Phosphoric Acid → trans-(+/-)-5-n-Propyl-4,4a,5,6,7,8,8a,9-octahydrothiazolo[4,5-g]quinoline

HRID 485673

Reaction equation

HRID 485673 reaction equation
N[C:2]1[S:3][C:4]2[CH2:13][C@H:12]3[C@@H:7]([CH2:8][CH2:9][CH2:10][N:11]3[CH2:14][CH2:15][CH3:16])[CH2:6][C:5]=2[N:17]=1.P(=O)(O)(O)O.N([O-])=O.[Na+].OP=O.[OH-].[NH4+]>O>[CH2:14]([N:11]1[C@@H:12]2[C@H:7]([CH2:6][C:5]3[N:17]=[CH:2][S:3][C:4]=3[CH2:13]2)[CH2:8][CH2:9][CH2:10]1)[CH2:15][CH3:16]

Participants

7

Reactant 5

HCID 1004Phosphoric Acid2×HCID 14923Ammonium HydroxideHCID 22497phosphenous acidHCID 13491309trans-(+/-)-2-Amino-5-n-propyl-4,4a,5,6,7,8,8a,9-octahydrothiazolo[4,5-g]quinolineHCID 23668193Sodium Nitrite

Product 1

HCID 18599021trans-(+/-)-5-n-Propyl-4,4a,5,6,7,8,8a,9-octahydrothiazolo[4,5-g]quinoline

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A solution of 0.24 g. of trans-(±)-2-amino-5-n-propyl-4,4a,5,6,7,8,8a,9-octahydrothiazolo[4,5-g]quinoline in 10 ml. of 85% phosphoric acid was cooled to about -8° C. A saturated solution of 1.17 g. of sodium nitrite in water was added below the surface of the phosphoric acid solution at such a rate as to keep the reaction temperature from going above about -4° C. The reaction mixture was then added in dropwise fashion to 10 ml. of 50% aqueous hypophosphorus acid kept at a temperature of about 0° C. This new reaction mixture was stirred until gas evolution had ceased, at which time it was poured over ice. The aqueous mixture was made strongly basic with aqueous ammonium hydroxide. The aqueous layer was extracted several times with chloroform. The chloroform extracts were combined, and the combined extracts washed, first with water and then with saturated aqueous sodium chloride, and then dried. Removal of the chloroform in vacuo yielded trans-(±)-5-n-propyl-4,4a,5,6,7,8,8a,9-octahydrothiazolo[4,5-g]quinoline free base having the following physical characteristics: tlc (9:1 CHCl3 /MeOH+Tr.NH4OH)Rf =0.70.

Workup

  1. customfrom going above about -4° C
  2. additionThe reaction mixture was then added in dropwise fashion to 10 ml
  3. customkept at a temperature of about 0° C
  4. additionwas poured over ice
  5. extractionThe aqueous layer was extracted several times with chloroform
  6. washthe combined extracts washed, first with water
  7. dry with materialwith saturated aqueous sodium chloride, and then dried
  8. customRemoval of the chloroform in vacuo

Sources & evidence

ORD record
ord-5d61e227d5bf43e58c0ea47180ef30cf
Source dataset
uspto-grants-1985_08
Patent number
US04537893

Linked notes

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