tert-butyl 4-(4-amino-3-nitrophenyl)-5,6-dihydropyridine-1(2H)-carboxylate → tert-Butyl 4-(3,4-diaminophenyl)-5,6-dihydropyridine-1(2H)-carboxylate

HRID 1397891Notes

Reaction equation

HRID 1397891 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[CH2:13][CH2:12][N:11]([C:14]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15])[CH2:10][CH:9]=2)=[CH:4][C:3]=1[N+:21]([O-])=O>C1COCC1.CCO.[Pd]>[NH2:21][C:3]1[CH:4]=[C:5]([C:8]2[CH2:13][CH2:12][N:11]([C:14]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15])[CH2:10][CH:9]=2)[CH:6]=[CH:7][C:2]=1[NH2:1]

Participants

5

Reactant 1

HCID 59843222tert-butyl 4-(4-amino-3-nitrophenyl)-5,6-dihydropyridine-1(2H)-carboxylate

Product 1

HCID 89726398tert-Butyl 4-(3,4-diaminophenyl)-5,6-dihydropyridine-1(2H)-carboxylateYield 96%

Reagents, catalysts & solvents 3

HCID 23938PalladiumCatalystHCID 702EthanolSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of compound 14 (2.1 g, 6.58 mmol) in a mixture of THF (15 mL) and EtOH (30 mL) was added Pd—C (0.21 g, 10% wet basis), and the mixture was subjected to hydrogenation in a Parr apparatus at 10 psi for 3 hours. After filtering over the pad of celite, the solution was concentrated and loaded over a silica column, eluting with ethyl acetate:hexanes (50:50), and then changing to (90:10) to get compound 18. Yield 96%, light brown gum. IR KBr, cm−1) 3429, 3330 (NH2), 3036 (Ar—H), 2983 (Alph-H), 1691 (CO), 1628, 1520, 1415 (C═C), 1229 (C—N), 1160 (CO); 1H NMR (500 MHz, CDCl3) δ 1.46 (s, 91-1, OC(CH3)3), 2.40 (br. s, 2H, CH2), 3.43 (m, 2H, CH2), 4.02 (br. s, 2H, CH2), 4.38 (br. s, 4H, 2NH2), 5.93 (br. s, 1H, CH), 7.06 (dd, J=2.6, 8.2 Hz, 1H, H-6), 730 (d, J=2.5 Hz, 1H, H-2), 7.46 (d, J=8.2 Hz, 1H, H-5). 13C NMR (125.7 MHz, CDCl3) δ 26.89 (CH2), 28.33 (OC(CH3)3), 29.39 (CH2), 42.84 (CH2), 79.99 (OC(CH3)3), 118.77 (CH), 119.19 (C-5), 120.37 (C-2), 129.19 (C-1), 130.65 (C-3), 131.16 (C-6), 141.82 (C4), 154.63 (CO). Anal. Calcd for C16H23N3O2. C, 66.41; H, 8.01; N, 14.52%. Found: C, 66.33; H, 8.07; N, 14.43%.

Workup

  1. filtrationAfter filtering over the pad of celite
  2. concentrationthe solution was concentrated
  3. washeluting with ethyl acetate:hexanes (50:50)

Sources & evidence

ORD record
ord-0e2b5d29cecb4cb38607d7bc821b8508
Source dataset
uspto-grants-2014_12
Patent number
US08901304B1

Reaction notes

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