2.5- Diisobutyl-3-methoxypyrazine

Diisobutyl-3-methoxypyrazine 1-oxide (277) gave a separable mixture of 2-acetoxy-3,6-diisobutyl-5-methoxypyrazine (278) and 2-(l-acetoxy-2-methyl-propyl)-5-isobutyl-3-methoxypyrazine (279) (neat Ac20, reflux, 90 min 73 and 12%, respectively).310... 

Diisobutyl-3-methoxypyrazine 1,4-dioxide with phosphorus trichloride in ethyl acetate at 40° gave 2,5-diisobutyl-3-methoxypyrazine (and 2,5-diisobutyl-4-methoxy-3-oxo-3,4-dihydropyrazine 1-oxide similarly treated gave 3,6-diisobutyl-I-methoxy-2-oxo-l, 2-dihydropyrazine) (see Section 15) (980). 

Cleavage of the Me-0 bond in 3,6-diisobutyl-l-methoxy-2-oxo-l,2-dihydro-pyrazine (93) with methylmagnesium iodide at 150° gave 2-hydroxy-3,6-diisobutyl-pyrazine 1-oxide (94) and the 1,4-dioxide was prepared similarly from 2,5-diisobutyl4-methoxy-3-oxo-3,4-dihydropyrazine 1-oxide and also from 2,5-diisobutyl-3-methoxypyrazine 1,4-dioxide (980). 

Reductive debenzylation. 2-Benzyloxy-3,6-diisobutyl-5-methoxypyrazine 4-oxide (21) gave 3,6-diisobutyl-5-methoxy-2(l//)-pyrazinone 4-oxide (22) (H2, Pd/C, EtOH, h 90% structure confirmed by X-ray analysis) 310 2,5-dibenzy-loxy-3,6-diphenylpyrazine likewise gave 5-hydroxy-3,6-diphenyl-2(l//)-pyrazinone (23) (43%).82... 

Benzyloxy-6-chloropyrazine 2-Benzyloxy-3,6-diisobutyl-5-methoxypyrazine 2-Benzyloxy-3,6-diisobutyl-5-methoxypyrazine 1-oxide 2-Benzyloxy-3,6-diisobutyl-5-methoxypyrazine 4-oxide... 

Chloro-3,6-difluoro-5-hydrazinopyrazine 2-Chloro-3,6-difluoro-5-methoxypyrazine 2-Chloro-3,6-diisobutyl-5-methoxypyrazine 2-Chloro-3,6-diisobutylpyrazine 2-Chloro-3,6-diisobutylpyrazine 1, 4-dioxide... 

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