3-tert-Butyl-4-oxo-3,4-dihydro­phthalazin-1-yl 3,5-dimethyl­benzoate

Dao-Xin Wu; Zheng-Wang Chen; Ye-Guo Ren; Ming-Zhi Huang

doi:10.1107/S1600536807061089

. 2007 Dec 6;64(Pt 1):o8. doi: 10.1107/S1600536807061089

3-tert-Butyl-4-oxo-3,4-dihydrophthalazin-1-yl 3,5-dimethylbenzoate

Dao-Xin Wu ^a,^*, Zheng-Wang Chen ^b, Ye-Guo Ren ^c, Ming-Zhi Huang ^c

PMCID: PMC2914898 PMID: 21200957

Abstract

The title compound, C₂₁H₂₂N₂O₃, was synthesized by the reaction of tert-butylhydrazine with phthalic anhydride and further O-benzoylation of the resulting intermediate by 3,5-dimethylbenzoyl chloride. Intermolecular C—H⋯O=C interactions link the molecules into layers.

Related literature

For ecdysone agonists, see: Wing (1988 ▶). For the synthesis, see: Hou et al. (2002 ▶). For C—N bond lengths, see: Sasada (1984 ▶).

Experimental

Crystal data

C₂₁H₂₂N₂O₃
M _r = 350.41
Monoclinic,
a = 8.7974 (2) Å
b = 18.7622 (4) Å
c = 11.7405 (3) Å
β = 92.634 (2)°
V = 1935.82 (8) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 296 (2) K
0.54 × 0.52 × 0.48 mm

Data collection

Bruker SMART APEX CCD area-detector diffractometer
Absorption correction: none
14969 measured reflections
3804 independent reflections
2879 reflections with I > 2σ(I)
R _int = 0.024

Refinement

R[F ² > 2σ(F ²)] = 0.043
wR(F ²) = 0.137
S = 1.06
3804 reflections
241 parameters
H-atom parameters constrained
Δρ_max = 0.23 e Å⁻³
Δρ_min = −0.21 e Å⁻³

Data collection: SMART (Bruker, 2000 ▶); cell refinement: SAINT (Bruker, 2000 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997 ▶); molecular graphics: SHELXTL (Bruker, 1997 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536807061089/ln2004sup1.cif

e-64-000o8-sup1.cif^{(20.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536807061089/ln2004Isup2.hkl

e-64-000o8-Isup2.hkl^{(186.5KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C8—H8⋯O1ⁱ	0.93	2.56	3.391 (2)	149
C12—H12⋯O3ⁱⁱ	0.93	2.27	3.149 (2)	157

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

The authors acknowledge financial support from the National Eleventh–Five Key Project of the People’s Republic of China (2006BAE01A01-4).

supplementary crystallographic information

Comment

DibendzoyIhydrazines insect growth regulators are well known as nonsteroidal ecdysone agonists, which induce prematurely abnormal and ultimately lethal larval molting (Wing, 1988). The title compound, (I), was obtained unintentionally as the product of an attempted synthesis of a dibendzoylhydrazine and we present its crystal structure here. The molecular structure of (I) is shown in Fig.1. The bond length of C18—N2 [1.517 (2) Å] is slightly greater than the normal value of C—N [1.47 Å; Sasada, 1984] because of the larger terminal group tert-butyl moiety. The crystal structure of (I) also involves two weak C—H···O?C hydrogen-bonding interactions, which link the molecules into layers which lie parallel to the (101) plane. (Fig. 2 and Table 1).

Experimental

Phthalic anhydride (0.015 mol) was heated to 323 K in acetic acid, tert-butyldrazine (0.015 mol) was added dropwise, the solution was stirred for 3 h at 383 K. Then the mixture was condensed and washed with water and filtered, which afforded 2-tert-butyl-4-hydroxyphthalazin-1(2H)-one (m.p. 391–393 K). This compound (0.01 mol) was heated to 333 K in butyl acetate (30 ml) and water (20 ml) in the presence of DMPA catalyst (0.1 g), 3,5-Dimethylbenzoyl chloride (0.01 mol) and a saturated solution of Na₂CO₃(0.02 mol) which were added dropwise, then the mixture reacted for 4 h (Hou et al., 2002). The solution was cooled, washed with water and dried. The product was concentrated and purified by column chromatography (silica gel, petroleum ether-acetate 10:1) to give the title compound, (I) (yield 46%, m.p. 421–422 K). 1H NMR (CDCl3, δ, p.p.m): 1.71 (9H, s), 2.43 (6H, s), 7.33–7.26 (1H, s), 7.74–7.57 (1H, s), 7.79–7.75 (2H, m), 7.90–7.89 (2H, s), 8.46–8.43 (1H, m). Compound (I) was recrystallized from ethyl acetate. Single crystals of (I), suitable for X-ray analysis, were grown by natural evaporation of the solvent.