1,4-Dimethy-1,2,3,4-tetrahydropyrido[3,4-b]pyrazine → 5,10-Diethyl-5,5a,6,7,8,9,9a,10-octahydropyrido[3,4-b]quinoxaline

HRID 1670655Notes

Reaction equation

HRID 1670655 reaction equation
CN1CCN(C)[C:4]2[CH:9]=NC=[CH:12][C:3]1=2.[C:13]([N:16]1[CH2:21][CH2:20][N:19]([C:22](=O)[CH3:23])[C:18]2[CH:25]=[CH:26][N:27]=[CH:28][C:17]1=2)(=O)[CH3:14]>CCOC(C)=O.CO>[CH2:22]([N:19]1[CH:20]2[CH:21]([CH2:12][CH2:3][CH2:4][CH2:9]2)[N:16]([CH2:13][CH3:14])[C:17]2[CH:28]=[N:27][CH:26]=[CH:25][C:18]1=2)[CH3:23]

Participants

4

Reactant 2

HCID 441857941,4-Dimethy-1,2,3,4-tetrahydropyrido[3,4-b]pyrazine4×HCID 597630781-(4-Acetyl-3,4-dihydro-2H-pyrido[3,4-b]pyrazin-1-yl)ethanone

Product 1

HCID 577342285,10-Diethyl-5,5a,6,7,8,9,9a,10-octahydropyrido[3,4-b]quinoxaline

Reagents, catalysts & solvents 1

HCID 21584119Ethylacetate methanolSolvent

Procedure

A suspension of 0.77 g (5.80 mmol) of AlCl3 in 30 ml of MTBE was stirred at room temperature for 45 minutes and subsequently cooled to 0° C. and 1.32 g (9.35 mmol) of LiAlH4 were then added in small portions. After the addition was complete and the mixture had been stirred for another 15 minutes, compound 14 (0.64 g, 2.23 mmol) was added and the mixture was stirred at 0° C. for 1 hour. It was subsequently refluxed for 8 hours and then cooled to room temperature and poured into ice water. The inorganic precipitate was filtered off with suction and washed twice with 30 ml of DCM. The aqueous phase was brought to a pH of 12 and extracted three times with 40 ml of DCM. The combined organic phases were dried over Na2SO4 and the solvent was distilled off on a rotary evaporator. The crude product obtained was purified by flash chromatography on silica gel (EtOAc/MeOH/NEt3, 10:2:1) and on basic aluminum oxide (EtOAc/MeOH, 10:1). This gave 0.30 g (1.22 mmol, 55%) of a colorless solid. Rf=0.32 (basic alumina, EtOAc/MeOH, 10:1). 1H NMR: (400 MHz, CDCl3): δ=1.11, 1.13 (t, 3J=7.2 Hz, H3C—CH2—N-5, 3J=7.2 Hz, H3C—CH2—N-10, 6-H), 1.37 (m, 2H, H-7,8), 1.56 (m, 3Jaa=6.8 Hz, 3Jee=3.2 Hz, 4H, H-6, H-9, H-7, H-8), 1.76 (m, 3Jae=3.2 Hz, 1H, H-9), 1.89 (m, 3Jae=3.2 Hz, 1H), 3.18 (dq, 3J=7.2 Hz, 2J=14.4 Hz, 2-H, H3C—CHAB—N-5, H3C—CHAB—N-10), 3.23 (ddd, 3Jae=2.8 Hz, 3Jae=3.2 Hz, 3Jaa=6.8 Hz, 1H, H-5a), 3.34 (ddd, 3Jae=2.8 Hz, 3Jae=3.2 Hz, 3Jae=3.2 Hz, H-1, H-9a), 3.43 (dq, 3J=7.2 Hz, 2J=14.4 Hz, H3C—CHAB—N-5, H3C—CHAB—N-10, 2H, H-1), 6.33 (d, 3J=5.6 Hz, 1H, H-4), 7.67 (s, 1H, H-1), 7.72 (d, 1H, H-3) ppm. 13C NMR (100 MHz, CDCl3): δ=10.8 (H3C—CH2—N-5), 11.8 (H3C—CH2—N-10), 21.7 (C-7), 22.9 (C-8), 27.3 (C-6), 27.8 (C-9), 40.4 (H3C—CH2—N-5), 41.7 (H3C—CH2—N-10), 52.8 (C-9a), 56.4 (C-5a), 104.3 (C-4), 130.6 (C-10a, C-1), 139.4 (C-3), 141.2 (C-4a) ppm. GC-MS (EI): RT 10.58 min, m/e (%) 246 (18), 245 (M+, 100), 231 (9), 230 (57), 217 (7), 216 (44), 207 (6), 186 (7), 174 (15), 162 (6), 160 (16), 158 (6), 148 (12), 146 (6), 132 (8); IR (neat): ν=3436 (s), 2970 (m), 2860 (vs), 2860 (s), 1628 (w), 1576 (vs), 1513 (vs), 1473 (w), 1447 (m), 1348 (s), 1317 (w), 1267 (s), 1211 (s), 1167 (w), 1125 (w), 1107 (w), 1077 (w), 1059 (w), 1040 (w), 920 (w), 798 (s) 777 (m), 746 (m) cm−1. HRMS (EI): calculated for C15H23N3 245.1892 [M+], found: 245.1889.

Workup

  1. customwas purified by flash chromatography on silica gel (EtOAc/MeOH/NEt3, 10:2:1) and on basic aluminum oxide (EtOAc/MeOH, 10:1)

Sources & evidence

ORD record
ord-5195bfd53e414c388c7ae9f88b875262
Source dataset
uspto-grants-2011_08
Patent number
US07994169B2

Reaction notes

Loading…