Breakthrough in Green and Economical Synthesis of Key GLP-1 Intermediate

At Hiray Pharma Solutions, our R&D team continues to deepen process innovation around key intermediates of next-generation metabolic drugs. Today, we are pleased to share progress on a more efficient and industrially viable synthesis of (4-Fluoro-3,5-dimethylphenyl)hydrazine hydrochloride, a crucial intermediate of Eli Lilly’s oral GLP-1 candidate Orforglipron.

• What We Improved

The original patented route relies on a palladium-catalyzed Buchwald coupling — effective, but costly and less suitable for large-scale industrial adoption.

Our team developed an improved pathway by replacing Pd catalysts with a cost-effective copper-catalyzed Ullmann reaction, achieving both scalability and economic advantage.

• Key Technical Highlights

✔ Copper bromide (CuBr2) used as catalyst

— Avoids catalyst oxidation poisoning often seen with Cu salts

— Delivers 80% overall yield of the target hydrazine intermediate

✔ Ligand engineering for catalytic efficiency

— A redox-active pyrrolyl hydrazide ligand enables Cu(II)/Cu(III) catalytic cycling

— Facilitates smooth oxidative addition and C–N bond formation

✔ Significant cost reduction

Replacing palladium acetate with inexpensive copper bromide greatly improves competitiveness for commercial-scale production. 

• Process Optimization Results 

1. Hydrazine hydrate equivalents

Increasing hydrazine equivalents elevated compound purity from 86.4% → 94.3%.

2. Catalyst screening

CuBr and CuI demonstrated superior performance, giving >92% purity of the desired product.

3. Solvent selection

DMSO proved optimal and robust for scale-up, outperforming alternative solvents such as isopropyl acetate, t-butanol, and Me-THF.

• Why This Matters

Orforglipron represents a promising direction in non-peptide oral GLP-1 therapies. By optimizing upstream intermediates with scalable, cost-competitive synthesis routes, Hiray Pharma strengthens its position as a dependable partner for global pharmaceutical development and manufacturing. 

We will continue investing in innovation that accelerates high-quality, industrially robust API and intermediate supply for partners worldwide.