Acetyl chloride → HCID 135584205, compound

HRID 1064252Notes

Reaction equation

HRID 1064252 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[C:7]([CH:16]([CH3:18])[CH3:17])=[C:8]2[N:13]([CH:14]=1)[N:12]=[CH:11][NH:10][C:9]2=[O:15])=O)[CH3:2].O.[NH2:20][NH2:21].C(Cl)(=O)C>O>[CH:16]([C:7]1[C:6]([C:4]2[O:3][C:1]([CH3:2])=[N:20][N:21]=2)=[CH:14][N:13]2[C:8]=1[C:9](=[O:15])[NH:10][CH:11]=[N:12]2)([CH3:18])[CH3:17]

Participants

5

Reactant 3

HCID 6367Acetyl chlorideHCID 24654Hydrazine hydrate (1:1)HCID 135410235Ethyl 4-oxo-5-(propan-2-yl)-1,4-dihydropyrrolo[2,1-f][1,2,4]triazine-6-carboxylate

Product 1

HCID 135584205HCID 135584205, compoundYield 35%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

Ethyl isocyanoacetate (80 g, 0.71 moles) was dissolved in 1 L of dry tetrahydrofuran under nitrogen and 1,8-diazabicyclo[5.4.0]undec-7-ene (107.7 g, 0.71 moles) was added to the solution. A solution of isobutyraldehyde (29.7 g, 0.41 moles) in 1.5 L of dry tetrahydrofuran was added dropwise at room temperature over 3 hours. The mixture was then stirred at room temperature for 16 h. The reaction mixture was concentrated under vacuum to a brown oil. The concentrate was partitioned between 1.2 L of ethyl acetate and 0.5 L of water. The organic layer was then washed with 0.4 L of 0.1 N hydrochloric acid followed by 0.3 L of saturated sodium bicarbonate solution and then 0.3 L of saturated brine. The organic layer was dried (sodium sulfate), filtered and concentrated under vacuum to a brown oil. The residue was dissolved in toluene and added to a 1600 ml (˜800 g) column of silica gel wet with hexane. Product was eluted at 15 PSI nitrogen pressure first with 4.8 L of hexane followed by 5 L of 20% ethyl acetate in hexane. Eluent containing product by TLC analysis was combined and concentrated under vacuum to a yellow oil. The concentrate was pumped dry under high vacuum giving product A, 3-(1-methylethyl)pyrrole-2,4-dicarboxylic acid diethyl ester (54 g, 60% yield) of yellow oil that solidified on standing at room temperature. TLC silica gel: Rf=0.2, hexane/ethyl acetate (4/1) uv visualization and PMA stain. 1H NMR: (CDCl3) δ 1.2-1.5 (m, 12H), 4.2-4.3 (m, 1H), 4.3-4.3 (m, 4H), 7.5 (d, 1H). B. To a suspension of NaH (13.9 g, 34 mmol, 60% in oil) in DMF (0.36 L) at 0° C. was added a solution of compound A (75 g, 29 mmol) in DMF (0.4 L). After stirring for 45 min., 2,4-dinitrohydroxylamine was added in small portions. After the addition was complete, the cold bath was removed and the mixture was allowed to warm to room temperature. After 2 h., the reaction mixture was poured into water and extracted with ethyl acetate. The organic layer was washed with saturated sodium bicarbonate, 10% lithium chloride (LiCl) and brine, then dried, and concentrated. The residue was purified to afford the desired compound 1-amino-3-(1-methylethyl)pyrrole-2,4-dicarboxylic acid diethyl ester, as an oil (81 g) at 80% purity which was used without further purification. C. Compound B (77.7 g, 0.29 M) was mixed with formamide (0.5 L) and heated to 160° C. After 8 h., the mixture was allowed to cool to RT, stirred for 2 days and then diluted with water (4 L). The product was extracted with ethyl acetate. The organic layer was concentrated, toluene was added to the residue and concentrated again. The brown solid was triturated with ether and dried under high vacuum to afford 5-(1-methylethyl)pyrrolo[2,1-f][1,2,4]triazin-4(3H)-one-6-carboxylic acid ethyl ester, as a light brown solid (45 g, 62%). LC/MS; (M+H)+=250.1 D. A suspension of 5-isopropyl-4-oxo-3,4-dihydro-pyrrolo[2,1-f][1,2,4]triazine-6-carboxylic acid ethyl ester was suspended in water (4 mL) and hydrazine hydrate (4 mL) was heated at 110° C. for 24 h. The reaction mixture was cooled down and the precipitate formed was isolated by filtration and air dried. The solid was suspended in ethyl acetate and acetyl chloride (853 μL, 12 mmol) was added. The mixture was stirred at RT for 2 days and the solid was isolated by filtration, washed with ethyl acetate and air-dried to afford 5-isopropyl-6-(5-methyl-[1,3,4]oxadiazol-2-yl)-3H-pyrrolo[2,1-f][1,2,4]triazin-4-one (575 mg, 35%). E. The procedure for chloroimidate formation described in Example 24 was used to convert 5-isopropyl-6-(5-methyl-[1,3,4]oxadiazol-2-yl)-3H-pyrrolo[2,1-f][1,2,4]triazin-4-one to 4-chloro-5-isopropyl-6-(5-methyl-[1,3,4]oxadiazol-2-yl)-pyrrolo[2,1-f][1,2,4]triazine in quantitative yield which was used directly without any purification. F. The procedure described in example 24 for coupling of aniline was employed to react 4-chloro-5-isopropyl-6-(5-methyl-[1,3,4]oxadiazol-2-yl)-pyrrolo[2,1-f][1,2,4]triazine and 4-fluoro-1H-pyrrolo[2,3-b]pyridin-5-ylamine to afford the title compound (41% yield). Monohydrochloride salt: 1H NMR (400 MHz, MeOD-d4) δ 8.26 (1H, s.), 8.00 (1H, s), 7.50 (1H, m), 6.69 (1H, m.), 4.08 (1H, m), 2.51 (3H, s), 1.40 (6H, d, J=7.1 Hz).

Workup

  1. temperatureThe reaction mixture was cooled down
  2. customthe precipitate formed
  3. customwas isolated by filtration and air
  4. customdried
  5. customthe solid was isolated by filtration
  6. washwashed with ethyl acetate
  7. customair-dried

Sources & evidence

ORD record
ord-3afb6093d33c4c66846d544b2128e544
Source dataset
uspto-grants-2005_11
Patent number
US06969717B2

Reaction notes

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