Sodium borohydride → 2,3-Diphenyl-1,2,3,4-tetrahydropyrido[3,4-b]pyrazine

HRID 1670657Notes

Reaction equation

HRID 1670657 reaction equation
[BH4-].[Na+].[CH:3]1[C:8]2=[N:9][C:10]3[CH2:11][CH2:12][CH2:13][CH2:14][C:15]=3[N:16]=[C:7]2[CH:6]=[CH:5][N:4]=1.CN1CCN(C)[C:20]2[CH:25]=N[CH:27]=[CH:28][C:19]1=2.[C:29](N1CCN(C(=O)C)C2C=CN=CC1=2)(=O)[CH3:30].N1CCNC2C=NC=C[C:46]1=2>CCOC(C)=O.CCN(CC)CC.O.C(O)C>[C:14]1([CH:15]2[CH:10]([C:19]3[CH:20]=[CH:25][CH:46]=[CH:27][CH:28]=3)[NH:9][C:8]3[CH:3]=[N:4][CH:5]=[CH:6][C:7]=3[NH:16]2)[CH:13]=[CH:12][CH:11]=[CH:30][CH:29]=1

Participants

9

Reactant 5

HCID 4311764Sodium borohydrideHCID 178014371H,2H,3H,4H-pyrido(3,4-b)pyrazineHCID 441857941,4-Dimethy-1,2,3,4-tetrahydropyrido[3,4-b]pyrazineHCID 574357846,7,8,9-Tetrahydropyrido[3,4-b]quinoxalineHCID 597630781-(4-Acetyl-3,4-dihydro-2H-pyrido[3,4-b]pyrazin-1-yl)ethanone

Product 1

HCID 141189682,3-Diphenyl-1,2,3,4-tetrahydropyrido[3,4-b]pyrazine

Reagents, catalysts & solvents 3

HCID 702EthanolSolventHCID 962WaterSolventHCID 22036596Ethyl acetate triethylamineSolvent

Conditions

Temperature
40 °C

Procedure

25 (6.25 g, 22.05 mmol) and 200 ml of ethanol were placed in a 500 ml flask. 6.25 g (165 mmol) of powdered NaBH4 were added to the solution and the reaction mixture was stirred at 40° C. for 48 hours. It was subsequently cooled to room temperature and the reaction was stopped by means of 10 ml of cold water. After stirring for a further 10 minutes, the reaction mixture was extracted twice with 100 ml of DCM and the combined organic phases were dried over Na2SO4. The crude product was purified by flash chromatography on silica gel (EtOAc/NEt3, 10:1). This gave a pale yellow solid. Rf=0.23 (EtOAc/NEt3, 10:1); 1H NMR: (300 MHz, CDCl3): δ=3.99 (s, 1H, N—H), 4.59 (s, 2H, 2,3-H), 4.62 (s, 1H, N—H), 6.39 (d, 3J=5.4 Hz, 1H, 8-H), 6.80 (dd, 4J=1.2 Hz, 3J=9.3 Hz, 2H, 2,6-phenyl-H), 6.84 (dd, 4J=1.2 Hz, 3J=9.3 Hz, 2H, 2,6-phenyl-H), 7.12 (m, 6H, 3,4,5-phenyl-H) ppm. 13C NMR (75 MHz, CDCl3): δ=58.6, 60.1 (C-2,3), 108.0 (C-8), 127.9-128.4 (phenyl-C), 129.8 (C-4a), 139.8 (Cq, phenyl-C), 140.0 (Cq, C-8a), 134.9 (C-5), 141.3 (C-7) ppm; MS (EI): m/e (%) 288 (22), 287 (M+, 100), 286 (24), 285 (7), 284 (6), 283 (8), 282 (5), 211 (13), 210 (78), 209 (5), 208 (13), 197 (4), 196 (26), 181 (13), 179 (3), 127 (4), 104 (7), 92 (3), 91 (32), 77 (5); IR (neat): ν=3215 (w), 2830 (w), 1596 (s), 1519 (s), 1493 (w), 1466 (w), 1452 (s), 1360 (m), 1290 (s), 1250 (m), 1231 (m), 1174 (s), 1120 (m), 1072 (m), 1050 (w), 1029 (w), 1005 (w), 989 (w), 950 (w), 905 (w), 844 (w), 810 (m), 770 (m), 723 (m), 675 (vs), 668 (w), 645 (w), 618 (m) cm−1. HRMS (EI): calculated for C19H17N3 287.1422 [M+], found: 287.1402.

Workup

  1. temperatureIt was subsequently cooled to room temperature
  2. stirringAfter stirring for a further 10 minutes
  3. extractionthe reaction mixture was extracted twice with 100 ml of DCM
  4. dry with materialthe combined organic phases were dried over Na2SO4
  5. customThe crude product was purified by flash chromatography on silica gel (EtOAc/NEt3, 10:1)
  6. customThis gave a pale yellow solid

Sources & evidence

ORD record
ord-f9c976315a4b4e3685443b89c528ac10
Source dataset
uspto-grants-2011_08
Patent number
US07994169B2

Reaction notes

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