338739-81-4 | tert-butyl 4-hydroxy-2-(methylthio)-5,8-dihydropyrido[3,4-d]pyrimidine-7(6H)-carboxylate

Packsize	Purity	Availability	Price	Discounted Price
250mg	97%	2 weeks	$97.00	$68.00
1g	97%	2 weeks	$290.00	$203.00
5g	97%	2 weeks	$839.00	$587.00

Description

• Catalog Number: BF33790
• Chemical Name: tert-butyl 4-hydroxy-2-(methylthio)-5,8-dihydropyrido[3,4-d]pyrimidine-7(6H)-carboxylate
• CAS Number: 338739-81-4
• Molecular Formula: C13H19N3O3S
• Molecular Weight: 297.3733
• SMILES: CSc1nc2CN(CCc2c(n1)O)C(=O)OC(C)(C)C

Upstream Synthesis Route

The synthesis of tert-butyl 4-hydroxy-2-(methylthio)-5,8-dihydropyrido[3,4-d]pyrimidine-7(6H)-carboxylate can be conceptualized with the following steps:

1. **Pyridine ring construction**: The process can begin with an appropriately substituted pyridine precursor or via a multi-step process constructing the pyridine ring via cyclization reactions such as the Chichibabin synthesis which involves condensation of aldehydes with ammonia or amines.

2. **Pyrimidinedione Formation**: Introducing the pyrimidine-2,4(1H,3H)-dione functionality could be done through urea condensation with a suitable diketone precursor. The urea will provide the amine group and amide carbonyls to form the dihydropyrimidine ring when reacted with the diketone under acidic conditions.

3. **C-5, C-6 Unsaturation Reduction**: Once the pyrimidine dione is formed, the next step is to reduce the double bond between C-5 and C-6 to form the dihydropyrido[3,4-d]pyrimidine structure. Reduction could be performed using a metal catalyst such as palladium on carbon (Pd/C) with hydrogen gas (H2) or by chemical means with a suitable reducing agent such as sodium borohydride (NaBH4) or lithium aluminum hydride (LiAlH4).

4. **Sulfur Introduction**: To introduce a methylthio group at C-2, a nucleophilic substitution reaction can be employed. This can generally be achieved using methylthiolate salts in a displacement reaction perhaps under phase transfer catalysis conditions to improve solubility in an organic solvent.

5. **Hydroxy Group Protection**: The hydroxy group at C-4 needs to be protected before the final step to prevent any side reactions. This protection could be done by converting the hydroxyl to a tert-butoxycarbonyl (BOC) group using di-tert-butyl dicarbonate (Boc2O) with a base such as triethylamine (Et3N) in an anhydrous solvent like dichloromethane (DCM).

6. **Esterification**: The final step is the esterification of the carboxylic acid group at C-7. Carboxylic acid can be converted into its ester derivative using tert-butanol in the presence of a condensing agent like dicyclohexylcarbodiimide (DCC) and a catalyst such as 4-dimethylaminopyridine (DMAP).

These synthetic routes leverage standard organic synthesis techniques and may require optimization depending on the choice of starting materials, reagents, and reaction conditions to minimize byproducts and improve overall yield. The suggested synthesis pathway assumes the availability of appropriately substituted starting materials for constructing the pyridine and subsequent pyrimidinedione rings.