Formaldehyde → 6-iodo-2,5-dimethyl-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole

HRID 2215895Notes

Reaction equation

[I:1][C:2]1[C:10]2[N:9]([CH3:11])[C:8]3[CH2:12][CH2:13][NH:14][CH2:15][C:7]=3[C:6]=2[CH:5]=[CH:4][CH:3]=1.[CH2:16]=O.[BH4-].[Na+]>CO.O>[I:1][C:2]1[C:10]2[N:9]([CH3:11])[C:8]3[CH2:12][CH2:13][N:14]([CH3:16])[CH2:15][C:7]=3[C:6]=2[CH:5]=[CH:4][CH:3]=1

Participants

Conditions

Temperature: 0 °C

Procedure

6-Iodo-5-methyl-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole (3.85 g, 12.3 mmol) was suspended in methanol (40 mL). Formaldehyde (14 mL of 37%) was added and heated at reflux for 2 h. The reaction was cooled to 0° C. in an ice bath and sodium borohydride (1.7 g, 46 mmol) was added slowly over 15 min and stirred for 2 h at 0–10° C. The reaction was diluted with water (200 mL) and extracted with CH2Cl2 (3×150 mL). The organics were collected, washed with brine (250 mL), dried over magnesium sulfate, filtered and concentrated under reduced pressure. The product was purified by silica gel column chromatography (3% MeOH/CH2Cl2) to give 6-iodo-2,5-dimethyl-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole (0.6 g, 15%). 1H NMR (CDCl3 300 MHz) δ 7.59 (d, 1H, J=7.4 Hz), 7.33 (d, 1H, J=7.6 Hz), 6.73 (t, 1H, J=7.7 Hz), 3.98 (s, 3H), 3.62 (s, 2H), 2.83 (s, 4H), 2.55 (s, 3H) ppm.

Workup

temperatureheated
temperatureat reflux for 2 h
extractionextracted with CH2Cl2 (3×150 mL)
customThe organics were collected
washwashed with brine (250 mL)
dry with materialdried over magnesium sulfate
filtrationfiltered
concentrationconcentrated under reduced pressure
customThe product was purified by silica gel column chromatography (3% MeOH/CH2Cl2)

Sources & evidence

ORD record: ord-7f3f2af5fb3f446ab7dace64660ac5b4
Source dataset: uspto-grants-2006_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07109339B2

Reaction notes

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