Hydrochloric Acid → 9-(4-fluorobenzyl)-2-methyl-1-oxo-4-(p-tolyl)-2,9-dihydro-1H-pyrido[3,4-b]indole-3-carboxylic acid

HRID 1473257Notes

Reaction equation

HRID 1473257 reaction equation
[F:1][C:2]1[CH:34]=[CH:33][C:5]([CH2:6][N:7]2[C:15]3[C:10](=[CH:11][CH:12]=[CH:13][CH:14]=3)[C:9]3[C:16]([C:26]4[CH:31]=[CH:30][C:29]([CH3:32])=[CH:28][CH:27]=4)=[C:17]([C:22]([O:24]C)=[O:23])[N:18]([CH3:21])[C:19](=[O:20])[C:8]2=3)=[CH:4][CH:3]=1.[Li+].[OH-].Cl>CO.O1CCCC1>[F:1][C:2]1[CH:3]=[CH:4][C:5]([CH2:6][N:7]2[C:15]3[C:10](=[CH:11][CH:12]=[CH:13][CH:14]=3)[C:9]3[C:16]([C:26]4[CH:27]=[CH:28][C:29]([CH3:32])=[CH:30][CH:31]=4)=[C:17]([C:22]([OH:24])=[O:23])[N:18]([CH3:21])[C:19](=[O:20])[C:8]2=3)=[CH:33][CH:34]=1

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 3939Lithium HydroxideHCID 89462632methyl 9-(4-fluorobenzyl)-2-methyl-1-oxo-4-(p-tolyl)-2,9-dihydro-1H-pyrido[3,4-b]indole-3-carboxylate

Product 1

HCID 894634589-(4-fluorobenzyl)-2-methyl-1-oxo-4-(p-tolyl)-2,9-dihydro-1H-pyrido[3,4-b]indole-3-carboxylic acidYield 98.2%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
0 °C

Procedure

A mixture of methyl 9-(4-fluorobenzyl)-2-methyl-1-oxo-4-(p-tolyl)-2,9-dihydro-1H-pyrido[3,4-b]indole-3-carboxylate (625 mg, 1.375 mmol) in Methanol (10 mL) and Tetrahydrofuran (THF) (10.00 mL) was treated with 2M LiOH (20 mL, 40.0 mmol) and then refluxed overnight. The mixture was cooled to 0° C., treated with HCl (1M) until pH<2 and then filtered to afford 9-(4-fluorobenzyl)-2-methyl-1-oxo-4-(p-tolyl)-2,9-dihydro-1H-pyrido[3,4-b]indole-3-carboxylic acid as a white solid (595 mg, 1.35 mmol, 98% yield). A suspension of 9-(4-fluorobenzyl)-2-methyl-1-oxo-4-(p-tolyl)-2,9-dihydro-1H-pyrido[3,4-b]indole-3-carboxylic acid (595 mg, 1.35 mmol) in thionyl chloride (10 mL, 137 mmol) was heated at 70° C. for 2 hours and then concentrated. The residue was dissolved in Tetrahydrofuran (THF) (10.00 mL), treated with sodium borohydride (520 mg, 13.75 mmol) and then heated at 70° C. for 2 hours. Additional NaBH4 (15 eq.) was added and then mixture was heated at 70° C. overnight. The mixture was concentrated, treated with NH4Cl (sat. aq) slowly at 0° C. and then extracted with ethyl acetate. The combined extracts were dried over Na2SO4, filtered and concentrated to afford 9-(4-fluorobenzyl)-3-(hydroxymethyl)-2-methyl-4-(p-tolyl)-2,9-dihydro-1H-pyrido[3,4-b]indol-1-one (520 mg, 1.22 mmol, 90% yield) as a white solid which was used in the next step without any further purification. 1H NMR (400 MHz, CHLOROFORM-d) ppm 7.30-7.44 (m, 7H) 7.19-7.27 (m, 3H) 6.95 (s, 4H) 6.62-6.70 (m, 1H) 6.14 (s, 3H) 4.57 (s, 2H) 3.92 (s, 3H) 2.52 (s, 3H); LCMS (m/z) ES+=427 (M+1).

Workup

  1. temperaturerefluxed overnight
  2. filtrationfiltered

Sources & evidence

ORD record
ord-9e680d48bf0f4287aaf0742fdbe8123e
Source dataset
uspto-grants-2015_04
Patent number
US09012642B2

Reaction notes

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