Hydrochloric Acid → 1-Phenyl-1,4-dihydrothiochromeno(4,3-c)pyrazole-3-carboxylic acid

HRID 1194704Notes

Reaction equation

HRID 1194704 reaction equation
[C:1]1([N:7]2[C:11]3[C:12]4[CH:19]=[CH:18][CH:17]=[CH:16][C:13]=4[S:14][CH2:15][C:10]=3[C:9]([C:20]([O:22]CC)=[O:21])=[N:8]2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[OH-].[Na+].Cl>O1CCOCC1>[C:1]1([N:7]2[C:11]3[C:12]4[CH:19]=[CH:18][CH:17]=[CH:16][C:13]=4[S:14][CH2:15][C:10]=3[C:9]([C:20]([OH:22])=[O:21])=[N:8]2)[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 14653456HCID 14653456, compound

Product 1

HCID 3309831-Phenyl-1,4-dihydrothiochromeno(4,3-c)pyrazole-3-carboxylic acidYield 90.9%

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Procedure

1,4-Dihydro-1-phenyl-[1]-benzothiopyrano[4,3-c]pyrazole-3-carboxylic acid, ethyl ester (3.36 g) suspended in dioxane (60 ml) is treated with N/1 NaOH (30 ml) under stirring at room temperature for 5 hours. The reaction mixture is diluted with ice water and acidified to pH 3 with 37% HCl. The precipitate is filtered, washed with water and dried in vacuo at 50° C. to give 1,4-dihydro-1-phenyl-[1]-benzothiopyrano[4,3-c]pyrazole-3-carboxylic acid (2.8 g) which is reacted with oxalyl chloride (17 g) under stirring, at room temperature for 8 hours. The reaction mixture is evaporated to dryness in vacuo and the residue, 1,4-dihydro-1-phenyl-[1]-benzothiopyrano[4,3-c]pyrazole-3-carbonyl chloride (2.9 g), is dissolved in dimethylformamide (10 ml) and added under stirring to a suspension obtained by treatment of 2-cyano-acetylamino-pyridine (1.62 ) with 50% sodium hydride (0.5 g) in dimethylformamide (5 ml). The reaction mixture is kept at room temperature for 20 hours. The basic aqueous solution is washed with ethyl ether and then is acidified to pH 5 with 37% HCl. The precipitate is filtered, washed with water and then crystallized from ethanol to give 2.7 g of 2-cyano-3-(1,4-dihydro-1-phenyl-[1]-benzothiopyrano[4,3-c]pyrazol-3-yl)-3-oxo-N-(2-pyridyl)-propanamide, m.p. 258°-260° C.

Workup

  1. filtrationThe precipitate is filtered
  2. washwashed with water
  3. customdried in vacuo at 50° C.

Sources & evidence

ORD record
ord-4d8ecb23c6564cd4b195d4d70f5b780f
Source dataset
uspto-grants-1989_03
Patent number
US04816467

Reaction notes

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