73 (1H, dd, J=8.7, 1.8 Hz); 7.44-7.27 (6H, m); 3.88 (3H, s); 3.83 (2H, br s); 3.73 (2H, br s) 2.95-2.88 (4H, m). MS (M+H)+=321.

1. concentrationThe reaction mixture was then concentrated
2. additiondiluted with acetic acid (5 mL)
3. concentrationconcentrated again
4. customto give an oily residue
5. customThe resulting reaction mixture
6. extractionThe aqueous layer was then extracted with dichloromethane (3×30 mL)
7. washthe combined organic layer was washed with water (2×30 mL)
8. dry with materialdried over MgSO4
9. filtrationfiltered
10. concentrationconcentrated

ORD record

ord-6c0bcc99134f412c9c3de14cd0938ac6

Source dataset

uspto-grants-2013_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08557822B2