Synthesis, structures and Hirshfeld surface analyses of 2-hy­droxy-N′-methyl­acetohydrazide and 2-hy­droxy-N-methyl­acetohydrazide

The crystal structures of 2-hy­droxy-N′-methyl­acetohydrazide and 2-hy­droxy-N-methyl­acetohydrazide are reported and discussed.

Abstract

The structures of the title compounds 2-hy­droxy-N′-methyl­acetohydrazide, 1, and 2-hy­droxy-N-methyl­acetohydrazide, 2, both C₃H₈N₂O₂, as regioisomers differ in the position of the methyl group relative to the N atoms in 2-hy­droxy-acetohydrazide. In the structure of 1, the 2-hy­droxy-acetohydrazide core [OH—C—C(=O)—NH—NH] is almost planar and the methyl group is rotated relative to this plane. As opposed to 1, in the structure of 2 all non-hydrogen atoms lie in the same plane. The hydroxyl and carbonyl groups in structures 1 and 2 are in trans and cis positions, respectively. The methyl amino group and carbonyl group are in the cis position relative to the C—N bond in structure 1, while the amino group and carbonyl group are in the trans position relative to the C—N bond in stucture 2. In the crystal, mol­ecules of 1 are linked by N—H⋯O and O—H⋯N inter­molecular hydrogen bonds, forming layers parallel to the ab crystallographic plane. A Hirshfeld surface analysis showed that the H⋯H contacts dominate the crystal packing with a contribution of 55.3%. The contribution of the H⋯O/O⋯H inter­action is somewhat smaller, amounting to 30.8%. In the crystal, as a result of the inter­molecular O—H⋯O hydrogen bonds, mol­ecules of 2 form dimers, which are linked by N—H⋯O hydrogen bonds and a three-dimensional supra­molecular network The major contributors to the Hirshfeld surface are H⋯H (58.5%) and H⋯O/O⋯H contacts (31.7%).

1. Chemical context

N-substituted hydrazides are widely used compounds in organic synthesis. Aza-peptides containing the N-alkyl hydrazide fragment have been investigated as wide-spectrum anti­biotics (Amabili et al., 2020 ▸), drugs for inflammatory acne treatment (Fournier et al., 2018 ▸), anti­viral agents (Breidenbach et al., 2021 ▸) and selective protease inhibitors (Corrigan et al., 2020 ▸). Additionally, N-alkyl hydrazides are very important starting reagents for the synthesis of 1,2-substituted 1,2,4-triazoles (Nguyen & Hong, 2021 ▸; Peese et al., 2020 ▸), 3-substituted 1,3,4-thia­diazol-2-ones and 1,3,4-oxo­diazol-2-ones (Kuzmina et al., 2019 ▸; Bi et al., 2019 ▸), 2,3-di­hydro-1H-pyrazoles (Shaker Ardakani et al., 2021 ▸), and other heterocyclic or spyrocyclic compounds (Kobayashi & Ainai, 2018 ▸; Tian et al., 2022 ▸).

Previously, we have obtained a series of N1- and N2-alkyl­ated 1,2,4-triazoles (Khomenko et al., 2022 ▸; Ohorodnik et al., 2023 ▸). The separation of the resulting regioisomers was achieved through flash column chromatography. The use of pure N-methyl regioisomers of hydrazides in the synthesis of 1,2,4-triazoles allows for the direct formation of the desired N1- and N2-methyl­ated compounds, thereby eliminating the need for an expensive flash chromatography step.

Usually, the inter­action of carb­oxy­lic acid derivatives with N-alkyl hydrazines leads to a mixture of regioisomers (Condon, 1972 ▸), while the desired N- or N′- regioisomer can be obtained from BOC or CBZ-protected N-alkyl hydrazines (Amabili et al., 2020 ▸; Peese et al., 2020 ▸). This method, however, has several disadvantages: expensive reagents, more steps, and the need for protecting other functional groups.

In this work, we report the one-step synthesis and purification procedure of 2-hy­droxy-N′-methyl­acetohydrazide (1) and 2-hy­droxy-N-methyl­acetohydrazide (2) using inexpensive reagents, their crystal structures and Hirshfeld surface analyses.

2. Structural commentary

Structures 1 and 2 are regioisomers and differ in the position of the methyl group relative to the N atoms in 2-hy­droxy-acetohydrazide (Fig. 1 ▸). Compound 1 crystallizes in the ortho­rhom­bic space group Pbca, while 2 crystallizes in the monoclinic space group C2/c.

Figure 1.

The mol­ecular structures of 1 and 2 with atom labeling and displacement ellipsoids drawn at the 50% probability level.

In the structure of 1, the 2-hy­droxy-acetohydrazide core [OH—C—C(=O)—NH—NH] is almost planar (r.m.s. deviation is 0.016 Å). The methyl group is rotated relative to this plane [the C2—N1—N2—C3 torsion angle is −124.1 (4)°]. The hydroxyl and carbonyl groups are in trans positions. The methyl amino group and carbonyl group are in the cis position relative to the C2—N1 bond. The O–C–N–N fragment shows features of conjugation, supported by the pronounced shortening of the C2—N1 [1.300 (6) Å] single bond compared to the average value of 1.355 Å (Orpen et al., 1994 ▸). This may be enhanced by the formation of the N1—H1A⋯O2′ inter­molecular hydrogen bond (Table 1 ▸).

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯N2i	0.87 (5)	1.90 (5)	2.767 (5)	172 (4)
N1—H1A⋯O2ii	0.71 (4)	2.17 (4)	2.848 (5)	159 (4)

Symmetry codes: (i) ; (ii) .

As opposed to 1, in the structure of 2 all non-hydrogen atoms lie in the same plane (r.m.s. deviation is 0.028 Å). The hydroxyl and carbonyl groups are in cis positions. The amino group and carbonyl group are in the trans position relative to the C2—N1 bond. Both the C2—O2 [1.251 (3) Å] and the N1—N2 [1.434 (3) Å] bonds are elongated compared to the average values of 1.234 and 1.420 Å, respectively (Orpen et al., 1994 ▸). The elongation of the N1—N2 bond, together with the absence of a shortening of the C1—N2 bond, may indicate a slight disruption of the conjugation within the O–C–N–N core. That is consistent with amino group rotation: C2—N1—N2—H torsion angles are +12° and −116°, indicating an in-plane position of the lone pair of the N2 atom, stabilized by the N2—H2A⋯O2 and N2—H2B⋯O1 inter­molecular hydrogen bonds (Table 2 ▸), so this lone pair cannot participate in the π-conjugation of the O–C–N–N fragment. The minor elongation of the C2=O2 double bond is probably caused by the presence of the inter­molecular bi-directional hydrogen bond O1—H1⋯O2 with the O—H group of an adjacent mol­ecule and the N2—H2B⋯O2′′ hydrogen with another mol­ecule (Table 2 ▸).

Table 2. Hydrogen-bond geometry (Å, °) for 2.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯O2i	0.78 (4)	2.39 (4)	3.078 (4)	148 (3)
N2—H2A⋯O2ii	1.00 (3)	2.08 (3)	3.062 (4)	169 (2)
N2—H2B⋯O1iii	0.92 (3)	2.21 (3)	3.129 (4)	173 (2)

Symmetry codes: (i) ; (ii) ; (iii) .

The N2 atom is pyramidal in both structures 1 and 2 (the sums of the valence angles is 225.93 and 317.93° in 1 and 2, respectively). The pyramidal configuration of the N2 atom is stabilized by inter­molecular hydrogen bonds O1—H1⋯N2 (in 1, Table 1 ▸) and N2—H2B⋯O1, N2—H2A⋯O2 (in 2, Table 2 ▸).

3. Supra­molecular features and Hirshfeld surface analysis

In the crystal, mol­ecules of 1 are linked by N—H⋯O and O—H⋯N hydrogen bonds (Table 1 ▸), forming layers parallel to the ab crystallographic plane (Fig. 2 ▸).

Figure 2.

Crystal packing of 1 viewed along the b axis (left) and 2 viewed along c axis (right). The hydrogen bonds are shown as blue dotted lines.

The inter­molecular inter­actions in the crystal structure of 1 were further analyzed by means of the d_norm property (Fig. 3 ▸) mapped over the Hirshfeld surface (Spackman & Jayatilaka, 2009 ▸), which was calculated using the CrystalExplorer21 program (Spackman et al., 2021 ▸). The strongest contacts, which are visualized on the Hirshfeld surface as the dark-red spots, correspond to the N—H⋯O and O—H⋯N hydrogen bonds between mol­ecules. The majority of the inter­molecular inter­actions of 1 are weak, and are represented in blue on the Hirshfeld surface.

Figure 3.

The Hirshfeld surface mapped over d_norm for visualizing the inter­molecular contacts of compound 1.

For further exploration of the inter­molecular inter­actions, two-dimensional fingerprint plots (McKinnon et al., 2007 ▸) were generated, as shown in Fig. 4 ▸. The major contributions to the crystal structure are from the H⋯H (55.3%) and H⋯O/O⋯H (30.8%) inter­actions. The N⋯H/H⋯N (9.2%) and O⋯C/C⋯O (2.5%) inter­actions are less impactful in comparison.

Figure 4.

Two-dimensional fingerprint plots for 1 showing (a) all inter­actions, and (b)–(d) delineated into contributions from other contacts (blue areas) [d_e and d_i represent the distances from a point on the Hirshfeld surface to the nearest atoms outside (external) and inside (inter­nal) the surface, respectively].

In the crystal of 2, as a result of the O—H⋯O inter­molecular hydrogen bonds (Table 2 ▸) the mol­ecules form dimers, which are linked by N—H⋯O inter­molecular hydrogen bonds to form a 3D supra­molecular network (Fig. 2 ▸).

Fig. 5 ▸ shows the Hirshfeld surface of 2 plotted over d_norm (normalized contact distance) and Fig. 6 ▸ the 2D fingerprint plots. The strongest contacts, which are visualized on the Hirshfeld surface as the dark-red spots, correspond to the O–H⋯O and N—H⋯O hydrogen bonds between mol­ecules. The major contributions to the crystal structure are from the H⋯H(58.5%) and H⋯O/O⋯H (31.7%) inter­action. The N⋯H/H⋯N (4.0%) and H⋯C/C⋯H (3.2%), O⋯N/N⋯O inter­actions are of lower relevance.

Figure 5.

The Hirshfeld surface mapped over d_norm for visualizing the inter­molecular contacts of compound 2.

Figure 6.

Two-dimensional fingerprint plots for 1 showing (a) all inter­actions, and (b)–(c) delineated into contributions from other contacts (blue areas) [d_e and d_i represent the distances from a point on the Hirshfeld surface to the nearest atoms outside (external) and inside (inter­nal) the surface, respectively].

4. Database survey

A search of the Cambridge Structural Database (CSD, version 2024.2.0; Groom et al., 2016 ▸) confirmed that the title compounds have not been previously published. Since hydrazides are very popular compounds and there are numerous entries in the database, the search was carried out for the specific fragment [OH—C—C(=O)—N—N—H], which represents the title structures albeit without the methyl substituent and excludes structures in which the terminal nitro­gen atom is engaged in a double bond. As a result of the search, six structures were found in which the defined fragment bears different substituents: JESVIN (Beckmann & Brooker, 2006 ▸); LACBOG (Andre et al., 1993 ▸); RAVZIX and RAVZOD (Andre et al., 1997 ▸); UVUTIQ (Noshiranzadeh et al., 2017 ▸); VOJBUS (Abu-Safieh et al., 2008 ▸); WETGEL (Chen et al., 2021 ▸). Four of these structures (LACBOG, RAVZIK, RAVZOD, WETGEL) have a pyramidal nitro­gen, which is involved in the formation of inter­molecular hydrogen bonds similar to what is observed in the crystals of the title compounds.

5. Synthesis and crystallization

To a solution of 12.14 ml (0.3 mol) of methyl­hydrazine in 50 ml of 2-propanole were added dropwise 9.5 ml (0.1 mol) of ethyl glycolate at room temperature and the obtained solution was heated under reflux for 6 h. After completion of the reaction, the reaction mixture was evaporated under reduced pressure to remove excess of methyl hydrazine and the residual oil was dissolved in 25 ml of 2-propanole for crystallization to obtain (1) as white crystals. The filtrate was evaporated under reduced pressure and compound (2) was extracted using boiling benzene (5 × 30 ml). The precipitated solid from the combined benzene fractions was filtered off and recrystallized from 25 ml of ethyl acetate to obtain hydrazide (2) as white crystals.

2-Hy­droxy-N’-methyl­acetohydrazide (1). Yield 3.9 g (37.5%), m.p. 350–3551 K (2-propanole). ¹H NMR (400 MHz, DMSO-d₆) δ 9.16 (1H, br.s, NHNCO), 5.34 (1H, br.s, OH), 4.81 [1H, br.s, NH(CH₃)], 3.82 (2H, s, CH₂), 2.42 (3H, s, CH₃). ¹³C NMR (101 MHz, DMSO-d₆) δ 170.2, 61.0, 38.6. IR data (in KBr, cm⁻¹): 3410, 3296, 2924, 1664, 1444, 1348, 1076, 880, 656, 572. MS (m/z, CI) 87.0 [M − OH]⁺,105.0 [M + H]⁺. Analysis calculated for C₃H₈N₂O₂: C, 34.61; H, 7.75; N, 26.91. Found: C, 34.67; H, 7.88; N, 26.90.

2-Hy­droxy-N-methyl­acetohydrazide (2). Yield 0.43 g (4.1%), m.p. 352–353 K (EtOAc). ¹H NMR (400 MHz, DMSO-d₆) δ 4.62 (2H, s, NH₂), 4.17 (2H, s, CH₂), 3.00 (3H, s, CH₃). ¹³C NMR (101 MHz, DMSO-d₆) δ 173.3, 59.8, 37.6. IR data (in KBr, cm⁻¹): 3424, 3330, 2930, 1670, 1438, 1398, 1250, 1074, 1074, 808, 620, 572. MS (m/z, CI) 87.0 [M − OH]⁺, 105.0 [M + H]⁺. Analysis calculated for C₃H₈N₂O₂: C, 34.61; H, 7.75; N, 26.91. Found: C, 34.66; H, 7.80; N, 26.87.

6. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 3 ▸. The low quality of the data is due to the fact that the quality of the crystals is not very good and we could not obtain bright distant reflections, which somewhat affects the final qu­anti­tative parameters·The O- and N-bound hydrogen atoms were identified in difference-Fourier maps and refined isotropically. The other H atoms were placed in calculated positions and refined using a riding model with Uiso(H) = nU_eq of the parent atom (n = 1.5 for methyl groups and n = 1.2 for other hydrogen atoms).

Table 3. Experimental details.

	1	2
Crystal data
Chemical formula	C3H8N2O2	C3H8N2O2
M r	104.11	104.11
Crystal system, space group	Orthorhombic, Pbca	Monoclinic, C2/c
Temperature (K)	296	296
a, b, c (Å)	9.4484 (8), 7.0977 (7), 15.3781 (14)	11.646 (10), 9.304 (10), 10.514 (10)
α, β, γ (°)	90, 90, 90	90, 105.65 (4), 90
V (Å3)	1031.28 (16)	1097.0 (18)
Z	8	8
Radiation type	Mo Kα	Mo Kα
μ (mm−1)	0.11	0.11
Crystal size (mm)	0.3 × 0.2 × 0.1	0.2 × 0.15 × 0.09
Data collection
Diffractometer	Bruker APEXII CCD	Bruker APEXII CCD
Absorption correction	Multi-scan (SADABS; Krause et al., 2015 ▸)	Multi-scan (SADABS; Krause et al., 2015 ▸)
Tmin, Tmax	0.602, 0.746	0.554, 0.746
No. of measured, independent and observed [I > 2σ(I)] reflections	10003, 909, 841	5355, 1259, 503
R int	0.072	0.099
(sin θ/λ)max (Å−1)	0.595	0.650
Refinement
R[F2 > 2σ(F2)], wR(F2), S	0.103, 0.199, 1.34	0.050, 0.126, 0.81
No. of reflections	909	1259
No. of parameters	77	77
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement	H atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3)	0.32, −0.35	0.14, −0.16

Computer programs: APEX2 and SAINT (Bruker, 2008 ▸), SHELXT2018/2 (Sheldrick, 2015a ▸), SHELXL2019/3 (Sheldrick, 2015b ▸) and OLEX2 (Dolomanov et al., 2009 ▸).

Supplementary Material

CCDC references: 2386931, 2386930

Additional supporting information: crystallographic information; 3D view; checkCIF report

supplementary crystallographic information

2-Hydroxy-N'-methylacetohydrazide (1) . Crystal data

C3H8N2O2	Dx = 1.341 Mg m−3
Mr = 104.11	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pbca	Cell parameters from 3322 reflections
a = 9.4484 (8) Å	θ = 2.7–29.8°
b = 7.0977 (7) Å	µ = 0.11 mm−1
c = 15.3781 (14) Å	T = 296 K
V = 1031.28 (16) Å3	Block, colourless
Z = 8	0.3 × 0.2 × 0.1 mm
F(000) = 448

2-Hydroxy-N'-methylacetohydrazide (1) . Data collection

Bruker APEXII CCD diffractometer	841 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.072
φ and ω scans	θmax = 25.0°, θmin = 2.7°
Absorption correction: multi-scan (SADABS; Krause et al., 2015)	h = −11→11
Tmin = 0.602, Tmax = 0.746	k = −8→8
10003 measured reflections	l = −17→18
909 independent reflections

2-Hydroxy-N'-methylacetohydrazide (1) . Refinement

Refinement on F2	Primary atom site location: iterative
Least-squares matrix: full	Hydrogen site location: mixed
R[F2 > 2σ(F2)] = 0.103	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.199	w = 1/[σ2(Fo2) + (0.0435P)2 + 3.1357P] where P = (Fo2 + 2Fc2)/3
S = 1.34	(Δ/σ)max < 0.001
909 reflections	Δρmax = 0.32 e Å−3
77 parameters	Δρmin = −0.35 e Å−3
0 restraints

2-Hydroxy-N'-methylacetohydrazide (1) . Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

2-Hydroxy-N'-methylacetohydrazide (1) . Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1	0.5603 (3)	0.3926 (5)	0.8883 (2)	0.0278 (8)
H1	0.575 (4)	0.275 (7)	0.875 (3)	0.022 (12)*
O2	0.2107 (3)	0.4802 (6)	0.8076 (2)	0.0415 (10)
N1	0.4200 (4)	0.4761 (5)	0.7415 (2)	0.0251 (9)
N2	0.3656 (4)	0.5300 (5)	0.6594 (2)	0.0258 (9)
H2	0.283 (5)	0.534 (7)	0.670 (3)	0.024 (13)*
H1A	0.495 (5)	0.467 (5)	0.741 (3)	0.000 (10)*
C1	0.4115 (4)	0.4115 (7)	0.8943 (3)	0.0317 (12)
H1B	0.389895	0.509200	0.936369	0.038*
H1C	0.372361	0.294298	0.916087	0.038*
C2	0.3402 (4)	0.4592 (6)	0.8099 (3)	0.0251 (10)
C3	0.3999 (5)	0.3911 (7)	0.5928 (3)	0.0371 (13)
H3A	0.352088	0.422889	0.539704	0.056*
H3B	0.370059	0.268531	0.611778	0.056*
H3C	0.500296	0.390350	0.583003	0.056*

2-Hydroxy-N'-methylacetohydrazide (1) . Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
O1	0.0221 (16)	0.0291 (18)	0.0321 (19)	0.0036 (13)	−0.0061 (13)	−0.0040 (14)
O2	0.0129 (16)	0.070 (3)	0.042 (2)	0.0013 (16)	0.0002 (13)	0.0016 (19)
N1	0.0095 (19)	0.038 (2)	0.028 (2)	0.0033 (17)	0.0011 (17)	0.0077 (18)
N2	0.0155 (18)	0.035 (2)	0.027 (2)	0.0017 (17)	0.0006 (16)	0.0096 (17)
C1	0.024 (2)	0.046 (3)	0.025 (3)	0.000 (2)	0.0034 (19)	0.000 (2)
C2	0.022 (2)	0.022 (2)	0.031 (3)	−0.0022 (18)	0.0041 (19)	−0.0043 (19)
C3	0.035 (3)	0.048 (3)	0.028 (3)	−0.007 (2)	0.000 (2)	0.001 (2)

2-Hydroxy-N'-methylacetohydrazide (1) . Geometric parameters (Å, º)

O1—H1	0.87 (5)	N2—C3	1.458 (6)
O1—C1	1.415 (5)	C1—H1B	0.9700
O2—C2	1.233 (5)	C1—H1C	0.9700
N1—N2	1.416 (5)	C1—C2	1.502 (6)
N1—H1A	0.71 (4)	C3—H3A	0.9600
N1—C2	1.300 (6)	C3—H3B	0.9600
N2—H2	0.80 (5)	C3—H3C	0.9600
C1—O1—H1	106 (3)	C2—C1—H1B	108.7
N2—N1—H1A	112 (3)	C2—C1—H1C	108.7
C2—N1—N2	122.4 (4)	O2—C2—N1	122.8 (4)
C2—N1—H1A	126 (3)	O2—C2—C1	119.8 (4)
N1—N2—H2	101 (3)	N1—C2—C1	117.4 (4)
N1—N2—C3	111.3 (4)	N2—C3—H3A	109.5
C3—N2—H2	112 (3)	N2—C3—H3B	109.5
O1—C1—H1B	108.7	N2—C3—H3C	109.5
O1—C1—H1C	108.7	H3A—C3—H3B	109.5
O1—C1—C2	114.3 (4)	H3A—C3—H3C	109.5
H1B—C1—H1C	107.6	H3B—C3—H3C	109.5
O1—C1—C2—O2	−179.6 (4)	N2—N1—C2—C1	−176.7 (4)
O1—C1—C2—N1	0.7 (6)	C2—N1—N2—C3	−124.1 (4)
N2—N1—C2—O2	3.5 (7)

2-Hydroxy-N'-methylacetohydrazide (1) . Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···N2i	0.87 (5)	1.90 (5)	2.767 (5)	172 (4)
N1—H1A···O2ii	0.71 (4)	2.17 (4)	2.848 (5)	159 (4)

Symmetry codes: (i) −x+1, y−1/2, −z+3/2; (ii) x+1/2, y, −z+3/2.

2-Hydroxy-N-methylacetohydrazide (2) . Crystal data

C3H8N2O2	F(000) = 448
Mr = 104.11	Dx = 1.261 Mg m−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 11.646 (10) Å	Cell parameters from 1019 reflections
b = 9.304 (10) Å	θ = 2.8–30.1°
c = 10.514 (10) Å	µ = 0.11 mm−1
β = 105.65 (4)°	T = 296 K
V = 1097.0 (18) Å3	Block, colourless
Z = 8	0.2 × 0.15 × 0.09 mm

2-Hydroxy-N-methylacetohydrazide (2) . Data collection

Bruker APEXII CCD diffractometer	503 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.099
φ and ω scans	θmax = 27.5°, θmin = 2.9°
Absorption correction: multi-scan (SADABS; Krause et al., 2015)	h = −14→15
Tmin = 0.554, Tmax = 0.746	k = −12→12
5355 measured reflections	l = −13→13
1259 independent reflections

2-Hydroxy-N-methylacetohydrazide (2) . Refinement

Refinement on F2	Primary atom site location: dual
Least-squares matrix: full	Hydrogen site location: mixed
R[F2 > 2σ(F2)] = 0.050	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.126	w = 1/[σ2(Fo2) + (0.060P)2] where P = (Fo2 + 2Fc2)/3
S = 0.81	(Δ/σ)max < 0.001
1259 reflections	Δρmax = 0.14 e Å−3
77 parameters	Δρmin = −0.16 e Å−3
0 restraints

2-Hydroxy-N-methylacetohydrazide (2) . Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

2-Hydroxy-N-methylacetohydrazide (2) . Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1	0.42646 (16)	0.2135 (2)	0.3887 (2)	0.0810 (7)
H1	0.446 (3)	0.251 (4)	0.331 (3)	0.106 (14)*
O2	0.61250 (14)	0.37066 (17)	0.37712 (16)	0.0690 (6)
N1	0.68310 (16)	0.40430 (19)	0.59936 (19)	0.0505 (6)
N2	0.6679 (2)	0.3683 (3)	0.7264 (2)	0.0644 (7)
H2A	0.650 (2)	0.461 (4)	0.765 (3)	0.112 (11)*
H2B	0.742 (2)	0.336 (3)	0.773 (3)	0.082 (9)*
C1	0.50426 (19)	0.2560 (3)	0.5132 (2)	0.0603 (7)
H1A	0.536650	0.171285	0.564015	0.072*
H1B	0.459633	0.310151	0.562713	0.072*
C2	0.60573 (19)	0.3481 (2)	0.4921 (2)	0.0480 (6)
C3	0.7826 (2)	0.4983 (3)	0.5913 (2)	0.0684 (8)
H3A	0.768514	0.593786	0.618254	0.103*
H3B	0.788558	0.500277	0.502060	0.103*
H3C	0.855570	0.462034	0.648489	0.103*

2-Hydroxy-N-methylacetohydrazide (2) . Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
O1	0.0648 (12)	0.1060 (18)	0.0656 (14)	−0.0291 (11)	0.0064 (11)	−0.0035 (12)
O2	0.0773 (13)	0.0799 (13)	0.0469 (11)	−0.0170 (9)	0.0118 (9)	0.0008 (9)
N1	0.0476 (11)	0.0557 (12)	0.0463 (12)	−0.0016 (10)	0.0095 (9)	0.0005 (10)
N2	0.0650 (16)	0.0812 (18)	0.0458 (14)	0.0090 (12)	0.0128 (12)	−0.0020 (12)
C1	0.0533 (14)	0.0660 (17)	0.0611 (17)	−0.0067 (13)	0.0146 (12)	−0.0046 (14)
C2	0.0486 (14)	0.0461 (15)	0.0464 (15)	0.0058 (11)	0.0079 (12)	0.0002 (12)
C3	0.0605 (16)	0.0652 (18)	0.0749 (19)	−0.0095 (13)	0.0102 (13)	−0.0013 (14)

2-Hydroxy-N-methylacetohydrazide (2) . Geometric parameters (Å, º)

O1—H1	0.78 (4)	N2—H2B	0.92 (3)
O1—C1	1.432 (3)	C1—H1A	0.9700
O2—C2	1.251 (3)	C1—H1B	0.9700
N1—N2	1.434 (3)	C1—C2	1.523 (3)
N1—C2	1.345 (3)	C3—H3A	0.9600
N1—C3	1.472 (3)	C3—H3B	0.9600
N2—H2A	1.00 (3)	C3—H3C	0.9600
C1—O1—H1	110 (2)	C2—C1—H1A	109.6
N2—N1—C3	119.29 (19)	C2—C1—H1B	109.6
C2—N1—N2	117.8 (2)	O2—C2—N1	122.8 (2)
C2—N1—C3	122.9 (2)	O2—C2—C1	119.3 (2)
N1—N2—H2A	105.6 (16)	N1—C2—C1	117.9 (2)
N1—N2—H2B	104.1 (16)	N1—C3—H3A	109.5
H2A—N2—H2B	109 (2)	N1—C3—H3B	109.5
O1—C1—H1A	109.6	N1—C3—H3C	109.5
O1—C1—H1B	109.6	H3A—C3—H3B	109.5
O1—C1—C2	110.3 (2)	H3A—C3—H3C	109.5
H1A—C1—H1B	108.1	H3B—C3—H3C	109.5
O1—C1—C2—O2	−2.5 (3)	N2—N1—C2—C1	2.8 (3)
O1—C1—C2—N1	176.05 (19)	C3—N1—C2—O2	0.3 (3)
N2—N1—C2—O2	−178.7 (2)	C3—N1—C2—C1	−178.2 (2)

2-Hydroxy-N-methylacetohydrazide (2) . Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O2i	0.78 (4)	2.39 (4)	3.078 (4)	148 (3)
N2—H2A···O2ii	1.00 (3)	2.08 (3)	3.062 (4)	169 (2)
N2—H2B···O1iii	0.92 (3)	2.21 (3)	3.129 (4)	173 (2)

Symmetry codes: (i) −x+1, y, −z+1/2; (ii) x, −y+1, z+1/2; (iii) x+1/2, −y+1/2, z+1/2.