Science of Synthesis

Seela, F.; Ramzaeva, N.; Rosemeyer, H., Science of Synthesis, (2004) 16, 973.

Diethoxymethyl acetate remains the best reagent for the preparation of 8-unsubstituted purines, with only a few side reactions being encountered.[‌207‌–‌211‌] Treatment of commercially available 4,6-dichloropyrimidin-5-amine with 2–3 equivalents of (15N)ammonia in ethanol and diisopropylamine (200°C, ∼7 atm, 12 h) gives the monosubstituted product 4-chloropyrimidine-5,6[15N]-diamine (95% yield). The annulation reaction is performed in neat diethoxymethyl acetate (100°C, 3.5 h) to give 6-chloro[9-15N]purine ‌36‌ (‌Scheme 29‌).[‌211‌]

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References

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• 8.Meeeee-Meee, (8888) M 8e8, 888.