Ethanol → ethyl 5-oxo-5H-[1,3]thiazolo[3,2-a]pyrimidine-6-carboxylate

HRID 1679680Notes

Reaction equation

HRID 1679680 reaction equation
[NH2:1][C:2]1[S:3][CH:4]=[CH:5][N:6]=1.C([O:9][CH:10]=[C:11]([C:17](OCC)=O)[C:12]([O:14][CH2:15][CH3:16])=[O:13])C.C(O)C.CO>ClC1C=CC(Cl)=CC=1Cl>[O:9]=[C:10]1[N:6]2[CH:5]=[CH:4][S:3][C:2]2=[N:1][CH:17]=[C:11]1[C:12]([O:14][CH2:15][CH3:16])=[O:13]

Participants

6

Reactant 4

HCID 702EthanolHCID 887MethanolHCID 21552-AminothiazoleHCID 6871Diethyl (ethoxymethylene)malonate

Product 1

HCID 838816ethyl 5-oxo-5H-[1,3]thiazolo[3,2-a]pyrimidine-6-carboxylate

Reagents, catalysts & solvents 1

HCID 131,2,4-TrichlorobenzeneSolvent

Procedure

A solution of 2-aminothiazole (10g., 100mM) and diethyl ethoxymethylenemalonate (21.6g., 100mM) in 1,2,4-trichlorobenzene (100ml) was heated at 150° C for 4 hours with collection of evolved ethanol. The reaction mixture was cooled and the required product filtered off and recrystallised from ethanol in 75.9% weight yield (17.0g). δ (CDCl3), 8.98 (1H,s, H5), 8.33 (1H,d, H1, J = 5.0Hz), 7.40 (1H,d, H2, J = 5.0Hz), 4.47 (2H,q, --CH2CH3), 1.41 (3H,t, --CH2CH3); λmax (MeOH) 235nm (εm 5000), 258nm (εm 4,550) and 346nm (εm 13,500); (Found: C, 47.84; H, 3,42; N, 12.19; S, 14.54%. C9H8N2O3S requires C, 48.22; H, 3.60; N, 12.50; S, 14.28%).

Workup

  1. temperatureThe reaction mixture was cooled
  2. filtrationthe required product filtered off
  3. customrecrystallised from ethanol in 75.9% weight
  4. customyield (17.0g)

Sources & evidence

ORD record
ord-8e88495a22df491083a5db4a01d3a9b3
Source dataset
uspto-grants-1978_03
Patent number
US04081545

Reaction notes

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